INFLUENCE OF DIFFERENT EXERCISE PROTOCOLS ON FUNCTIONAL-CAPACITY AND SYMPTOMS IN PATIENTS WITH CHRONIC HEART-FAILURE

This study compares hemodynamic, metabolic, and gas exchange responses , catecholamine levels, and symptoms in 35 male patients with chronic heart failure (CHF) ([mean +/- SD] age 53 +/- 11 yr; ejection fraction 24 +/- 11%) during three differently graded exercise test protocols. On three consecutive days patients performed cycle ergometry supine, w ith prolonged steps (prol BE) and right heart catheterization, ramplik e cycle ergometry sitting (ramp BE), and ramplike treadmill walking (T MW). As in routine clinical practice, the prol BE was terminated when pathologic central hemodynamics and/or increased symptomology occurred , and ramp BE and TMW due to increased symptomology and/or physician's decision. During prol BE at ventilatory threshold (VT) the VO2 (8.6 /- 1.8 ml . kg(-1). min(-1)) was lower than during ramp BE (9.3 +/- 2. 1 ml . k(-1). min(-1)) (P < 0.017) and TMW (11.8 +/- 2.3 ml . kg(-1). min(-1)) (P < 0.0001). Prol BE, ramp BE, and TMW also differed signifi cantly with respect to ventilation (22 +/- 7 l . min(-1); 26 +/- 6 l . min(-1); 29 +/- 7 l . min(-1) P < 0.01) and heart rate (100 +/- 15 be ats . min(-1): 103 +/- 18 beats . min(-1): 110 +/- 16 beats . min(-1); P < 0.017). No differences were found in lactate levels, catecholamin e levels, and ratings of leg fatigue and dyspnea; At test termination, the peak VO2 during prol BE (10.8 +/- 3.3 ml . kg(-1). min(-1)) was l ower than during ramp BE (13.3 +/- 4.1 ml . kg(-1). min(-1)) (P < 0.00 01) and TMW (14.7 +/- 3.4 ml . kg(-1). min(-1)) (P < 0.0001). Peak nor epinephrine value during ramp BE (4.531 +/- 2.788 nmol . l(-1)) was hi gher than during prol BE (3.707 +/- 2.262 nmol . l(-1)) (P < 0.001). A mong the three tests, no significant differences were found for peak v alues of heart rate, lactate, and ratings of dyspnea. Although the VO2 . kg(-1) at VT was significantly higher during ramp BE and TMW compar ed to prol BE (P < 0.001), the values expressed as a percent of peak V O2 . kg(-1) were significantly lower (70 +/- 4%; 72 +/- 6%; 79 +/- 3%; P < 0.017). A systematic effect on aerobic capacity with reduced peak values during ramp BE and TMW was demonstrated when test termination was based primarily on pathological findings of central hemodynamics f rom prol BE.