Surgery for ventricular tachycardia in patients undergoing surgical ventricular restoration: The Karolinska approach

Surgical Endoepicardial Linear Ablation for Ventricular Tachycardia With Postinfarction Left Ventricular Aneurysm

This retrospective study evaluated the feasibility of surgical endoepicardial linear ablation for ventricular tachycardia in patients with postinfarction left ventricular aneurysm. Sixty-four patients with multivessel coronary artery disease and left ventricular aneurysm but no mural thrombosis of the aneurysm or valve disease were treated at our institution from March 2012 through July 2015. All underwent off-pump coronary artery bypass grafting and left ventricular aneurysm repair by linear plication. Twenty-three patients (35.9%) had ventricular tachycardia and underwent surgical endoepicardial linear ablation on the beating heart guided by epicardial substrate mapping with the Carto 3 system. The remaining 41 patients (64.1%) composed the no-ablation group. The effectiveness of surgical linear ablation in the ablation group was evaluated. Safety and clinical outcomes were evaluated and compared between the groups. The ventricular tachycardia recurrence rate in the ablation group was 17.4% in the immediate postoperative period and 23.8% at last follow-up (39 ± 21 mo). Early (<30-d) mortality rates were 8.7% in the ablation group and 4.9% in the no-ablation group (P=0.41); the respective late mortality rates were 19.1% and 18% (P=0.70). Multivariate Cox regression analysis indicated that preoperatively poor left ventricular function was an independent risk factor for early and late death in both groups. The groups were similar in terms of the need for postoperative mechanical circulatory support, intensive care unit stay, and cumulative survival rate. We conclude that, for carefully selected candidates, surgical endoepicardial linear ablation combined with off-pump coronary artery bypass grafting and left ventricular aneurysm linear plication is a feasible treatment for ventricular tachycardia with postinfarction left ventricular aneurysm.

Open chest epicardial and transapical endocardial substrate ablation for ventricular tachycardia with left ventricular aneurysm in a porcine model

BACKGROUND

Endo-epicardial radiofrequency catheter ablation (RFCA) of ventricular tachycardia (VT) as a first-line strategy has been shown to improve outcomes. This study sought to evaluate the feasibility and validity of open-chest epicardial and transapical endocardial substrate ablation for VT with left ventricular aneurysm (LVA) applying to routine cardiac surgery.

METHODS

Porcine models of LVA with VT were developed and were divided into a study group (RFCA from the epicardium via direct-view and endocardium via transapical access) and a control group (endocardial RFCA via retrograde transaortic access). Substrate-based mapping and ablation targeting abnormal potentials were performed under thoracotomy. Outcomes, including procedural success and acute freedom from VT, were analysed.

RESULTS

Twenty-four of 35 (68.57%) acute myocardial infarction (AMI) pigs developed LVA with VT in a 6-week survival period and were randomly divided into a study group (n=12) and a control group (n=12). All animals in the study group successfully underwent endocardial mapping and ablation by transapical access. The scar size of the endocardium and the left ventricular chamber volume were similar in the two groups. Acute freedom from VT in the study group was remarkably superior to that in the control group (88.33% vs. 58.33%, p=0.04).

CONCLUSIONS

Combined, direct epicardial and transapical endocardial substrate mapping and ablation appeared to be feasible and effective for treating VT with LVA under thoracotomy.

Recommendations for the use of electrophysiological study: Update 2018

The field of cardiac electrophysiology has greatly developed during the past decades. Consequently, the use of electrophysiological studies (EPSs) in clinical practice has also significantly augmented, with a progressively increasing number of certified electrophysiology centers and specialists. Since Zipes et al published the Guidelines for Clinical Intracardiac Electrophysiology and Catheter Ablation Procedures in 1995, no official document summarizing current EPS indications has been published. The current paper focuses on summarizing all relevant data of the role of EPS in patients with different types of cardiac pathologies and provides up-to-date recommendations on this topic. For this purpose, the PubMed database was screened for relevant articles in English up to December 2018 and ESC and ACC/AHA Clinical Practice Guidelines, and EHRA/HRS/APHRS position statements related to the current topic were analyzed. Current recommendations for the use of EPS in clinical practice are discussed and presented in 17 distinct cardiac pathologies. A short rationale, evidence, and indications are provided for each cardiac disease/group of diseases. In conclusion, because of its capability to establish a diagnosis in patients with a variety of cardiac pathologies, the EPS remains a useful tool in the evaluation of patients with cardiac arrhythmias and conduction disorders and is capable of establishing indications for cardiac device implantation and guide catheter ablation procedures.

Surgical linear ablation for ventricular tachycardia with postinfarction ventricular aneurysm

BACKGROUND

Left ventricular aneurysm (LVA) might be an arrhythmogenic substrate. Endocardiectomy and cryoablation for ventricular tachycardia (VT) with LVA can cause extensive myocardial damage. We aimed to evaluate the feasibility of surgical radial linear ablation for VT with LVA guided by electrophysiological mapping.

MATERIALS AND METHODS

Porcine models of VT with LVA were developed. Endocardial and epicardial substrate mapping during sinus rhythm were performed under thoracotomy. Surgical radial linear ablation was achieved by a bipolar radiofrequency ablation device. Outcomes, including procedural success and acute freedom of VT, were analyzed.

RESULTS

Fifteen of 20 pigs developed LVA in a 6-wk survival period. A total of 28 sustained monomorphic VTs were initiated in 13 of 15 pigs (86.67%). The number of potential points captured from the endocardium and epicardium were 319 ± 45 and 358 ± 52 per animal, respectively. The ablative targets containing abnormal potentials were located largely on the border zone of LVA. Eight linear lesions from core to border zone of LVA were achieved per animal in a radial and even manner continuously, and ablation was repeated three times to transect border zone. The acute freedom of VT was 84.62%, P < 0.05.

CONCLUSIONS

Surgical linear endo-epicardial ablation seemed to be feasible in a porcine model with VT and LVA.

Surgical cryoablation of drug resistant ventricular tachycardia and aneurysmectomy of postinfarction left ventricular aneurysm

Heart failure is usually associated with left ventricle remodelling, wall thickening, and worsening of the systolic function. Ventricular tachycardia is a common and a negative prognostic factor in patients with endocardial scarring following myocardial infarction and aneurysm formation. The authors present a case of a 51-year-old man with ischemic heart disease, who suffered myocardial infarction four years ago. The patient was admitted to the hospital with sustained ventricular tachycardia despite maximal pharmacotherapy and also underwent unsuccessful percutaneous radiofrequency ablation in the right ventricle. Transthoracic echocardiography revealed left ventricle dysfunction with ejection fraction of 25%, aneurysm of the apex of the left ventricle with thrombus formation inside the aneurysm. Surgical therapy consisted of the cryoablation applied at the transitional zone of the scar and viable tissue and the resection of the aneurysm. The patient remained free of any ventricular tachycardia four months later.

Surgery for ventricular tachycardia in patients undergoing surgical ventricular restoration

This article is a presentation of direct surgery for ventricular tachycardia in patients undergoing surgical ventricular restoration. The procedure includes a non-electrophysiologically guided subtotal endocardiectomy and cryoablation in addition to endoventricular patch plasty of the left ventricle. Coronary artery bypass surgery and mitral valve repair are performed concomitantly as needed. In our experience, this procedure yielded a 90% success rate in terms of freedom from spontaneous ventricular tachycardia, with an early mortality rate of 3.8%. Perioperative considerations and a short overview of the literature are presented.