Hemodynamic effects of moricizine at rest and during supine bicycle exercise: Results in patients with ventricular tachycardia and left ventricular dysfunction

To evaluate the hemodynamic effects of moricizine, 20 patients with frequent nonsustained ventricular tachycardia (VT) with a mean left ventricular ejection fraction (EF) of 39 ± 14% were enrolled in a prospective single-blind, placebo-controlled study. Hemodynamic measurements were performed at rest and during supine bicycle exercise on placebo and moricizine therapy (10 mg/kg/day). Although 16 of 19 patients experienced no rest or exercise deterioration in hemodynamic parameters during drug dosing, three patients had acute deterioration of pulmonary capillary wedge pressure and cardiac index (CI) on moricizine. During follow-up of 6 ± 3 months, two subgroups were identified: 10 of 19 patients had effective long-term reduction in VT, whereas 9 of 19 patients had poor control of ventricular arrhythmia or congestive heart failure and were discontinued from the trial. Baseline EF and hemodynamic parameters at rest were similar in both patient subgroups. However, protocol dropouts had a hemodynamic response to exercise on moricizine that was significantly depressed as compared to patients with a favorable antiarrhythmic outcome (p < 0.02). The following hemodynamic profile characterizes patients unlikely to have an antiarrhythmic response to moricizine: (1) an increase in CI of < 1.0 L/min/m² and (2) no increase in left ventricular stroke work index during supine exercise.