Ventricular Tachyarrhythmias Complicating Acute Myocardial Infarction

In the thrombolytic era the incidence of ventricular tachyarrhythmias complicating AMI declined, and the prognosis of reperfused patients with these arrhythmias improved. Early VT/VF does not seem to predict late outcome after AMI. Patency of the infarct-related artery seems to reduce the incidence of ventricular tachyarrhythmias and to improve the electrical instability after AMI. The "arrhythmia suppression theory" and the consequent use of long-term antiarrhythmic therapy to prevent primary VT/VF seems to be of little benefit, and may rather expose patients to proarrhythmic side effects. The use of prophylactic β-blockers is a more promising approach to prevent sudden death after AMI than the drug suppression of ventricular arrhythmias. Amiodarone seems to be effective in reducing arrhythmic death and resuscitated VF in post-MI patients. The effectiveness of magnesium is controversial and may be beneficial when given early before reperfusion occurs, especially in non-thrombolysed patients. The recently suggested use of ICD in high-risk patients (LVEF <35%) with asymptomatic nonsustained inducible VT, nonsuppressible by procainamide (10% of post-MI patients), seems to be superior to conventional antiarrhythmic therapy.