Adverse hemodynamic and clinical effects of encainide in severe chronic heart failure.
OBJECTIVE
To evaluate the hemodynamic effects of the antiarrhythmic drug, encainide, in patients with severe chronic heart failure.


METHODS
Unblinded, before-after study.


METHODS
Referral center for patients with heart failure.


METHODS
Thirty patients with severe chronic heart failure and a left ventricular ejection fraction less than 40%.


METHODS
Invasive hemodynamic measurements were done (using a balloon-tipped thermodilution catheter) before and for 3 hours after a single oral dose of 50 mg of encainide.


RESULTS
Ninety to one hundred and twenty minutes after its administration, encainide produced a significant deterioration in cardiac performance, as reflected by a fall in cardiac index from 2.3 to 1.8 L/min.m2 body surface (mean change 0.5 +/- 0.1; P less than 0.001), a fall in stroke work index from 26 to 18 g.m/m2 (mean change 8 +/- 2; P less than 0.001), and an increase in left ventricular filling pressure from 19 to 22 mm Hg (mean change 3 +/- 2; P less than 0.05). These deleterious hemodynamic effects were accompanied by worsening symptoms of heart failure in 8 of the 30 patients. Serum levels of encainide and its metabolites, O-desmethylencainide and 3-methoxy-O-desmethylencainide, were within the therapeutic range in most patients.


CONCLUSIONS
Encainide can cause adverse hemodynamic and clinical effects in patients with severe chronic heart failure.
Gottlieb
S S
SS
Mount Sinai School of Medicine, City University of New York, New York.
Kukin
M L
ML
Yushak
M
M
Medina
N
N
Packer
M
M
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000813:Anilides / Q000009:adverse effects* / Q000097:blood / Q000627:therapeutic use; D000889:Anti-Arrhythmia Agents / Q000009:adverse effects* / Q000097:blood / Q000627:therapeutic use; D001145:Arrhythmias, Cardiac / Q000150:complications / Q000188:drug therapy; D004417:Dyspnea / Q000139:chemically induced; D016700:Encainide; D005260:Female; D006333:Heart Failure / Q000150:complications / Q000503:physiopathology*; D006439:Hemodynamics / Q000187:drug effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction / Q000187:drug effects; D013318:Stroke Volume / Q000187:drug effects
D000813:Anilides; D000889:Anti-Arrhythmia Agents; D016700:Encainide