Kop Willem J, Krantz David S, Nearing Bruce D, Gottdiener John S, Quigley John F, O'Callahan Mark, DelNegro Albert A, Friehling Ted D, Karasik Pamela, Suchday Sonia, Levine Joseph, Verrier Richard L
Department of Medical and Clinical Psychology, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Rd, Bethesda, Md 20814, USA.
Circulation. 2004 Apr 20;109(15):1864-9. doi: 10.1161/01.CIR.0000124726.72615.60. Epub 2004 Mar 22.
Malignant cardiac arrhythmias can be triggered by exercise and by mental stress in vulnerable patients. Exercise-induced T-wave alternans (TWA) is an established marker of cardiac electrical instability. However, the effects of acute mental stress on TWA have not been investigated as a vulnerability marker in humans.
TWA responses to mental stress (anger recall and mental arithmetic) and bicycle ergometry were evaluated in patients with implantable cardioverter defibrillators (ICDs) and documented coronary artery disease (n=23, age 62.1+/-12.3 years) and controls (n=17, age 54.2+/-12.1 years). TWA was assessed from digitized ECGs by modified moving average analysis. Dual-isotope single photon emission computed tomography was used to assess myocardial ischemia. TWA increased during mental stress and exercise (P values <0.001), and TWA responses were higher in ICD patients than in controls (arithmetic Delta=8.9+/-1.4 versus 4.3+/-2.2 microV, P=0.043; exercise Delta=21.4+/-2.8 versus 13.8+/-3.2 microV, P=0.038). TWA increases with mental stress occurred at substantially lower heart rates (anger recall Delta=9.7+/-7.7 bpm, arithmetic Delta=14.3+/-13.3 bpm) versus exercise (Delta=53.7+/-22.7 bpm; P values <0.001). After adjustment for heart rate increases, mental stress and exercise provoked increased TWA in ICD patients (P values <0.05), but not in controls (P values >0.2). Ejection fraction and stress-induced myocardial ischemia were not associated with TWA.
Mental stress can induce cardiac electrical instability, as assessed via TWA, among patients with arrhythmic vulnerability and occurs at lower heart rates than with exercise. Pathophysiological mechanisms of mental stress-induced arrhythmias may therefore involve central and autonomic nervous system pathways that differ from exercise-induced arrhythmias.
在易患患者中，恶性心律失常可由运动和精神压力诱发。运动诱发的T波交替（TWA）是心脏电不稳定的既定标志物。然而，急性精神压力对TWA的影响尚未作为人类易感性标志物进行研究。
在植入式心脏复律除颤器（ICD）且有冠状动脉疾病记录的患者（n = 23，年龄62.1±12.3岁）和对照组（n = 17，年龄54.2±12.1岁）中评估TWA对精神压力（愤怒回忆和心算）以及自行车测力计运动的反应。通过改良移动平均分析法从数字化心电图评估TWA。采用双同位素单光子发射计算机断层扫描评估心肌缺血。TWA在精神压力和运动期间增加（P值<0.001），ICD患者的TWA反应高于对照组（心算时Δ= 8.9±1.4对4.3±2.2μV，P = 0.043；运动时Δ= 21.4±2.8对13.8±3.2μV，P = 0.038）。与运动相比，精神压力导致TWA增加时的心率显著更低（愤怒回忆时Δ= 9.7±7.7次/分钟，心算时Δ= 14.3±13.3次/分钟）（运动时Δ= 53.7±22.7次/分钟；P值<0.001）。在调整心率增加后，精神压力和运动在ICD患者中诱发TWA增加（P值<0.05），但在对照组中未诱发（P值>0.2）。射血分数和压力诱发的心肌缺血与TWA无关。
在有心律失常易感性的患者中，精神压力可通过TWA评估诱发心脏电不稳定，且发生时的心率低于运动时。因此，精神压力诱发心律失常的病理生理机制可能涉及与运动诱发心律失常不同的中枢和自主神经系统途径。
