Cardiac dysregulation in Duchenne muscular dystrophy: An ECG analysis

Duchenne Muscular Dystrophy (DMD) is a progressive X-linked recessive disorder characterized by severe muscle degeneration and premature death, often due to cardiac complications. Despite the high prevalence of arrhythmogenic cardiomyopathy in DMD, the utility of Electrocardiogram (ECG) analysis in detecting subclinical cardiac dysregulation remains underexplored. This study aimed to investigate alterations in Lead II ECG parameters in children with DMD, potentially indicating an elevated risk of Sudden Cardiac Death (SCD).

In this cross-sectional study, Lead II ECG recordings from 54 genetically confirmed DMD patients were compared against 31 age-matched healthy-controls. Parameters analyzed included PR interval, QRS duration, QT and QTc intervals, Tp-Te interval, and amplitudes of P, Q, R, S, and T waves. Analysis was conducted using LabChart Pro 8 software and the Hamilton-Tompkins QRS detection algorithm. Heart-rate-corrected QT interval (QTc) was calculated using Bazett's formula (QTc = QT/√RR). An independent samples t-test with a significance level of p < 0.05 was used for comparisons between groups.

The study revealed significant ECG alterations in the DMD group compared to controls, included a reduced PR interval, prolonged QRS and QT intervals, decreased QTc, and increased Tp-Te interval. Additionally, significant increases in P, Q, R wave amplitudes, and ST height were observed, indicative of atrial hypertrophy and potential ventricular arrhythmias.

Lead II ECG analysis in children with DMD demonstrates critical alterations suggestive of subclinical cardiac dysregulation, highlighting a potential non-invasive marker for early detection of cardiac involvement. These findings emphasize the importance of regular cardiac monitoring in DMD patients to mitigate SCD risk through timely interventions and underscore the need for further research into the underlying pathophysiological mechanisms.