PATHOPHYSIOLOGY AND NATURAL HISTORY CONGESTIVE HEART FAILURE Isometric exercise in patients with chronic advanced heart failure: hemodynamic and neurohumoral evaluation

We evaluated the hemodynamic effects of isometric exercise in 53 patients with congestive heart failure (CHF) and compared them with those found in 10 normal subjects. In both groups, isometric exercise increased heart rate and blood pressure. Systemic resistance increased in patients with CHF (1862 + 520 vs 2126 ± 642 dyne-sec-cm-5; p < .001) but not in normal subjects (1359 + 268 vs 1380 ± 252 dyne-sec-cm-5). Cardiac index and stroke volume index increased mildly but not significantly in the normal subjects (2.8 0.5 vs 3. 1 ± 0.7 liters/min/m2 and 46 + 8 vs 47 ± 7 mI/M2) and showed a significant fall in the patients with CHF (2.1 ± 0.6 to 1.9 ± 0.6 liters/min/m2, p < .01 and 23 ± 7 vs 20 + 7 ml/m2, p < .01). Mean pulmonary arterial wedge pressure increased in patients with CHF from 26 ± 7 to 30 ± 8 mm Hg (p < .001). Although no significant change was found in mean value for stroke work index (21 ± 9 vs 20 + 9 g-m/m2), the individual changes were variable, with marked decrease (>15%) in 17 of the patients. This hemodynamic deterioration could not be predicted from resting hemodynamics, left ventricular ejection fraction, or functional classification. Isometric exercise resulted in no significant change in circulatory catecholamine levels or plasma renin concentration in our 10 normal subjects. In the patients with CHF renin (measured in 12 patients) and epinephrine (measured in 16 patients) also did not change during isometric exercise, but norepinephrine levels (measured in 16 patients) increased significantly. No correlation was found between changes in hormonal levels and any of the hemodynamic changes during static exercise. We conclude that in patients with chronic CHF, isometric exercise can lead to a significant increase in left ventricular outflow resistance and filling pressure and to a fall in cardiac performance. In the presence of CHF, this form of exercise results in a consistent elevation in norepinephrine levels, but there is no correlation between changes in its plasma level and in hemodynamic values. There is considerable individual variation in the hemodynamic response, with a significant deterioration in cardiac performance in some patients, which cannot be separated by resting hemodynamic values, left ventricular ejection fraction, or clinical status. Circulation 72, No. 5, 975-981, 1985. THE EFFECTS of isometric exercise on the cardiovascular system and their neurohumoral mechanisms have been extensively investigated in animals and in normal individuals. 14 In contrast, few data are available on the consequences of isometric exercise in patients with chronic congestive heart failure (CHF), in whom both hemodynamic and neurohumoral status is significantly altered. In this study we evaluated the hemodynamic From the Department of Medicine, Sections of Cardiology and Endocrinology, LAC/USC Medical Center, University of Southern California School of Medicine, Los Angeles. Address for correspondence: Uri Elkayam, M.D., USC School of Medicine, Section of Cardiology, 2025 Zonal Ave., Los Angeles, CA 90033. Received April 22, 1985; revision accepted July 18, 1985. Vol. 72, No. 5, November 1985 effects of isometric exercise and the response of plasma catecholamines and renin concentration in patients with severe advanced CHF.