Lidocaine in the early phase of acute myocardial infarction: the controversy over prophylactic or selective use

In acute myocardial infarction, lidocaine is considered the drug of choice for the treatment of malignant ventricular arrhythmias. While initially a so-called "selective" treatment strategy prevailed, in which lidocaine was administered only after the onset of certain "warning arrhythmias," the prophylactic use of lidocaine in acute myocardial infarction has been gaining wider usage in intravenous and intramuscular application in recent years. Both therapeutic applications have been found to be problematic of late, which has led to increasingly restrictive use of lidocaine. While in selective treatment forms, the definition and prompt recognition of the so-called warning arrhythmias created especially acute problems, the prophylactic therapeutic use is problematic due to the occurrence of sometimes serious side effects, which is to be expected as the size of the collective being treated increases. Both treatment forms also appear limited by the narrow preventive efficacy of lidocaine against malignant ventricular arrhythmias, especially against ventricular fibrillation. The current therapeutic recommendation for lidocaine in acute myocardial infarction should be limited to patients presenting with very frequent and complex ventricular arrhythmias, especially when these are elicited by an R-on-T phenomenon. Side effects and other therapeutic problems encountered when the therapeutic modality is switched or adjusted can be greatly reduced by careful dosing and selection of the optimal combination substances.