Early Repolarization Electrocardiographic Phenotypes Associated With Favorable Long-Term Outcome

• Published in: Circulation (New York, N.Y.) Vol. 123; no. 23; pp. 2666 - 2673
• Main Authors: Tikkanen, Jani T., Junttila, M. Juhani, Anttonen, Olli, Aro, Aapo L., Luttinen, Samuli, Kerola, Tuomas, Sager, Solomon J., Rissanen, Harri A., Myerburg, Robert J., Reunanen, Antti, Huikuri, Heikki V.
• Format: Journal Article
• Language: English
• Published: Hagerstown, MD Lippincott Williams & Wilkins 14.06.2011
• Subjects: Adolescent; Arrhythmias, Cardiac - diagnosis; Arrhythmias, Cardiac - mortality; Biological and medical sciences; Blood and lymphatic vessels; Cardiology. Vascular system; Death, Sudden, Cardiac - epidemiology; Death, Sudden, Cardiac - prevention & control; Diseases of the peripheral vessels. Diseases of the vena cava. Miscellaneous; Electrocardiography; Finland - epidemiology; Follow-Up Studies; Humans; Male; Medical sciences; Middle Aged; Phenotype; Pilot Projects; Prognosis; Risk Factors; Sarcoidosis. Granulomatous diseases of unproved etiology. Connective tissue diseases. Elastic tissue diseases. Vasculitis; Sports - statistics & numerical data; Time Factors; United States - epidemiology; United States; Finland; Repolarization; Phenotype; follow-up studies; risk factors; Prognosis; Arrhythmia; Follow up study; Heart disease; Risk factor; Electrocardiography; Cardiovascular disease; Epidemiology
• ISSN: 0009-7322; 1524-4539; 1524-4539
• DOI: 10.1161/CIRCULATIONAHA.110.014068

Early repolarization (ER) in inferior/lateral leads of standard ECGs increases the risk of arrhythmic death. We tested the hypothesis that variations in the ST-segment characteristics after the ER waveforms may have prognostic importance. ST segments after ER were classified as horizontal/descending or rapidly ascending/upsloping on the basis of observations from 2 independent samples of young healthy athletes from Finland (n=62) and the United States (n=503), where ascending type was the dominant and common form of ER. Early repolarization was present in 27/62 (44%) of the Finnish athletes and 151/503 (30%) of the US athletes, and all but 1 of the Finnish (96%) and 91/107 (85%) of US athletes had an ascending/upsloping ST variant after ER. Subsequently, ECGs from a general population of 10 864 middle-aged subjects were analyzed to assess the prognostic modulation of ER-associated risk by ST-segment variations. Subjects with ER ≥0.1 mV and horizontal/descending ST variant (n=412) had an increased hazard ratio of arrhythmic death (relative risk 1.43; 95% confidence interval 1.05 to 1.94). When modeled for higher amplitude ER (>0.2 mV) in inferior leads and horizontal/descending ST-segment variant, the hazard ratio of arrhythmic death increased to 3.14 (95% confidence interval 1.56 to 6.30). However, in subjects with ascending ST variant, the relative risk for arrhythmic death was not increased (0.89; 95% confidence interval 0.52 to 1.55). ST-segment morphology variants associated with ER separates subjects with and without an increased risk of arrhythmic death in middle-aged subjects. Rapidly ascending ST segments after the J-point, the dominant ST pattern in healthy athletes, seems to be a benign variant of ER.