Clinical and electrophysiologic effects of chronic lorcainide therapy in refractory ventricular tachycardia

The clinical, electrophysiologic and pharmacologic effects of chronic lorcainide therapy in patients with refractory ventricular tachycardia were evaluated using programmed electrical stimulation. Twelve patients with recurrent refractory ventricular tachycardia and organic heart disease, 10 men and 2 women aged 41 to 76 years, with no evidence of prior high degree atrioventricular or bifascicular block were studied. Programmed electrical stimulation was performed in the control, drug-free state and after chronic administration of lorcainide (dose range 200 to 600 mg/day, duration 48 to 240 hours, mean 106 hours) in 11 patients. One patient developed intolerable drug side effects and treatment was discontinued after 36 hours. In the 11 other patients, there was a significant increase in PR interval (187 ± 55 to 219 ± 56 ms; p 0.2). The ventricular effective refractory period increased from 234 ± 21 to 266 ± 15 ms (p Long-term lorcainide therapy was continued in the four responders. During a 2 to 12 month follow-up period, two patients have remained arrhythmia-free, one patient developed intolerable side effects requiring discontinuation of the drug and one patient with advanced renal failure died. It is concluded that chronic lorcainide therapy has significant electrocardiographic and electrophysiologic effects, but has a limited role in the long-term treatment of patients with refractory sustained ventricular tachycardia.