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Micera S, Menciassi A, Cianferotti L, Gruppioni E, Lionetti V. Organ Neuroprosthetics: Connecting Transplanted and Artificial Organs with the Nervous System. Adv Healthc Mater 2024:e2302896. [PMID: 38656615 DOI: 10.1002/adhm.202302896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 04/01/2024] [Indexed: 04/26/2024]
Abstract
Implantable neural interfaces with the central and peripheral nervous systems are currently used to restore sensory, motor, and cognitive functions in disabled people with very promising results. They have also been used to modulate autonomic activities to treat diseases such as diabetes or hypertension. Here, this study proposes to extend the use of these technologies to (re-)establish the connection between new (transplanted or artificial) organs and the nervous system in order to increase the long-term efficacy and the effective biointegration of these solutions. In this perspective paper, some clinically relevant applications of this approach are briefly described. Then, the choices that neural engineers must implement about the type, implantation location, and closed-loop control algorithms to successfully realize this approach are highlighted. It is believed that these new "organ neuroprostheses" are going to become more and more valuable and very effective solutions in the years to come.
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Affiliation(s)
- Silvestro Micera
- The BioRobotics Institute and Department of Excellence in Robotics and AI, Scuola Superiore Sant'Anna, Pisa, 56127, Italy
- Interdisciplinary Research Center Health Science, Scuola Superiore Sant'Anna, Pisa, 56127, Italy
- Bertarelli Foundation Chair in Translational Neuroengineering, Neuro-X Institute, School of Engineering, Ecole Polytechnique Federale de Lausanne (EPFL), Lausanne, 1015, Switzerland
| | - Arianna Menciassi
- The BioRobotics Institute and Department of Excellence in Robotics and AI, Scuola Superiore Sant'Anna, Pisa, 56127, Italy
- Interdisciplinary Research Center Health Science, Scuola Superiore Sant'Anna, Pisa, 56127, Italy
| | - Luisella Cianferotti
- Department of Experimental and Clinical Biomedical Sciences, University of Florence, Florence, 50121, Italy
| | | | - Vincenzo Lionetti
- Interdisciplinary Research Center Health Science, Scuola Superiore Sant'Anna, Pisa, 56127, Italy
- UOSVD Anesthesia and Resuscitation, Fondazione Toscana G. Monasterio, Pisa, 56127, Italy
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Trends, Burden, and Impact of Arrhythmias on Cardiac Transplant Recipients: A 16-year Nationwide Study. Curr Probl Cardiol 2023; 48:101504. [PMID: 36402222 DOI: 10.1016/j.cpcardiol.2022.101504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 11/11/2022] [Indexed: 11/18/2022]
Abstract
Orthotopic heart transplantation is the most effective long-term therapy for end-stage heart disease. Denervation with the loss of autonomic modulation, vasculopathy, utilization of immunosuppressant drugs, and allograft rejection may result in an increased prevalence of arrhythmias in transplanted hearts. We aim to describe the trends, distribution, and the clinical impact of arrhythmias in patients with transplanted hearts. We queried the National Inpatient Sample with administrative codes for cardiac transplant patients using procedure ICD-9-CM codes 37.5 and 33.6. Arrhythmias were extracted using validated ICD-9-CM codes. Statistical Analysis System (SAS) version 9.4 was used for analysis. There were a total of 30,020 hospitalizations of heart transplant recipients between 1999 and 2014 in the United States of which 1,6342 (54.4%) had an arrhythmia. The frequency of total arrhythmias increased from 53.6% (n=1,158) in 1999 to 67.3% (n=1,575) in 2014. Transplant patients with arrythmias was not associated with significantly higher inpatient mortality (7.72% vs 6.90%, P = 0.225). The most common arrythmia was atrial fibrillation ([AF]26.83%) followed by ventricular tachycardia (22.86%). Trends in mortality associated with arrhythmias following heart transplant has been decreasing from 12.3% in 1999 to 8.9% in 2014 (P = 0.04). Subgroup analysis of ventricular arrythmias (VA) following heart transplant were associated with increased mortality (8.61% vs 6.94%, P = 0.0229). Over half of patients develop 1 or more cardiac arrhythmia after heart transplant. There is an increasing secular trend in the frequency of arrhythmias post cardiac transplant with atrial fibrillation determined to be the most common arrhythmia.
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Effect of Physical Training on the Morphology of Parasympathetic Atrial Ganglia after Unilateral Vagotomy in Rats. J Cardiovasc Dev Dis 2022; 9:jcdd9110391. [DOI: 10.3390/jcdd9110391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2022] [Revised: 10/30/2022] [Accepted: 11/11/2022] [Indexed: 11/16/2022] Open
Abstract
Cardiac denervation is a serious problem in a number of patients, including patients after heart transplantation. The status of the parasympathetic ganglia after crossing the preganglionic fibers of the vagus nerve has not been enough studied. The aim of our study was to assess the effect of physical training on the morphological parameters of the parasympathetic atrial ganglia and autonomic regulation of heart rate after right- and left-sided vagotomy in rats. Morphometric characteristics of the right atrial ganglia were evaluated using an immunohistochemical method after a study that included a three-time assessment of heart rate variability. It was found that right-sided vagotomy leads to both an increase in the volume of ganglion and autonomic dysfunction. No significant change in the number of nerve cells was found in animals with false and left-sided vagotomy while maintaining preganglionic innervation after the physical training, whereas exercises led to a decrease in the volume of nerve tissue of rats with right-sided denervation. It was also found that in animals with preserved vagal innervation, the volume of atrial ganglion tissue correlates with overall heart rate variability and a normalized parasympathetic component. Therefore, a positive effect from regular physical activity on parasympathetic regulation can be expected only if preganglionic vagal influence is preserved.
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Huang Y, He Z, Manyande A, Feng M, Xiang H. Nerve regeneration in transplanted organs and tracer imaging studies: A review. Front Bioeng Biotechnol 2022; 10:966138. [PMID: 36051591 PMCID: PMC9424764 DOI: 10.3389/fbioe.2022.966138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Accepted: 07/21/2022] [Indexed: 11/13/2022] Open
Abstract
The technique of organ transplantation is well established and after transplantation the patient might be faced with the problem of nerve regeneration of the transplanted organ. Transplanted organs are innervated by the sympathetic, parasympathetic, and visceral sensory plexuses, but there is a lack of clarity regarding the neural influences on the heart, liver and kidneys and the mechanisms of their innervation. Although there has been considerable recent work exploring the potential mechanisms of nerve regeneration in organ transplantation, there remains much that is unknown about the heterogeneity and individual variability in the reinnervation of organ transplantation. The widespread availability of radioactive nerve tracers has also made a significant contribution to organ transplantation and has helped to investigate nerve recovery after transplantation, as well as providing a direction for future organ transplantation research. In this review we focused on neural tracer imaging techniques in humans and provide some conceptual insights into theories that can effectively support our choice of radionuclide tracers. This also facilitates the development of nuclear medicine techniques and promotes the development of modern medical technologies and computer tools. We described the knowledge of neural regeneration after heart transplantation, liver transplantation and kidney transplantation and apply them to various imaging techniques to quantify the uptake of radionuclide tracers to assess the prognosis of organ transplantation. We noted that the aim of this review is both to provide clinicians and nuclear medicine researchers with theories and insights into nerve regeneration in organ transplantation and to advance imaging techniques and radiotracers as a major step forward in clinical research. Moreover, we aimed to further promote the clinical and research applications of imaging techniques and provide clinicians and research technology developers with the theory and knowledge of the nerve.
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Affiliation(s)
- Yan Huang
- Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
- Department of Interventional Therapy, the First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning, China
| | - Zhigang He
- Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Anne Manyande
- School of Human and Social Sciences, University of West London, London, United Kingdom
| | - Maohui Feng
- Department of Gastrointestinal Surgery, Wuhan Peritoneal Cancer Clinical Medical Research Center, Zhongnan Hospital of Wuhan University, Hubei Key Laboratory of Tumor Biological Behaviors and Hubei Cancer Clinical Study Center, Wuhan, Hubei, China
- *Correspondence: Maohui Feng, ; Hongbing Xiang,
| | - Hongbing Xiang
- Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
- *Correspondence: Maohui Feng, ; Hongbing Xiang,
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Sinha T, Lyon A, Kahwash R. A case report: pause and consider the late complications of heart transplantation. Eur Heart J Case Rep 2019; 3:ytz107. [PMID: 31660483 PMCID: PMC6764535 DOI: 10.1093/ehjcr/ytz107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Revised: 03/15/2019] [Accepted: 07/10/2019] [Indexed: 11/14/2022]
Abstract
Background A 75-year-old woman with a past medical history significant for non-ischaemic cardiomyopathy status post orthotopic heart transplant, type II diabetes mellitus, hypertension, chronic kidney disease stage III, chronic anaemia, and chronic diarrhoea presented with nausea, vomiting, and an unexplained fall 23 years after original transplantation. Case summary During her hospital stay, she had multiple episodes of sinus arrest with syncope, preceded by seizure like activity. She was stabilized, and broad work up revealed an occult brain mass that was ultimately resected and consistent with post-transplant lymphoproliferative disease. Discussion Features that make this case study unique include the late onset and location of the malignancy, the absence of Epstein–Barr virus involvement, and asystole that was potentially neurologically mediated and induced by a brain space occupying mass. This case offers insight into potential late parasympathetic reinnervation of transplanted hearts, adds to the growing literature regarding the connection between the brain and the heart, and reviews potential complications in patients with a remote history of heart transplantation.
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Affiliation(s)
- Tejas Sinha
- Department of Internal Medicine, The Ohio State University Wexner Medical Center, 395 W. 12th Ave, 3rd Floor, Columbus, OH 43210, USA
| | - Amanda Lyon
- Department of Cardiology, The Ohio State University Wexner Medical Center, 452 W 12th Ave, Columbus, OH 43210, USA
| | - Rami Kahwash
- Department of Cardiology, The Ohio State University Wexner Medical Center, 452 W 12th Ave, Columbus, OH 43210, USA
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Farid TA, Omer MA, Gosch K, Moser A, Austin B, Magalski A, Wimmer AP. Stability of pacing indices and need for pacing in cardiac transplant patients over 1 year of follow-up. J Interv Card Electrophysiol 2017; 49:27-32. [PMID: 28181107 DOI: 10.1007/s10840-017-0226-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Accepted: 01/24/2017] [Indexed: 12/01/2022]
Abstract
BACKGROUND A significant minority of cardiac transplant patients require permanent pacemaker (PPM) implant, primarily for sinus node dysfunction. The stability of pacing indices has not been determined in this unique patient population, and data regarding ongoing need for pacing are limited. METHODS Pacing indices (sensing, threshold, and impedance) as well as the percentage of time patients required pacing were recorded, from 30 cardiac transplant patients that underwent PPM implant, over 1 year of follow-up. Repeated measure ANOVA (analysis of variance) was used to compare pacing indices and the percentage of time patients required pacing in each cardiac chamber (right atrium (RA) and right ventricle (RV)) and at different time points. RESULTS There was no difference in sensing among the follow-up time points (p = 0.9). Thresholds at 3 months were significantly higher compared to the day of implant (p = 0.005) and the day after implant (p = 0.03). Impedances at implant were significantly higher compared to day 1 (p < 0.001), 3 months (p < 0.003), and 12 months (p < 0.001) post-implant. The mean percentage of RA pacing was 85 ± 6% the day after implant, 74 ± 6% at 3 months, and 80 ± 6% at 1 year (p = 0.17). CONCLUSION In cardiac transplant patients, pacing impedances decrease and thresholds trend up in short-term follow-up, but subsequent sensing, threshold, and impedance remain stable at 1 year. This is comparable to the pattern observed among noncardiac transplant PPM recipients. The atrial pacing percentage was stable over 1 year, suggesting continued relative sinus node dysfunction.
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Affiliation(s)
- Talha A Farid
- Department of Internal Medicine, University of Missouri-Kansas City (UMKC) School of Medicine, Kansas City, MO, USA. .,Department of Cardiovascular Medicine, University of Louisville, 201 Abraham Flexner Way, Louisville, KY, 40292, USA.
| | - Mohamed A Omer
- Department of Internal Medicine, University of Missouri-Kansas City (UMKC) School of Medicine, Kansas City, MO, USA
| | - Kensey Gosch
- St. Luke's Mid America Heart Institute, Kansas City, MO, USA
| | - Ashley Moser
- Department of Internal Medicine, University of Missouri-Kansas City (UMKC) School of Medicine, Kansas City, MO, USA.,St. Luke's Mid America Heart Institute, Kansas City, MO, USA
| | - Bethany Austin
- Department of Internal Medicine, University of Missouri-Kansas City (UMKC) School of Medicine, Kansas City, MO, USA.,St. Luke's Mid America Heart Institute, Kansas City, MO, USA
| | - Anthony Magalski
- Department of Internal Medicine, University of Missouri-Kansas City (UMKC) School of Medicine, Kansas City, MO, USA.,St. Luke's Mid America Heart Institute, Kansas City, MO, USA
| | - Alan P Wimmer
- Department of Internal Medicine, University of Missouri-Kansas City (UMKC) School of Medicine, Kansas City, MO, USA.,St. Luke's Mid America Heart Institute, Kansas City, MO, USA
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Abstract
Hypertension is a common complication among post cardiac transplant recipients affecting more than 95% of patients. Increased blood pressure poses a significant cardiovascular morbidity and mortality in these patients; it should be identified quickly and needs to be managed appropriately. Understanding the pathophysiology and contributing factors to this disease in these complex and unique patients is the key to appropriate treatment selection.
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Affiliation(s)
- Amanda L Bennett
- Department of Internal Medicine, Ochsner Clinic Foundation, 1514 Jefferson Highway, New Orleans, LA 70121, USA.
| | - Hector O Ventura
- Department of Cardiomyopathy & Heart Transplantation, John Ochsner Heart and Vascular Institute, 1514 Jefferson Highway, New Orleans, LA 70121, USA
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Awad M, Czer LSC, Hou M, Golshani SS, Goltche M, De Robertis M, Kittleson M, Patel J, Azarbal B, Kransdorf E, Esmailian F, Trento A, Kobashigawa JA. Early Denervation and Later Reinnervation of the Heart Following Cardiac Transplantation: A Review. J Am Heart Assoc 2016; 5:JAHA.116.004070. [PMID: 27802930 PMCID: PMC5210323 DOI: 10.1161/jaha.116.004070] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Morcos Awad
- Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA
| | - Lawrence S C Czer
- Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA
| | - Margaret Hou
- Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA
| | - Sarah S Golshani
- Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA
| | - Michael Goltche
- Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA
| | | | - Michelle Kittleson
- Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA
| | - Jignesh Patel
- Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA
| | - Babak Azarbal
- Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA
| | - Evan Kransdorf
- Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA
| | - Fardad Esmailian
- Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA
| | - Alfredo Trento
- Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA
| | - Jon A Kobashigawa
- Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA
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Barge-Caballero E, Jiménez-López J, Chávez-Leal S, Barge-Caballero G, Paniagua-Martin MJ, Marzoa Rivas R, Grille-Cancela Z, Cuenca-Castillo JJ, Castro-Beiras A, Crespo-Leiro MG. Significado pronóstico y evolución a largo plazo de la frecuencia cardiaca en los pacientes con trasplante cardiaco. Rev Esp Cardiol 2015. [DOI: 10.1016/j.recesp.2014.09.027] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Wachter SB, McCandless SP, Gilbert EM, Stoddard GJ, Kfoury AG, Reid BB, McKellar SH, Nativi-Nicolau J, Saidi A, Barney J, McCreath L, Koliopoulou A, Wright SE, Fang JC, Stehlik J, Selzman CH, Drakos SG. Elevated resting heart rate in heart transplant recipients: innocent bystander or adverse prognostic indicator? Clin Transplant 2015; 29:829-34. [DOI: 10.1111/ctr.12587] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/01/2015] [Indexed: 11/28/2022]
Affiliation(s)
- S. Blake Wachter
- School of Medicine; University of Utah; Salt Lake City UT USA
- UTAH Cardiac Transplant Program; Salt Lake City UT USA
| | | | - Edward M. Gilbert
- School of Medicine; University of Utah; Salt Lake City UT USA
- UTAH Cardiac Transplant Program; Salt Lake City UT USA
| | - Gregory J. Stoddard
- School of Medicine; University of Utah; Salt Lake City UT USA
- UTAH Cardiac Transplant Program; Salt Lake City UT USA
| | - Abdallah G. Kfoury
- UTAH Cardiac Transplant Program; Salt Lake City UT USA
- Intermountain Heart Institute; Salt Lake City UT USA
| | - Bruce B. Reid
- UTAH Cardiac Transplant Program; Salt Lake City UT USA
- Intermountain Heart Institute; Salt Lake City UT USA
| | - Stephen H. McKellar
- School of Medicine; University of Utah; Salt Lake City UT USA
- UTAH Cardiac Transplant Program; Salt Lake City UT USA
| | - Jose Nativi-Nicolau
- School of Medicine; University of Utah; Salt Lake City UT USA
- UTAH Cardiac Transplant Program; Salt Lake City UT USA
| | - Abdulfattah Saidi
- School of Medicine; University of Utah; Salt Lake City UT USA
- UTAH Cardiac Transplant Program; Salt Lake City UT USA
| | - Jacob Barney
- School of Medicine; University of Utah; Salt Lake City UT USA
| | - Lauren McCreath
- School of Medicine; University of Utah; Salt Lake City UT USA
| | - Antigone Koliopoulou
- School of Medicine; University of Utah; Salt Lake City UT USA
- UTAH Cardiac Transplant Program; Salt Lake City UT USA
| | | | - James C. Fang
- School of Medicine; University of Utah; Salt Lake City UT USA
- UTAH Cardiac Transplant Program; Salt Lake City UT USA
| | - Josef Stehlik
- School of Medicine; University of Utah; Salt Lake City UT USA
- UTAH Cardiac Transplant Program; Salt Lake City UT USA
| | - Craig H. Selzman
- School of Medicine; University of Utah; Salt Lake City UT USA
- UTAH Cardiac Transplant Program; Salt Lake City UT USA
| | - Stavros G. Drakos
- School of Medicine; University of Utah; Salt Lake City UT USA
- UTAH Cardiac Transplant Program; Salt Lake City UT USA
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Prognostic Significance of Heart Rate and its Long-term Trend in Cardiac Transplant Patients. ACTA ACUST UNITED AC 2015; 68:943-50. [PMID: 25869124 DOI: 10.1016/j.rec.2014.09.028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Accepted: 09/19/2014] [Indexed: 11/23/2022]
Abstract
INTRODUCTION AND OBJECTIVES The aim of the present study was to examine the prognostic significance of heart rate and its trend in heart transplantation. METHODS This observational study enrolled 170 patients who received a bicaval heart transplant between 1995 and 2005; all were in sinus rhythm. The resting heart rate was determined via electrocardiography at the end of the first posttransplant year and annually until the tenth year. Cox analysis was used to evaluate the incidence of adverse events with a mean (standard deviation) follow-up of 8.9 (3.1) years. The primary study end point was the composite outcome of death or graft dysfunction. RESULTS The resting heart rate at the end of the first posttransplant year was an independent predictor of the primary composite end point (hazard ratio=1.054; 95% confidence interval, 1.028-1.080; P<.001) and was significantly associated with total mortality (hazard ratio=1.058; 95% confidence interval, 1.030-1.087; P<.001) and mortality from cardiac causes (hazard ratio=1.069; 95% confidence interval, 1.026-1.113; P=.001), but not with graft dysfunction (hazard ratio=1.028; 95% confidence interval, 0.989-1.069; P=.161). For patients with a heart rate ≥ 105 or<90 bpm vs those with 90-104 bpm, the hazard ratios of the primary end point were 2.233 (95% confidence interval, 1.250-3.989; P=.007) and 0.380 (95% confidence interval, 0.161-0.895; P=.027), respectively. Heart rate tended to decrease in the first 10 years after transplantation (P=.001). Patients with a net increase in heart rate during follow-up showed a higher incidence of adverse events. CONCLUSIONS An elevated heart rate is an adverse prognostic marker after heart transplantation.
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Nytrøen K, Gullestad L. Exercise after heart transplantation: An overview. World J Transplant 2013; 3:78-90. [PMID: 24392312 PMCID: PMC3879527 DOI: 10.5500/wjt.v3.i4.78] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2013] [Revised: 07/15/2013] [Accepted: 07/25/2013] [Indexed: 02/05/2023] Open
Abstract
While life expectancy is greatly improved after a heart transplant, survival is still limited, and compared to the general population, the exercise capacity and health-related quality of life of heart transplant recipients are reduced. Increased exercise capacity is associated with a better prognosis. However, although several studies have documented positive effects of exercise after heart transplantation (HTx), little is known about the type, frequency and intensity of exercise that provides the greatest health benefits. Moreover, the long-term effects of exercise on co-morbidities and survival are also unclear. Exercise restrictions apply to patients with a denervated heart, and for decades, it was believed that the transplanted heart remained denervated. This has since been largely disproved, but despite the new knowledge, the exercise restrictions have largely remained, and up-to-date guidelines on exercise prescription after HTx do not exist. High-intensity, interval based aerobic exercise has repeatedly been documented to have superior positive effects and health benefits compared to moderate exercise. This applies to both healthy subjects as well as in several patient groups, such as patients with metabolic syndrome, coronary artery disease or heart failure. However, whether the effects of this type of exercise are also applicable to heart transplant populations has not yet been fully established. The purpose of this article is to give an overview of the current knowledge about the exercise capacity and effect of exercise among heart transplant recipients and to discuss future exercise strategies.
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Shah AB, Patel JK, Rafiei M, Morrissey RP, Kittleson MM, Kobashigawa JA. The impact of mean first-year heart rate on outcomes after heart transplantation: does it make a difference? Clin Transplant 2013; 27:659-65. [PMID: 23924048 DOI: 10.1111/ctr.12188] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/05/2013] [Indexed: 11/29/2022]
Abstract
BACKGROUND Cardiac denervation following transplantation has a variable effect on heart rate (HR), and the consequence of this is not known. We examined the impact of first-year HR on five-yr outcomes after heart transplant. METHODS We evaluated 544 heart transplant recipients from 1994 to 2008. Patients were divided into groups by mean first-year HR: group 1, HR < 90 (mean 85.0 ± 4.3); group 2, 90 ≤ HR < 110 (mean 97.8 ± 4.9); group 3, HR ≥ 110 (mean 111.5 ± 1.8). Endpoints included one-yr freedom from treated rejection, five-yr survival, five-yr freedom from cardiac allograft vasculopathy (CAV), and five-yr freedom from non-fatal major adverse cardiac events (NF-MACE). RESULTS One-yr freedom from treated rejection, five-yr survival and freedom from CAV were not significantly different between groups. Five-yr freedom from NF-MACE was significantly lower in group 3 compared with group 2, 69% vs. 91%, p < 0.01, mainly due to higher prevalence of congestive heart failure (CHF) in group 3 over five yr. CONCLUSIONS Mean first-year HR does not provide prognostic significance for one-yr freedom from treated rejection, five-yr survival or development of CAV five yr after heart transplant. These results suggest that HR post-heart transplantation does not affect long-term outcomes, but high first-year HRs may be associated with new-onset CHF.
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Affiliation(s)
- Ankit B Shah
- Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
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Nazé F, Suin V, Lamoral S, Francart A, Brochier B, Roels S, Mast J, Kalai M, Van Gucht S. Infectivity of rabies virus-exposed macrophages. Microbes Infect 2012; 15:115-25. [PMID: 23159243 DOI: 10.1016/j.micinf.2012.10.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2012] [Revised: 10/29/2012] [Accepted: 10/30/2012] [Indexed: 11/17/2022]
Abstract
Rabies virus distributes widely in infected mice, including lymphoid tissues and spleen macrophages. The infection characteristics in murine macrophages and the infectivity of virus-exposed macrophages were examined upon inoculation in mice. In vitro, Mf4/4 spleen macrophages supported mild virus production (10(4)-fold less than neuroblastoma), with formation of typical virions. Bone marrow-derived macrophages (BMM) were most efficient to capture virus, but new virus production was not detected. Virus-induced cell death was significantly stronger in BMM, which might have eliminated BMM with productive infection. Still, viral RNA remained detectable in the remaining BMM for at least 4 weeks. Injection of in vitro-infected Mf4/4 in the nose or brain proved efficient to propagate infection in mice, even when cells were pre-incubated with neutralizing antibodies. Surprisingly, injection of ex-vivo-infected BMM in the brain also led to lethal infection in 8 out of 12 mice. Injection of infected Mf4/4 in the muscle mostly favoured a protective antibody response. Despite that macrophages are less fit to support virus production, they can still act as a source of infectious virus upon transfer in mice. This may be relevant for screening donor organs/cells, for which RT-PCR should be preferred over the traditional antigen or virus isolation assays.
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Affiliation(s)
- Florence Nazé
- National Reference Laboratory of Rabies, Viral Diseases, Communicable and Infectious Diseases, Scientific Institute of Public Health, Engeland St. 642, B-1180 Brussels, Belgium
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Sekar B, Critchley WR, Williams SG, Shaw SM. Should we consider heart rate reduction in cardiac transplant recipients? Clin Cardiol 2012; 36:68-73. [PMID: 22911227 DOI: 10.1002/clc.22048] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2012] [Revised: 07/13/2012] [Indexed: 12/21/2022] Open
Abstract
Increased resting heart rate is an independent modifiable risk factor for the development of cardiovascular disease. Numerous studies have demonstrated improved clinical outcomes with heart rate reduction in patients with coronary artery disease and heart failure, but its role in transplanted hearts is not yet established. Sinus tachycardia is more common in heart transplant recipients due to graft denervation. Although a large number of studies have recognized increased heart rate as a predictor of native coronary artery atherosclerosis and overall cardiac mortality, contradicting results have been observed in heart transplant recipients. There is no clear consensus about what the normal range of heart rate should be following heart transplantation. The aim of this article was to review the literature to evaluate whether heart rate reduction should be considered in heart transplant recipients.
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Affiliation(s)
- Baskar Sekar
- The Transplant Centre, Wythenshawe Hospital, University Hospital of South Manchester NHS Foundation Trust, Wythenshawe, United Kingdom.
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17
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[Heart failure secondary to atrial tachycardia in the early phase of heart transplantation. Usefulness of the electrophysiological study]. Med Intensiva 2011; 36:377-9. [PMID: 22037020 DOI: 10.1016/j.medin.2011.09.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2011] [Revised: 08/31/2011] [Accepted: 09/05/2011] [Indexed: 11/22/2022]
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Chronotropic responses to exercise in heart transplant recipients: 1-yr follow-up. Am J Phys Med Rehabil 2011; 90:579-88. [PMID: 21765276 DOI: 10.1097/phm.0b013e31821f711d] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
OBJECTIVE Partial normalization of the heart rate (HR) response can take place some time after heart transplantation (HTx), but the extent to which this occurs, its time course, and functional significance remain unclear. DESIGN Seventy-seven heart transplantation patients underwent an exercise test at approximately 1, 6, and 12 mos after heart transplantation, consisting of a resting period, a submaximal exercise test, and a maximal exercise test with stair climbing, followed by a recovery period. An HR monitor was used for continuous surveillance of HR. RESULTS During the follow-up, HR at rest did not change, whereas all other HR parameters obtained during and after exercise improved, demonstrating a more rapid increase, a higher peak, and a more rapid decline in HR after stopping exercise. Age-predicted maximum HR at baseline was 73% ± 9%, improving to 83% ± 10% at 6 mos (P < 0.001) and to 90% ± 10% at 12 mos (P < 0.001), whereas the Chronotropic Response Index at baseline was 0.49 ± 0.15, improving to 0.67 ± 0.17 at 6 mos (P < 0.001) and to 0.81 ± 0.23 at 12 mos (P < 0.001). CONCLUSIONS Partial normalization of HR was achieved by 71% of heart transplantation patients at 12 mos, with significant changes occurring within 6 mos in most subjects. These findings should contribute to reducing the exercise restrictions that apply to the denervated heart.
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Resting heart rate: a predictor of allograft vasculopathy? Int J Cardiol 2010; 145:504; author reply 505. [PMID: 20004030 DOI: 10.1016/j.ijcard.2009.11.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2009] [Accepted: 11/15/2009] [Indexed: 11/23/2022]
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Porta A, Catai AM, Takahashi ACM, Magagnin V, Bassani T, Tobaldini E, van de Borne P, Montano N. Causal relationships between heart period and systolic arterial pressure during graded head-up tilt. Am J Physiol Regul Integr Comp Physiol 2010; 300:R378-86. [PMID: 20962207 DOI: 10.1152/ajpregu.00553.2010] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In physiological conditions, heart period (HP) affects systolic arterial pressure (SAP) through diastolic runoff and Starling's law, but, the reverse relation also holds as a result of the continuous action of baroreflex control. The prevailing mechanism sets the dominant temporal direction in the HP-SAP interactions (i.e., causality). We exploited cross-conditional entropy to assess HP-SAP causality. A traditional approach based on phases was applied for comparison. The ability of the approach to detect the lack of causal link from SAP to HP was assessed on 8 short-term (STHT) and 11 long-term heart transplant (LTHT) recipients (i.e., less than and more than 2 yr after transplantation, respectively). In addition, spontaneous HP and SAP variabilities were extracted from 17 healthy humans (ages 21-36 yr, median age 29 yr; 9 females) at rest and during graded head-up tilt. The tilt table inclinations ranged from 15 to 75° and were changed in steps of 15°. All subjects underwent recordings at every step in random order. The approach detected the lack of causal relation from SAP to HP in STHT recipients and the gradual restoration of the causal link from SAP to HP with time after transplantation in the LTHT recipients. The head-up tilt protocol induced the progressive shift from the prevalent causal direction from HP to SAP to the reverse causality (i.e., from SAP to HP) with tilt table inclination in healthy subjects. Transformation of phases into time shifts and comparison with baroreflex latency supported this conclusion. The proposed approach is highly efficient because it does not require the knowledge of baroreflex latency. The dependence of causality on tilt table inclination suggests that "spontaneous" baroreflex sensitivity estimated using noncausal methods (e.g., spectral and cross-spectral approaches) is more reliable at the highest tilt table inclinations.
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Affiliation(s)
- Alberto Porta
- Department of Technologies for Health, University of Milan, Milan, Italy.
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Bacal F, Abuhab A, Mangini S, Fioreli AI, Santos RHB, Stolf NG, Bocchi EA. Dobutamine stress echocardiography in heart transplant recipients' evaluation: the role of reinnervation. Transplant Proc 2010; 42:539-41. [PMID: 20304187 DOI: 10.1016/j.transproceed.2010.01.021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
INTRODUCTION Orthotopic heart transplantation renders the recipient denervated. This remodeling of the intrinsic cardiac nervous system should be taken in account during functional evaluation for allograft coronary artery disease. Dobutamine stress echocardiography (DSE) has been used to detect patients at greater risk. The aim of this study was to determine whether patients with various autonomic response levels, and supposed reinnervation patterns, show the same response to DSE. METHODS We studied 20 patients who had survived more than 5 years after orthotopic heart transplantation. All patients underwent a Holter evaluation. We considered patients with low variability to be those with less than a 40-bpm variation from the lowest to highest heart rate, so-called "noninnenervated" (group NI). Patients who had 40-bpm or more variation were considered to show high variability and called "reinnervated" (group RI). After that, all patients performed an ergometric test and DSE. RESULTS Groups were defined as NI (n = 9) and RI (n = 11). Ergometric tests confirmed this response with NI patients showing less variability when compared to RI patients (P = .0401). During DSE, patients showed similar median heart rate responses according to the dobutamine dose. Spearmen correlation showed r = 1.0 (P = .016). CONCLUSIONS DES was effective to reach higher heart rates, probably related to catecholamine infusion. These findings may justify a better response when evaluating cardiac allograft vasculopathy in heart transplant patients.
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Affiliation(s)
- F Bacal
- Cardiology Department, Heart Failure Unit, Heart Institute (InCor), University of São Paulo Medical School, São Paulo, Brazil.
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On A, Karapolat H, Zoghi M, Nalbantgil S, Yagdi T, Ozbaran M. Analysis of heart rate variability with electromyography in heart transplant recipients. Arch Phys Med Rehabil 2009; 90:1635-8. [PMID: 19735794 DOI: 10.1016/j.apmr.2009.03.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2009] [Revised: 03/12/2009] [Accepted: 03/13/2009] [Indexed: 12/19/2022]
Abstract
OBJECTIVE To investigate vagal parasympathetic functions by electromyographic R-R interval variation analyses in heart transplant recipients. DESIGN Cross-sectional and longitudinal study. SETTING Department of physical medicine and rehabilitation, university hospital. PARTICIPANTS Early (n=8; <3 mo) and late (n=17; >1 y) heart transplant recipients and healthy volunteers (n=20) were included. INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES The R-R interval variations at rest and in response to deep breathing, Valsalva, and tilt/standup maneuvers were analyzed in all patient and control groups. Further, 8 early heart transplant recipients were followed up at the sixth and twelfth months after transplantation. RESULTS Compared with controls, both early and late transplant recipients had significantly lower R-R interval variation ratios (P<.05). There were no statistically significant differences between the early and late groups (P>.05). R-R interval variation ratios showed no significant changes from baseline (P>.025) in the early heart transplant recipients. CONCLUSIONS The findings of the study suggest that parasympathetic activities are suppressed in the early stage after heart transplantation and do not significantly recover with time. The electromyographic analysis of R-R interval variation is a simple test that may offer an attractive alternative for routine evaluation of autonomic dysfunction in heart transplant recipients.
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Affiliation(s)
- Arzu On
- Department of Physical Medicine, University of Ege, Izmir, Turkey
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Preuss MAR, Faber ML, Tan GS, Bette M, Dietzschold B, Weihe E, Schnell MJ. Intravenous inoculation of a bat-associated rabies virus causes lethal encephalopathy in mice through invasion of the brain via neurosecretory hypothalamic fibers. PLoS Pathog 2009; 5:e1000485. [PMID: 19543379 PMCID: PMC2691950 DOI: 10.1371/journal.ppat.1000485] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2009] [Accepted: 05/22/2009] [Indexed: 11/18/2022] Open
Abstract
The majority of rabies virus (RV) infections are caused by bites or scratches from rabid carnivores or bats. Usually, RV utilizes the retrograde transport within the neuronal network to spread from the infection site to the central nervous system (CNS) where it replicates in neuronal somata and infects other neurons via trans-synaptic spread. We speculate that in addition to the neuronal transport of the virus, hematogenous spread from the site of infection directly to the brain after accidental spill over into the vascular system might represent an alternative way for RV to invade the CNS. So far, it is unknown whether hematogenous spread has any relevance in RV pathogenesis. To determine whether certain RV variants might have the capacity to invade the CNS from the periphery via hematogenous spread, we infected mice either intramuscularly (i.m.) or intravenously (i.v.) with the dog-associated RV DOG4 or the silver-haired bat-associated RV SB. In addition to monitoring the progression of clinical signs of rabies we used immunohistochemistry and quantitative reverse transcription polymerase chain reaction (qRT-PCR) to follow the spread of the virus from the infection site to the brain. In contrast to i.m. infection where both variants caused a lethal encephalopathy, only i.v. infection with SB resulted in the development of a lethal infection. While qRT-PCR did not reveal major differences in virus loads in spinal cord or brain at different times after i.m. or i.v. infection of SB, immunohistochemical analysis showed that only i.v. administered SB directly infected the forebrain. The earliest affected regions were those hypothalamic nuclei, which are connected by neurosecretory fibers to the circumventricular organs neurohypophysis and median eminence. Our data suggest that hematogenous spread of SB can lead to a fatal encephalopathy through direct retrograde invasion of the CNS at the neurovascular interface of the hypothalamus-hypophysis system. This alternative mode of virus spread has implications for the post exposure prophylaxis of rabies, particularly with silver-haired bat-associated RV. Rabies virus (RV) infects mammalian neurons and cycles in regionally distinct animal populations such as the red fox in Europe, domestic canines in Asia, or raccoons, skunks and bats in Northern America. Although human rabies can be prevented by pre- and post-exposure prophylaxis, more than 50,000 people die annually from the severe encephalopathy caused by RV. Recently, two cases of RV transmission by organ transplantation were reported. In our study, using intravenous inoculation of mice, we evaluated the pathogenetic relevance of virions that reach the bloodstream. Mice inoculated intravenously with a canine-derived RV survived the infection in contrast to intramuscularly injected mice, while mice infected with a silver-haired bat-related RV succumbed to the disease regardless of the route of inoculation. We found that the silver-haired bat-related RV was able to transit from the blood to the brain by invading neurosecretory fibers of the hypothalamus, which form neurohemal synapses lacking a blood-brain-barrier. This newly described route of brain invasion might reflect how RV reached the central nervous system from transplanted organs, since it takes longer to establish the neural connections between host and grafted tissue necessary for classical RV migration than the time until the infection became symptomatic in the two reported cases.
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Affiliation(s)
- Mirjam A. R. Preuss
- Institute of Anatomy and Cell Biology, Department of Molecular Neuroscience, Philipps University Marburg, Marburg, Germany
- Jefferson Vaccine Center, Department of Microbiology and Immunology, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Marie-Luise Faber
- Jefferson Vaccine Center, Department of Microbiology and Immunology, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Gene S. Tan
- Jefferson Vaccine Center, Department of Microbiology and Immunology, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Michael Bette
- Institute of Anatomy and Cell Biology, Department of Molecular Neuroscience, Philipps University Marburg, Marburg, Germany
| | - Bernhard Dietzschold
- Jefferson Vaccine Center, Department of Microbiology and Immunology, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Eberhard Weihe
- Institute of Anatomy and Cell Biology, Department of Molecular Neuroscience, Philipps University Marburg, Marburg, Germany
| | - Matthias J. Schnell
- Jefferson Vaccine Center, Department of Microbiology and Immunology, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
- * E-mail:
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Anand RG, Reddy MT, Yau CL, Myers L, Amin RR, Stahls PF, Dumas D, Frohlich ED, Ventura HO. Usefulness of heart rate as an independent predictor for survival after heart transplantation. Am J Cardiol 2009; 103:1290-4. [PMID: 19406274 DOI: 10.1016/j.amjcard.2009.01.022] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2008] [Revised: 01/05/2009] [Accepted: 01/05/2009] [Indexed: 11/18/2022]
Abstract
It was unclear whether increased heart rate (HR) increased long-term mortality after heart transplantation (HT). The aim of this study was to evaluate whether HR predicted survival after HT. A retrospective analysis of patients who underwent HT at our institution was performed. Ethnicity, gender, date of birth, age at transplantation, length of follow-up after transplantation, cardiac rhythm within 3 months after transplantation, age at death, reason for transplantation, cause of death, and baseline medications after transplantation were recorded. Continuous variables, such as HR, blood pressure, cardiac ejection fraction, presence of allograft vasculopathy, and serum creatinine, were recorded at <3 months, 6 months, and 1 year after HT, then annually to 10 years after HT. Seventy-eight patients with a mean age of 50 +/- 13 years were identified. Mean survival was 8.5 +/- 6.5 years. Of 78 patients, 32 patients had an HR <or=90 beats/min, and 46 patients had an HR >90 beats/min within 3 months after HT. There was a mean decrease in HR of 6 beats/min during 10 years (p <0.03). Multivariate survival analysis showed that HR >90 beats/min was a significant predictor of early mortality (hazard ratio 2.8, 95% confidence interval 1.5 to 5.1, p <0.0013). Patients with a net increase in HR during 10 years had an increased risk of death compared with patients with no change or a net decrease in HR (hazard ratio 4.7, 95% confidence interval 1.9 to 12.0, p <0.002). No significant differences in cause of death between patients with an HR <or=90 or >90 beats/min existed. In conclusion, HT patients with an HR >90 beats/min within the first 3 months after HT were 2.8 times more likely to die than patients with an HR <or=90 beats/min. Patients with a net increase in HR were 4.7 times more likely to die than those whose HR did not change or decreased over time.
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Affiliation(s)
- Rishi G Anand
- Department of Cardiology, Division of Electrophysiology, University of Maryland Medical System, Baltimore, Maryland, USA
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Postural tachycardia syndrome and reflex syncope: similarities and differences. J Pediatr 2009; 154:481-5. [PMID: 19324216 PMCID: PMC3810291 DOI: 10.1016/j.jpeds.2009.01.004] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2008] [Revised: 12/02/2008] [Accepted: 01/06/2009] [Indexed: 11/24/2022]
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Wong S, Carrault G, Kervio G, Cruz J, Bansard JY, Carre F. Application of multiple correspondence analysis to asses the relation between time after transplantation and sympathetic activity in cardiac transplant recipient. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2009; 2008:4403-6. [PMID: 19163690 DOI: 10.1109/iembs.2008.4650187] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The aim of the present study was to evidence that the heart reinnervation can occur and it is related with the time after transplantation (evolution with time). Data were evaluated using Multiple Correspondence Analyses (MCA), which is the ideal method to study the relation, probably nonlinear, between the Time After Transplantation (TAT) and the probable restoration of normal heart rate responses of sinus node regulated by the autonomic nervous system. Twenty four nonrejecting transplant recipients (60 +/- 48 months after transplantation) and nine healthy subjects were studied by heart rate variability parameters. Results showed that sympathetic activity is restored some time after transplantation. Until 48 months, the recent HTR are in direct correlation to low values SD and LF and for the oldest transplant recipient, these parameters are similar to that observed in normal subjects.
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Affiliation(s)
- S Wong
- Electronic and Circuit Department, Simón Bolívar University, Caracas, Venezuela.
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Dalla Pozza R, Fuchs A, Bechtold S, Kozlik-Feldmann R, Daebritz S, Netz H. Short-term testing of heart rate variability in heart-transplanted children: equal to 24-h ECG recordings? Clin Transplant 2007; 20:438-42. [PMID: 16842518 DOI: 10.1111/j.1399-0012.2006.00502.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
INTRODUCTION Heart rate variability (HRV) is reduced in adults and children after cardiac transplantation. Testing of HRV has been used to assess re-innervation of the cardiac graft; its reliability in ruling out acute graft rejection is still under investigation. This study used a short-term test on HRV in 23 heart and heart-lung transplanted children and adolescents and compared the results with 24-h ECG recordings. PATIENTS AND METHODS Twenty-three subjects (16.3+/-4.2 yr; 10 females) underwent a 10-min HRV test at two occasions and one 24-h ECG. HRV was calculated according to the time domain method (RR interval, standard deviation of RR interval) and the frequency domain method (total power, LF and HF for assessment of sympathovagal modulation of heart rate). RESULTS Correlation between the short-term tests and 24-h ECG was high with regard to the frequency domain analysis of HRV. Correlation was less pronounced in the time domain method. CONCLUSIONS In heart and heart-lung-transplanted children and adolescents, due to reduced overall HRV short-term testing may give as reliable data as 24-h ECG. Therefore, especially when power spectral analysis has to be performed as a longitudinal assessment of re-innervation of the cardiac graft, short-term testing may offer an easily applicable and non-invasive diagnostic tool. Further studies are warranted to investigate whether HRV testing may contribute to rule out acute graft rejection.
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Affiliation(s)
- R Dalla Pozza
- Department of Pediatric Cardiology [corrected] Ludwig-Maximilians University, Munich, Germany.
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Kociolek LK, Bierig SM, Herrmann SC, Labovitz AJ. Efficacy of Atropine as a Chronotropic Agent in Heart Transplant Patients Undergoing Dobutamine Stress Echocardiography. Echocardiography 2006; 23:383-7. [PMID: 16686620 DOI: 10.1111/j.1540-8175.2006.00223.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND After heart transplant (HTX), the heart is completely denervated. While sympathetic reinnervation is likely to occur, there is conflicting evidence regarding parasympathetic reinnervation. Accordingly, it is unclear if atropine is efficacious as a chronotropic agent in HTX patients undergoing dobutamine stress echocardiography (DSE), since cholinergic cardiac stimulation is required for atropine to exert its effect. The purpose of this study was to demonstrate that atropine can sufficiently increase the heart rate (HR) in HTX patients undergoing DSE. METHODS A retrospective review was performed on 68 HTX patients who underwent DSE as part of their routine annual HTX follow-ups. Dobutamine was administered in the standard fashion of 10, 20, 30, 40, 50 mcg/kg per minute with blood pressure and electrocardiographic monitoring. If target HR was not attained, atropine was administered to aid in achieving 85% of maximum age-predicted HR. RESULTS Mean patient age was 58 +/- 10 years. Mean period since transplant was 9 +/- 4 years. Forty-seven (69%) patients received dobutamine only, and 21 (31%) required additional atropine to reach target HR. Of the 21 patients who received atropine, 10 (48%) reached target HR. Neither time from transplant, age, gender, resting HR, medications, nor atherosclerotic risk factors predicted responsiveness to atropine. Those responding to dobutamine had a significantly greater resting HR than those receiving additional atropine. CONCLUSIONS The adjunctive use of atropine in HTX patients during DSE aids in reaching 85% of maximum predicted HR in some patients. Furthermore, resting HR may predict the additional need of atropine during DSE.
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Dalla Pozza R, Kleinmann A, Bechtold S, Netz H. Hypertension in Heart and Heart-Lung Transplanted Children: Does Impaired Baroreceptor Function Play a Role? Transplantation 2006; 81:71-5. [PMID: 16421479 DOI: 10.1097/01.tp.0000189927.70547.ef] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Baroreceptor control of beat-to-beat blood pressure in heart and heart-lung-transplanted children is impaired. Time-related trends of baroreceptor function recovery are studied and a possible correlation of baroreflex impairment and systolic hypertension may give evidence for supplemental medical treatment of hypertension. METHODS Seventeen patients (six female) 6.1 +/- 3.7 years (range 0.8-13.0 years) after heart (n = 14) and heart-lung (n = 3) transplantation (TX) were studied. Twelve healthy children and 10 children after liver and bone marrow TX taking cyclosporine A (CyA) served as control groups 1 and 2, respectively. Baroreceptor sensitivity (BRS) was calculated from noninvasive systolic beat-to-beat blood pressure (sBP) measurement during a resting phase and a tilt-table test. RESULTS BRS was significantly impaired in the study group at rest and during tilting; mean sBP was slightly elevated. Significant difference between patients on CyA and healthy controls was not observed. Discrete recovery of BRS occurred after 4 years postTX with decreased sBP (n = 12 pts, BRS 6.78 +/- 7.44 msec/mmHg, sBP 116.2 +/- 12.4 mmHg) when compared to a postTX time course of less than 4 years (n = 5 pts, BRS 4.02 +/- 4.21 msec/mmHg, sBP 122.0 +/- 6.7 mmHg, P = NS). CONCLUSION BRS is disturbed after TX in children; four years postTX, a minimal recovery of BRS and a discrete reduction of sBP seem to occur. Those patients with a persistent low BRS and elevated sBP may profit from pharmacological influence in sympathovagal imbalance.
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Affiliation(s)
- Robert Dalla Pozza
- Department of Pediatric Cardiology, Ludwig-Maximilians-University, Munich, Germany.
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Pachon JC, Pachon EI, Pachon JC, Lobo TJ, Pachon MZ, Vargas RNA, Jatene AD. "Cardioneuroablation"--new treatment for neurocardiogenic syncope, functional AV block and sinus dysfunction using catheter RF-ablation. Europace 2005; 7:1-13. [PMID: 15670960 DOI: 10.1016/j.eupc.2004.10.003] [Citation(s) in RCA: 179] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2004] [Accepted: 10/05/2004] [Indexed: 11/16/2022] Open
Abstract
Cardiac neuroablation is a new technique for management of patients with dominantly adverse parasympathetic autonomic influence. The technique is based on radiofrequency (RF) ablation of autonomic connections in the three main ganglia around the heart. Their connections are identified by Fast-Fourier Transforms (FFTs) of endocardial signals: sites of autonomic nervous connections show fractionated signals with FFTs shifted to the right. In contrast, normal myocardium without these connections does not show these features. RF-ablation is thought to inflict permanent damage on the parasympathetic autonomic influence because its cells are adjacent to the heart whereas sympathetic cells are remote. Twenty-one patients with a mean age of 48 years, neurally mediated reflex syncope in six, functional high grade atrioventricular block in seven and sinus node dysfunction in 13 (there is overlap between the second and third groups) were treated. Follow-up for a mean of 9.2 months demonstrated success in all cases with relief of symptoms. No complications occurred.
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Affiliation(s)
- Jose C Pachon
- Sao Paulo Heart Hospital and Dante Pazzanese Cardiology Institute, Pacemaker and Arrhythmias, Acoce, 515/31 Indianopolis, 04075023 Sao Paulo, SP, Brazil.
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Beckers F, Ramaekers D, Speijer G, Ector H, Vanhaecke J, Verheyden B, Van Cleemput J, Droogné W, Van de Werf F, Aubert AE. Different evolutions in heart rate variability after heart transplantation: 10-year follow-up. Transplantation 2005; 78:1523-31. [PMID: 15599318 DOI: 10.1097/01.tp.0000141093.04132.41] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
BACKGROUND After heart transplantation, the donor heart is extrinsically denervated. No input of sympathetic or vagal nerves can influence the heart rate, resulting in a flat power spectrum of the beat-to-beat variability. The occurrence and the significance of reinnervation remain controversial. METHODS AND RESULTS We monitored the evolution of heart rate variability (HRV) after heart transplantation, starting from a few weeks postoperatively up to 10 years after surgery. Twenty-four-hour Holter recordings of 216 heart-transplant patients were analyzed using time and frequency domain analysis of HRV. Analysis of all data revealed an increase in 24-hour and night-time total power starting from 2 years after transplantation. Low-frequency oscillations calculated over the total 24 hours, day- and nighttime increased significantly starting from year 4 and onward (year 4-8: P < 0.005). No evolution was found in high-frequency power. Subgroup analysis revealed a group with a clear spectral component (n = 16), a group with a small component (n = 124), and a group with a flat spectrum (n = 76). Only the first group revealed an evolution in both high- and low-frequency power. CONCLUSION These results indicate three different types of evolution in HRV, with reinnervating patterns present in only a minority of the patients. The vast majority of the patients show no signs of reinnervation.
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Affiliation(s)
- Frank Beckers
- Laboratory of Experimental Cardiology, Department of Cardiology, University Hospital Gasthuisberg, K.U. Leuven, 3000 Leuven, Belgium
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Hansson M. Receptor binding occurrence and plasma levels of natriuretic peptides in response to sympathectomy. Microsc Res Tech 2005; 67:90-9. [PMID: 16037981 DOI: 10.1002/jemt.20192] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
In the present investigation the relationship between the sympathetic nervous system and the endocardial levels of receptor binding sites for natriuretic peptides and the plasma content of atrial natriuretic peptide were analyzed in rats. In order to destruct the cardiac sympathetic nerve terminals, chemical sympathectomy with 6-hydroxydopamine was made in parallel with intravenous measurements of blood pressure and heart frequency. By use of immunohistochemical and enzyme-linked-immunosorbent techniques the expression of tyrosine hydroxylase-positive sympathetic nerve terminals and plasma levels of pro-atrial natriuretic peptide were determined, respectively. The occurrence of receptor binding sites for natriuretic peptides was examined by in vitro receptor autoradiography. In contrast to the marked occurrence of natriuretic peptide receptor binding sites seen in the ventricular endocardium of control rats, the sympathectomized rats exhibited a decreased number of binding sites for natriuretic peptides in the endocardium of both the right and left chambers. Interestingly, this was found in parallel with a significant decrease of systolic and diastolic blood pressure and increased plasma levels of pro-atrial natriuretic peptide in the treated group of rats. These findings, together with those in previous studies, give support to an idea that one part of the blood pressure-decreasing effects, seen in patients treated with beta-adrenergic blockade, might be through a reduction of the natriuretic clearance receptor C, then giving rise to increased levels of atrial natriuretic peptide.
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Affiliation(s)
- Magnus Hansson
- Department of Integrative Medical Biology, Section for Anatomy, and Department of Medical Biosciences, Section for Pathology, Umeå University, SE-901 87 Umeå, Sweden.
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Zupan I, Vrtovec B, Breskvar UD, Gabrijelcic T. Noninvasive monitoring of rejection therapy based on intramyocardial electrograms after orthotopic heart transplantation. Initial experience with 14 cases. Int Immunopharmacol 2005; 5:59-65. [PMID: 15589460 DOI: 10.1016/j.intimp.2004.09.019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Despite the use of increasingly specific immunosuppressive therapy, rejection remains the leading cause of death in cardiac transplant patients. Endomyocardial biopsy (EMB) is the gold standard for early detection and monitoring of cardiac transplant rejection. However, this approach is invasive and not suitable for routine use. A noninvasive alternative for monitoring cardiac transplant patients uses the analysis of the ventricular evoked response (VER) obtained by programmed electrical stimulation. Rejection-sensitive parameters (RSP) and infection-specific parameters (ISP) are extracted from changes in the slope of the T-wave and from the duration of repolarization, respectively. For the analysis of intramyocardial electrograms, separate left and right ventricular pacing at a rate of 100 beats/min and lasting 60 s is required, following the same protocol. From year 2000, telemetric pacemakers were implanted in 14 patients undergoing heart transplantation at this institution. A total of 95 endomyocardial biopsies and 275 ventricular evoked response measurements were carried out. Five out of 6 cases with significant rejection were correctly identified by RSP values below a threshold of 98% (sensitivity=80%, specificity=50%, negative predictive value=97%, positive predictive value=11%; P<0.002). Of the EMBs, 45% could have been saved if the diagnosis model had been used to indicate need for EMB. Noninvasive cardiac graft monitoring can reduce the need for surveillance biopsies and may offer a tool to optimize immunosupressive therapy after heart transplantation. Rejection grade 2 or higher can safely be detected.
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Affiliation(s)
- I Zupan
- Department of Cardiology, University Medical Centre Ljubljana, Zaloska 7, 1000 Ljubljana, Slovenia.
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Abstract
Over the past 30 years, heart transplantation has evolved into a definitive therapy for patients with end-stage cardiomyopathy. However, perioperative management of patients undergoing heart transplantation remains a challenge for anesthesiologists. The presence of biventricular failure, arrhythmias and associated multisystem organ dysfunction may contribute to significant intraoperative hemodynamic instability prior to the initiation of cardiopulmonary bypass (CPB). Even after an uneventful transplantation, weaning from CPB may be difficult. Acute right ventricular failure can develop in the recipient secondary to pre-existing pulmonary hypertension. Treatment options frequently focus on therapeutic interventions directed towards decreasing pulmonary vascular resistance and improving right ventricular contractility. Intraoperative use of transesophageal echocardiography (TEE) enables the anesthesiologist to diagnose acute right ventricular failure early on and guide therapy. Concurrent pathology including kinking of the pulmonary artery anastomosis or valvular insufficiency in the transplanted heart can also be recognized and addressed. The number of patients undergoing cardiac transplantation is continually increasing. In addition, the use of more effective immunosuppressive agents has curtailed transplant rejection and permitted longer survival. Consequently, heart transplant recipients are more frequently presenting for non-cardiac surgical procedures. Thus, an understanding of physiological and pharmacological implications associated with heart transplantation is crucial for managing these patients in the perioperative period.
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Affiliation(s)
- H K Eltzschig
- Klinik für Anaesthesiologie und Intensivmedizin, Eberhard-Karls-Universität Tübingen.
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Squires RW, Leung TC, Cyr NS, Allison TG, Johnson BD, Ballman KV, Wagner JA, Olson LJ, Frantz RP, Edwards BS, Kushwaha SS, Dearani JA, Daly RC, McGregor CGA, Rodeheffer RJ. Partial normalization of the heart rate response to exercise after cardiac transplantation: frequency and relationship to exercise capacity. Mayo Clin Proc 2002; 77:1295-300. [PMID: 12479515 DOI: 10.4065/77.12.1295] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
OBJECTIVE To determine the frequency of partial normalization of the heart rate response to graded exercise and its relationship to exercise capacity in cardiac transplant recipients. SUBJECTS AND METHODS The study subjects were 95 adults (77 men, 18 women) who were available to perform a cardiopulmonary exercise test 1 year after orthotopic cardiac transplantation, which occurred between June 1988 and September 1998. All subjects received standard immunosuppressant medications. At the time of the exercise tests, the mean +/- SD age of the subjects was 49+/-14 years. The mean +/- SD resting left ventricular ejection fraction was 62%+/-8%. All subjects participated in a 6- to 8-week supervised exercise program, starting no later than 1 month after surgery. Subjects were given an exercise prescription for independent exercise training after finishing the supervised program. Self-reported weekly exercise training had a median value of 90 minutes (interquartile range, 0-210 minutes). Symptom-limited graded exercise was performed on a treadmill, with breath-by-breath analysis of expired air. RESULTS For the entire cohort, peak exercise oxygen uptake was 19.9+/-4.8 mL x kg(-1) x min(-1) (61%+/-15% of age and sex predicted). Thirty-two subjects (34%) had a partially normalized heart rate response to graded exercise. The frequency was similar for men (25/77 [33%]) and for women (7/18 [39%]) and was independent of recipient or donor age. Peak exercise heart rate (147+/-18 vs 134+/-21 beats/min; P=.008) and heart rate reserve (46+/-15 vs 33+/-15 beats/min; P<.001) were greater for subjects with a partial normalization of heart rate response. Peak exercise oxygen uptake was similar for subjects with or without partial normalization of the heart rate response (20.9+/-5.8 vs 19.4+/-4.2 mL x kg(-1) x min(-1); P=.22). Submaximal exercise oxygen uptake during the first few minutes of exercise was also not affected by normalization of the heart rate response. CONCLUSION At 1 year after cardiac transplantation, approximately one third of subjects had partial normalization of the heart rate response to graded exercise. However, a higher peak exercise heart rate and a larger heart rate reserve did not result in better aerobic exercise capacity.
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Affiliation(s)
- Ray W Squires
- Division of Cardiovascular Diseases and Internal Medicine, Mayo Clinic, Rochester, Minn 55905, USA.
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Chowdhary S, Harrington D, Bonser RS, Coote JH, Townend JN. Chronotropic effects of nitric oxide in the denervated human heart. J Physiol 2002; 541:645-51. [PMID: 12042368 PMCID: PMC2290318 DOI: 10.1113/jphysiol.2001.015107] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Nitric oxide synthase is expressed in the sino-atrial node and animal data suggests a direct role for nitric oxide on pacemaker activity. Study of this mechanism in intact humans is complicated by both reflex and direct effects of nitric oxide on cardiac autonomic control. Thus, we have studied the direct effects of nitric oxide on heart rate in human cardiac transplant recipients who possess a denervated donor heart. In nine patients, the chronotropic effects of systemic injection of the nitric oxide synthase inhibitor N(G)-monomethyl-L-arginine (L-NMMA) (3 mg kg(-1)) or increasing bolus doses of the nitric oxide donor, sodium nitroprusside (SNP), were studied. Injection of L-NMMA increased mean arterial pressure by 17 +/- 2 mmHg (mean +/- S.E.M.; P < 0.001) and also had a significant negative chronotropic effect, lengthening the R-R interval by 54 +/- 8 ms (P < 0.001). This bradycardia was not reflex in origin since injection of the non-NO-dependent vasoconstrictor, phenylephrine (100 microg) achieved a similar rise in mean arterial pressure (18 +/- 3 mmHg; P < 0.001) but failed to change R-R interval duration (Delta R-R = -3 +/- 4 ms). Furthermore, no change in levels of circulating adrenaline was observed with L-NMMA. Conversely, injection of sodium nitroprusside resulted in a positive chronotropic effect with a dose-dependent shortening of R-R interval duration, peak Delta R-R = -25 +/- 8 ms with 130 microg (P < 0.01). These findings indicate that nitric oxide exerts a tonic, direct, positive chronotropic influence on the denervated human heart. This is consistent with the results of animal experiments showing that nitric oxide exerts a facilitatory influence on pacemaking currents in the sino-atrial node.
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Affiliation(s)
- S Chowdhary
- Department of Cardiovascular Medicine, University Hospital Birmingham and the University of Birmingham, Birmingham, UK.
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Beckers F, Ramaekers D, Van Cleemput J, Droogné W, Vanhaecke J, Van de Werf F, Aubert AE. Association between restoration of autonomic modulation in the native sinus node and hemodynamic improvement after cardiac transplantation. Transplantation 2002; 73:1614-20. [PMID: 12042649 DOI: 10.1097/00007890-200205270-00016] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Little is known about the autonomic control of the native sinus node (NSN) after heart transplantation because its electrical activity is difficult to detect with skin electrodes. METHODS AND RESULTS The intracardiac electrogram of the NSN and the donor heart electrocardiogram were measured simultaneously. A total of 351 recordings of 107 heart transplant patients (age 53.6+/-12.3 years) were obtained up to 1 year after transplantation. In a subgroup of 41 patients, consecutive recordings were made. Eleven recordings of heart failure patients (age 56.2+/-6.5 years) awaiting cardiac transplantation were used as controls. To examine a relationship between autonomic indices of the NSN and hemodynamics of the donor heart, intracardiac pressures and cardiac output were recorded in the same session. Heart rate variability (HRV) parameters in time and frequency domain of the NSN showed a significant increase starting at 6 months after transplantation, whereas heart rate of the NSN tended to decrease. Heart rate and HRV parameters remained constant over the first year in the donor heart. Higher values of low-frequency and high-frequency powers in the NSN were associated with lower values of right ventricular, pulmonary artery, and mean atrial pressure and cardiac output. Recordings of patients with rejection could not be distinguished from those without rejection based on the spectral content of HRV of either the NSN or the donor heart. CONCLUSIONS These data suggest a restoration of autonomic modulation of the NSN. This restoration is associated with hemodynamic improvement of the donor heart.
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Affiliation(s)
- Frank Beckers
- Laboratory of Experimental Cardiology, Department of Cardiology, University Hospital Gasthuisberg, 3000 Leuven, Belgium
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Desai MY, De la Peña-Almaguer E, Mannting F. Abnormal heart rate recovery after exercise as a reflection of an abnormal chronotropic response. Am J Cardiol 2001; 87:1164-9. [PMID: 11356391 DOI: 10.1016/s0002-9149(01)01487-4] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Abnormal decline in heart rate (HR) after exercise has been linked to increased cardiac mortality. This study compares the decrease in HR in different patient types, elucidates the relation between the increase and decrease of HR with exercise, and studies the role of beta blockers on the recovery of HR after exercise. One hundred patients with coronary artery disease (CAD), 50 subjects with a very low likelihood of CAD (normals), and 21 postcardiac transplant (Tx) patients underwent Bruce protocols. Peak HR, percent of peak HR achieved, HR reserve percent, and decline in HR at 1, 3, 5, and 8 minutes were obtained for all groups and also for subgroups based on the use of beta blockers. HR recovery at 1, 3, 5, and 8 minutes differed significantly between patients with CAD, normals, and Tx patients. HR recovery at 1, 3, 5, and 8 minutes also differed significantly within the groups (normal and CAD) based on the use of beta blockers. There was highly significant correlation between decrease in HR and peak HR, percent peak HR and HR reserve percent in normal and CAD groups. After correction of the HR recovery for dependence on peak HR and HR reserve percent, the difference in HR recovery between normal and CAD groups was markedly reduced. The difference in the decrease of HR within each group (normal and CAD), based on the use of beta blockers or not, was also markedly reduced. beta blockers have a significant impact on the decrease in HR due to its effect on chronotropism. HR recovery rate is highly dependent on the chronotropic response. Hence, the main portion of the abnormality in HR recovery after exercise can be explained by chronotropic incompetence.
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Affiliation(s)
- M Y Desai
- Division of Nuclear Cardiology, Department of Radiology, Brigham & Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA
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Elhendy A, van Domburg RT, Vantrimpont P, Sozzi FB, Bax JJ, Poldermans D, Roelandt JR, Maat LP, Balk AH. Impact of heart transplantation on the safety and feasibility of the dobutamine stress test. J Heart Lung Transplant 2001; 20:399-406. [PMID: 11295577 DOI: 10.1016/s1053-2498(00)00319-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND Dobutamine myocardial perfusion imaging is a useful method for evaluation of coronary artery disease. However, this technique does not allow for ischemia monitoring, which may have an impact on the safety of the test in heart transplant recipients due to cardiac sensory denervation. The aim of this study was to assess the impact of heart transplantation on the feasibility and complications of the dobutamine stress test. METHODS We studied 225 heart transplant recipients (mean age 57 +/- 7 years) and a control group of 225 patients without previous transplant matched for age and gender by dobutamine (up to 40 microg/kg per minute) stress myocardial perfusion imaging. RESULTS During the test, transplant recipients had a lower prevalence of premature ventricular contractions (23% vs. 37%, p < 0.001) and ventricular tachycardia (0.04% vs 7.5%, p < 0.0001) compared with control patients. By multivariate analysis, heart transplantation was a powerful independent variable associated with a reduced risk of ventricular arrhythmias (chi(2) = 20.8, p < 0.0001) and minor side effects (nausea, dizziness, anxiety, flushing, chills) (chi(2) = 20, p < 0.0001) during dobutamine stress. The target heart rate was reached in 82% of transplant recipients and in 77% of the control group. Overall feasibility (achievement of the target heart rate and/or an ischemic end-point) was 87% in the transplant and 86% in the control group. CONCLUSIONS Dobutamine stress myocardial perfusion imaging is a safe and feasible method for evaluation of coronary artery disease in heart transplant recipients. The prevalence of arrhythmias and minor complications using the dobutamine stress test is lower in heart transplant recipients compared with control patients. The independent association between heart transplantation and reduced risk of arrhythmias and minor side effects of the dobutamine stress test indicates that cardiac sensory and autonomic nerve function plays a major role in the induction of these complications during the test.
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Affiliation(s)
- A Elhendy
- Department of Cardiovascular Disease and Internal Medicine, Mayo Clinic, Rochester, Minnesota, USA.
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Murphy DA, Thompson GW, Ardell JL, McCraty R, Stevenson RS, Sangalang VE, Cardinal R, Wilkinson M, Craig S, Smith FM, Kingma JG, Armour JA. The heart reinnervates after transplantation. Ann Thorac Surg 2000; 69:1769-81. [PMID: 10892922 DOI: 10.1016/s0003-4975(00)01240-6] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND Whether cardiac reinnervation occurs after transplantation remains controversial. If reinnervation does occur, how sympathetic and parasympathetic efferent neurons do this remains unknown. METHODS Power spectral analysis of heart rate variability was assessed for 1 year after cardiac autotransplantation in 9 dogs. After induction of anesthesia 13 months after transplantation, cardiac and intrinsic cardiac neuronal responses elicited by both electrical stimulation of parasympathetic or sympathetic efferent neurons and systemic or local coronary artery administration of nicotine (5 microg/kg), angiotensin II (0.75 microg/kg), and tyramine (1.2 microg/kg) were studied. The transmembrane electrical properties of intrinsic cardiac neurons were studied in vitro. Ventricular tissue catecholamine content, alpha-tubulin expression, and beta-adrenergic receptor density and affinity were studied. The presence of axons crossing suture lines was sought histologically. RESULTS Nerves were identified crossing suture lines. Electrical or chemical (ie, nicotine or angiotensin II) activation of sympathetic efferent neurons enhanced cardiodynamics, as did tyramine. Stimulating vagal efferent preganglionic axons induced bradycardia in half of the dogs. Functional reinnervation did not correlate with specific power spectra derived from rate variability in the conscious state. Responding to nicotine and angiotensin II in situ, transplanted intrinsic cardiac neurons generated spontaneous activity. These neurons displayed nicotine-dependent synaptic inputs in vitro. Ventricular tissue had normal beta-adrenergic receptor affinity and density but reduced catecholamine and alpha-tubulin contents. CONCLUSIONS The intrinsic cardiac nervous system receives reduced input from extracardiac sympathetic efferent neurons after transplantation and inconsistent input from parasympathetic efferent preganglionic neurons. These heterogeneous neuronal inputs are not reflected in heart rate variability or ventricular beta-adrenergic receptor function. Transplanted angiotensin II-sensitive intrinsic cardiac neurons exert greater cardiac control than do nicotine-sensitive ones. The intrinsic cardiac nervous system remodels itself after cardiac transplantation, and this indicates that direct assessment of extracardiac and intrinsic cardiac neuronal behavior is required to fully understand cardiac control after transplantation.
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Affiliation(s)
- D A Murphy
- Department of Surgery, Dalhousie University, Halifax, Nova Scotia, Canada
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Abstract
The transplanted heart is characterized physiologically by autonomic denervation, chronotropic incompetence, intermittent episodes of allograft rejection, and frequently by diastolic dysfunction. Sinus node dysfunction resulting in bradycardia is common in the early postoperative period following standard orthotopic cardiac transplantation. Bradycardia tends to remit spontaneously but there are no factors that accurately identify patients who will need long-term pacing. Patients in whom bradycardia persists beyond the second postoperative week despite treatment with theophylline require permanent pacemaker implantation. It has been observed that chronotropic incompetence and diastolic dysfunction are important determinants of exercise capacity following heart transplantation. Pacing that restores chronotropic competence improves exercise capacity, confirming the importance of impaired heart rate response. As in other settings, pacing that preserves atrioventricular (AV) synchrony results in increased cardiac output. For these reasons when pacing is necessary we recommend the DDDR mode (AAIR if intact AV nodal conduction is present) so that the 30%-50% of patients who remain pacemaker-dependent long-term obtain maximal benefit from their transplant.
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Affiliation(s)
- I C Melton
- Department of Cardiovascular Electrophysiology, Virginia Commonwealth University/Medical College of Virginia Hospital, and the McGuire VA Medical Center, Richmond 23298-0053, USA
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