Electrocardiographic J wave: Early repolarization, Brugada wave, and conduction delay

The J wave is a deflection between the QRS complex and the ST segment whose polarity is commonly in the same major direction of the QRS complex. The J wave may stand as a distinct delta wave following the QRS or be partially buried inside the QRS as QRS notching or slurring. 1 Yan G.X. Antzelevitch C. Cellular basis for the electrocardiographic J wave. Circulation. 1996; 93: 372-379 Crossref PubMed Scopus (685) Google Scholar , 2 Badri M. Patel A. Yan G.X. Cellular and ionic basis of J-wave syndromes. Trends Cardiovasc Med. 2015; 25: 12-21 Abstract Full Text Full Text PDF PubMed Scopus (25) Google Scholar , 3 Liu T. Zheng J. Yan G.X. J wave syndromes: history and current controversies. Korean Circ J. 2016; 46: 601-609 Crossref PubMed Scopus (8) Google Scholar Since the J wave occurs at the junction that marks the completion of ventricular depolarization and beginning of ventricular repolarization, it can be part of either conduction delay or early repolarization. In other words, the J wave is simply an electrocardiographic (ECG) definition that does not clearly tell us whether it belongs to ventricular depolarization or repolarization. This then raises 2 key questions: (1) What could be the mechanism underlying the J wave if it is part of ventricular repolarization? (2) How can the J wave from repolarization be distinguished from the J wave from depolarization clinically? Dynamicity of hypothermia-induced J waves and the mechanism involvedHeart RhythmVol. 16Issue 1PreviewJ waves develop during hypothermia, but the dynamicity of hypothermia-induced J waves is poorly understood. Full-Text PDF