The efficacy of
antiarrhythmic drugs for terminating sustained
ventricular tachycardia (VT) has been disappointing.
Lignocaine is the traditional
drug but it is not very effective.
Sotalol, one of the most effective drugs in suppressing spontaneous or induced VT, should theoretically be useful in this setting. We have compared
lignocaine with
sotalol for the acute termination of spontaneous sustained VT not causing
cardiac arrest in 33 patients (26 males, 7 females, aged 21-90) whose underlying
heart disease was old
myocardial infarction (28), acute
myocardial infarction (2),
dilated cardiomyopathy (1), or idiopathic
cardiomyopathy (2). Left-ventricular ejection fraction was 35% (range 18-76%). Patients were randomly allocated in a double-blind fashion to
lignocaine 100 mg (n = 17) or
sotalol 100 mg (n = 16) given intravenously over 5 min. Those with persistent VT 15 min after onset of administration of the first
drug were crossed over to the other
drug.
Sotalol was significantly more effective than
lignocaine whether analysed on an intention-to-treat basis (69% vs 18%; 95% confidence interval for absolute difference of 51% 22-80%, p = 0.003) or by analysis limited to the 31 patients with subsequent electrophysiologically proven VT (69% vs 20%). 1 patient in each group required
cardioversion after the first
drug.
Tachycardia persisted in 14 patients in the
lignocaine group and 4 in the
sotalol group after 15 min.
Tachycardia ceased in 7 (50%) patients who crossed over to
sotalol, and in 1 patient who crossed over to
lignocaine. There was 1 death in each group after the first
drug and 1 death after both drugs. We conclude that
sotalol was superior to
lignocaine for the acute termination of sustained VT. The incidence of adverse effects was similar for the two drugs.