[Ineffective use of lidocaine in preventing reperfusion arrhythmias in patients with acute myocardial infarct]

To study the efficacy of prophylactic lidocaine treatment on the genesis of ventricular tachyarrhythmias following recanalization of an occluded coronary artery, 49 patients with an acute myocardial infarction were studied. All patients underwent intracoronary thrombolysis. Patients were admitted within 3 hours of the onset of symptoms and were randomized into two groups: 23 patients received an intravenous infusion of lidocaine (2 mg/min), following an initial bolus of 200 mg, and the remaining 26 patients received no lidocaine. Reperfusion arrhythmias were documented in 16 of 20 successfully recanalized patients who received lidocaine and in 15 of 21 successfully recanalized patients without lidocaine treatment. There were no statistically significant differences between the two patient groups in the frequency of occurrence of ventricular tachycardias or ventricular fibrillation. Independent of lidocaine treatment, two types of ventricular tachycardia could be distinguished: the most frequent type 1 met the electrocardiographic criteria of tachycardia caused by enhanced automaticity, whereas the characteristics of the less frequent type 2 tachycardia suggested reentry or triggered activity as the underlying mechanism. Only type 2 ventricular tachycardias were accompanied by haemodynamic deterioration. Our results show that lidocaine, in the dosage given here, does not influence incidence or mechanisms of reperfusion tachyarrhythmias.