Cardiorespiratory functional assessment after pediatric heart transplantation

Limited data are available on the exercise capacity of Young heart transpla nt recipients. The aim of this study was therefore to assess cardiorespirat ory responses to exercise in this group of patients. Fourteen consecutive h eart transplant recipients (six girls and eight boys, age-range 5-15 yr) an d 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 transp lantation. rejections per year, and immunosuppressive drugs received. The r ecipients also underwent the following lung function tests: forced vital ca pacity (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 in crease 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 imm unosuppressive drugs (r=0.60: p <0.05). The recipients had normal FVC and F EV1 values. After Surgery, few heart transplant recipients undertake physic al activity. possibly owing to over-protective parents and teachers and to a lack of Suitable supervised facilities. The authors stress the importance or a cardiorespiratory functional evaluation for assessment of health stat us and to encourage recipients, if possible, to undertake regular physical activity.