Association of Early Repolarization and Sudden Cardiac Death During an Acute Coronary Event

Study Questions:

What is the association between early repolarization (ER) pattern and sudden cardiac death (SCD) during an acute coronary event?

Methods:

This study included 432 consecutive victims of SCD due to an acute coronary event and 532 survivors of such an event, in whom 12-lead electrocardiograms (ECGs) recorded before and unrelated to the event could be evaluated. SCDs were verified to be due to acute coronary event by medicolegal autopsy. ER was defined as an elevation of the QRS-ST junction in at least two inferior or lateral leads, manifested as QRS notching or slurring.

Results:

The prevalence of ER pattern ≥0.1 mV was more common in cases (62/432, 14.4%) than controls (42/532, 7.9%) (p = 0.001). The victims of SCD had been younger, were more commonly males and smokers, and had lower body mass index, elevated heart rate, prolonged QRS complex, and lower prevalence of history of prior cardiovascular diseases than controls. After adjustments for baseline differences, the odds ratio for J waves without ST-segment elevation in the SCD group was 2.15 (95% confidence interval, 1.20-3.85; p = 0.01).

Conclusions:

The authors concluded that the presence of ER increases the vulnerability to fatal arrhythmia during acute myocardial ischemia.

Perspective:

This study reports a significant and independent association between electrocardiographic early repolarization pattern, documented in a random ECG recording before and remote to the event, and risk of SCD at the time of an ischemic event in a general population sample. Before and after multivariate adjustments, ER pattern was associated with a twofold risk of SCD during an acute coronary event. The data give physicians some guidance on how to treat asymptomatic subjects with the ER pattern, with emphasis on primary prevention of the first ischemic event in these subjects to prevent a fatal event.

Clinical Topics: Acute Coronary Syndromes, Arrhythmias and Clinical EP, Prevention, Implantable Devices, SCD/Ventricular Arrhythmias

Keywords: Survivors, Risk, Myocardial Infarction, Acute Coronary Syndrome, Heart Conduction System, Cardiovascular Diseases, Electrocardiography, Heart Rate, Death, Sudden, Cardiac, Primary Prevention


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