Prognostic value of electrocardiographic monitoring of patients with severe diphtheria.

The clinical, the 12-lead, and the 24-hour electrocardiographic findings in 15 consecutively studied Vietnamese children (aged 7 months to 16 years) with severe diphtheria were documented. Five patients died, three from respiratory arrest and two from cardiogenic shock; one of these two patients had complete heart block that necessitated insertion of a pacemaker. Electrocardiographic abnormalities were detected by 24-hour monitoring in all 15 cases, even though most patients had no clinical signs of myocarditis. Rates of supraventricular and ventricular ectopy were elevated and remained high long after other clinical manifestations were no longer noted. The degree of ventricular ectopy at the time of presentation was significantly associated with fatal outcome. In this series, more than two ventricular ectopic beats on a recording upon admission to the hospital predicted fatal outcome with 100% sensitivity and 100% specificity. A variety of nonsustained bradyarrhythmias and tachyarrhythmias were also observed up until discharge from the hospital. The time course of recovery from diphtheritic myocarditis is longer than has been appreciated previously.