Rovamo L, Mäkijärvi M, Pesonen E, Wallgren E I, Toivonen L
Unit of Cardiology, Children's Hospital, University of Helsinki, Finland.
Pediatr Cardiol. 1995 May-Jun;16(3):114-9. doi: 10.1007/BF00801908.
After corrective surgery for congenital heart defects, scars may create fractionation and delay of the electrical signals in the heart muscle, providing a substrate for arrhythmias. Signal-averaged electrocardiograms (SAECGs) were obtained from 33 children after right ventriculotomy, on average 6 years after surgery, and from 38 healthy controls of the same age. The duration of the filtered QRS complex (fQRS), the duration of the low amplitude signal (< 40 microV) in the terminal QRS complex (LAS40), and the root mean square amplitude of the terminal 40 ms of the QRS complex (RMS40) were determined. The values of fQRS > or = 117 ms, RMS40 < or = 25 microV, and LAS40 > or = 35 ms, which were beyond the mean +/- 2 SD of the healthy controls, were considered abnormal. Most patients had right bundle branch block and therefore a prolonged fQRS. Late potentials were defined as present if both the RMS40 and LAS40 were abnormal. Altogether nine patients (27%) had late potentials. In the patients with late potentials the incidence of serious ventricular arrhythmias was 44% (4 of 9) and in the patients without late potentials 0% (0 of 24). In seven patients with enlargement of the right ventricle, the incidence of arrhythmias was 57% (4 of 7) when late potentials were present and 0% (0 of 7) when they were absent. In the present study late potentials were associated with a history of arrhythmias, especially when the right ventricle was enlarged. Therefore the SAECG may be useful for determining the risk of serious arrhythmia events in children operated for congenital heart defects.
先天性心脏缺陷矫正手术后，疤痕可能会导致心肌电信号的碎裂和延迟，为心律失常提供了基础。对33名接受右心室切开术的儿童在术后平均6年时进行了信号平均心电图（SAECG）检查，并与38名同龄健康对照者进行比较。测定了滤波后的QRS波群时限（fQRS）、终末QRS波群中低振幅信号（<40微伏）的时限（LAS40）以及QRS波群终末40毫秒的均方根振幅（RMS40）。fQRS≥117毫秒、RMS40≤25微伏以及LAS40≥35毫秒，超出健康对照者平均值±2标准差的情况被视为异常。大多数患者存在右束支传导阻滞，因此fQRS延长。如果RMS40和LAS40均异常，则定义为存在晚电位。共有9名患者（27%）存在晚电位。存在晚电位的患者中严重室性心律失常的发生率为44%（9例中的4例），而无晚电位的患者中发生率为0%（24例中的0例）。在7名右心室扩大的患者中，存在晚电位时心律失常的发生率为57%（7例中的4例），不存在晚电位时为0%（7例中的0例）。在本研究中，晚电位与心律失常病史相关，尤其是在右心室扩大时。因此，SAECG可能有助于确定先天性心脏缺陷手术患儿发生严重心律失常事件的风险。
