Chronotropic competence in endurance trained heart transplant recipients: heart rate is not a limiting factor for exercise capacity

• Published in: Journal of the American College of Cardiology Vol. 33; no. 1; pp. 192 - 197
• Main Authors: Richard, Ruddy, Verdier, Jean-Claude, Duvallet, Alain, Rosier, Sully-Pierre, Leger, Philippe, Nignan, Alexis, Rieu, Michel
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01.01.1999; Elsevier Science
• Subjects: Adult; Biological and medical sciences; Exercise Test; Follow-Up Studies; Heart Rate - physiology; Heart Transplantation - physiology; Heart Transplantation - rehabilitation; Humans; Male; Medical sciences; Middle Aged; Oxygen - blood; Physical Education and Training; Physical Endurance - physiology; Postoperative Complications - physiopathology; Postoperative Complications - rehabilitation; Reference Values; Surgery (general aspects). Transplantations, organ and tissue grafts. Graft diseases; Surgery of the heart; Pmax; VO2peak; VO2pmax; HTR; T-HTR; HR; HRpmax; S-HTR; HRpeak; MET; HRrace; Heart; Human; Heart rate; Physical fitness; Physical training; Prognosis; Treatment; Surgery; Transplantation; Endurance; Homotransplantation
• ISSN: 0735-1097; 1558-3597
• DOI: 10.1016/S0735-1097(98)00513-0

Objectives. The purpose of this study was to show that the chronotropic potential of the well trained heart transplant recipient (HTR) does not limit exercise capacity. Background. Chronotropic incompetence is considered to be the main limiting factor of the functional capacity of heart transplant recipients. However, no systematic study had been published on patients who had spontaneously undergone heavy endurance training for several years. Methods. Heart rate (HR) and respiratory gas exchanges (VO2, VCO2, VE) were measured in 14 trained HTRs (T-HTRs) during exercise tests on a bicycle, on a treadmill and by Holter electrocardiography during a race. Results. Peak values observed in T-HTRs during the treadmill test were higher than those reached during the bicycle test (VO2peak:39.8 ± 6.9 vs. 32.5 ± 7.8 ml·kg−1·min−1, p < 0.001; HRpeak: 169 ± 14 vs. 159 ± 16 bpm, p < 0.01). During treadmill exercise VO2peakand HRpeakvalues observed were very close to the mean predicted VO2pmaxand HRpmax. The maximum heart rate during the race (HRrace) was greater than HRpeakvalues during the treadmill test (179 ± 14 vs 169 ± 14 bpm, p < 0.01) and slightly above the mean predicted values (HRrace/HRpmax× 100 = 101 ± 10%). The treadmill exercise test yields more reliable data than does the bicycle test. Conclusions. Extensive endurance training enables heart transplant recipients to reach physical fitness levels similar to those of normal sedentary subjects; heart rate does not limit their exercise capacity.