Separation of afterload reduction and a direct beneficial cardiac effect of nifedipine in congestive cardiomyopathy.
To assess whether the calcium antagonist nifedipine has a specific, direct effect on left ventricular diastolic function separate from its vasodilatory action, we studied 10 patients with idiopathic congestive cardiomyopathy (ages 28-69, New York Heart Association Class III or IV) at 30 min, 2 h, and 6 h after administration of 10 mg of sublingual nifedipine. Hemodynamic parameters were assessed with Swan-Ganz catheter and two-dimensional echo images were processed with computer-assisted analysis (Quantic 1200) to obtain left ventricular chamber areas and an index of rapid diastolic filling. Indices of left ventricular systolic performance (cardiac index and left ventricular area change fraction) improved during the early (30 min and 2 h) observation periods as afterload (estimated by systolic blood pressure and systemic vascular resistance) was reduced (p less than .05 vs. baseline). Pulmonary capillary wedge pressure fell from 17 mmHg to 11 mmHg and rapid diastolic filling index increased from .28 (% area change/ms) to .37 (% area change/ms) (p less than .05 vs. baseline) during the early observation periods. Indices of left ventricular systolic performance and afterload had returned to baseline at the late (6 h) observation period. However, pulmonary capillary wedge pressure remained reduced significantly at 10 mmHg after 6 h (p less than .05 vs. baseline). Preload (estimated by left ventricular end-diastolic chamber area) did not vary throughout the study period. Reduction of pulmonary capillary wedge pressure at 6 h, despite return of afterload reduction to baseline and no change in preload, suggests improved left ventricular chamber compliance after sublingual nifedipine, not related to alteration of left ventricular loading conditions.
Division of Cardiology, University Hospital of Jacksonville, Florida 32209.
R F
RF
Percy
T A
TA
Bass
D A
DA
Conetta
A B
AB
Miller
D000328:Adult; D000368:Aged; D002311:Cardiomyopathy, Dilated / Q000188:drug therapy / Q000503:physiopathology*; D003331:Coronary Vessels / Q000187:drug effects; D003864:Depression, Chemical; D004452:Echocardiography; D005260:Female; D006321:Heart / Q000503:physiopathology*; D006352:Heart Ventricles / Q000503:physiopathology; D006439:Hemodynamics / Q000187:drug effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction / Q000187:drug effects; D009543:Nifedipine / Q000494:pharmacology* / Q000627:therapeutic use; D014666:Vasomotor System / Q000187:drug effects
D009543:Nifedipine