Risk of Mortality Associated With QT and JT Intervals at Different Levels of QRS Duration (from the Third National Health and Nutrition Examination Survey).
QT prolongation in the setting of QRS >120 ms is believed to be triggered by prolonged depolarization rather than repolarization. Hence, JT interval is suggested as an alternative to QT interval when QRS duration is prolonged. It is unclear, however, if JT and QT intervals portend similar risk of mortality for different durations of QRS. We examined the association between QT and JT, separately, with all-cause mortality across different levels of QRS duration in 8,025 participants (60 ± 13 years, 41% white and 54% women) from the Third National Health and Nutrition Examination Survey. At baseline (1986 to 1994), 486 participants (6%) had QRS duration ≥120 ms. During a follow-up of up to 18 years, 3,045 deaths (38%) occurred. There were significant nonlinear relations of QT and JT intervals with mortality (p <0.001). Hence, QT and JT were categorized as prolonged (>95th percentile), shortened (<5th percentile), and normal (reference group). In multivariate-adjusted Cox regression models, prolonged JT (hazard ratio [HR] 4.75, 95% confidence interval [CI] 1.86 to 12.11) was associated with increased risk of mortality more than prolonged QT (HR 1.50, 95% CI 1.03 to 2.17) in participants with QRS ≥120 ms (interaction p = 0.02). In participants with QRS duration <120 ms, prolonged QT and JT were equally predictive of all-cause mortality (HR 1.27, 95% CI 1.06 to 1.54, and HR 1.31, 95% CI 1.10 to 1.55, respectively). Similar patterns were observed with shortened QT and JT intervals. In conclusion, although both QT and JT intervals are predictive of mortality, JT is more predictive in the setting of QRS duration >120 ms supporting the use of JT interval in patients with prolonged QRS.
Division of Hospitalist Medicine, Department of Internal Medicine, Wake Forest School of Medicine, Winston Salem, North Carolina.
Muhammad A
MA
Zulqarnain
Section on Cardiovascular Medicine, Department of Internal Medicine, Wake Forest School of Medicine, Winston Salem, North Carolina. Electronic address: wqureshi@wakehealth.edu.
Waqas T
WT
Qureshi
Department of Internal Medicine, Wake Forest School of Medicine, Winston Salem, North Carolina.
Wesley T
WT
O'Neal
Division of Cardiology, Department of Internal Medicine, Emory University School of Medicine, Atlanta, Georgia.
Amit J
AJ
Shah
Section on Cardiovascular Medicine, Department of Internal Medicine, Wake Forest School of Medicine, Winston Salem, North Carolina; Epidemiological Cardiology Research Center (EPICARE), Department of Epidemiology and Prevention, Wake Forest School of Medicine, Winston Salem, North Carolina.
Elsayed Z
EZ
Soliman
D000368:Aged; D001145:Arrhythmias, Cardiac / Q000175:diagnosis* / Q000401:mortality / Q000503:physiopathology*; D015992:Body Mass Index; D053840:Brugada Syndrome; D000075224:Cardiac Conduction System Disease; D048909:Diabetes Complications / Q000453:epidemiology; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006329:Heart Conduction System / Q000002:abnormalities* / Q000503:physiopathology*; D006339:Heart Rate; D006801:Humans; D006973:Hypertension / Q000453:epidemiology; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009749:Nutrition Surveys; D011237:Predictive Value of Tests; D011379:Prognosis; D012307:Risk Factors; D012680:Sensitivity and Specificity; D012907:Smoking / Q000009:adverse effects; D015996:Survival Rate; D014481:United States / Q000453:epidemiology