Epicardial and subselective transcoronary chemical ablation of incessant ventricular tachycardia

Ethanol Ablation for Ventricular Arrhythmias: A Systematic Review and Meta-analysis

INTRODUCTION

Ethanol ablation (EA) is as an alternative option for subjects with ventricular arrhythmias (VAs) refractory to conventional medical and ablative treatment. However, data on efficacy and safety of EA remain sparse.

METHODS

A systematic literature search was conducted. The primary outcomes were 1) freedom from the targeted VA and 2) freedom from any VAs post EA. Additional safety outcomes were also analysed.

RESULTS

Ten studies were selected accounting for a population of 174 patients (62.3±12.5 years, 94% male) undergoing 185 procedures. The overall acute success rate of EA was 72.4% (CI_95% 65.6-78.4). After a mean follow-up of 11.3±5.5 months, the incidence of relapse of the targeted VA was 24.4% (CI_95% 17.1-32.8), while any VAs post EA occurred in 41.3% (CI_95% 33.7-49.1). The overall incidence of procedural complications was 14.1% (CI_95% 9.8-19.8), with pericardial complications and complete atrioventricular block being the most frequent. An anterograde transarterial approach was associated with a higher rate of VA recurrences and complications compared to a retrograde transvenous route; however, differences in the baseline population characteristics and in the targeted ventricular areas should be accounted.

CONCLUSION

EA is a valuable therapeutic option for VAs refractory to conventional treatment and can result in 1-year freedom from VA recurrence in 60 to 75% of the patients. However, anatomical or technical challenges preclude acute success in almost 30% of the candidates and the rate of complication is not insignificant, highlighting the importance of well-informed patient selection. The certainty of the evidence is low, and further research is necessary. This article is protected by copyright. All rights reserved.

Alternative Approaches for Ablation of Resistant Ventricular Tachycardia

Ventricular tachycardia (VT) ablation is usually performed with an ablation catheter that delivers unipolar radiofrequency (RF) energy to eliminate the re-entry circuit responsible for VT. However, there are some instances when unipolar RF ablation fails, notably in VTs with a deep intramural origin, or cases in which epicardial access is not attainable due to prior cardiac surgery. To overcome these limitations, several alternative approaches have been used in clinical practice, including alcohol ablation or coil embolization, simultaneous unipolar or bipolar RF ablation, surgical ablation, or noninvasive ablation with stereotactic radiosurgery. This review article describes some of these alternative techniques.

Epicardial ablation as a bailout in electrical storm?

Electrical storm (ES) is one of the most challenging clinical scenarios facing electrophysiologists, and in certain settings emergency ablation should be performed. The majority of ES occurs in patients with structural heart disease, predominantly coronary heart disease and nonischemic heart disease like right ventricular arrhythmogenic dysplasia and previous myocarditis as well as other cardiomyopathies. Implantable cardioverter-defibrillators (ICDs) are the first-line therapy in patients with ventricular tachycardia (VT) and structural heart disease. Recurrent VT episodes or ES are major problems in patients who receive an ICD after a spontaneous sustained VT. In addition, in patients with an ICD implanted for primary prevention of sudden cardiac death, 20 % will experience at least one VT episode within 3-5 years after ICD implantation. Catheter ablation has a high success rate in the acute setting in eliminating clinical VT. However, several factors make enodocardial catheter ablation of VT more difficult especially in advanced ischemic heart disease with heart failure and aneurysm. Frequently in nonischemic cardiomyopathies (NICM) there tends to be an epicardial and intramyocardial substrate where the critical VT zone can occasionally be epicardial or intramural in location. In some patients, an epicardial approach should be warranted first together with an endocardial approach or after failure of enodocardial ablation. Currently, the success rates of endocardial ablation in the acute setting are acceptable, but in the long term they are still not well defined. The purpose of this article is to highlight the importance of epicardial ablation as an alternative approach in controlling ES and to confirm the need for highly qualified centers to manage such challenging cases.

Incessant ventricular tachycardia acutely controlled with intracoronary injection of radiographic contrast media

Management of patients with incessant monomorphic ventricular tachycardia is challenging. We report on 2 patients who had incessant ventricular tachycardia despite emergency treatment with antiarrhythmic drugs and repeated electrical cardioversions. In both cases, the arrhythmia was acutely terminated with intracoronary administration of radiographic contrast media, allowing hemodynamic stabilization. No tachycardia recurrences occurred.

Nonsurgical transthoracic epicardial radiofrequency ablation: an alternative in incessant ventricular tachycardia

OBJECTIVES

The purpose of this study was to analyze the feasibility, efficacy, and safety of epicardial radiofrequency (RF) ablation in patients with incessant ventricular tachycardia (VT).

BACKGROUND

Management of patients with incessant VT is a difficult clinical problem. Drugs and RF catheter ablation are not always effective. A nonsurgical transthoracic epicardial RF ablation can be an alternative in patients refractory to conventional therapy.

METHODS

Epicardial RF ablation was performed in 10 patients who presented with incessant VT despite the use of two or more intravenous antiarrhythmic drugs.

RESULTS

In eight patients, endocardial ablation (EdA) failed to control the tachycardia. In the remaining two patients, epicardial ablation (EpA) was first attempted because of left ventricular thrombus and severe artery disease, respectively. Eight patients had a diagnosis of coronary artery disease with healed myocardial infarction. One patient had dilated cardiomyopathy, and one patient had idiopathic, incessant VT. In patients with structural heart disease, the mean ejection fraction was 0.28 +/- 0.10%. Four patients previously received an implantable defibrillator. The EpA effectively terminated the incessant tachycardia in eight patients, which represents a success rate of 80%. In them, after a follow-up of 18 +/- 18 months, a single episode of a different VT was documented in one patient. No significant complications occurred related to the procedure.

CONCLUSIONS

In patients with incessant VT despite the use of drugs or standard EdA, the epicardial approach was very effective and should be considered as an alternative in this life-threatening situation.

Encircling endocardial cryoablation for ventricular tachycardia after myocardial infarction: experience with 33 patients

Encircling endocardial cryoablation, consisting of circumferential cryoablation of the infarct scar, can be curative in selected patients with ventricular tachycardia (VT). We describe our experience with and long-term outcome in 33 patients undergoing this procedure. The interval between myocardial infarction and the onset of tachycardia varied from 2 weeks to 22 years (mean 38 +/- 63 months and median 3 months). All patients had a left ventricular aneurysm (anterior in 20, posterior in 12, and lateral in 1) and significant coronary artery disease. Fourteen patients had clinical evidence of heart failure preoperatively. Twenty-eight patients had sustained monomorphic VT (incessant in 3); 3 had polymorphic or nonsustained tachycardia; 2 had primary ventricular fibrillation; and 1 had associated Wolff-Parkinson-White syndrome. Surgery was undertaken after failed drug therapy and consideration of left ventricular anatomy and function. At surgery, 32 patients had encircling endocardial cryoablation, and 1 patient had partial right ventricular free-wall disconnection (right ventricular infarct). Thirteen patients underwent concomitant coronary artery bypass grafting. An implantable cardioverter defibrillator (ICD) was implanted in 2 patients and prophylactic ICD patches in 1. One patient died postoperatively; 3 had recurrent VT perioperatively; 1 was treated with amiodarone; and 2 had ICD implantation. During long-term follow-up (mean 5 years), all patients who were free of tachycardia at discharge remained alive and free of arrhythmias or syncope. The patient receiving amiodarone sustained a cardiac arrest subsequently and received an ICD implant. One patient with an ICD continued to receive appropriate shocks frequently and died 2 years after surgery. Nine patients had congestive heart failure postoperatively.(ABSTRACT TRUNCATED AT 250 WORDS)

Catheter ablation of ventricular tachycardia occurring late after myocardial infarction: a point-of-view

Ventricular tachycardia can be controlled by radiofrequency or chemical ablation of the site of origin of the arrhythmia. However, these techniques are far from being accepted as routine treatment for this problem. This article describes the theoretical and practical background of catheter ablation of ventricular tachycardia occurring late after myocardial infarction.