Static exercise with congestive heart failure and the response to vasodilating drugs

The hemodynamic response to static exercise in 28 patients with congestive heart failure (CHF) was compared with that in 8 control subjects. Static handgrip exercise at 50% of the maximal voluntary contraction was performed to fatigue. In patients with CHF, pulmonary arterial wedge pressure increased from 20 ± 18 to 31 ± 10 mm Hg (p <0.001) (mean ± standard deviation) and systemic vascular resistance increased from 1,730 ± 454 to 2,151 ± 724 dynes s cm^-5 (p <0.001). Although cardiac index did not change significantly, stroke volume index and stroke work index decreased from 24 ± 6 to 20 ± 6 ml/m² (p <0.001) and 28 ± 11 to 25 ± 12 g-m/s² (p <0.05), respectively. In control subjects, pulmonary arterial wedge pressure did not change significantly; cardiac index increased from 3.6 ± 0.3 to 4.0 ± 0.4 liters/min/m² (p <0.05) and systemic vascular resistance increased slightly, from 1,011 ± 186 to 1,106 ± 180 dynes s cm^-5 (p <0.05). The effects of arterial dilation with hydralazine on the response to static exercise were assessed in 10 of the patients with CHF. Compared with predrug exercise, cardiac index increased 68% (p <0.01), stroke volume index increased 76% (p <0.01) and systemic vascular resistance decreased 47% (p <0.01) after administration of hydralazine. Thus, static exercise can have adverse effects on cardiac performance in patients with CHF. The increases in pulmonary artery wedge pressure and systemic vascular resistance and inability to increase cardiac output differ from the response to static exercise in control subjects. The beneficial effects of arterial dilation on cardiac performance at rest are maintained during the response to static exercise.