Distrofia muscular de Duchenne: análise eletrocardiográfica de 131 pacientes

Background: Cardiac involvement is known to occur in patients with Duchenne muscular dystrophy (DMD). The electrocardiogram (ECG) shows some typical changes in DMD, which makes it a useful test for the diagnosis of cardiac lesion in this disease. Objective: To evaluate the electrocardiographic change; in patients with DMD and to correlate these changes with the age of the population studied. Methods: ECG of 131 patients diagnosed with DMD were examined. Several electrocardiographic variables were analyzed, and the patients were divided into two groups - One with and one without changes, for each variable studied. The correlation between the two groups and the age of the patients was analyzed. Garson's criteria were used to establish the electrocardiographic parameters of normality. Results: ECG was abnormal in 78.6% of the patients. All showed normal sinus rhythm. The following percentages were found for the main variables studied: short PR interval = 18.3%; abnormal R waves in V-1 = 29.7%; abnormal Q waves in V = 21.3%; abnormal ventricular repolarization = 54.9%; abnormal QS waves in inferior and/or upper lateral wall = 37.4%; conduction disturbances in right bundle branch = 55.7%; prolonged QT(1) interval = 35.8%, and wide QRS = 23.6%. Unpaired t test was used to establish the correlation between age and the electrocardiographic variables studied in the two groups. Statistically significant differences were found only for the abnormal repolarization variable. Conclusion: Electrocardiographic abnormalities are common in DMD, revealing early cardiac involvement. Only the abnormal ventricular repolarization variable was more frequent, however at a lower age range (p < 0.05) (Arq Bras Cardiol 2010:94(5):583-586)