右室流出道室性心律失常起源处舒张期电位的分布和意义

The significance of isolated diastolic potentials in origin regions of idiopathic right ventricular outflow tract ventricular arrhythmias

目的分析右室流出道室性心律失常起源处舒张期电位(IDPs)的电生理特点,对其可能的致心律失常机制作初步探讨。方法选取30例经导管射频消融的右室流出道室性心律失常患者作为病例组,5例电生理检查阴性患者作为对照组。窦性心律下建立右室流出道三维电解剖图,分析IDPs的电生理特点及其与消融靶点之间的关系。结果病例组患者及1例对照组患者均于右室流出道处记录到IDPs。病例组中IDPs区位于肺动脉环下约1.4±0.3 cm,电解剖面积为1.4±0.3 cm2,最大振幅为0.3±0.1mV,三维电压标测示该区多位于电压移行带(0.5～1.5 mV)。80.0%(24/30)成功消融靶点位于IDPs区内,20.0%(6/30)位于IDPs区边缘。IDPs区内组和边缘组在靶点处局部心室激动时间和起搏相似度上无统计学差异(P>0.05)。结论右室流出道室性心律失常患者均可记录到IDPs,且消融成功靶点均位于IDPs区内或边缘。

Objective To investigate the eleetrophysiological characterisitics of isolated diastolic potentials （IDPs） and its role in arrhythmogenesis in patients with idiopathic right ventricular outflow tract （RVOT） . Methods Thirty consec- utive patients with idiopathic RVOT-VAs （premature ventricular contractions and/or nonsustained ventricular tachycardia） and five control subjects were studied. Eleetroanatomical mapping was performed in RVOT during sinus rhythm. The elec- trophysiological characteristics of IDPs and its relation to successful ablation site were examined. Results IDPs were re- corded in the RVOT in all patients and in one control subject. IDPs were mainly located in the transitional-voltage zone （0. 5-1.5 mV） with the maximal amplitude of the IDPs was 0.3±0.1 mV, in an electroanatomic area of 1.4±0.3 cm^2 in size and the mean distance from pulmonary valve was 1.4±0.3 cm. The optimal ablation site was within the IDPs area in 24 pa- tients （80.0%） and was on the borderline of the IDPs area in the other 6 patients. There was no difference in the mean earliest activation time and mean pace mapping score at successful ablation site between patients whose optimal ablation site was within or on the border of the IDPs area （ P〉0. 05 ）. Conclusion IDPs present in patients with idiopathic ventricu- lar arrhythmias arising from RVOT, and the successful target site is always within or on the border of IDPs.