Chahal Harpreet S, Mostofsky Elizabeth, Mittleman Murray A, Suskin Neville, Speechley Mark, Skanes Allan C, Leong-Sit Peter, Manlucu Jaimie, Yee Raymond, Klein George J, Gula Lorne J
Department of Epidemiology and Biostatistics, Schulich Medicine and Dentistry, Western University, London, Ontario, Canada; Cardiovascular Epidemiology Research Unit, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA.
Cardiovascular Epidemiology Research Unit, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA; Department of Epidemiology, Harvard School of Public Health, Boston, Massachusetts, USA.
Can J Cardiol. 2016 Apr;32(4):533-8. doi: 10.1016/j.cjca.2015.12.026. Epub 2015 Dec 28.
Brief episodes of physical exertion are associated with an immediately greater risk of cardiovascular events. Previous studies on the risk of ventricular arrhythmia (VA) shortly after exertion have not assessed if this risk differs according to the level of aerobic fitness or sedentary behaviour. Therefore, we conducted a prospective cohort study of patients with implantable cardioverter-defibrillators (ICDs) with a nested case-crossover analysis to examine the risk of VA shortly after exertion and whether this risk is modified by aerobic fitness and sedentary behaviour.
Ninety-seven consecutive patients were recruited at the time of ICD implantation and 30 confirmed events occurred among patients who completed interviews about physical exertion preceding ICD therapy. We compared the frequency of exertion within an hour of ICD discharge to each patient's usual frequency of exertion reported at the time of ICD implantation.
Within an hour of episodes of exertion, the risk of VA was 5.3 (95% confidence interval [CI], 2.7-10.6) times greater compared with periods of rest. The association was higher among patients with aerobic fitness below the median (relative risk [RR] = 17.5; 95% CI, 5.2-58.5) than for patients with aerobic fitness above the median (RR, 1.2; 95% CI, 0.4-4.2; P homogeneity = 0.002) and higher among patients who were sedentary (RR, 52.8; 95% CI, 10.1-277) compared with individuals who were not sedentary (RR, 3.2; 95% CI, 1.3-7.6; P homogeneity = 0.0002).
Within 1 hour of episodes of exertion, there is an increased risk of VA, especially among individuals with lower levels of aerobic fitness and with sedentary behaviour.
短暂的体力活动与心血管事件的即刻风险增加有关。既往关于体力活动后不久发生室性心律失常（VA）风险的研究未评估该风险是否因有氧适能水平或久坐行为而异。因此，我们对植入式心脏复律除颤器（ICD）患者进行了一项前瞻性队列研究，并采用巢式病例交叉分析，以检查体力活动后不久发生VA的风险，以及该风险是否因有氧适能和久坐行为而改变。
在ICD植入时连续招募了97例患者，30例确诊事件发生在完成ICD治疗前体力活动访谈的患者中。我们将ICD放电后1小时内的体力活动频率与每位患者在ICD植入时报告的通常体力活动频率进行了比较。
在体力活动发作后1小时内，VA风险比休息期高5.3倍（95%置信区间[CI]，2.7 - 10.6）。有氧适能低于中位数的患者中该关联更高（相对风险[RR]=17.5；95%CI，5.2 - 58.5），高于有氧适能高于中位数的患者（RR，1.2；95%CI，0.4 - 4.2；P同质性=0.002），久坐患者中该关联更高（RR，52.8；95%CI，10.1 - 277），高于非久坐个体（RR，3.
