Haemodynamic and antiarrhythmic effects of intravenous flecainide acetate in chronic congestive heart failure.

The objective of this study was to evaluate the haemodynamic and antiarrhythmic effects of flecainide acetate in patients with heart failure. Flecainide acetate, a class Ic antiarrhythmic agent, was given intravenously to 9 patients with congestive heart failure and frequent ventricular arrhythmias with nonsustained ventricular tachycardia. The drug (2 mg/kg) was infused slowly over 60 minutes. The maximum plasma level achieved was 218 (range 142-350) ng/ml. Six of the 9 patients experienced a 90% suppression of their arrhythmias for an average of 6.5 (range 2-15) hours. Pre-ejection period control (PEPc, 148.8 +/- 3.6 msec) increased to 157 msec and pre-ejection period/ejection time (PEP/ET) [control 0.449 +/- 0.027] to 0.516 (p less than 0.005), while the ejection time index (ETI) did not change. Cardiac index (control 2.4 +/- 0.36 L/min/m2) decreased by 11% (p less than 0.02), and pulmonary wedge pressure (control 13.4 +/- 2.4mm Hg) increased by 23% (p less than 0.05). Stroke work index, arterial pressure and vascular resistance did not change significantly. The parameters returned to control values on completion of the infusion. Flecainide acetate can be safely administered at the usual dose of 2 mg/kg to patients with congestive heart failure, provided that the infusion time is doubled. Antiarrhythmic efficacy under these conditions is good even at lower plasma concentrations.