Prognostic Significance of Electrocardiographic Changes in Diphtheria Myocarditis: A Cross-Sectional Study

Background: Diphtheria is still endemic in India due to inadequate immunization. The incidence of myocarditis is higher in these patients. Objectives: The objective of this study was to study clinical profile, clinical outcomes as well as immunization status of the patients diagnosed with diphtheria myocarditis in Indian scenario. Methodology: This prospective observational study was carried out in one of the tertiary care hospital of south India from August 2011 to December 2012. A total of 33 cases with clinically confirmed diagnosis of diphtheria myocarditis were enrolled depending upon the inclusion and exclusion criteria of the study. Electrocardiography and 2-dimensional echocardiography was done at the time of admission and repeated when required. Results: The most common age group affected is 5 - 10 years, with no sex difference in occurrence. Only 1 patient, out of 33 patients, was adequately immunized. Asymptomatic myocardial involvement (with only changes in electrocardiogram) was seen in 21 patients whereas 12 patients were symptomatic. The average duration of resolution of electrocardiographic changes was 4 - 6 weeks. It should be noted that out of 28 patients who developed conduction abnormalities, 24 patients died. Temporary pacemaker support was given for 8 patients, of whom only one patient recovered. The patient was followed till hospital discharge. Conclusion: The mortality associated with diphtheria myocarditis is higher in Indian population. As diphtheria can be prevented by adequate vaccination, efforts should be maximized for 90% coverage with three doses of diphtheria toxoid in children below one year of age and immunity towards it should be maintained by booster doses.