Hemodynamic responses during leg press exercise in patients with chronic congestive heart failure

To increase muscle mass and strength in patients with chronic congestive he art failure (CHF), there is a need for implementing resistance exercises in exercise training programs. This study sought to assess the safety of rhyt hmic strength exercise with respect to left ventricular function in 9 patie nts with stable CHF, compared with 6 stable coronary patients with mild lef t ventricular dysfunction (control group). With use of right-sided catheter ization, changes in left ventricular function were assessed during double l eg press exercise at loads of 60% and 80% of maximum voluntary contraction. The exercise sessions lasted 14 minutes each, divided into work and recove ry phases of 60/120 seconds. In CHF, during exercise at a 60% load, there w as a significant increase in heart rate (mean +/- SEM 90 +/- 4 beats/min; p <0.05), mean arterial blood pressure (95 +/- 3 mm Hg; p <0.01), diastolic pulmonary artery pressure (20.2 +/- 2.7 mm Hg; p <0.01), and cardiac index (3 +/- 0.3 L/m(2)/min; p <0.05). Additionally, during leg press exercise at an 80% load, there was a significant decrease In systemic vascular resista nce (1,086 +/- 80 dynes.s.cm(-5) p <0.001), an increased cardiac index (3.4 +/- 0.1; p <0.001) and left ventricular stroke work index (75 +/- 5 g.m/m( 2); p <0.01), suggesting enhanced left ventricular function. Compared with controls, in CHF the magnitude of changes in hemodynamic parameters during exercise, demonstrated at a 60% load, was significantly smaller (systemic v ascular resistance: [mean] 1,613 --> 1000 vs 1472 --> 1,247 dynes.s.cm(-5); cardiac index: 2.4 --> 3 vs 2.8 --> 4.4 L/m(2)/min, and stroke work index: 60 --> 69 vs 114 --> 155 g.m/m(2); p <0.05 each). Nevertheless, changes in dicated an enhanced contractile function of the left ventricle in CHF. This study demonstrates stability of left ventricular function during resistanc e exercise in well-compensated CHF patients with optimal drug therapy, as w ell as the appropriateness of the chosen mode and intensity applied as thes e factors relate to cardiovascular stress. This conclusion cannot be extrap olated to patients with less well-compensated heart failure, or to more pro tracted resistance training. (C) 1999 by Excerpta Medica, Inc.