From the Division of Public Health Sciences, Department of Epidemiology and Prevention, Epidemiological Cardiology Research Center (EPICARE) (E.Z.S., Y.L., P.M.R.) and Section on Cardiology, Department of Internal Medicine (E.Z.S.), Wake Forest School of Medicine, Winston Salem, NC; Department of Epidemiology, Emory University, Atlanta, GA (A.J.S.); and Department of Internal Medicine, Wake Forest Baptist Medical Center, Winston Salem, NC (A.B.).
Circ Arrhythm Electrophysiol. 2014 Jun;7(3):400-6. doi: 10.1161/CIRCEP.113.001396. Epub 2014 Apr 24.
Prolonged-QT commonly coexists in the ECG with left ventricular hypertrophy (ECG-LVH). However, it is unclear whether to what extent QT prolongation coexisting with ECG-LVH can explain the prognostic significance of ECG-LVH, and whether prolonged-QT coexisting with ECG-LVH should be considered as an innocent consequence of ECG-LVH.
The study population consisted of 7506 participants (mean age, 59.4±13.3 years; 49% whites; and 47% men) from the US Third National Health and Nutrition Examination Survey. ECG-LVH was defined by Cornell voltage criteria. Prolonged heart-rate-adjusted QT (prolonged-QTa) was defined as QTa≥460 ms in women or 450 ms in men. Cox proportional hazards analysis was used to calculate the hazard ratios with 95% confidence intervals for the risk of all-cause mortality for various combinations of ECG-LVH and prolonged-QTa. ECG-LVH was present in 4.2% (N=312) of the participants, of whom 16.4% had prolonged-QTa. In a multivariable-adjusted model and compared with the group without ECG-LVH or prolonged-QTa, mortality risk was highest in the group with concomitant ECG-LVH and prolonged-QTa (hazard ratio, 1.63; 95% confidence interval, 1.12-2.36), followed by isolated ECG-LVH (1.48; 1.24-1.77), and then isolated prolonged-QTa (1.27; 1.12-1.46). In models with similar adjustment where ECG-LVH and prolonged-QTa were entered as 2 separate variables and subsequently additionally adjusted for each other, the mortality risk was essentially unchanged for both variables.
Although prolonged-QT commonly coexists with LVH, both are independent markers of poor prognosis. Concomitant presence of prolonged-QT and ECG-LVH carries a higher risk than either predictor alone.
心电图（ECG）左心室肥厚（ECG-LVH）常伴有长 QT 间期（prolonged-QT）。然而，目前尚不清楚 QT 间期延长与 ECG-LVH 共存在何种程度上可以解释 ECG-LVH 的预后意义，以及是否应将伴有 ECG-LVH 的长 QT 间期延长视为 ECG-LVH 的无害后果。
研究人群为来自美国第三次国家健康和营养检查调查的 7506 名参与者（平均年龄 59.4±13.3 岁；49%为白人；47%为男性）。ECG-LVH 采用 Cornell 电压标准定义。校正心率后的 QT 间期延长（prolonged-QTa）定义为女性 QTa≥460ms 或男性 QTa≥450ms。使用 Cox 比例风险分析计算不同 ECG-LVH 和 prolonged-QTa 组合的全因死亡率风险的风险比及其 95%置信区间。4.2%（n=312）的参与者存在 ECG-LVH，其中 16.4%伴有 prolonged-QTa。在多变量调整模型中，与无 ECG-LVH 或 prolonged-QTa 的组相比，同时伴有 ECG-LVH 和 prolonged-QTa 的组死亡率最高（风险比 1.63；95%置信区间 1.12-2.36），其次是孤立性 ECG-LVH（1.48；1.24-1.77），然后是孤立性 prolonged-QTa（1.27；1.12-1.46）。在调整相似的模型中，将 ECG-LVH 和 prolonged-QTa 作为 2 个独立变量输入，随后彼此进一步调整，这 2 个变量的死亡率风险基本不变。
虽然长 QT 间期常与 LVH 共存，但两者都是预后不良的独立标志物。伴有 prolonged-QT 和 ECG-LVH 的同时存在比任何单一预测因子的风险都更高。
