RESUMEN
OBJECTIVE: To determine the prognosis in patients with diphtherial myocarditis and bradyarrhythmias and to assess the results of ventricular pacing in those with third degree atrioventricular block. DESIGN: Case series. SETTING: Referral department of cardiology in a teaching hospital. PATIENTS: Twenty four out of 46 patients admitted with diphtherial myocarditis over 10 years had bradyarrhythmias. Six had sinus bradycardia, 15 atrioventricular or intraventricular conduction disturbances, and three atrioventricular dissociation. MAIN OUTCOME MEASURE: Death rate. RESULTS: Eleven patients died (46%): all seven patients with third degree atrioventricular block, the patient with bifascicular block, and three of the six patients with bundle branch block. Seven died of cardiogenic shock and four of ventricular fibrillation. All nine patients with sinus bradycardia or atrioventricular dissociation survived. CONCLUSION: Conduction system disturbances in patients with diphtherial myocarditis are markers of severe myocardial damage and a poor prognosis. In addition, ventricular pacing does not improve survival.