Sosa E, Scanavacca M, D'Avila A, Piccioni J, Sanchez O, Velarde J L, Silva M, Reolão B
Heart Institute, University São Paulo Medical School, Brazil.
J Cardiovasc Electrophysiol. 1998 Mar;9(3):229-39. doi: 10.1111/j.1540-8167.1998.tb00907.x.
An epicardial site of origin of ventricular tachycardia (VT) may explain unsuccessful endocardial radiofrequency (RF) catheter ablation. A new technique to map the epicardial surface of the heart through pericardial puncture was presented recently and opened the possibility of using epicardial mapping to guide endocardial ablation or epicardial catheter ablation. We report the efficacy and safety of these two approaches to treat 10 consecutive patients with VT and Chagas' disease.
Epicardial mapping was carried out with a regular steerable catheter introduced into the pericardial space. An epicardial circuit was found in 14 of 18 mapable VTs induced in 10 patients. Epicardial mapping was used to guide endocardial ablation in 4 patients and epicardial ablation in 6. The epicardial earliest activation site occurred 107+/-60 msec earlier than the onset of the QRS complex. At the epicardial site used to guide endocardial ablation, earliest activation occurred 75+/-55 msec before the QRS complex. Epicardial mid-diastolic potentials and/or continuous electrical activity were seen in 7 patients. After 4.8+/-2.9 seconds of epicardial RF applications, VT was rendered noninducible. Hemopericardium requiring drainage occurred in 1 patient; 3 others developed pericardial friction without hemopericardium. Patients remain asymptomatic 5 to 9 months after the procedure. Interruption during endocardial pulses occurred after 20.2+/-14 seconds (P = 0.004), but VT was always reinducible and the patients experienced a poor outcome.
Epicardial mapping does not enhance the effectiveness of endocardial pulses of RF. Epicardial applications of RF energy can safely and effectively treat patients with VT and Chagas' disease.
室性心动过速（VT）起源于心外膜部位可能是心内膜射频（RF）导管消融失败的原因。最近提出了一种通过心包穿刺对心脏心外膜表面进行标测的新技术，这为使用心外膜标测来指导心内膜消融或心外膜导管消融开辟了可能性。我们报告了这两种方法治疗10例连续性VT合并恰加斯病患者的疗效和安全性。
使用常规可操控导管进入心包腔进行心外膜标测。在10例患者诱发的18次可标测VT中，14次发现有心外膜环路。4例患者用心外膜标测指导心内膜消融，6例指导心外膜消融。心外膜最早激动部位比QRS波群起始提前107±60毫秒。在用于指导心内膜消融的心外膜部位，最早激动发生在QRS波群之前75±55毫秒。7例患者可见心外膜舒张中期电位和/或连续性电活动。心外膜RF应用4.8±2.9秒后，VT不能被诱发。1例患者发生需要引流的心包积血；另外3例出现心包摩擦但无心包积血。术后5至9个月患者仍无症状。心内膜脉冲期间的中断发生在20.2±14秒后（P = 0.004），但VT总是可再诱发，患者预后较差。
心外膜标测不能提高心内膜RF脉冲的有效性。心外膜应用RF能量可安全有效地治疗VT合并恰加斯病患者。
