Prognostic significance of electrocardiographic abnormalities in diphtheritic myocarditis after hospital discharge: a long-term follow-up study.

OBJECTIVE: We aimed to investigate the long-term cardiac mortality and the relationship between cardiac mortality and electrocardiographic abnormalities in patients with diphtheritic myocarditis who survived after hospital discharge.
MATERIALS AND METHODS: Between 1991 and 1996, 32 patients (all males, mean age 21.00 +/- 3.77 years) surviving diphtheritic myocarditis were included in the study and they were followed up for an average of 16.3 months (range 10.3-26.8 months) after hospital discharge. Clinical evaluation, ECG, and echocardiography were performed on admission, daily while in hospital and at the time of discharge. ECG changes were permanent during the follow-up period. The causes of death of the patients during follow-up period were inferred from the death records of the patients and talking to the people witnessing cardiac arrest.
RESULTS: We observed that the patients with left bundle branch block (LBBB) and T wave inversion at hospital discharge had lower survival rates than that of the patients without these ECG changes in the long term. Although univariate Cox regression analysis identified LBBB (P = 0.001) and T wave inversion (P = 0.014) as the predictors of survival, only LBBB was an independent predictor of survival in multivariate Cox regression analysis. Adjusted hazard ratio was calculated as 13.67 for LBBB (P = 0.001; CI = 2.81-66.28).
CONCLUSION: Diphtheritic myocarditis does not only demonstrate a malignant clinical course during acute phase of the disease, but also during the long-term follow-up period, especially in patients with LBBB and T wave inversion. Besides, T wave inversion and LBBB can help us to predict survival rate of the patients in long term. Moreover, LBBB is an independent predictor of long-term survival in diphtheritic myocarditis.