REPERFUSION AND ARRHYTHMIAS

Reperfusion arrhythmias were described from the first trials of intrac oronary thrombolysis for myocardial infarction. The prevalence of vent ricular fibrillation during intravenous thrombolysis is low (< 7 %) an d comparable to that observed with classical treatment. Holter recordi ng shows that ventricular tachycardia and accelerated idioventricular rhythms occur in over 80 % of cases. These arrthythmias are generally well tolerated and do not require specific therapy. A bradycardia-hypo tension syndrome is observed in about a quarter of reperfused patients , nearly always in inferior wall infarction. It normally resolves spon taneously or after atropine or vascular filling. Reperfusion is associ ated with a clearcut increase in the number of episodes of arrhythmia. Some arrhythmias such as sustained ventricular tachycardia, early acc elerated idioventricular rhythms (occuring in the first 6 hours) or th e bradycardia-hypotension syndrome may be considered as non-invasive c riteria of reperfusion. More severe ischemia and sudden reperfusion fa vour the arrhytmogenicity of reperfusion in the animal. Recent data su ggest that this may be the case in the clinical context. In some uncon trolled studies, lidocaine, betablockers and aspirin did not affect th e prevalence of the arrhythmias. Preliminary trials indicate that flun arizine and captopril may reduce the incidence of reperfusion arrhythm ias in man. Ventricular arrthythmias and myocardial stunning could be the result of sa single phenomenon (the extent of die ischemic lesions or reperfusion lesions). Studies currently under way should clarify t he relationship between die incidence of arrhythmias, the severity of stunning and myocardial recovery. Protocols evaluating therapeutic int erventions on the reperfusate should include Holter monitoring.