EFFECTS OF MUSCLE ELECTRICAL-STIMULATION ON PEAK (VO2)-O-CENTER-DOT IN CARDIAC TRANSPLANT PATIENTS

Peak oxygen consumption (peak (V) over dot O-2) has become a critical component in the evaluation of heart transplant recipients (HTR). in t hese patients, peak (V) over dot O-2 remains tow after cardiac transpl antation mainly because of persisting peripheral limitations in the wo rking muscles. Muscular electrical stimulation, on the other hand, has been shown to enhance the oxidative capacity of healthy muscle. it wa s the purpose of our investigation to study the effects of ES on the p eak (V) over dot O-2 of HTR. Fourteen (11 males and 3 females) HTR (ag e: 57 +/- 7 yr, mean +/- SD; height: 163 +/- 7 cm, weight: 70.5 +/- 8. 6 kg) were selected as subjects and each of them was randomly assigned to one of two groups: (a) group EXP (n = 7), receiving electrical sti mulation on both quadriceps muscles during a period of 8 weeks, and (b ) group CONT (n = 7), not receiving electrical stimulation. Before (PR E) and after (POST) the aforementioned 8-week period, respectively, al l the subjects performed a cardiopulmonary exercise test (ramp protoco l) on a cycle ergometer for peak (V) over dot O-2 determination. PRE v alues of peak (V) over dot O-2 were similar in both groups (17.1 +/- 2 .0 vs 16.9 +/- 3.8 ml x kg(-1) x min(-1) in EXP and CONT, respectively ). However, peak values of (V) over dot O-2 significantly increased in EXP (p < 0.05) after the period of electrical stimulation (POST peak (V) over dot O-2: 18.7 +/- 2.0 ml x kg(-1)), whereas no change was obs erved in CONT (POST peak (V) over dot O-2: 16.2 +/- 3.2 ml x kg(-1) x min(-1)). In conclusion, electrical stimulation could therefore be use d to improve the functional capacity of HTR, and might be included in the rehabilitation programs of this population group.