小儿先天性心脏病术后异位性心动过速常见类型及发生机制探讨

目的探讨小儿先天性心脏病(CHD)术后出现的异位性心动过速常见类型及发生机制。方法对术后发生异位性心动过速的23例进行血生化、心电图检查，12例行食管电生理检查，11例行心内电生理检查。结果房扑，折返性房速11例，交界性异位性心动过速(JET)5例，室速3例，房室折返性心动过速(AVRT)2例，房室结折返性心动过速(AVNRT)1例，紊乱性房速1例。3例房速、1例房扑的发生基础为电激动围绕心房切口折返，3例房扑乃电激动围绕三尖瓣环折返，房室及房室结折返性心动过速为围绕旁路或双径路折返引起，1例室速为折返所致。5例JET、1例紊乱性房速与术后心脏细胞自律性增高有关。1例室速为高血钾诱发。结论房扑，折返性房速、JET是较常见的小儿术后异位性心动过速。该类心律失常的机制复杂多样，部分与心脏手术因素关系密切，部分病例则与手术无关。

The pattern and mechanism of postoperative ectopic tachycardia in children with congenital heart disease

Objective: The aim of this study was to investigate the common patterns of postoperative ectopic tachycardia in children with congenital heart diseases (CHD) and to probe into their possible mechanism and etiology. Methods: Twenty-three CHD children with postoperative ectopic tachycardia were retrospectively analysed. Serum electrolytes were measured in each patient. All children underwent 12-leads ECG examination. 12 cases received transesophageal electrophysiologic evaluation. 11 received intracardiac electrophysiologic evaluation. Results: Typical trial flutter(AFL) was found in 7 patients, while atypical AFL in 1 pati ent, intra-atrial reentrant tachycardia (IART) in 3, junctional ectopic tachycardia (JET) in 5, ventricular tachycardia (VT) in 3, atrioventrular reentrant tachycardia (AVRT) in 2, atrioventrular nodal reentrant tachycardia (AVNRT) in 1, and multifocal atrial tachycardia in 1. The mechanisms of tachycardia include (1) Reentry: 3 IART and 1 atypical AFL originated from a previous atrial incisional scar around which a reentrant circuit rotated. 3 typical AFL had a counterclockwise loop around the tricuspid valve. 1 VT patient occurred because of reentrant circuit. The substrate of AVRT was congenital atrioventrular accessory pathway while AVNRT was atrioventrular node double pathway. (2) Increased automaticity: 5 JET occurred because of atrioventrular junctional increased automaticity, and 1 confused atrial tachycardia might be developed from increased atrial cell automaticity. (3) Abnormal serum electrolytes level especially serum potassium level. Conclusion: AFL/IART and JET were common patterns of postoperative actopic tachycardia in CHD children. In some cases, the mechanisms of postoperative tachycardia were related with operation.