Long-term hemodynamic effects of prenalterol in patients with severe congestive heart failure.

In a controlled, randomized, double-blind study we investigated the long-term effects of the beta 1-adrenoceptor agonist prenalterol in 16 patients with severe congestive heart failure (NYHA class III or IV). Previous to and 1 week, 3 months, and 6 months after continuous oral intake of 40 to 120 mg prenalterol a day, catheterization of the right heart combined with an ergometer test was carried out; M mode and two dimensional echocardiograms as well as systolic time intervals were also recorded. With prenalterol the heart rate increased within 1 week from 81 +/- 7 to 90 +/- 7 beats/min (mean +/- SD) (p less than .05) and remained increased after 3 months (93 +/- 9 beats/min, p less than .01) and 6 months (91 +/- 6 beats/min, p less than .05). After 1 week the cardiac index rose from 2.7 +/- 0.7 to 3.3 +/- 0.7 l/min/m2 (p less than .01), and after 3 and 6 months it fell again to 3.0 +/- 0.9 l/min/m2 and 2.9 +/- 0.7 l/min/m2, respectively. In the ergometer test the improvement in performance was not significant. The mean velocity of circumferential fiber shortening initially increased from 0.58 +/- 0.20 to 0.79 +/- 0.28 circumferences/sec (p less than .01), but dropped after 3 months to 0.62 +/- 0.31 circumferences/sec. The ejection fraction determined from the two-dimensional echocardiogram rose after 1 week from 20 +/- 10 to 27 +/- 12% (p less than .05), but decreased again after 3 months (23 +/- 11%) and 6 months (20 +/- 10%).(ABSTRACT TRUNCATED AT 250 WORDS)