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Spence CM, Foshaug R, Rowland S, Krysler A, Conway J, Urschel S, West L, Stickland M, Boulanger P, Spence JC, Khoury M. Evaluating a Telemedicine Video Game-Linked High-Intensity Interval Training Exercise Programme in Paediatric Heart Transplant Recipients. CJC PEDIATRIC AND CONGENITAL HEART DISEASE 2023; 2:198-205. [PMID: 37969861 PMCID: PMC10642108 DOI: 10.1016/j.cjcpc.2023.04.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Accepted: 04/04/2023] [Indexed: 11/17/2023]
Abstract
Paediatric heart transplant recipients (HTRs) have reduced exercise capacity, physical activity (PA), health-related quality of life (HRQoL), and self-efficacy towards PA. Exercise interventions have demonstrated improvements in exercise capacity and functional status in adult HTRs, with a specific emerging interest in the role of high-intensity interval training (HIIT). Studies of exercise interventions in paediatric HTRs have been limited and nonrandomized to date. HIIT has not yet been evaluated in paediatric HTRs. We thus seek to evaluate the safety and feasibility of a randomized crossover trial of a 12-week, home-based, video game-linked HIIT intervention using a cycle ergometer with telemedicine and remote physiological monitoring capabilities (MedBIKE) in paediatric HTRs. The secondary objective is to evaluate the impact of the intervention on (1) exercise capacity, (2) PA, (3) HRQoL and self-efficacy towards PA, and (4) sustained changes in secondary outcomes at 6 and 12 months after intervention. After a baseline assessment of the secondary outcomes, participants will be randomized to receive the MedBIKE intervention (12 weeks, 36 sessions) or usual care. After the intervention and a repeated assessment, all participants will cross over. Follow-up assessments will be administered at 6 and 12 months after the MedBIKE intervention. We anticipate that the MedBIKE intervention will be feasible and safely yield sustained improvements in exercise capacity, PA, HRQoL, and self-efficacy towards PA in paediatric HTRs. This study will serve as the foundation for a larger, multicentre randomized crossover trial and will help inform exercise rehabilitation programmes for paediatric HTRs.
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Affiliation(s)
- Christopher M. Spence
- Division of Pediatric Cardiology, Department of Pediatrics, Stollery Children's Hospital, University of Alberta, Edmonton, Alberta, Canada
| | - Rae Foshaug
- Division of Pediatric Cardiology, Department of Pediatrics, Stollery Children's Hospital, University of Alberta, Edmonton, Alberta, Canada
| | - Samira Rowland
- Division of Pulmonary Medicine, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada
| | - Amanda Krysler
- Division of Pediatric Cardiology, Department of Pediatrics, Stollery Children's Hospital, University of Alberta, Edmonton, Alberta, Canada
| | - Jennifer Conway
- Division of Pediatric Cardiology, Department of Pediatrics, Stollery Children's Hospital, University of Alberta, Edmonton, Alberta, Canada
| | - Simon Urschel
- Division of Pediatric Cardiology, Department of Pediatrics, Stollery Children's Hospital, University of Alberta, Edmonton, Alberta, Canada
| | - Lori West
- Division of Pediatric Cardiology, Department of Pediatrics, Stollery Children's Hospital, University of Alberta, Edmonton, Alberta, Canada
| | - Michael Stickland
- Division of Pulmonary Medicine, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada
| | - Pierre Boulanger
- Department of Computing Science, Faculty of Science, University of Alberta, Edmonton, Alberta, Canada
| | - John C. Spence
- Sedentary Living Laboratory, Faculty of Kinesiology, Sport, and Recreation, University of Alberta, Edmonton, Alberta, Canada
| | - Michael Khoury
- Division of Pediatric Cardiology, Department of Pediatrics, Stollery Children's Hospital, University of Alberta, Edmonton, Alberta, Canada
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2
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Bovard JM, DE Souza AM, Harris KC, Human DG, Hosking MCK, Potts JE, Armstrong K, Sandor GGS, Cote AT. Physiological Responses to Exercise in Pediatric Heart Transplant Recipients. Med Sci Sports Exerc 2019; 51:850-857. [PMID: 30629048 DOI: 10.1249/mss.0000000000001889] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
INTRODUCTION Pediatric heart transplant (HTx) recipients have reduced exercise capacity typically two-thirds of predicted values, the mechanisms of which are not fully understood. We sought to assess the cardiorespiratory responses to progressive exercise in HTx relative to controls matched for age, sex, body size, and work rate. METHODS Fourteen HTx recipients and matched controls underwent exercise stress echocardiography on a semisupine cycle ergometer. Hemodynamics, left ventricular (LV) dimensions, and volumes were obtained and indexed to body surface area. Oxygen consumption (V˙O2) was measured, and arteriovenous oxygen difference was estimated using the Fick Principle. RESULTS At rest, LV mass index (P = 0.03) and volumes (P < 0.001) were significantly smaller in HTx, whereas wall thickness (P < 0.01) and LV mass-to-volume ratio (P = 0.01) were greater. Differences in LV dimensions and stroke volume persisted throughout exercise, but the pattern of response was similar between groups as HR increased. As exercise progressed, heart rate and cardiac index increased to a lesser extent in HTx. Despite this, V˙O2 was similar (P = 0.82) at equivalent work rates as HTx had a greater change in arteriovenous oxygen difference (P < 0.01). CONCLUSIONS When matched for work rate, HTx had similar metabolic responses to controls despite having smaller LV chambers and an attenuated increase in hemodynamic responses. These findings suggest that HTx may increase peripheral O2 extraction as a compensatory mechanism in response to reduced cardiovascular function.
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Affiliation(s)
- Joshua M Bovard
- School of Kinesiology, University of British Columbia, Vancouver, British Columbia, CANADA
| | - Astrid M DE Souza
- Children's Heart Centre, BC Children's Hospital, Vancouver, British Columbia, CANADA
| | - Kevin C Harris
- Children's Heart Centre, BC Children's Hospital, Vancouver, British Columbia, CANADA.,Department of Pediatrics (Cardiology), University of British Columbia, Vancouver, British Columbia, CANADA
| | - Derek G Human
- Children's Heart Centre, BC Children's Hospital, Vancouver, British Columbia, CANADA.,Department of Pediatrics (Cardiology), University of British Columbia, Vancouver, British Columbia, CANADA
| | - Martin C K Hosking
- Children's Heart Centre, BC Children's Hospital, Vancouver, British Columbia, CANADA.,Department of Pediatrics (Cardiology), University of British Columbia, Vancouver, British Columbia, CANADA
| | - James E Potts
- Children's Heart Centre, BC Children's Hospital, Vancouver, British Columbia, CANADA.,Department of Pediatrics (Cardiology), University of British Columbia, Vancouver, British Columbia, CANADA
| | - Kathryn Armstrong
- Children's Heart Centre, BC Children's Hospital, Vancouver, British Columbia, CANADA
| | - George G S Sandor
- Children's Heart Centre, BC Children's Hospital, Vancouver, British Columbia, CANADA.,Department of Pediatrics (Cardiology), University of British Columbia, Vancouver, British Columbia, CANADA
| | - Anita T Cote
- Department of Pediatrics (Cardiology), University of British Columbia, Vancouver, British Columbia, CANADA.,School of Human Kinetics, Trinity Western University, Langley, British Columbia, CANADA
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Peterson S, Su JA, Szmuszkovicz JR, Johnson R, Sargent B. Exercise capacity following pediatric heart transplantation: A systematic review. Pediatr Transplant 2017; 21. [PMID: 28419703 DOI: 10.1111/petr.12922] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 02/24/2017] [Indexed: 12/23/2022]
Abstract
Pediatric HTs account for 13% of all HTs with >60% of recipients surviving at least 10 years post-HT. The purpose of this systematic review is to synthesize the literature on exercise capacity of pediatric HT recipients to improve understanding of the mechanisms that may explain the decreased exercise capacity. Six databases were searched for studies that compared the exercise capacity of HT recipients ≤21 years old with a control group or normative data. Sixteen studies were included. Pediatric HT recipients, as compared to controls or normative data, exhibit significantly higher resting HR, and at peak exercise exhibit significantly decreased HR, VO2 , power, work, minute ventilation, and exercise duration. Peak VO2 appears to improve within the first 2.5 years post-HT; peak work remains constant; and there is inconclusive evidence that peak HR, HR recovery, and HR reserve improve with time since HT. These results are discussed in the context of the mechanisms that may explain the impaired exercise capacity of pediatric HT recipients, including chronotropic incompetence, graft dysfunction, side effects of immunosuppression therapy, and deconditioning. In addition, the limited literature on rehabilitation after pediatric HT is summarized.
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Affiliation(s)
- Sara Peterson
- Division of Pediatric Rehabilitation Medicine, Physical Therapy, Children's Hospital Los Angeles, Los Angeles, CA, USA.,Division of Biokinesiology & Physical Therapy, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, CA, USA
| | - Jennifer A Su
- Division of Cardiology, Department of Pediatrics, Children's Hospital Los Angeles, Los Angeles, CA, USA
| | - Jacqueline R Szmuszkovicz
- Division of Cardiology, Department of Pediatrics, Children's Hospital Los Angeles, Los Angeles, CA, USA
| | - Robert Johnson
- Norris Medical Library, University of Southern California, Los Angeles, CA, USA
| | - Barbara Sargent
- Division of Biokinesiology & Physical Therapy, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, CA, USA
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Yeung JP, Human DG, Sandor GGS, De Souza AM, Potts JE. Serial measurements of exercise performance in pediatric heart transplant patients using stress echocardiography. Pediatr Transplant 2011; 15:265-71. [PMID: 21492351 DOI: 10.1111/j.1399-3046.2010.01467.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Heart transplantation is an increasingly acceptable therapeutic option for children with end-stage and complex congenital heart disease. With advances in surgery, immunosuppression, and follow-up care, functional outcomes need to be evaluated. We report the results of serial exercise testing performed using stress echocardiography in a cohort of pediatric HTP. HTP (n = 7) exercised on a semi-recumbent ergometer to volitional fatigue. Echocardiography-Doppler measurements, HR, and blood pressure were taken at rest and during staged exercise. Results were compared with healthy CON (n = 12). HTP did significantly less work during exercise (940 vs. 1218 J/kg, p < 0.03). Their SVI (33 vs. 49 mL/m(2), p < 0.003), CI (5.16 vs. 9.25 L/min/m(2), p < 0.0005), and HR (162 vs. 185 bpm, p < 0.02) were lower at peak exercise. HTP had a lower SF at peak exercise (48% vs. 52%, p < 0.03) and an abnormal relationship between the MVCFc and σPS. During follow-up, hemodynamics and left ventricular function remained relatively constant in HTP. HTP are able to exercise safely; however, their exercise tolerance is reduced, and hemodynamics and contractility are diminished. Over time, their hemodynamics and left ventricular function have remained relatively constant.
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Affiliation(s)
- Joanne P Yeung
- Department of Pediatrics, BC Children's Hospital, The University of British Columbia, Vancouver, BC, Canada
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Exercise Capacity Improves With Time in Pediatric Heart Transplant Recipients. J Heart Lung Transplant 2009; 28:585-90. [DOI: 10.1016/j.healun.2009.01.025] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2008] [Revised: 01/12/2009] [Accepted: 01/21/2009] [Indexed: 11/20/2022] Open
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Andreassen AK. Point:Counterpoint: Cardiac denervation does/does not play a major role in exercise limitation after heart transplantation. J Appl Physiol (1985) 2008; 104:559-60. [PMID: 17615275 DOI: 10.1152/japplphysiol.00694.2007] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Affiliation(s)
- Arne K Andreassen
- Department of Cardiology, Rikshospitalet-Radiumhospitalet Medical Center, University of Oslo, Oslo, Norway.
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7
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Marino BS, Pasquali SK, Wernovsky G, Bockoven JR, McBride M, Cho CJ, Spray TL, Paridon SM. Exercise performance in children and adolescents after the Ross procedure. Cardiol Young 2006; 16:40-7. [PMID: 16454876 DOI: 10.1017/s1047951105002076] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 06/27/2005] [Indexed: 12/13/2022]
Abstract
OBJECTIVES The Ross procedure is increasingly utilized in the treatment of aortic valvar disease in children and adolescents. Our purpose was to compare pre- and post-operative exercise state in this population. METHODS We included patients who underwent the Ross procedure at our institution between January, 1995, and December, 2003, and in whom we had performed pre- and post-operative exercise stress tests. We used a ramp bicycle protocol to measure consumption of oxygen and production of carbon dioxide. Cardiac output was estimated from effective pulmonary blood flow by the helium acetylene re-breathing technique. RESULTS We studied 26 patients, having a median age at surgery of 15.7 years, with a range from 7.5 to 24.1 years. The primary indication for surgery in two-thirds was combined aortic stenosis and insufficiency. Median time from the operation to the post-operative exercise stress test was 17.4 months, with a range from 6.7 to 30.2 months. There was a trend toward lower maximal consumption of oxygen after the procedure, at 36.3 plus or minus 7.6 millilitres per kilogram per minute (83.9% predicted) as opposed to 38.6 plus or minus 8.4 millilitres per kilogram per minute (88.5% predicted, p equal to 0.06). Patients after the procedure, however, had significantly increased adiposity, so that there was no difference in maximal consumption of oxygen indexed to ideal body weight before and after the operation. In 20 of the patients, aerobic capacity improved or was stable after the operation. There was no post-operative chronotropic impairment. CONCLUSIONS In the majority of patients following the Ross procedure, exercise performance is stable and within the normal range of a healthy age and sex matched population, despite sedentary lifestyles and increased adiposity.
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Affiliation(s)
- Bradley S Marino
- Division of Cardiology, at the Cardiac Center of The Children's Hospital of Philadelphia, and the Department of Pediatrics at the University of Pennsylvania School of Medicine 19104, USA
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9
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Abstract
This article discusses exercise physiology and its application in the pediatric population. This article discusses exercise physiology and its application in the pediatric population. The authors briefly review the normal physiologic response to exercise. They then discuss populations in which exercise testing is most useful, the indications and contraindications for graded exercise, and the usual parameters that are measured during testing. Finally, the authors review some of the recent data on exercise performance in specific pediatric populations.
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Affiliation(s)
- Paul Stephens
- Department of Pediatrics, University of Pennsylvania School of Medicine, Philadelphia, PA, USA.
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Abarbanell G, Mulla N, Chinnock R, Larsen R. Exercise assessment in infants after cardiac transplantation. J Heart Lung Transplant 2004; 23:1334-8. [PMID: 15607660 DOI: 10.1016/j.healun.2003.09.019] [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] [Received: 04/23/2003] [Revised: 09/02/2003] [Accepted: 09/05/2003] [Indexed: 10/26/2022] Open
Abstract
BACKGROUND Few data describe exercise performance after cardiac transplantation during infancy. The aim of this study was to compare the cardiorespiratory response to exercise in healthy subjects with that of subjects who had undergone heart transplantation during infancy to treat hypoplastic left heart syndrome. METHODS Subjects (24 heart transplant recipients and 25 healthy controls) exercised on a treadmill using pediatric ramp protocols. We measured heart rate (HR), blood pressure, and metabolic data. Median age at transplantation was 20 days (range, 4 to 97 days). Age of recipients at exercise testing was 9.7 +/- 2.3 years and in healthy subjects was 10.5 +/- 1.4 years (p=not significant [NS]). RESULTS Exercise duration was similar in both groups (10.3 +/- 2.0 minutes in recipients vs 11.1 +/- 1.5 minutes in healthy subjects, (p=NS). Heart rate at rest was greater in recipients (94 +/- 15 beats per minute [bpm] vs 85 +/- 11 bpm, p=0.02). Peak HR also was less in the recipient group (158 +/- 15 bpm vs 189 +/- 12 bpm, p <0.001). Peak oxygen consumption was 14% less in the recipients (32.3 +/- 5.6 ml/kg/min vs 36.8 +/- 5.5 ml/kg/min, p <0.01). Ventilatory anaerobic threshold was decreased in recipients, 27.6 +/- 9.6 vs 32.8 +/- 6.0, p <0.05. Respiratory exchange ratio at peak exercise was equal in both groups (1.06 +/- 0.06 vs 1.06 +/- 0.08). Oxygen pulse index did not differ significantly, 5.5 +/- 1.1 ml/beat/m2 in recipients and 6.1 +/- 1.7 ml/beat/m2 in healthy subjects (p=NS). CONCLUSIONS Overall, children who undergo cardiac transplantation in infancy have exercise capacities within the normal range. These recipients have a decreased heart rate reserve that may account for the differences in peak oxygen consumption when compared with healthy subjects.
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Affiliation(s)
- Ginnie Abarbanell
- Department of Pediatrics, Loma Linda Children's Hospital, Loma Linda University, Loma Linda, California 92354, USA
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11
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Abstract
Exercise intolerance in heart transplant recipients (HTR) has a multifactorial origin, involving complex interactions among cardiac, neurohormonal, vascular, skeletal muscle and pulmonary abnormalities. However, the role of these abnormalities may differ as a function of time after transplantation and of many other variables. The present review is aimed at evaluating the role of cardiac, pulmonary and muscular factors in limiting maximal aerobic performance of HTR, and the benefits of chronic exercise. Whereas pulmonary function does not seem to affect gas exchange until a critical value of diffusing lung capacity is attained, cardiac and skeletal muscle function deterioration may represent relevant factors limiting maximal and submaximal aerobic performance. Cardiac function is mainly limited by chronotropic incompetence and diastolic dysfunction, whereas muscle activity seems to be limited by impaired oxygen supply as a consequence of the reduced capillary network. The latter may be due to either immunosuppressive regimen or deconditioning. Endurance and strength training may greatly improve muscle function and maximal aerobic performance of HTR, and may also reduce side effects of immunosuppressive therapy and control risk factors for cardiac allograft vasculopathy. For the above reasons exercise should be considered an important therapeutic tool in the long-term treatment of heart transplant recipients.
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Affiliation(s)
- Claudio Marconi
- Muscle Physiology and Proteome Section, IBFM-Consiglio Nazionale delle Ricerche, LITA, v Flli Cervi 93, Segrate, 20090 Milan, Italy.
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Pastore E, Turchetta A, Attias L, Calzolari A, Giordano U, Squitieri C, Parisi F. Cardiorespiratory functional assessment after pediatric heart transplantation. Pediatr Transplant 2001; 5:425-9. [PMID: 11737767 DOI: 10.1034/j.1399-3046.2001.t01-2-00032.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Limited data are available on the exercise capacity of young heart transplant recipients. The aim of this study was therefore to assess cardiorespiratory responses to exercise in this group of patients. Fourteen consecutive heart transplant recipients (six girls and eight boys, age-range 5-15 yr) and 14 healthy matched controls underwent a Bruce treadmill test to determine: duration of test; resting and maximum heart rates; maximum systolic blood pressure; peak oxygen consumption (VO2 peak); and cardiac output. Duration of test and heart rate increase were then compared with: time since transplantation, rejections per year, and immunosuppressive drugs received. The recipients also underwent the following lung function tests: forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1). When compared with healthy controls, transplant recipients had tachycardia at rest (126 +/- 3.7 beats/min; p < 0.001); significantly reduced tolerance (9.3 +/- 0.4 min; p < 0.001), a maximum heart rate of 169 +/- 5.4 beats/min (p < 0.05); a cardiac output of 5.65 +/- 0.6 L/min (p < 0.05); and a lower heart-rate increase from rest to peak exercise (p < 0.001) but a similar VO2 peak. The heart-rate increase correlated significantly with time post-transplant (r = 0.55; p < 0.05), number of rejection episodes per year (r = - 0.63; p < 0.05), and number of immunosuppressive drugs (r = - 0.60; p < 0.05). The recipients had normal FVC and FEV1 values. After surgery, few heart transplant recipients undertake physical activity, possibly owing to over-protective parents and teachers and to a lack of suitable supervised facilities. The authors stress the importance of a cardiorespiratory functional evaluation for assessment of health status and to encourage recipients, if possible, to undertake regular physical activity.
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Affiliation(s)
- E Pastore
- Department of Sport Medicine, Bambino Gesù Children's Hospital, Rome, Italy, Italian National Health Istitute, Rome, Italy
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13
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Notarius CF, Levy RD, Tully A, Fitchett D, Magder S. Cardiac versus noncardiac limits to exercise after heart transplantation. Am Heart J 1998; 135:339-48. [PMID: 9489986 DOI: 10.1016/s0002-8703(98)70103-6] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND To determine whether the reduced exercise capacity of patients after heart transplantation is primarily a result of decreased cardiac or peripheral vascular factors, we examined the cardiac output (CO) and right atrial pressure (Pra) relation during graded cycle ergometry. METHODS AND RESULTS We studied 12 male patients (51.2+/-15.3 years [mean+/-SD]) 35.3+/-12.5 weeks after heart transplantation and 6 young healthy men. Patients had a normal increase in CO with increasing oxygen uptake (VO2) (CO = 0.00597 VO2 + 4.4, r = 0.83). Mean (+/-SEM) heart rate increased from 97.0+/-5.0 beats/min at rest to 146.9+/-6.9 beats/min at peak effort compared with the increase of 67.2+/-1.9 beats/min to 187.2+/-2.5 beats/min in the normal group. Pra in patients increased from 1.6+/-1.0 mm Hg at rest to 8.9+/-1.6 mm Hg during mild exercise but did not increase further at the highest work rates, even though CO continued to increase. In the normal group there was an initial increase in Pra from rest to exercise transition but little further change in Pra with increasing CO. Aerobic capacity (peak VO2) did not increase when cardiac function was increased with dobutamine during exercise in two patients. CONCLUSIONS The steep increase in CO relative to Pra during severe exercise in patients who undergo heart transplantation argues against the heart as the sole limiting factor during maximal effort.
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Affiliation(s)
- C F Notarius
- Critical Care Division, Royal Victoria Hospital, McGill University, Montreal, Quebec, Canada
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Nixon PA, Fricker FJ, Noyes BE, Webber SA, Orenstein DM, Armitage JM. Exercise testing in pediatric heart, heart-lung, and lung transplant recipients. Chest 1995; 107:1328-35. [PMID: 7750327 DOI: 10.1378/chest.107.5.1328] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Cardiorespiratory responses to progressive exercise were examined in 38 children who had undergone heart (n = 16), heart-lung (n = 13), or double-lung (n = 9) transplantation, and in 41 healthy controls. The four groups were similar in age, but the control subjects and heart transplant recipients were significantly larger than the heart-lung and lung recipients as assessed by body mass index (BMI). Time since transplant was significantly longer in the heart (601 days) compared with heart-lung (146 days) and lung (125 days) transplant groups. Physical work capacity and peak oxygen uptake were significantly reduced (43 to 64% of predicted) in the three transplant groups compared with the control group. Peak heart rate (percent predicted) was significantly higher in the control subjects (94%) compared with the heart (66%), heart-lung (70%), and lung (77%) transplant recipients. Peak minute ventilation was significantly higher in the control (72.9 L/min) and heart transplant (51.0 L/min) groups than the heart-lung (37.4 L/min) and lung (41.3 L/min) transplant groups. The control group had a higher peak tidal volume than the three transplant groups, and a higher peak respiratory rate than the lung transplant recipients. Correlational analysis revealed that physical work capacity (PWC) was significantly related to heart rate at peak exercise (HRpeak) and minute ventilation at peak exercise (VE-peak) in the heart transplant recipients, BMI, VEpeak, and FEV1 in the heart-lung transplant recipients, and BMI, HRpeak, VEpeak, FEV1, and number of days posttransplant in the lung transplant recipients. In addition to these variables, physical deconditioning and factors related to pharmacotherapy, infection, and rejection may also contribute to the decreased PWC observed in the transplant recipients.
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Affiliation(s)
- P A Nixon
- Children's Hospital of Pittsburgh, PA 15213, USA
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