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Guo X, Gong C, Song R, Wan K, Han Y, Chen Y. First-pass perfusion cardiovascular magnetic resonance parameters as surrogate markers for left ventricular diastolic dysfunction: a validation against cardiac catheterization. Eur Radiol 2022; 32:8131-8139. [PMID: 35779091 DOI: 10.1007/s00330-022-08938-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 05/25/2022] [Accepted: 05/30/2022] [Indexed: 02/05/2023]
Abstract
OBJECTIVES The non-invasive assessment of left ventricular (LV) diastolic dysfunction remains a challenge. The role of first-pass perfusion cardiac magnetic resonance (CMR) parameters in quantitative hemodynamic analyses has been reported. We therefore aimed to validate the diagnostic ability and accuracy of such parameters against cardiac catheterization for LV diastolic dysfunction in patients with left heart disease (LHD). METHODS We retrospectively enrolled 77 LHD patients who underwent CMR imaging and cardiac catheterization. LV diastolic dysfunction was defined as pulmonary capillary wedge pressure (PCWP) or LV end-diastolic pressure (LVEDP) > 12 mmHg on catheterization. On first-pass perfusion CMR imaging, pulmonary transit time (PTT) was measured as the time for blood to pass from the left ventricle to the right ventricle (RV) through the pulmonary vasculature. Pulmonary transit beat (PTB) was the number of cardiac cycles within the interval, and pulmonary blood volume indexed to body surface area (PBVi) was the product of PTB and RV stroke volume index (RVSVi). RESULTS Of the 77 LHD patients, 53 (68.83%) were found to have LV diastolic dysfunction, and showed significantly higher PTTc, PTB, and PBVi (p < 0.05) compared with those without. In multivariate analyses, only PTTc and PTB were identified as independent predictors of LV diastolic dysfunction (p < 0.05). With an optimal cutoff of 11.9 s, PTTc yielded the best diagnostic performance for LV diastolic dysfunction (area under the curve = 0.83, p < 0.001). CONCLUSIONS PTTc may represent a non-invasive quantitative surrogate marker for the detection and assessment of diastolic dysfunction in LHD patients. KEY POINTS • PTTc yielded the best diagnostic accuracy for diastolic dysfunction, with an optimal cutoff of 11.9 s, and a specificity of 100%. • PTTc and PTB were found to be independent predictors of LV diastolic dysfunction across different multivariate models with high reproducibility. • PTTc is a promising non-invasive surrogate marker for the detection and assessment of diastolic dysfunction in LHD patients.
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Affiliation(s)
- Xinli Guo
- Department of Cardiology, West China Hospital, Sichuan University, Chengdu, Sichuan Province, 610041, China
| | - Chao Gong
- Department of Cardiology, West China Hospital, Sichuan University, Chengdu, Sichuan Province, 610041, China
| | - Rizhen Song
- Department of Cardiology, West China Hospital, Sichuan University, Chengdu, Sichuan Province, 610041, China
| | - Ke Wan
- Department of Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan Province, 610041, China
| | - Yuchi Han
- Department of Medicine (Cardiovascular Division), University of Pennsylvania, Philadelphia, PA, USA
| | - Yucheng Chen
- Department of Cardiology, West China Hospital, Sichuan University, Chengdu, Sichuan Province, 610041, China.
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Harms HJ, Bravo PE, Bajaj NS, Zhou W, Gupta A, Tran T, Taqueti VR, Hainer J, Bibbo C, Dorbala S, Blankstein R, Mehra M, Sörensen J, Givertz MM, Di Carli MF. Cardiopulmonary transit time: A novel PET imaging biomarker of in vivo physiology for risk stratification of heart transplant recipients. J Nucl Cardiol 2022; 29:1234-1244. [PMID: 33398793 PMCID: PMC8254830 DOI: 10.1007/s12350-020-02465-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 10/12/2020] [Indexed: 01/05/2023]
Abstract
BACKGROUND Myocardial blood flow (MBF) can be quantified using dynamic PET studies. These studies also inherently contain tomographic images of early bolus displacement, which can provide cardiopulmonary transit times (CPTT) as measure of cardiopulmonary physiology. The aim of this study was to assess the incremental prognostic value of CPTT in heart transplant (OHT) recipients. METHODS 94 patients (age 56 ± 16 years, 78% male) undergoing dynamic 13N-ammonia stress/rest studies were included, of which 68 underwent right-heart catherization. A recently validated cardiac allograft vasculopathy (CAV) score based on PET measures of regional perfusion, peak MBF and left-ventricular (LV) ejection fraction (LVEF) was used to identify patients with no, mild or moderate-severe CAV. Time-activity curves of the LV and right ventricular (RV) cavities were obtained and used to calculate the difference between the LV and RV bolus midpoint times, which represents the CPTT and is expressed in heartbeats. Patients were followed for a median of 2.5 years for the occurrence of major adverse cardiac events (MACE), including cardiovascular death, hospitalization for heart failure or acute coronary syndrome, or re-transplantation. RESULTS CPTT was significantly correlated with cardiac filling pressures (r = .434, P = .0002 and r = .439, P = .0002 for right atrial and pulmonary wedge pressure), cardiac output (r = - .315, P = .01) and LVEF (r = - .513, P < .0001). CPTT was prolonged in patients with MACE (19.4 ± 6.0 vs 14.5 ± 3.0 heartbeats, P < .001, N = 15) with CPTT ≥ 17.75 beats showing optimal discriminatory value in ROC analysis. CPTT ≥ 17.75 heartbeats was associated with a 10.1-fold increased risk (P < .001) of MACE and a 7.3-fold increased risk (P < .001) after adjusting for PET-CAV, age, sex and time since transplant. CONCLUSION Measurements of cardiopulmonary transit time provide incremental risk stratification in OHT recipients and enhance the value of multiparametric dynamic PET imaging, particularly in identifying high-risk patients.
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Affiliation(s)
- H J Harms
- Cardiovascular Imaging Program, Departments of Radiology and Medicine; Division of Nuclear Medicine and Molecular Imaging, Brigham and Women's Hospital, and Harvard Medical School, 75 Francis Street, Boston, MA, USA
- Institute of Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - P E Bravo
- Division of Cardiovascular Medicine, Department of Medicine; and Division of Nuclear Medicine, Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia, PA, USA
| | - N S Bajaj
- Cardiovascular Imaging Program, Departments of Radiology and Medicine; Division of Nuclear Medicine and Molecular Imaging, Brigham and Women's Hospital, and Harvard Medical School, 75 Francis Street, Boston, MA, USA
| | - W Zhou
- Cardiovascular Imaging Program, Departments of Radiology and Medicine; Division of Nuclear Medicine and Molecular Imaging, Brigham and Women's Hospital, and Harvard Medical School, 75 Francis Street, Boston, MA, USA
| | - A Gupta
- Cardiovascular Imaging Program, Departments of Radiology and Medicine; Division of Nuclear Medicine and Molecular Imaging, Brigham and Women's Hospital, and Harvard Medical School, 75 Francis Street, Boston, MA, USA
| | - T Tran
- Cardiovascular Imaging Program, Departments of Radiology and Medicine; Division of Nuclear Medicine and Molecular Imaging, Brigham and Women's Hospital, and Harvard Medical School, 75 Francis Street, Boston, MA, USA
| | - V R Taqueti
- Cardiovascular Imaging Program, Departments of Radiology and Medicine; Division of Nuclear Medicine and Molecular Imaging, Brigham and Women's Hospital, and Harvard Medical School, 75 Francis Street, Boston, MA, USA
| | - J Hainer
- Cardiovascular Imaging Program, Departments of Radiology and Medicine; Division of Nuclear Medicine and Molecular Imaging, Brigham and Women's Hospital, and Harvard Medical School, 75 Francis Street, Boston, MA, USA
| | - C Bibbo
- Cardiovascular Imaging Program, Departments of Radiology and Medicine; Division of Nuclear Medicine and Molecular Imaging, Brigham and Women's Hospital, and Harvard Medical School, 75 Francis Street, Boston, MA, USA
| | - S Dorbala
- Cardiovascular Imaging Program, Departments of Radiology and Medicine; Division of Nuclear Medicine and Molecular Imaging, Brigham and Women's Hospital, and Harvard Medical School, 75 Francis Street, Boston, MA, USA
| | - R Blankstein
- Cardiovascular Imaging Program, Departments of Radiology and Medicine; Division of Nuclear Medicine and Molecular Imaging, Brigham and Women's Hospital, and Harvard Medical School, 75 Francis Street, Boston, MA, USA
| | - M Mehra
- Cardiovascular Imaging Program, Departments of Radiology and Medicine; Division of Nuclear Medicine and Molecular Imaging, Brigham and Women's Hospital, and Harvard Medical School, 75 Francis Street, Boston, MA, USA
| | - J Sörensen
- Institute of Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark
- Department of Surgical Sciences, Nuclear Medicine and PET, Uppsala University, Uppsala, Sweden
| | - M M Givertz
- Cardiovascular Imaging Program, Departments of Radiology and Medicine; Division of Nuclear Medicine and Molecular Imaging, Brigham and Women's Hospital, and Harvard Medical School, 75 Francis Street, Boston, MA, USA
| | - M F Di Carli
- Cardiovascular Imaging Program, Departments of Radiology and Medicine; Division of Nuclear Medicine and Molecular Imaging, Brigham and Women's Hospital, and Harvard Medical School, 75 Francis Street, Boston, MA, USA.
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Chou J, Rinehart JB. Computer simulated modeling of healthy and diseased right ventricular and pulmonary circulation. J Clin Monit Comput 2018; 32:1015-1024. [PMID: 29330837 DOI: 10.1007/s10877-018-0099-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Accepted: 01/04/2018] [Indexed: 01/27/2023]
Abstract
We have previously developed a simulated cardiovascular physiology model for in-silico testing and validation of novel closed-loop controllers. To date, a detailed model of the right heart and pulmonary circulation was not needed, as previous controllers were not intended for use in patients with cardiac or pulmonary pathology. With new development of controllers for vasopressors, and looking forward, for combined vasopressor-fluid controllers, modeling of right-sided and pulmonary pathology is now relevant to further in-silico validation, so we aimed to expand our existing simulation platform to include these elements. Our hypothesis was that the completed platform could be tuned and stabilized such that the distributions of a randomized sample of simulated patients' baseline characteristics would be similar to reported population values. Our secondary outcomes were to further test the system in representing acute right heart failure and pulmonary artery hypertension. After development and tuning of the right-sided circulation, the model was validated against clinical data from multiple previously published articles. The model was considered 'tuned' when 100% of generated randomized patients converged to stability (steady, physiologically-plausible compartmental volumes, flows, and pressures) and 'valid' when the means for the model data in each health condition were contained within the standard deviations for the published data for the condition. A fully described right heart and pulmonary circulation model including non-linear pressure/volume relationships and pressure dependent flows was created over a 6-month span. The model was successfully tuned such that 100% of simulated patients converged into a steady state within 30 s. Simulation results in the healthy state for central venous volume (3350 ± 132 ml) pulmonary blood volume (405 ± 39 ml), pulmonary artery pressures (systolic 20.8 ± 4.1 mmHg and diastolic 9.4 ± 1.8 mmHg), left atrial pressure (4.6 ± 0.8 mmHg), PVR (1.0 ± 0.2 wood units), and CI (3.8 ± 0.5 l/min/m2) all met criteria for acceptance of the model, though the standard deviations of LAP and CI were somewhat narrower than published comparators. The simulation results for right ventricular infarction also fell within the published ranges: pulmonary blood volume (727 ± 102 ml), pulmonary arterial pressures (30 ± 4 mmHg systolic, 12 ± 2 mmHg diastolic), left atrial pressure (13 ± 2 mmHg), PVR (1.6 ± 0.3 wood units), and CI (2.0 ± 0.4 l/min/m2) all fell within one standard deviation of the reported population values and vice-versa. In the pulmonary hypertension model, pulmonary blood volume of 615 ± 90 ml, pulmonary arterial pressures of 80 ± 14 mmHg systolic, 36 ± 7 mmHg diastolic, and the left atrial pressure of 11 ± 2 mmHg all met criteria for acceptance. For CI, the simulated value of 2.8 ± 0.4 l/min/m2 once again had a narrower spread than most of the published data, but fell inside of the SD of all published data, and the PVR value of 7.5 ± 1.6 wood units fell in the middle of the four published studies. The right-ventricular and pulmonary circulation simulation appears to be a reasonable approximation of the right-sided circulation for healthy physiology as well as the pathologic conditions tested.
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Affiliation(s)
- Jody Chou
- Department of Anesthesiology and Perioperative Care, University of California Irvine, 101 The City Drive South, Orange, CA, 92868, USA
| | - Joseph B Rinehart
- Department of Anesthesiology and Perioperative Care, University of California Irvine, 101 The City Drive South, Orange, CA, 92868, USA.
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Ricci F, Barison A, Todiere G, Mantini C, Cotroneo AR, Emdin M, De Caterina R, Galllina S, Aquaro GD. Prognostic value of pulmonary blood volume by first-pass contrast-enhanced CMR in heart failure outpatients: the PROVE-HF study. Eur Heart J Cardiovasc Imaging 2017; 19:896-904. [DOI: 10.1093/ehjci/jex214] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Accepted: 08/16/2017] [Indexed: 12/24/2022] Open
Affiliation(s)
- F Ricci
- Institute for Advanced Biomedical Technologies, “G. d'Annunzio” University, Via Luigi Polacchi, 11 - 66100 Chieti, Italy
- Department of Neuroscience, Imaging and Clinical Sciences, “G. d'Annunzio” University, Via dei Vestini. 31 - 66100 Chieti, Italy
- Institute of Cardiology, Department of Neuroscience, Imaging and Clinical Sciences, “G. d'Annunzio” University, Via dei Vestini, 31 - 66100 Chieti, Italy
| | - A Barison
- G. Monasterio Foundation, MRI-laboratory, Via Giuseppe Moruzzi, 1 - 56124 Pisa, Italy
| | - G Todiere
- G. Monasterio Foundation, MRI-laboratory, Via Giuseppe Moruzzi, 1 - 56124 Pisa, Italy
| | - C Mantini
- Department of Neuroscience, Imaging and Clinical Sciences, “G. d'Annunzio” University, Via dei Vestini. 31 - 66100 Chieti, Italy
| | - A R Cotroneo
- Department of Neuroscience, Imaging and Clinical Sciences, “G. d'Annunzio” University, Via dei Vestini. 31 - 66100 Chieti, Italy
| | - M Emdin
- G. Monasterio Foundation, MRI-laboratory, Via Giuseppe Moruzzi, 1 - 56124 Pisa, Italy
| | - R De Caterina
- Institute of Cardiology, Department of Neuroscience, Imaging and Clinical Sciences, “G. d'Annunzio” University, Via dei Vestini, 31 - 66100 Chieti, Italy
| | - S Galllina
- Institute of Cardiology, Department of Neuroscience, Imaging and Clinical Sciences, “G. d'Annunzio” University, Via dei Vestini, 31 - 66100 Chieti, Italy
| | - G D Aquaro
- G. Monasterio Foundation, MRI-laboratory, Via Giuseppe Moruzzi, 1 - 56124 Pisa, Italy
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Eriksson A, Hansson K, Häggström J, Järvinen AK, Lord P. Pulmonary Blood Volume in Mitral Regurgitation in Cavalier King Charles Spaniels. J Vet Intern Med 2010; 24:1393-9. [DOI: 10.1111/j.1939-1676.2010.0619.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Møller S, Burchardt H, Øgard CG, Schiødt FV, Lund JO. Pulmonary blood volume and transit time in cirrhosis: relation to lung function. Liver Int 2006; 26:1072-8. [PMID: 17032407 DOI: 10.1111/j.1478-3231.2006.01343.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
BACKGROUND/AIMS In cirrhosis a systemic vasodilatation leads to an abnormal distribution of the blood volume with a contracted central blood volume. In addition, the patients have a ventilation/perfusion imbalance with a low diffusing capacity. As the size of the pulmonary blood volume (PBV) has not been determined separately we assessed PBV and pulmonary transit time (PTT) in relation to lung function in patients with cirrhosis and in controls. METHODS Pulmonary and cardiac haemodynamics and transit times were determined by radionuclide techniques in 22 patients with alcoholic cirrhosis and in 12 controls. The lung function including diffusing capacity for carbon monoxide (DL, CO) was determined by conventional single breath technique. RESULTS In the patients, PTT was shorter, 3.9+/-1.2 vs 5.7+/-1.0 s in the controls, P<0.001, and the PBV was lower, 362+/-151 vs 587+/-263 ml, in the controls, P<0.005. Both PTT and PBV were lowest in patients with advanced disease. DL, CO was reduced in the patients and correlated significantly with PTT (r=0.58, P=0.007) and PBV (r=0.49, P<0.03). CONCLUSIONS The results suggest that the reduced PBV contributes to the reduced effective blood volume in cirrhosis. The relation between PBV and PTT and the low diffusing capacity suggests the pulmonary vascular compartment as an important element in the pathophysiology of the lung dysfunction in cirrhosis.
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Affiliation(s)
- Søren Møller
- Department of Clinical Physiology, Hvidovre Hospital, University of Copenhagen, Copenhagen, Denmark.
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7
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Lord P, Eriksson A, Häggström J, Järvinen AK, Kvart C, Hansson K, Maripuu E, Mäkelä O. Increased Pulmonary Transit Times in Asymptomatic Dogs with Mitral Regurgitation. J Vet Intern Med 2003; 17:824-9. [PMID: 14658719 DOI: 10.1111/j.1939-1676.2003.tb02521.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Pulmonary transit time (PTT) normalized to heart rate (nPTT) is a measure of the pulmonary blood volume (PBV) to stroke volume ratio (PBV/SV). It is an index of cardiac performance. To determine the effect of compensated mitral regurgitation (CMR) and decompensated mitral regurgitation (DMR) caused by valvular endocardiosis on the index nPTT, we measured nPTT by first-pass radionuclide angiocardiography and ECG in 13 normal dogs, 18 dogs with CMR, and 13 dogs with DMR. PTT was measured as time between onset of appearance of activity at the pulmonary trunk and the left atrium. In the normal dogs, the relationship between PTT and mean R-R interval (mRR) was PTT = 4.08 x mRR + 0.15 (R2 = 0.71). Normal nPTT was 4.4 +/- 0.6 (SD) (range. 3.6-5.3). in CMR, 6.3 +/- 1.6 (SD) (range, 4.0-9.7). and in DMR, 11.9 +/- 3.4 (SD) (range, 8.0-18.8). The differences among all groups were significant. Heart rates were 110 +/- 22 bpm in normal dogs, 111 +/- 20 in dogs with CMR, and 144 +/- 18 in dogs with DMR (P < .001 for difference between DMR group and normal and CMR groups). Increased nPTT in CMR indicates preclinical heart pump dysfunction. Heart rate-normalized pulmonary transit times may be a useful index of heart function in mitral regurgitation.
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Affiliation(s)
- Peter Lord
- Department of Clinical Radiology, Faculty of Veterinary Medicine, Swedish University of Agricultural Sciences, Uppsala, Sweden.
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8
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Zerahn B, Jensen BV, Olsen F, Petersen JR, Kanstrup IL. The effect of thoracentesis on lung function and transthoracic electrical bioimpedance. Respir Med 1999; 93:196-201. [PMID: 10464878 DOI: 10.1016/s0954-6111(99)90008-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
This study aimed to determine the relationship between improvement in lung function and changes in transthoracic electrical bioimpedance (TEB) after thoracentesis in patients with pleural effusions. Fifteen patients with pleural effusions due to either malignant (n = 8) or cardiac (n = 7) diseases were included. Pulmonary function was assessed before and after thoracentesis. During thoracentesis the patients were monitored with TEB. Using linear correlation analysis, the increases for each litre of aspirated thoracic fluid were: forced expiratory volume in 1 s (FEV1) 0.261; forced vital capacity (FVC) 0.331; total lung capacity (TLC) 0.58; and the lung diffusing capacity (DLCO); 2.4 ml min-1 mmHg-1. Baseline impedance increased by 2.3 Ohm l-1 aspirated thoracic fluid. The relative increase in baseline impedance was twice as high for patients with cancer as for patients with heart failure (P < 0.05). We found only minor changes in systolic blood pressure and mean arterial pressure. The improvements in diffusing capacity, airflow, and lung volumes after thoracentesis are correlated to an increase in baseline impedance, but changes are dependent on the primary disease.
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Affiliation(s)
- B Zerahn
- Department of Clinical Physiology and Nuclear Medicine, Herlev Hospital, University of Copenhagen, Denmark.
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Henriksen JH, Møller S, Bendtsen F, Ring-Larsen H, Stokholm KH, Møgelvang J, Sørensen TI, Gerbes AL. Assessment of central blood volume in cirrhosis by radionuclide angiography: what does it really mean? Hepatology 1994; 20:1652-6. [PMID: 7982670 DOI: 10.1002/hep.1840200651] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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Stokholm KH, Breum L, Astrup A. Cardiac contractility, central haemodynamics and blood pressure regulation during semistarvation. CLINICAL PHYSIOLOGY (OXFORD, ENGLAND) 1991; 11:513-23. [PMID: 1769186 DOI: 10.1111/j.1475-097x.1991.tb00671.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Eight obese patients were studied before and after 2 weeks of treatment by a very-low-calorie diet (VLCD). Cardiac output and central blood volume (pulmonary blood volume and left atrial volume) were determined by indicator dilution (125I-albumin) and radionuclide angiocardiography (first pass and equilibrium technique by [99Tcm]red blood cells). Cardiac output decreased concomitantly with the reduction in oxygen uptake as the calculated systemic arteriovenous difference of oxygen was unaltered. There were no significant decreases in left ventricular contractility indices, i.e. the ejection fraction, the peak ejection rate and changes in end-systolic volume. Also the diastolic function evaluated by the peak filling rate remained normal. Furthermore, no sign of backward failure could be demonstrated since the central blood volume was not significantly increased. Both systolic and diastolic blood pressure (BP) declined. The fall in BP was caused by the reduction in cardiac output as the total peripheral resistance was unchanged. Finally, the decline in total blood volume was not significant. These findings together with a reduction in heart rate indicated that a reduced sympathetic tone via increased capacitance of the venous bed was the main operator of a reduced venous return. Thus, the haemodynamic alterations in obese patients during short-term semistarvation may be caused by the fall in oxygen uptake and produced mainly by changes in the sympathetic tone.
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Affiliation(s)
- K H Stokholm
- Department of Clinical Physiology and Nuclear Medicine, Hvidovre Hospital, Denmark
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Capewell S, Wathen CG, Hannan WJ, Muir AL. The haemodynamic effects of long term felodipine therapy in previously untreated essential hypertension. Eur J Clin Pharmacol 1990; 39:539-43. [PMID: 2095339 DOI: 10.1007/bf00316091] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Sixteen patients with previously untreated mild/moderate hypertension (WHO Stage I) were studied: 7 women and 9 men, mean age 56.2 y. Haemodynamics, central and pulmonary blood volumes were measured by radionuclide techniques and repeated after 8 weeks felodipine therapy. To achieve a target diastolic blood pressure of less than 95 mm Hg 12 patients required 5 mg bid, 2 10 mg bid and 1 2.5 mg bid; 1 withdrew after 2 weeks. Mean (SD) arterial blood pressure (mm Hg) was 189/106 before, and 182/103 after 2 weeks placebo treatment and fell to 148/84 after 8 weeks felodipine therapy. Relative systemic vascular resistance fell by 19% from 2146 to 1734 dyn.s.cm-5. There were no significant changes in heart rate, cardiac index, total blood volume, pulmonary blood volume or left ventricular ejection fraction. Plasma renin activity did not rise significantly. Short lived vasodilator side effects occurred in 7/16 patients during initial treatment and mild ankle oedema persisted in 4/16 patients. In contrast to the haemodynamic changes seen acutely with felodipine, the only sustained changes after 8 weeks therapy are reductions in systemic vascular resistance and blood pressure.
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Affiliation(s)
- S Capewell
- Department of Medicine, Royal Infirmary, Edinburgh, UK
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12
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Stokholm KH, Stubgaard M, Møgelvang J, Henriksen O. Combined left and right ventricular volume determination by radionuclide angiocardiography using double bolus and equilibrium technique. CLINICAL PHYSIOLOGY (OXFORD, ENGLAND) 1990; 10:475-88. [PMID: 2245597 DOI: 10.1111/j.1475-097x.1990.tb00827.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Eighteen patients with ischaemic heart disease were studied. Left and right ventricular volumes including cardiac output (forward flow) were determined by radionuclide angiocardiography using a double bolus and equilibrium technique. As reference, cardiac output was simultaneously measured by indicator dilution. The radionuclide technique comprised four steps: (1) a first-pass study of right ventricle; (2) a bolus study of left ventricle; (3) an equilibrium study of left ventricle; (4) determination of the distribution volume of red blood cells. Absolute volumes of left ventricle were determined from steps 2 + 3 + 4. Absolute volumes of right ventricle were calculated from stroke volume and right ventricular ejection fraction (EF) which in turn was determined from step 1 by creating composite systolic and composite diastolic images. There was an acceptable agreement between stroke volume determinations by radionuclide angiocardiography and indicator dilution (r = 0.74; P less than 0.001). Stroke volume determination by radionuclide was 83 +/- 20 ml (mean +/- SD) and by indicator dilution 84 +/- 20 ml with a difference of -1 +/- 15 ml (NS). Cardiac output determination by radionuclide was 5.24 +/- 1.37 l min-1 and by indicator dilution 5.28 +/- 1.23 l min-1 with a difference of -0.04 +/- 0.95 l min-1 (NS). Left ventricular EF was 0.44 +/- 0.14 and right ventricular EF 0.57 +/- 0.10. The intra-observer coefficient of variation for duplicate calculations of the radionuclide determinations was 5.5% for stroke volume, 2.5% for left ventricular EF and 4.8% for right ventricular EF.
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Affiliation(s)
- K H Stokholm
- Department of Clinical Physiology and Nuclear Medicine, Hvidovre Hospital, University of Copenhagen, Denmark
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