The Prevalence and Significance of the Early Repolarization Pattern in Sudden Arrhythmic Death Syndrome Families

Greg Mellor, Christopher P. Nelson, Claire Robb, Hariharan Raju, Yanushi Wijeyeratne, Christian Hengstenberg, Wibke Reinhard, Michael Papadakis, Sanjay Sharma, Nilesh J. Samani, Elijah R. Behr
2016 Circulation: Arrhythmia and Electrophysiology  
Background-The early repolarization (ER) pattern is associated with sudden death and has been shown to be heritable. Its significance when identified in families affected by sudden arrhythmic death syndrome (SADS) remains unclear. Methods and Results-We analyzed 12-lead ECGs of 401 first-degree relatives of individuals who had died from SADS. The prevalence of ER patterns was compared with family-clustered controls. ER was more common in SADS family members than in controls (21% versus 8%; odds
more » ... ratio: 5.14; 95% confidence interval, 3.37-7.84) independent of the presence of a familial cardiac diagnosis. Both ascending and horizontal ER patterns were more common. In addition, ER was investigated for associations with findings from ajmaline provocation (n=332), exercise ECG (n=304), and signalaveraged ECG (n=118) when performed. ER was associated with a trend toward late depolarization, in general was suppressed with exercise and was unaffected by ajmaline. Inferior and horizontal patterns were, however, more likely to persist during exercise. Augmentation of ER with ajmaline was rare. Conclusions-The ER pattern is more common in SADS family members than controls adjusted in particular for relatedness. The increased prevalence is irrespective of ER subtype and the presence of other inherited arrhythmia syndromes. ER may therefore represent an underlying heritable arrhythmia syndrome or risk factor for sudden death in the context of other cardiac pathology. The differing response of ER subtypes to exercise and ajmaline provocation suggests underlying mechanisms of both abnormal repolarization and depolarization. (Circ Arrhythm Electrophysiol. 2016;9:e003960. Similarly to previous studies, 32,33 the J-point was suppressed or remain unchanged with ajmaline provocation in the Figure 4. Early repolarization (ER) persisting with exercise. The inferior leads of ECGs from a single individual are shown. ECGs are recorded at rest, pre-exercise, and at time of peak exercise. ER with a notched J-point and horizontal ST segment is seen in all inferior leads at rest. The J-point notching persists, with minimal reduction in amplitude at peak exercise. by guest on December 11, 2017
doi:10.1161/circep.116.003960 pmid:27255966 fatcat:ratetonbnzebjixepqsrkwbx5a