Idiopathic Left Ventricular Aneurysm: An Unusual Substrate of Ventricular Fibrillation and Ventricular Tachycardia

Idiopathic left ventricular aneurysm (LVA) is a very rare clinical condition. This article describes a patient with idiopathic LVA associated with episodes of ventricular tachycardia and ventricular fibrillation. Clinical and instrumental examinations did not reveal the pathogenesis of the aneurysm. The malignant clinical course suggests that an aggressive antiarrhythmic treatment, including ICD implantation, may be warranted.     

高血压左室肥厚与室性心律失常的研究进展

研究表明高血压左室肥厚的患者室性心律失常,尤其是复杂性室性心律失常发生率增高,目前认为主要与左室重构、心肌缺血、肥厚心肌的电生理改变、神经内分泌因子分泌异常等多种因素有关。在对高血压病的患者进行降压治疗的同时逆转左室肥厚能减少室性心律失常的发生,肾素-血管紧张素系统抑制剂因在此方面作用显著而倍受关注。     

Ablation of Ventricular Arrhythmias in Arrhythmogenic Right Ventricular Dysplasia

VT Ablation in Right Ventricular Dysplasia. Arrhythmogenic right ventricular dysplasia (ARVD) is a genetically determined myocardial disease characterized by fibrofatty replacement of the right ventricular wall. Ventricular tachyarrhythmias can be seen in the early stages of the disease, which is one of the most important causes of sudden death in young healthy individuals. Radiofrequency (RF) catheter ablation is an option for the treatment of medically refractory ventricular arrhythmias and it has shown to successfully abolish recurrent ventricular tachycardias (VT) as well as reduce the frequency in defibrillator therapies. However, variable acute and long‐term success rates have been reported. The current mapping and ablation techniques include activation and entrainment mapping during tolerated VT and substrate ablation using 3‐dimensional electroanatomic mapping systems. This article aims at providing a comprehensive review of RF catheter ablation of ventricular arrhythmias in the context of ARVD. (J Cardiovasc Electrophysiol, Vol. 21, pp. 473‐14, April 2010)     

Prognosis in Patients with Left Ventricular Dysfunction and Ventricular Tachycardia Following Programmed Ventricular Stimulation

We performed programmed ventricular stimulation on 69 patients with left ventricular ejection dysfunction (ejection fraction < 50%) and clinically recognized ventricular tachycardia including 28 patients with sustained ventricular tachycardia and 41 patients with nonsustained ventricular tachycardia. An inducible arrhythmia (> 6 beats ventricular tachycardia) was found in 74% of patients. Patients with clinically sustained arrhythmias were frequently inducible (89%) with a high incidence of inducible monomorphic ventricular tachycardia (82%). Patients with clinically nonsustained ventricular tachycardia had a lower rate of inducibility (63%) including a high incidence of inducible polymorphic ventricular tachycardia (27%). Inducible patients with left ventricular dysfunction and ventricular tachycardia had a low incidence of electrophysiologically demonstrated effective drug therapy (16%). However, if an effective drug was found, the prognosis was good. Empirical drug therapy was associated with a poor prognosis in inducible and noninducible patients. Finally, an unfavorable prognosis was associated with a clinically sustained arrhythmia, a lower ejection fraction, and the presence of a left ventricular aneurysm. An inducible arrhythmia did not predict an unfavorable course. Indeed, patients with noninducible ventricular tachycardia in this group of patients were still at risk for sudden cardiac death.     

左室重量指数与复杂性室性心律失常

目的探讨左室重量指数预测复杂性室性心律失常的临床价值。方法对１１６例轻、中度高血压病人行超声心动图和动态心电图监测。４０例健康人作对照组。结果复杂性室性心律失常发生率在左室重量指数法和左室实测值法左室肥厚组分别为３６．９％，１３．９％，二者差异显著（Ｐ＜０．０１）。结论左室重量指数法左室肥厚对预测复杂室性心律失常有重要价值。     

Diastolic Ventricular Interaction and Ventricular Diastolic Filling

Because the ventricles share a common septum, the filling of one may influence the compliance of the other, a phenomenon known as direct diastolic ventricular interaction (DVI). This interaction is markedly enhanced when the force exerted by the surrounding pericardium is raised (pericardial constraint). In health, in the resting state, we operate near the top of the flat component of a J-shaped pericardial stress–strain relation. Therefore, pericardial constraint (and hence DVI) is only minor. When right ventricular volume/pressure acutely increases, such as during exercise, massive pulmonary embolism, or right ventricular infarction, pericardial constraint increases and significant DVI develops. In this setting, the measured left ventricular intracavitary diastolic pressure markedly overestimates the true left ventricular filling pressure, because the external forces must be subtracted. Although the pericardium can grow during chronic cardiac enlargement, we present evidence that in certain chronic disease processes, including heart failure, DVI may also be important.     

Frequent Premature Ventricular Complexes Originating from the Right Ventricular Outflow Tract Are Associated with Left Ventricular Dysfunction

Background : Recent case series have shown reversal of left ventricular (LV) dysfunction after catheter ablation of frequent premature ventricular complexes (PVCs) originating from the right ventricular outflow tract (RVOT). We conducted a retrospective study to evaluate the prevalence of patients with frequent RVOT PVCs (≥10 per hour) and LV dysfunction. Methods : RVOT PVC was defined as PVC with left bundle branch block morphology and inferior axis on a 12‐lead ECG. We included patients with frequent RVOT PVCs on 24‐hours Holter monitor who had a recent evaluation of LV function. Patients with structural heart disease, including obstructive coronary artery disease, were excluded. Patients were divided into three groups based on the number of PVCs (<1000/24 hour, 1000–10,000/24 hour, ≥10,000/24 hour), and the prevalence of LV dysfunction was evaluated in each group. Results : Our analysis included 108 patients: 24 patients had <1000PVCs/24 hour, 55 patients had 1000–10,000PVCs/24 hour, and 29 patients had ≥10,000PVCs/24 hour. The prevalence of LV dysfunction was 4%, 12%, and 34%, respectively (P = 0.02). With logistic regression analysis, non‐sustained ventricular tachycardia was an independent predictor of LV dysfunction with odds ratio of 3.6 (1.3–10.1). Conclusion : We demonstrated a significant association between frequent RVOT PVCs and LV dysfunction in patients without structural heart disease.     

Ablation of Ventricular Tachycardia Due to a Postinfarct Ventricular Septal Defect:

Outer Loop Tachycardia. Introduction : Ventricular tachycardia (VT) alter postinfarct ventricular septal defect (VSD) repair has not been well characterized.
Methods and Results: A 55-year-old man developed refractory VT after inferior wall infarction and VSD repair. Entrainment demonstrated a broad reentry circuit path (outer loop) between the tricuspid annulus and VSD patch. A series of radiofrequency (RF) lesions transected this path, abolishing VI' and producing conduction block between the inferior and superior aspects of the basal right ventricular septum.
Conclusion: Some VTs have broad reentry loops requiring ablation by a series of RF lesions across the path to create a line of block. This approach is analogous to that for atrial flutter.     

Case Report: Adenosine Induced Ventricular Fibrillation in a Patient with Stable Ventricular Tachycardia

Adenosine is frequently used in emergency departments and intensive care units for the termination of narrow complex tachycardias. Recently its utility in terminating wide complex tachycardias has been reported in the literature. Adenosine is generally felt to be a safe medication even though its proarrhythmic effects in the setting of narrow complex or supraventricular tachycardias have been well documented. Herein, we describe the first case to our knowledge of adenosine inducing ventricular fibrillation in a patient with a stable wide complex tachycardia that was subsequently proven to be ventricular tachycardia at electrophysiologic study.     

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。     

Radiofrequency Catheter Ablation of Ventricular Tachycardia in Right Ventricular Cardiomyopathy:

RF Catheter Ablation of VT. Radiofrequency (RF) catheter ablation of ventricular tachycardia (VT) in patients with a right ventricular (RV) cardiomyopathy has only rarely been successful. This report demonstrates reentrant VT in the setting of RV cardiomyopathy in which the tricuspid valve annulus acted as one of the harriers of an isthmus of slow conduction, identified by the presence of entrainment with concealed fusion. The RF pulse was further targeted by analysis of the relationship between the postpacing interval with the tachycardia cycle length, and of the local activation time with the stimulation time. Long-term clinical follow-up has documented no recurrent VT.     

Surgery for Ventricular Tachycardia

The treatment of drug-refractory chronic ventricular tachycardia (VT) has undergone a revolution over the last 50 years. We now have automatic implantable cardioverter defibrillator therapy with pace-terminating capabilities, and catheter ablation of VT has refined mapping and improved methods of lesion generation. Between 1980 and 1993, Houston Methodist Hospital became a leader in the diagnosis and surgical ablation of VT and other arrhythmias. This is a brief account of that period and some of the experiences and lessons that have led to significant advances used today.     

左室质量比值和左室质量指数对高血压左室重构识别的比较

目的 比较左室质量比值(％PLM)和左室质量指数(LVMI)对左室重构识别的价值。方法 对187例高血压患者进行超声心动图检查，测量其心脏结构和功能。结果 左室质量适宜(aLVM)、过高(iLVM)和不足的分布分别占48.1％、48．7％和3．2％。％PLM与左室收缩功能的相关系数高于LVMI与左室收缩功能的相关系数。左室肥厚(LVH)时，iLVM的左室射血分数、左室短轴缩短率低于aLVM(P＜0．01)。但在aLVM或iLVM中．LVH和无LVH两组间的左室收缩功能无明显差异(P＞0．05)。结论 ％PLM识别左室重构比LVMI更符合生理情况，更能精确地对高血压患者进行危险分层。     

右心室心肌病室性心动过速诊治的新进展

致心律失常右心室心肌病室性心动过速是青壮年猝死的常见疾病,传统的治疗方法是在药物基础上的植入埋藏式自动复律仪治疗;由于我国的经济欠发达状况,普通患者难以负担植入埋藏式自动复律仪,以及导管消融新设备的开发和消融技术的进步,导管消融技术已经是部分患者的一线治疗。现就致心律失常右心室心肌病诊治新进展进行综述。     

单纯收缩期高血压患者左心室肥厚与室性心律失常的关系

目的探讨单纯收缩期高血压的病人左室肥厚与心律失常的关系。方法采用２４ｈ动态心电图和彩色多普勒超声观察患者左室肥厚及心律失常的发生情况，并观察单纯收缩期高血压与舒张期高血压左室结构改变。结果左室肥厚组室性心律失常发生率明显高于非左室肥厚组（Ｐ＞０．０１），单纯收缩期高血压组左室肥厚高于舒张期高血压组。结论左室肥厚可使室性心律失常发生率增加，收缩压增高较舒张压增高更易导致左室肥厚。     

Ventricular Tachycardia

Congenitally Corrected Transposition and VT. Ventricular tachycardia (VT) is an uncommon finding in patients with congenitally corrected transposition of the great arteries (CCTGA). Cardiac death in patients with CCTGA has been attributed to complete heart block, systemic ventricular dysfunction, or severe AV valve regurgitation with heart failure. We descrihe the case of a patient who presented with palpitations and near-syncope that was associated with clinical episodes of VT. Programmed ventricular stimulation revealed easily inducible sustained VT that immediately degenerated to ventricular fibrillation and subsequently required therapy with an implantable cardioverter defibrillator.     

先天性心室憩室的研究进展

先天性心室憩室是一种少见的心脏畸形。大部分为左室憩室,右室憩室较少,也可发生在两个心室。心室憩室常伴有其他的异常。先天性心室憩室多见于婴幼儿和儿童,但亦可见于各年龄组人群。现对先天性心室憩室的研究进展做一综述。     

普通心室电极导线经心脏静脉行左室起搏的实验研究

探讨普通电极导线经心脏静脉行左室起搏的可行性和牢固性。选用 10个新鲜猪心 ,用 3种形态的普通电极导线 (4翼、2翼和无翼 )分别插入右室心尖部、心大静脉、左室后静脉和心中静脉 ,测电极导线在心脏静脉的深度、阻抗和拔出力量。右室心尖部作为对照组 ,仅测阻抗和拔出力量。结果 :三种普通电极导线都能成功地送入心脏静脉。三种电极导线在同一心脏静脉进入深度之间无差异 (P >0 .0 5 ) ,在不同心脏静脉进入深度之间有显著差异(P <0 .0 5 )。电极导线在所有心脏静脉的拔出力量都大于右室心尖部 (P <0 .0 5 )。三种电极导线在同一心脏静脉拔出力量之间无差异 (P >0 .0 5 ) ;4翼、2翼电极导线在不同心脏静脉拔出力量之间也无差异 (P >0 .0 5 ) ,而无翼电极导线有差异 (P =0 .0 4)。电极导线进入心脏静脉深度与拔出力量之间存在正相关 (r=0 .48,P <0 .0 0 1)。电极导线在心脏静脉的阻抗为 6 35± 32 3Ω。结论 :三种普通心室电极导线都可以送入心脏静脉远端 ,都较牢固     

小儿右室流出道起搏

对于一些需要安装永久起搏器的患者来讲,由于易于固定,起搏阈值低等优点,右心室起搏常将起搏电极置于心尖部,但长期随访发现,心尖部起搏可改变心室激动顺序,导致心室收缩不同步,造成二尖瓣反流、心房颤动和心功能不全。研究发现右室流出道起搏对左室功能的保护较右室心尖部起搏有利,由于右室流出道起搏靠近His束,电活动近似正常生理状态,可使左右心室电-机械活动更协调,从而抑制心室重构并保护心功能,因此,右室流出道起搏是替代右室心尖部起搏的较好选择。