Related Experiment Videos
Long-term hemodynamic effects of prenalterol in patients with severe congestive heart failure
Insights
Prenalterol, a beta 1-adrenoceptor agonist, initially improved heart function in severe heart failure patients. However, these benefits diminished over six months, suggesting limited long-term efficacy for this treatment.
Area of Science:
- Cardiology
- Pharmacology
- Heart Failure Research
Background:
- Severe congestive heart failure (CHF) presents significant challenges in treatment.
- Beta-1 adrenoceptor agonists are explored for their potential inotropic effects on the heart.
Purpose of the Study:
- To evaluate the long-term effects of prenalterol, a beta 1-adrenoceptor agonist, in patients with severe congestive heart failure (CHF).
- To assess hemodynamic and echocardiographic changes over a six-month period.
Main Methods:
- A controlled, randomized, double-blind study involving 16 patients with severe CHF (NYHA class III or IV).
- Continuous oral intake of prenalterol (40-120 mg/day).
- Right heart catheterization, ergometer tests, M-mode and 2D echocardiograms, and systolic time intervals were recorded at baseline, 1 week, 3 months, and 6 months.
Main Results:
- Prenalterol increased heart rate and cardiac index within one week, but these effects diminished by 3 and 6 months.
- Initial improvements in mean velocity of circumferential fiber shortening and ejection fraction were observed but not sustained long-term.
- No significant improvement in exercise performance was noted in the ergometer test.
Conclusions:
- While prenalterol demonstrated short-term improvements in cardiac function in severe CHF patients, its long-term efficacy appears limited.
- The study highlights the transient nature of prenalterol's benefits, suggesting a need for alternative or adjunctive therapies for sustained management of severe heart failure.
Abstract:
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)