室性早搏与心室颤动的导管消融治疗的病例选择

室早、室速/室颤常有共同的起源和病理基质,是相互联系与动态演变的统一体。消融与否,不取决于其发病形式,而取决于其病因、症状和预后的严重性。消融方法无固定的模式,应根据病人的具体情况灵活多变,以追求简单、安全、高效和对正常组织损伤最小为原则。目前消融的有效性主要取决于室早/室颤的基础疾病和起源部位。特发与病变局限的室早/室颤,消融效果好,病变广泛或进行性发展的室早/室颤,消融效果有待提高。起源靠近心内膜,尤其是起源于希氏-蒲肯野系统的室早/室颤,容易消融;起源靠近心外膜或心脏的重要结构,如左主干开口,希氏束旁者,消融的难度或风险大。     

20极标测电极指导左室乳头肌起源室性期前收缩射频消融的初步应用

目的：探讨应用20极标测电极（DD电极）指导左室乳头肌起源室性期前收缩（室早）射频消融的可行性及有效性。方法：回顾性收集阜外医院2019年5月至2019年12月间11例左室乳头肌起源的频发室早患者,按照标测方法分为DD标测组（6例）和传统4极消融导管逐点（PBP）标测组（5例）,确定理想的室早起源靶点后进行放电消融。收集两组患者临床资料、心电图资料以及术中参数,观察两种标测方法随访期的消融成功率。结果：本研究共纳入11例左室乳头肌频发室早患者,年龄41±18岁,男性5例(45.5%),平均24h室早负荷18.6%±8.2%。与PBP标测组相比,DD标测组总手术时间（95.8±7.4 vs. 141.2±12.3min）、消融时间（6.1±3.0 vs. 15.8±4.7min）、射线曝光时间（14.2±1.5 vs. 24.4±5.4min）明显缩短,消融点数（6.8±1.9 vs. 14.8±3.6个）明显减少,室早时靶点局部V波领先体表室早QRS间期(37.8±7.2 vs. 25.4±2.8ms)明显提前。术中及术后随访期间,DD标测组未发生标测及消融相关并发症,而PBP标测组术中出现1例心包积液。随访15.1±1.3月,DD标测组所有患者经射频消融后均无室早再发,成功率为100%,而PBP标测组3例消融成功,成功率为60%。结论：DD电极可易化左室乳头肌室早射频消融,缩短手术时间及减少X线曝光,随访期消融成功率均较高,具有良好的可行性及有效性。     

Idiopathic Ventricular Arrhythmias Originating from the Papillary Muscles in the Left Ventricle: Prevalence, Electrocardiographic and Electrophysiological Characteristics, and Results of the Radiofrequency Catheter Ablation

Idiopathic VAs Originating from the LV Papillary Muscles.   Introduction: Idiopathic ventricular arrhythmias (VAs) can originate from the left ventricular (LV) papillary muscles (PAMs). This study investigated the prevalence, electrocardiographic and electrophysiological characteristics, and results of catheter ablation of these VAs, and compared them with other LV VAs.
Methods and Results: We studied 71 patients with VAs originating from the LV anterolateral and posteroseptal regions among 159 patients undergoing successful catheter ablation of idiopathic LV VAs. PAM VAs were uncommon, rare in a sustained form, and more common from the posterior papillary muscle (PPM) than anterior papillary muscle (APM). A younger age was a good predictor for differentiating left posterior fascicular VAs from PPM VAs. There were several electrocardiographic features that accurately differentiated PAM and LV fascicular VAs from mitral annular VAs. However, an R/S ratio ≤1 in lead V6 in the LV anterolateral region and a QRS duration >160 ms in the LV posteroseptal region were the only reliable predictors for differentiating PAM VAs from LV fascicular VAs. A sharp ventricular prepotential was recorded at the successful ablation site during 42% of the PAM VAs. Radiofrequency current with an irrigated or conventional 8-mm tip ablation catheter was required to achieve a lasting ablation of the PAM VA origins whereas that with a nonirrigated 4-mm tip ablation catheter produced excellent results in LV fascicular and mitral annular VAs.
Conclusions: There are differences in the electrocardiographic and electrophysiological features among VAs originating from these regions that are helpful for their diagnosis and effective catheter ablation. (J Cardiovasc Electrophysiol, Vol. 21, pp. 62–69, January 2010)     

Idiopathic Ventricular Tachycardia and Fibrillation

Idiopathic Ventricular Tachycardia and Fibrillation. Important data have recently been added to our understanding of sustained ventricular tachyarrhythmias occurring in the absence of demonstrable heart disease. Idiopathic ventricular tachycardia (VT) is usually of monomorphic configuration and can be classified according to its site of origin as either right monomorphic (70% of all idiopathic VTs) or left monomorphic VT. Several physiopathological types of monomorphic VT can be presently individualized, according to their mode of presentation, their relationship to adrenergic stress, or their response to various drugs. The long-term prognosis is usually good. Idiopathic polymorphic VT is a much rarer type of arrhythmia with a less favorable prognosis. Idiopathic ventricular fibrillation may represent an underestimated cause of sudden cardiac death in ostensibly healthy patients. A high incidence of inducibility of sustained polymorphic VT with programmed ventricular stimulation has been found by our group, but not by others. Long-term prognosis on Class IA antiarrhythmic medications that are highly effective at electrophysiologic study appears excellentJfy Cardiovasc Electrophysiol, Vol. 4, pp. 356–368, June 1993 ).     

乳头肌起源的特发性室性心动过速的研究和治疗进展

近年来的研究发现,除心室流出道、动脉瓣和二尖瓣环外,心室乳头肌也参与了特发性室性心动过速的发生和维持,起源于乳头肌的特发性室性心动过速有其电生理学和心电图表现的特点,使用各种手段对乳头肌实施消融是这类心律失常有效的治疗手段,但其治疗特点和难点与一般心律失常有所不同。现对这种类型心律失常的研究和治疗的现状做一综述。     

Clinical Results with Catheter Ablation: AV Junction, Atrial Fibrillation and Ventricular Tachycardia

With the limitations of pharmacologic and device therapies for atrial fibrillation and ventricular tachycardia, catheter ablation is assuming a larger role in the management of patients with these common arrhythmias. Multiple case series and clinical trials have helped to define the evolving role of these techniques for ablation of the atrioventricular node, atrial fibrillation, and ischemic ventricular tachycardia. Based on very low complication rates, excellent efficacy and proven outcomes with radiofrequency ablation of the atrioventricular node, this approach with permanent pacing should play a larger role in the treatment of symptomatic patients with permanent atrial fibrillation. While linear ablation of atrial fibrillation has limited clinical utility for the treatment of this common arrhythmia, the results of multiple case series of focal atrial fibrillation ablation indicate the potential for an expanding role of this curative technique. Catheter ablation techniques for ventricular tachycardia in the setting of coronary artery disease have a role as supplemental therapy to the implantable cardioverter defibrillator in patients with recurrent pharmacologically refractory ventricular arrhythmias requiring frequent device interventions.     

Papillary muscle ventricular ectopy ablation in a malignant mitral valve prolapse

Patients with mitral valve prolapse (MVP) have a heterogeneous clinical spectrum, ranging from benign to severe clinical presentations such as sudden cardiac death (SCD). Some of the markers of “arrhythmic MVP” include inverted/biphasic T-waves, QT prolongation, and polymorphic premature ventricular contractions (PVCs) originating from the left ventricular outflow tract and papillary muscles (PMs). The genesis of arrhythmias in MVP recognizes the combination of the substrate (fibrosis) and the trigger (mechanical stretch). Therefore, ablation of ventricular arrhythmias originating from PMs in a patient with MVP can be considered an adjunctive strategy to lower the arrhythmic burden and reduce the risk of ICD shocks.     

Idiopathic Focal Ventricular Arrhythmias Originating from the Anterior Papillary Muscle in the Left Ventricle

Introduction: Focal ventricular arrhythmias (VAs) have been reported to arise from the posterior papillary muscle in the left ventricle (LV). We report a distinct subgroup of idiopathic VAs arising from the anterior papillary muscle (APM) in the LV.
Methods and Results: We studied 432 consecutive patients undergoing catheter ablation for VAs based on a focal mechanism. Six patients were identified with ventricular tachycardia (VT, n = 1) or premature ventricular contractions (PVCs, n = 5) with the earliest site of ventricular activation localized to the base (n = 3) or middle portion (n = 3) of the LV APM. No Purkinje potentials were recorded at the ablation site during sinus rhythm or the VAs. All patients had a normal baseline electrocardiogram and normal LV systolic function. The VAs exhibited a right bundle branch block (RBBB) and right inferior axis (RIA) QRS morphology in all patients. Oral verapamil and/or Na⁺ channel blockers failed to control the VAs in 4 patients. VT was not inducible by programmed electrical stimulation in any of the patients. In 4 patients, radiofrequency current with an irrigated or conventional 8-mm-tip ablation catheter was required to achieve a lasting success. Two patients had recurrent PVCs after a conventional radiofrequency ablation with a 4-mm-tip ablation catheter had initially suppressed the arrhythmia.
Conclusions: VAs may arise from the base or middle portion of the APM and are characterized by an RBBB and RIA QRS morphology and focal mechanism. Catheter ablation of APM VAs is typically challenging, and creation of a deep radiofrequency lesion may be necessary for long-term success.     

Mapping and Ablating Ventricular Premature Contractions That Trigger Ventricular Fibrillation: Trigger Elimination and Substrate Modification

Ventricular fibrillation (VF) is a malignant arrhythmia, usually initiated by a ventricular premature contraction (VPC) during the vulnerable period of cardiac repolarization. Ablation therapy for VF has been described and increasingly reported. Targets for VF triggers are VPC preceded Purkinje potentials or the right ventricular outflow tract (RVOT) in structurally normal hearts, and VPC triggers preceded by Purkinje potentials in ischemic cardiomyopathy. The most important issue before the ablation session is the recording of the 12‐lead electrocardiogram (ECG) of the triggering event, which can prove invaluable in regionalizing the origin of the triggering VPC for more detailed mapping. In cases where the VPC is not spontaneous or inducible, ablation may be performed by pacemapping. During the session, mapping should be focused on the earliest activation and determining the earliest potential is the key to a successful ablation. However, a modification of the Purkinje network might be applied when the earliest site cannot be determined or is located close to the His‐bundle. Furthermore, the electrical isolation of the pulmonary artery (PA) can suppress RVOT type polymorphic ventricular tachycardia in some patients with rapid triggers from the PA. Suppression of VF can be achieved by not only the elimination of triggering VPCs, but also by substrate modification of possible reentry circuits in the Purkinje network, or between the PA and RVOT. Further studies are needed to evaluate the precise mechanisms of this arrhythmia.     

Long‐Term Results of Transcatheter Atrial Fibrillation Ablation in Patients with Impaired Left Ventricular Systolic Function

AF Ablation and Impaired Left Ventricular Function. Introduction: Long‐term outcome of AF ablation in patients with impaired LVEF is unknown. The aim of this study is to evaluate sinus rhythm (SR) maintenance, clinical status, and echocardiographic parameters over a long‐term period following atrial fibrillation (AF) transcatheter ablation in patients with left ventricular ejection fraction (LVEF) <50%. Methods and Results: A total of 196 patients (87.2% males, age 60.5 ± 10.2 years) with LVEF <50% underwent radiofrequency transcatheter ablation for paroxysmal (22.4%) or persistent (77.6%) AF. Patients were followed up for 46.2 (16.4–63.5) months regarding AF recurrences, functional class, and echocardiographic parameters. All patients underwent pulmonary vein isolation, while 167 (85.2%) required additional atrial lesions. Eleven (5.6%) patients suffered procedural complications. During follow‐up, 58 (29.6%) patients required repeated ablations. At the follow‐up end, 15 (7.7%) patients died, while 74 (37.8%) documented at least one episode of AF, atrial flutter, or atrial ectopic tachycardia. Eighty‐three (47.2%) patients maintained antiarrhythmic drugs. During follow‐up, NYHA class improved by at least one class more frequently among patients maintaining SR compared to those experiencing relapses (70.6% vs 47.9%, P = 0.003). LVEF showed a broader relative increase in patients maintaining SR (32.7% vs 21.4%; P = 0.047) and mitral regurgitation grading significantly decreased (P <0.001) only within these patients. At multivariable analysis SR maintenance emerged as an independent predictor (odds ratio 4.26, 95% CI 1.69–10.74, P = 0.002) of long‐term clinical improvement (reduction in NYHA class ≥1 and relative increase in LVEF ≥10%). Conclusions: Although not substantially worse than in patients with preserved LVEF, AF ablation in patients with impaired LVEF is affected by high long‐term recurrence rate. Among these patients SR maintenance is associated with greater clinical improvement. (J Cardiovasc Electrophysiol, Vol. 24, pp. 24‐32, January 2013)