Characteristics of early repolarization parameters and prognostic implications in the general ambulatory Korean population.
BACKGROUND
We tested a hypothesis that the 2 fundamental components of early repolarization (ER), J wave and ST elevation (STE) might have different prevalence and prognostic implications.


METHODS
The study population comprised 26,345 general ambulatory Korean subjects (mean 48.0±10.2years old, 53.2% male) who underwent medical checkups from January 2002 to December 2002. ER was found in 2950 subjects (11.2%), who were divided into 3 groups (J [J wave only, n=1874, 7.1%], JST [both J wave and STE, n=489, 1.8%], and ST [STE only, n=587, 2.3%]).


RESULTS
The prevalence of STE decreased with age, whereas J waves remained at a constant level in all age groups. The most common pattern of ER was the J pattern, with a horizontal/descending ST segment in the inferior leads; in lateral precordial leads, ST or JST patterns with ascending ST segments were more common. During the mean follow-up of 126.0±11.1months, a total of 710 subjects died (2.7%). Subjects in the J group were at higher risk (Hazard ratio 1.60, 95% confidence interval 1.27-2.01, p<0.001), while those in the JST and ST groups showed similar survival outcomes compared to controls without J waves or STE.


CONCLUSIONS
J waves and STE showed different age and lead distributions and prognostic implications. The presence of the J wave itself was associated with a higher relative risk of mortality. However, due to the low event rate, its clinical significance appears to be limited.
Heart Institute, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.
Min Soo
MS
Cho
Division of Cardiology, Department of Internal Medicine, Konkuk University Medical Center, Konkuk University School of Medicine, Seoul, South Korea.
Chang Hee
CH
Kwon
Heart Institute, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea. Electronic address: gbnam@amc.seoul.kr.
Gi-Byoung
GB
Nam
Department of Cardiology, Veterans Health Service Medical Center, Seoul, South Korea.
Woo Seok
WS
Lee
Division of Cardiology, Department of Internal Medicine, Pusan National University Yangsan Hospital, Pusan National University of Medicine, Yangsan, South Korea.
Ki Won
KW
Hwang
Division of Cardiology, Department of Internal Medicine, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, South Korea.
Yong Giun
YG
Kim
Division of Cardiology, Department of Internal Medicine, Soonchunhyang University Hospital, Soonchunhyang University College of Medicine, Bucheon, South Korea.
Hyung Oh
HO
Choi
Division of Cardiology, Seoul St. Mary's General Hospital, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, South Korea.
Sung-Hwan
SH
Kim
Department of Health Screening and Promotion Center, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.
Jeongsoon
J
Kim
Department of Health Screening and Promotion Center, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.
Hyo-Jung
HJ
Nam
Department of Health Screening and Promotion Center, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.
Sun-Yang
SY
Min
Heart Institute, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.
Minsu
M
Kim
Heart Institute, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.
Ji Hyun
JH
Lee
Heart Institute, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.
You Mi
YM
Hwang
Heart Institute, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.
Uk
U
Jo
Heart Institute, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.
Jun
J
Kim
Heart Institute, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.
Kee-Joon
KJ
Choi
Heart Institute, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.
You-Ho
YH
Kim
D000328:Adult; D000368:Aged; D000553:Ambulatory Care / Q000379:methods; D000704:Analysis of Variance; D001145:Arrhythmias, Cardiac / Q000175:diagnosis* / Q000401:mortality / Q000628:therapy*; D002423:Cause of Death; D015331:Cohort Studies; D016001:Confidence Intervals; D016757:Death, Sudden, Cardiac / Q000517:prevention & control*; D004562:Electrocardiography; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology*; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models; D056910:Republic of Korea; D012189:Retrospective Studies; D018570:Risk Assessment; D012720:Severity of Illness Index; D015996:Survival Rate; D013997:Time Factors; D016896:Treatment Outcome
Age distribution; Early repolarization; Electrocardiography; J wave; Mortality; Outcome