Open AccessShort QT in a Cohort of 1.7 Million Persons: Prevalence, Correlates, and Prognosis
Author(s) -
Iribarren Carlos,
Round Alfred D.,
Peng Jonathan A.,
Lu Meng,
Klatsky Arthur L.,
Zaroff Jonathan G.,
Holve Taylor J.,
Prasad Amit,
Stang Paul
Publication year - 2014
Publication title -
annals of noninvasive electrocardiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.494
H-Index - 48
eISSN - 1542-474X
pISSN - 1082-720X
DOI - 10.1111/anec.12157
Subject(s) - medicine , qt interval , cardiology , atrial fibrillation , population , sudden cardiac death , confidence interval , short qt syndrome , epidemiology , cohort , long qt syndrome , environmental health
Background Short QT syndrome (QTc ≤ 300 ms) is a novel hereditary channelopathy linked to syncope, paroxysmal atrial fibrillation, and sudden cardiac death. However, its epidemiological features remain unsettled. Objectives (1) To assess the prevalence of short QT in a large population‐based sample; (2) to evaluate its demographic and clinical correlates and; (3) to determine its prognosis. Methods A database of 6.4 million electrocardiograms (ECGs) obtained between 1995 and 2008 among 1.7 million persons was used. An internal, population‐based method for heart rate correction (QT creg ) was used and all ECGs with QT creg ≤300 ms were manually validated. Linked health plan databases were used for covariate and survival ascertainment. Results Of 6,387,070 ECGs, 1086 had an ECG with machine‐read QT creg ≤300 ms. Only 4% (45/1086) were validated yielding a prevalence of 0.7 per 100,000 or 1 of 141,935 ECGs. At the person level, the overall prevalence of QT creg ≤300 ms was 2.7 per 100,000 or 1 of 37,335. The factors independently and significantly associated with validated QT creg ≤300 ms were age over 65 years, Black race, prior history of ventricular dysrhythmias, chronic obstructive pulmonary disease, ST‐T abnormalities, ischemia, bigeminy pattern, and digitalis effect. After 8.3 years of median follow‐up and relative to normal QT creg , validated QT creg ≤300 ms was associated after multivariate adjustment with a 2.6‐fold (95% confidence interval [CI] = 1.9–3.7) increased risk of death. Conclusion QT creg ≤300 ms was extraordinarily rare and was associated with significant ECG abnormalities and reduced survival.