Catheter ablation of ventricular tachycardia after left ventricular reconstructive surgery for ischemic cardiomyopathy

Understanding the scope of intracardiac echocardiography in catheter ablation of ventricular arrhythmia

Over the last few decades, catheter ablation has emerged as the first-line treatment for ventricular arrhythmias. However, detailed knowledge of cardiac anatomy during the surgery remains the prerequisite for successful ablation. Intracardiac echocardiography (ICE) is a unique imaging technique, which provides real-time visualization of cardiac structures, and is superior to other imaging modalities in terms of precise display of cardiac tissue characteristics as well as the orientation of anatomical landmarks. This article aimed to introduce the various advantages and limitations of ICE in the ablation of ventricular arrhythmias.

Hybrid epicardial ventricular tachycardia ablation with lateral thoracotomy in a patient with a history of left ventricular reconstruction surgery

Although a hybrid procedure involving surgical access may be feasible for epicardial catheter ablation in individuals with prior cardiac surgery, surgical approaches in thoracotomy are important in patients with advanced adhesions. We performed an epicardial ventricular tachycardia (VT) ablation in a patient with dilated phase hypertrophic cardiomyopathy after left ventricular reconstruction. We gained surgical epicardial access via lateral thoracotomy based on the anticipated VT circuit in the apical anteroseptal area, which was estimated using prior endocardial mapping. The remaining epicardial myocardium around the surgical incision was involved in the central isthmus, and the VT was eliminated by radiofrequency catheter ablation. <Learning objective: Postoperative adhesions hampered the percutaneous catheter approach by subxiphoid puncture in patients with a history of cardiac surgery. Combining anatomical consideration by computed tomography imaging and information from endocardial ablation helped to perform a minimally invasive surgical epicardial approach. The remaining epicardial myocardium around the surgical incision was assumed to be involved in the reentry circuit of the ventricular tachycardia in a patient diagnosed with dilated-phase hypertrophic cardiomyopathy with a previous history of left ventricular reconstruction.>.

Catheter ablation of ventricular tachycardia in patients with prior cardiac surgery: An analysis from the International VT Ablation Center Collaborative Group

INTRODUCTION

Patients with prior cardiac surgery may represent a subgroup of patients with ventricular tachycardia (VT) that may be more difficult to control with catheter ablation.

METHODS

We evaluated 1901 patients with ischemic and nonischemic cardiomyopathy who underwent VT ablation at 12 centers. Clinical characteristics and VT radiofrequency ablation procedural outcomes were assessed and compared between those with and without prior cardiac surgery. Kaplan-Meier analysis was used to estimate freedom from recurrent VT and survival.

RESULTS

There were 578 subjects (30.4%) with prior cardiac surgery identified in the cohort. Those with prior cardiac surgery were older (66.4 ± 11.0 years vs. 60.5 ± 13.9 years, p < .01), with lower left ventricular ejection fraction (30.2 ± 11.5% vs. 34.8 ± 13.6%, p < .01) and more ischemic heart disease (82.5% vs. 39.3%, p < .01) but less likely to undergo epicardial mapping or ablation (9.0% vs. 38.1%, p<.01) compared to those without prior surgery. When epicardial mapping was performed, a significantly greater proportion required surgical intervention for access (19/52 [36.5%] vs. 14/504 [2.8%]; p < .01). Procedural complications, including epicardial access-related complications, were lower (5.7% vs. 7.0%, p < .01) in patients with versus without prior cardiac surgery. VT-free survival (75.1% vs. 74.1%, p = .805) and survival (86.5% vs. 87.9%, p = .397) were not different between those with and without prior heart surgery, regardless of etiology of cardiomyopathy. VT recurrence was associated with increased mortality in patients with and without prior cardiac surgery.

CONCLUSION

Despite different clinical characteristics and fewer epicardial procedures, the safety and efficacy of VT ablation in patients with prior cardiac surgery is similar to others in this cohort. The incremental yield of epicardial mapping in predominant ischemic cardiomyopathy population prior heart surgery may be low but appears safe in experienced centers.

Catheter ablation of ventricular tachycardia in a patient with a left endoventricular patch: a case report

Surgical resection of a left ventricular aneurysm in the setting of ventricular tachycardia (VT) was first described by Couch in 1959. The technique was further developed by Dor et al. with performance of endocardiectomy and complete myocardial revascularization. Despite an attempt to remove the arrhythmogenic substrate, however, recurrences of VT remain an issue. Furthermore, the surgical technique used entails limited access to the potential area of interest with regard to a percutaneous catheter ablation procedure. We present a case report of a 65-year-old man who was referred for catheter ablation due to recurrent episodes of VT. He had undergone a coronary artery bypass surgery 8 years previously. During surgery, resection of an apical thrombus and reconstruction of an apical aneurysm with a Fontan stitch and an endoventricular patch were performed. The mapping and ablation procedure was aided by intracardiac echocardiography. During mapping, the ablation catheter was noticed to enter the apical pouch from the inferoseptal border of the endoventricular patch. During the ablation procedure, one of the VTs was successfully ablated in the inferior aspect of the apical pouch. This report confirms that the arrhythmogenic substrate underneath an endoventricular patch may be accessed in some instances and that these complex catheter ablation procedures may benefit from the use of intracardiac echocardiography.

Improvements in Left Ventricular Diastolic Mechanics After Parachute Device Implantation in Patients With Ischemia Heart Failure: A Cardiac Computerized Tomographic Study

BACKGROUND

Percutaneous ventricular restoration therapy with the use of a left ventricle (LV)-partitioning Parachute device has emerged as a clinical treatment option for LV apical aneurysm after extensive anterior myocardial infarction (AMI). We assessed changes of diastolic mechanics and functional improvements following LV Parachute device implantation by means of cardiac computerized tomography (CCT).

METHODS AND RESULTS

CCT data were obtained from 28 patients before and after LV Parachute device implantation. Diastolic functional indices were determined by means of quantitative CCT assessment: 1) transmitral velocities in early (E) and late (A) diastole and ratio (E/A); 2) early diastolic mitral septal tissue velocity (Ea) and E/Ea; and 3) vortex formation time (VFT). Functional improvements were assessed with the use of New York Heart Association (NYHA) functional classification. Among the study patients, there were no significant differences in all transmitral velocities and E/A, though there was significantly increased Ea, reduced E/Ea, and greater VFT 6 months after LV Parachute device implantation. Finally, the improvement of diastolic functional indices after Parachute treatment correlated with observed clinical functional alterations (Δ E/Ea and Δ NYHA functional class:, r = 0.563; P = .002; Δ VFT and Δ NYHA functional class: r = -0.507; P = .006).

CONCLUSIONS

LV Parachute device implantation therapy in heart failure caused by AMI and LV apical aneurysm formation showed improvements in several diastolic functional mechanics according to CCT-based measures.

Catheter ablation of frequent ventricular tachycardia after interventional left ventricular restoration with the Revivent-Transcatheter(™)-system

The Revivent-TC(™)-system is able to restore LV volumes in patients with severe ischemic cardiomyopathy. We are presenting a case report of successful implantation of the Revivent-TC(™)-system, but postprocedural development of sustained VT. This case report is presenting one way to successfully treat patients with postprocedural frequent VT.

Ventricular arrhythmias and sudden cardiac death

Management strategies for ventricular arrhythmias are guided by the risk of sudden death and severity of symptoms. Patients with a substantial risk of sudden death usually need an implantable cardioverter defibrillator (ICD). Although ICDs effectively end most episodes of ventricular tachycardia or ventricular fibrillation and decrease mortality in specific populations of patients, they have inherent risks and limitations. Generally, antiarrhythmic drugs do not provide sufficient protection from sudden death, but do have a role in reducing arrhythmias that cause symptoms. Catheter ablation is likewise important for reducing the frequency of spontaneous arrhythmias and is curative for some patients, usually those with idiopathic arrhythmias and no heart disease. Arrhythmia surgery is now infrequent, offered by only a few specialised centres for refractory arrhythmias. Advances in understanding of genetic arrhythmia syndromes and in technology for mapping and ablation of ventricular arrhythmias, and enhanced algorithms in implantable devices for rhythm management, have contributed to improved outcomes.