Early repolarization syndrome and Brugada syndrome: Is there any linkage?

Early repolarization syndrome (ERS) is characterized by the presence, in most cases in mid-to-lateral precordial leads, of a J wave on the downsloping portion of the QRS complex, followed by an elevation of the ST-segment with upward concavity. ERS is considered a benign electrocardiographic pattern of ventricular repolarization and, thus far, clinical interest in this syndrome has been confined to its differential diagnosis from myocardial infarction and pericarditis. Brugada syndrome (BS), an inherited cardiac disease first described in 1992, exhibits a characteristic electrocardiographic pattern consisting of a J wave mimicking a right bundle branch block with typical ST-segment elevation in the right precordial leads. Believed to be a normal repolarization variant for more than three decades, the syndrome is now known instead to be associated with a high incidence of life-threatening ventricular tachyarrhythmias and is responsible for a number of sudden deaths in young adults worldwide. Although clinical findings seem to differentiate the two syndromes, similarities between BS and ERS in terms of response to heart rate, pharmacologic agents, and neuromodulation could suggest a linkage in their pathophysiological mechanism. The authors review the clinical and experimental data in order to test this hypothesis.