Hemodynamic dose-response effects of flecainide in acute myocardial infarction with and without left ventricular decompensation.
We evaluated the hemodynamic effects of the class I antiarrhythmic flecainide in 20 patients within 18 hours of an acute myocardial infarction. Equal numbers of patients with normal (group 1) or decompensated (group 2) ventricular function were studied. Both groups received flecainide, 1 mg/kg, as an intravenous bolus over 10 minutes, followed by infusion (1.6 mg/kg/hr) over the next 120 minutes. Plasma concentrations increased linearly with the cumulative flecainide dosage in both groups. There was no difference between the groups in the plasma levels reached, which were within the recognized antiarrhythmic range for flecainide (200 to 1000 ng/ml) throughout the infusion. The hemodynamic effects of flecainide for each group were decreases in systolic blood pressure (maximum 3% fall in group 1 and 8% fall in group 2), cardiac index (9% fall in group 1 and 18% fall in group 2), stroke volume index (13% fall in group 1 and 23% fall in group 2), stroke work index (14% fall in group 1 and 27% fall in group 2), with an increased heart rate (8% rise in group 1 and 5% rise in group 2), pulmonary artery occluded pressure (27% rise in group 1 and 21% rise in group 2), and systemic vascular resistance (11% rise in group 1 and 18% rise in group 2). Diastolic and mean arterial blood pressures did not change. Our data demonstrate that flecainide induced significant cardiodepression in both groups of patients. These effects were not significantly greater in patients with adequately controlled heart failure. These data suggest that the mild negative inotropic properties of flecainide in patients with recent myocardial infarction are comparable to those described for other class I antiarrhythmics.
D000328:Adult; D000368:Aged; D000889:Anti-Arrhythmia Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D001794:Blood Pressure / Q000187:drug effects; D002986:Clinical Trials as Topic; D004305:Dose-Response Relationship, Drug; D005424:Flecainide; D006339:Heart Rate / Q000187:drug effects; D006352:Heart Ventricles / Q000503:physiopathology; D006439:Hemodynamics / Q000187:drug effects*; D006801:Humans; D007263:Infusions, Parenteral; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000188:drug therapy*; D010880:Piperidines / Q000008:administration & dosage / Q000627:therapeutic use*; D013318:Stroke Volume / Q000187:drug effects; D013997:Time Factors; D014655:Vascular Resistance / Q000187:drug effects
D000889:Anti-Arrhythmia Agents; D010880:Piperidines; D005424:Flecainide