Anand Nitasha, McCrindle Brian W, Chiu Christine C, Hamilton Robert M, Kirsh Joel A, Stephenson Elizabeth A, Gross Gil J
Cardiology Division, Hospital for Sick Children, University of Toronto, 555 University Avenue, Toronto, Ontario, Canada M5G 1X8.
Eur Heart J. 2006 Sep;27(17):2069-73. doi: 10.1093/eurheartj/ehl080. Epub 2006 Jun 8.
Atrial flutter causes late postoperative morbidity in congenital heart disease (CHD). Sinoatrial node dysfunction is associated with late postoperative atrial flutter, but pacing interventions driven by minimum heart rates (HR) have yielded mixed results.
A retrospective case-control study was used to test the hypothesis that late postoperative atrial flutter is associated with chronotropic incompetence in active young CHD patients. Control CHD patients aged < or =18 years without documented supraventricular ectopy (n = 42) were matched with 42 patients (cases) having atrial flutter onset > or =6 months postoperatively. Minimum, average, and maximum non-flutter HRs were obtained from outpatient ambulatory 24 h ECG (Holter) recordings and graded exercise tests. Chronotropic competence was assessed using percentage of age-specific predicted maximum HR achieved, and calculated chronotropic index. Effects of rate-adaptive programming and maximum atrial pacing rates were analysed in 19 permanently paced cases. Least square estimates of minimum HRs were similar in cases and controls (54+/-2 vs. 52+/-2 bpm). Average HRs were lower in cases (75+/-2 vs. 81+/-2 bpm, P=0.02). Cases and controls differed most significantly with respect to percentage of predicted maximum HR achieved (67+/-2 vs. 80+/-2%, P < 0.001). This difference remained highly significant when the data were adjusted for age, sex, permanent pacing, and negatively chronotropic medication usage at the time of testing. Among paced patients, atrial flutter was significantly less likely to be observed in the setting of rate-adaptive pacing [odds ratio (OR) = 0.36; P < 0.05], and the likelihood of detecting atrial flutter decreased relative to the maximum programmed atrial pacing rate (OR 0.87 for every 5% increment in maximum pacing rate relative to maximum predicted HR for age; P < 0.05).
Late postoperative atrial flutter is associated with chronotropic incompetence in paediatric CHD patients.
心房扑动会导致先天性心脏病（CHD）患者术后出现晚期发病情况。窦房结功能障碍与术后晚期心房扑动相关，但基于最低心率（HR）的起搏干预效果不一。
采用回顾性病例对照研究来检验这一假设，即术后晚期心房扑动与活动的年轻CHD患者的变时功能不全有关。将年龄≤18岁且无记录的室上性心律失常的对照CHD患者（n = 42）与42例术后≥6个月出现心房扑动的患者（病例组）进行匹配。从门诊动态24小时心电图（Holter）记录和分级运动试验中获取最低、平均和最高非扑动心率。使用达到年龄特异性预测最大心率的百分比和计算变时指数来评估变时功能。对19例永久起搏的病例分析了频率适应性编程和最大心房起搏率的影响。病例组和对照组的最低心率最小二乘估计值相似（54±2对52±2次/分钟）。病例组的平均心率较低（75±2对81±2次/分钟，P = 0.02）。病例组和对照组在达到预测最大心率的百分比方面差异最为显著（67±2对80±2%，P < 0.001）。当对测试时的年龄、性别、永久起搏和负性变时药物使用情况进行数据调整后，这种差异仍然非常显著。在起搏患者中，频率适应性起搏情况下观察到心房扑动的可能性显著降低[优势比（OR）= 0.36；P < 0.05]，并且相对于最大程控心房起搏率，检测到心房扑动的可能性降低（相对于年龄最大预测心率，最大起搏率每增加5%，OR为0.87；P < 0.05）。
术后晚期心房扑动与小儿CHD患者的变时功能不全有关。
