Clyne Christopher A, Athar Haris, Shah Anuj, Kahr Rosemarie, Rentas Angel
Henry Low Heart Center at Hartford Hospital, and University of Connecticut School of Medicine, Hartford, Connecticut, USA.
Pacing Clin Electrophysiol. 2007 Mar;30(3):343-51. doi: 10.1111/j.1540-8159.2007.00674.x.
Acute and long-term success of catheter ablation of right ventricular outflow tract tachycardia (RVOT VT) may be limited by the inability to reproduce the arrhythmia at the time of activation (AM) and pace mapping (PM). We have observed early initiation of the clinical VT when subtherapeutic radiofrequency (RF) energy was applied to the target area (TA), defined as a 2-cm(2) area around a pace match. We describe a novel approach using thermal mapping (TM) to guide the ablation of RVOT VT.
Thirteen patients (10 female, mean age 46.2 +/- 13.7 years) with symptomatic VT of left bundle branch block (LBBB) inferior axis morphology and no structural heart disease underwent standard electrophysiologic evaluation with PM (n = 13), AM (n = 13), and 3D noncontact mapping (n = 4). Thermal mapping was performed after standard techniques failed to induce stable sustained VT for mapping in all 13 patients: RF was applied for 5-10 seconds in the TA to achieve a tip temperature of 45-50 degrees C. At sites where morphologically consistent with the clinical VT was induced, RF was applied at target temperature between 50 and 60 degrees C for 30-60 seconds. TM was repeated before and after intravenous Isoproterenol infusion until no further VT could be induced by low temperature application.
Noninducibility was achieved in all 13 patients. During a mean follow-up of 29 months (9-69 months), all patients remain arrhythmia-free, off antiarrhythmic medications.
Thermal mapping is a safe and effective adjunctive technique for the mapping and ablation of RVOT VT when sustained tolerated clinical VT cannot be induced.
右心室流出道心动过速（RVOT VT）导管消融的急性和长期成功率可能会受到激活（AM）和起搏标测（PM）时无法重现心律失常的限制。我们观察到，当将低于治疗剂量的射频（RF）能量应用于目标区域（TA）时，临床室性心动过速（VT）会提前发作，目标区域定义为起搏匹配点周围2平方厘米的区域。我们描述了一种使用热标测（TM）来指导RVOT VT消融的新方法。
13例有症状的左束支传导阻滞（LBBB）下轴形态且无结构性心脏病的室性心动过速患者（10例女性，平均年龄46.2±13.7岁）接受了标准电生理评估，包括起搏标测（n = 13）、激活标测（n = 13）和三维非接触标测（n = 4）。在所有13例患者中，在标准技术未能诱发稳定的持续性室性心动过速进行标测后，进行热标测：在目标区域施加射频5 - 10秒，使尖端温度达到45 - 50摄氏度。在诱发形态与临床室性心动过速一致的部位，在50至60摄氏度的目标温度下施加射频30 - 60秒。在静脉注射异丙肾上腺素前后重复热标测，直到低温刺激不再诱发室性心动过速。
13例患者均实现了不能诱发。平均随访29个月（9 - 69个月）期间，所有患者均未出现心律失常，且停用了抗心律失常药物。
当无法诱发持续性可耐受的临床室性心动过速时，热标测是一种安全有效的辅助技术，用于RVOT VT的标测和消融。
