Division of Cardiology, Institute of Clinical Medicine, University of Oulu, Oulu, Finland.
Heart Rhythm. 2012 Jul;9(7):1083-9. doi: 10.1016/j.hrthm.2012.02.030. Epub 2012 Mar 3.
Postexercise measurement of heart rate (HR) recovery and QT interval dynamics provides prognostic information in various patient populations.
The purpose of this study was to assess whether the measurement of the spatial relationship between the depolarization and repolarization wavefronts (total cosine R-to-T [TCRT]) during the postexercise recovery phase would yield prognostic information.
The population consisted of 1297 patients (56 ± 13 years; 67% men) who performed a clinically indicated bicycle stress test. The exercise-recovery hysteresis of TCRT was quantified from the 12-lead exercise electrocardiogram by measuring the TCRT/HR loop area bounded by the exercise and first 3-minute postexercise recovery curves. The HR-corrected TCRT/HR hysteresis was calculated by dividing the area with the HR decrement during the first 3 minutes of recovery. HR recovery was measured at 1 minute postexercise recovery. End points were cardiac death and sudden cardiac death.
During an average follow-up of 45 ± 12 months, 74 patients died (5.7%); 35 (2.6%) were cardiac deaths and 24 (1.9%) were sudden cardiac deaths. Reduced TCRT/HR loop area and TCRT/HR hysteresis were associated with cardiac mortality (P <.001). After adjustments for clinical variables, including ejection fraction, TCRT/HR loop area remained an independent predictor of cardiac death (hazard ratio 5.6; 95% confidence interval 1.6-19.1; P = .007) and sudden cardiac death (10.7; 95% confidence interval 1.4-83.7; P = .024). HR recovery did not remain a significant predictor in the multivariate analysis.
Attenuated hysteresis of the depolarization and repolarization wavefronts during postexercise recovery is associated with an increased risk of cardiac and sudden cardiac death. Analysis of repolarization dynamics from exercise electrocardiogram represents a promising tool for risk stratification.
运动后心率（HR）恢复和 QT 间期动力学的测量可提供各种患者群体的预后信息。
本研究旨在评估在运动后恢复期测量去极化和复极化波阵面（总余弦 R 到 T [TCRT]）之间的空间关系是否会提供预后信息。
该人群由 1297 名患者（56±13 岁；67%为男性）组成，他们进行了临床指征的自行车压力测试。通过测量运动和首次 3 分钟运动后恢复期曲线之间的 TCRT/HR 环面积来量化 TCRT 的运动-恢复期滞后。通过将面积除以恢复期前 3 分钟内 HR 的减少量，计算出 HR 校正的 TCRT/HR 滞后。HR 恢复在运动后 1 分钟时测量。终点为心脏性死亡和心源性猝死。
在平均随访 45±12 个月期间，74 例患者死亡（5.7%）；35 例（2.6%）为心脏性死亡，24 例（1.9%）为心源性猝死。TCRT/HR 环面积减小和 TCRT/HR 滞后与心脏死亡率相关（P<.001）。在调整了包括射血分数在内的临床变量后，TCRT/HR 环面积仍然是心脏死亡的独立预测因素（风险比 5.6；95%置信区间 1.6-19.1；P=0.007）和心源性猝死（10.7；95%置信区间 1.4-83.7；P=0.024）。在多变量分析中，HR 恢复不再是一个显著的预测因素。
运动后恢复期去极化和复极化波阵面滞后的减弱与心脏性死亡和心源性猝死的风险增加相关。运动心电图复极动力学分析是一种有前途的风险分层工具。
