Influence of different exercise protocols on functional capacity and symptoms in patients with chronic heart failure

Abstract

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, with prolonged steps (prol BE) and right heart catheterization, ramplike cycle ergometry sitting (ramp BE), and ramplike treadmill walking (TMW). 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.kg-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 significantly 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 beats.min-1; 103 +/- 18 beats.min-1; 110 +/- 16 beats.min-1; P < 0.017). No differences were found in lactate levels, catecholamine levels, and ratings of leg fatigue and dyspnea. At test termination, the peak VO2 during prol BE (100.8 +/- 3.3 ml.kg-1.min-1) was lower than during ramp BE (13.3 +/- 4.1 ml.kg-1.min-1) (P < 0.0001) and TMW (14.7 +/- 3.4 ml.kg-1.min-1) (P < 0.0001). Peak norepinephrine value during ramp BE (4.531 +/- 2.788 nmol.l-1) was higher than during prol BE (3.707 +/- 2.262 nmol.l-1) (P < 0.001). Among the three tests, no significant differences were found for peak values of heart rate, lactate, and ratings of dyspnea. Although the VO2.kg-1 at VT was significantly higher during ramp BE and TMW compared to prol BE (P < 0.001), the values expressed as a percent of peak VO2.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 from prol BE.

Long-standing, insulin-treated type 2 diabetes patients with complications respond well to short-term resistance and interval exercise training

“…Exercise intervention studies in chronic heart failure patients have taught us that short bouts of high-intensity interval training (HIT) represent a safe and effective type of exercise regimen that may increase maximal workload and peak whole-body oxygen uptake capacity (VO 2peak ) in deconditioned subjects (16,17). Since exercise intensity and subsequent muscle fibre-type recruitment patterns during resistance exercise and HIT are likely to be similar, HIT on top of resistance exercise could represent an attractive style of exercise training in deconditioned T2D patients.…”

Mechanism of Increase in Anaerobic Threshold During Recovery Phase in Patients With Acute Myocardial Infarction

“…13 These findings are also in agreement with a study of patients with congestive heart failure. 14 Taking into consideration these reports and the postural effect on O2 pulse at AT before the phase II program in this study, it is suggested that an inadequate response to gravity stress during exercise led to a shorter exercise time to AT and lowered AT in the sitting position.…”

Development of a Servo-Controller of Heart Rate Using a Treadmill

“…The HR response (HR(ƒ)) is expressed as HR(ƒ) = G(ƒ) SP(ƒ) + HRn(ƒ) [1] where ƒ indicates frequency and HRn(ƒ) indicates the HR variation independent of exercise. Sources of HRn(ƒ) may include respiratory sinus arrhythmia and emotional changes etc.…”

“…Using C(ƒ), SP(ƒ) is expressed as SP(ƒ) = C(ƒ) (HRt(ƒ) -HR(ƒ)) [2] where HRt(ƒ) is the target HR. Substituting for SP(ƒ) in [1] Japanese Circulation Journal Vol.63, December 1999 with [2] and rearranging it for HR(ƒ) yields…”

“…Greater muscle mass is involved in treadmill exercise as evidenced by a higher peak oxygen uptake relative to cycle ergometer exercise. [1][2][3] However, difficulties in prescribing exercise intensity have limited the utility of the treadmill in the field of exercise training. The exercise intensity of treadmill exercise depends not only on the speed and elevation of the treadmill, but also on the weight, height and exercise mode of the subjects, the latter including whether the subject is walking or running, holding a handrail or not during the exercise etc.…”