先天性心脏病外科手术后切口性房性心动过速三维电磁导管标测及射频消融

目的；探讨天先性心脏病外科手术后切口性房性心动过速（房速）三维电磁导管（即Carto)标测特点及射频消融价值。方法：5例切口性房速患者，应用Carto系统标则右心房，实时重建心腔三维电解剖图，标识瘢痕区，观察电热图，传导图，于折返所经过的关键峡部位线性消融，结果：4例房速呈持续性，1例（三房心）术中不能诱发，电势图示低电压区主要分布于右房游离壁，在右房中侧壁下侧壁分别标测到瘢痕区1（S1）和瘢痕区2（S2）。4例持续性房速发生机理与折返有关，折返环位于低电压区，中心解剖障碍区均为中侧壁瘢痕区1，3例折返经过S1－S2，1例经过S1－三尖瓣环之间的关键峡部，于上述关键峡部消融，均获成功，三房心患者（未诱导心动过速）于S1－S及三尖瓣环－下腔静脉之间行线性消融，无并发症，随访2－24个月，其中1例（三房心）于术后1个月出现不典型心房扑动，结论：提示先天性心脏病术后房速的发生机理与折返有关，应用Carto系统标测可清楚地显示折返途径，消融折返所经过的关键峡部可望达到根治目的。

Electroanatomical mapping and radiofrequency ablation of incisional atrial tachycardia after surgery for congenital heart disease

Objective To characterize the electroanatomical mapping and to assess the value of radiofrequency ablation of incisional atrial tachycardia (IAT)after surgery for congenital heart disease(CHD). Methods Five patients with IATs after surgery for CHD were studied. Three-dimensional electroanatomical maps were constructed using electroanatomical mapping system (Carto). Scars (S) were marked, and the voltage maps or propagation maps were observed. Lines of ablation were directed at the channels through which the reentrant circuits propagated. Results 1.The IATs were sustained in 4 cases and the tachycardia could not be induced in 1 patient (Tricoratriam, TrA). A large area of low bipolar voltage involved most of the free wall of right atrium in all patients. 2. Two scars (S1,S2)were marked in mid-lateral and inferior-lateral parts of atrium respectively. 3. The sustained IATs in 4 cases were associated with reentrant tachycardias whose central obstacles were S1 and the circuits propagated through the channels formed by S1-S2 ( n =3)or S1-tricuspid annulus (TA) ( n =1). 4.The IATs were ablated successfully within the channels. Lines of ablation were performed within the channels of S1-S2 and the isthmus of TA-inferior vena cava in the patient with TrA. 5. No complication occurred. During a period of 2-24 months follow-up, an atypical atrial flutter occurred in one case(TrA).Conclusion These results suggest that the IAT is related with reentrant mechanism, and the electroanatomic mapping can clearly demonstrate reentrant circuit, and the ablation within the channel where the circuit propagates through may eliminate IAT.