Heart rate dependency of cardiac performance in heart failure patients treated with metoprolol.

• To investigate whether a low heart rate is necessary to maintain improvement in myocardial function after long-term treatment with a beta-blocker in patients with heart failure.Forty-eight patients with congestive heart failure were investigated: 30 patients with dilated cardiomyopathy participating in a placebo-controlled trial (15 on placebo, 15 on metoprolol), and 18 patients treated by metoprolol in an open protocol. Investigations of spontaneous heart rate and of matched paced heart rates were performed at baseline and after 3, 6 and 12 months of follow-up by radionuclide angiography. There were significant signs of improvement in systolic indices of the spontaneous heart rate in the metoprolol-treated group (peak ejection rate: 0.98 to 1.32 end-diastolic volume.s-1, P = 0.015) as compared to placebo (1.14 to 1.19 end-diastolic volume.s-1, not significant). Similar effects were observed during the matched paced heart rate (peak ejection rate: metoprolol 0.91 to 1.38 end-diastolic volume.s-1, P = 0.037; placebo 1.22 to 1.12 end-diastolic volume.s-1, not significant). No effects were observed in the early peak filling rate. Left ventricular volumes decreased during metoprolol treatment, both for the spontaneous heart rate and during matched pacing.These data imply that beta-blocker treatment improves the force-frequency relationship of myocardial performance. A lower heart rate is not necessary to maintain cardiac function on a short-term basis, once myocardial recovery has occurred.

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Kardiologi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Cardiac and Cardiovascular Systems (hsv//eng)

Nyckelord

Adrenergic beta-Antagonists

pharmacology

therapeutic use

Adult

Aged

Cardiac Output

drug effects

Double-Blind Method

Female

Follow-Up Studies

Heart Failure

diagnosis

drug therapy

mortality

physiopathology

Heart Rate

drug effects

Hemodynamics

drug effects

Humans

Male

Metoprolol

pharmacology

therapeutic use

Middle Aged

Survival Rate

Treatment Outcome

Ventricular Function

Left

drug effects

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)