Lorcainide therapy for the high-risk patient post myocardial infarction.

Nonsustained ventricular tachycardia (VT) in the late period (7 to 21 days) after myocardial infarction (MI) is reported to be a predictor of sudden death. Patients with 3-beat VT on Holter monitoring in the late infarction period would be suspected to demonstrate electrical instability on electrophysiologic studies. Forty-seven patients were identified as having at least 3-beat VT on Holter monitoring. Eighteen patients refused electrophysiologic studies or were not referred. Eight patients died; 3 were sudden deaths in 13 +/- 5 months, a 17% incidence. Twenty-nine patients underwent invasive electrophysiologic studies and 28 had inducible VT, 18 sustained and 10 nonsustained. Lorcainide prevented VT induction in 21 of the 28 patients, whereas 12 of the 22 patients studied on procainamide were protected. Lidocaine, tested in 21 patients, prevented VT induction in only 5. Lorcainide and procainamide prolonged refractoriness in those patients protected at programmed electrical stimulation (PES), whereas the QT interval was prolonged in patients in whom VT could still be induced. Twenty-seven of the 28 patients were placed on drugs predicted to be effective by PES studies, 19 on lorcainide. After a mean follow-up of 12.5 +/- 4 months the patient with noninducible arrhythmia is alive and 26 of the 28 patients with inducible arrhythmia are alive and well. Two patients died, 1 of stroke and 1 of pump failure after a second MI. No sudden deaths were observed in this group. Two patients had breakthrough arrhythmias and were treated by alternative antiarrhythmic therapy that was also effective on initial electrophysiologic studies.(ABSTRACT TRUNCATED AT 250 WORDS)