Concomitant treatment of sustained ventricular tachycardia and hypertrophic cardiomyopathy with transcoronary ethanol ablation: a case report

Background

The recommended treatment for recurrent ventricular tachycardia in patients with hypertrophic cardiomyopathy that is not amenable to defibrillator implantation due to shock burden is radiofrequency ablation. In patients with deeply intramural foci of ventricular tachycardia, traditional unipolar ablation has a lower probability of success.

Case summary

A 66-year-old Caucasian man was admitted with ventricular tachycardia, which recurred despite antiarrhythmic drugs. On cardiac magnetic resonance imaging, he was discovered to have septal hypertrophic cardiomyopathy, which was not significant on echocardiogram. The focus of ventricular tachycardia was suspected to be buried deeply within the hypertrophic segment as localized by late gadolinium enhancement. The patient underwent transcoronary ethanol ablation, which abated the ventricular tachycardia while also completely decreasing his invasively measured left ventricular outflow tract obstruction gradient from 45 to 17 mmHg.

Discussion

Transcoronary ethanol ablation may be successfully applied to simultaneously treat ventricular arrhythmia superimposed within a segment of hypertrophic cardiomyopathy. Further data are needed to evaluate long-term success of this strategy vs. traditional radiofrequency ablation.

Transcoronary mapping using a guidewire during transcoronary ethanol ablation for ventricular tachycardia with a deep intramural substrate: a case report

Background

Transcoronary ethanol ablation is effective in treating ventricular tachycardia (VT) in the deep myocardium. The selection of the target coronary artery plays an important role in the success of transcoronary ethanol ablation. Transcoronary mapping, using a guidewire, may be effective for identifying the target coronary artery.

Case summary

A 72-year-old man, who had undergone thrombolytic therapy for acute myocardial infarction 40 years ago, was admitted to the emergency department with a chief complaint of syncope. Five years ago, a cardiac resynchronization therapy defibrillator was implanted for a left bundle branch block (QRS duration 153 ms), with New York Heart Association Class Ⅲ and a left ventricular ejection fraction of 30%.Due to VT, he experienced a critical deterioration in his vital parameters, leading to shock. The first VT ablation was performed on the 3rd day of hospitalization. Activation mapping showed that the earliest activation site was located in the mid-anterior septum of the left ventricle. Mapping from the endocardial surface showed no mid-diastolic potential around the VT. Radiofrequency catheter ablation therapy was performed at the targeted site, resulting in transient termination of VT. However, the VT showed recurrence the next day. A transcoronary ethanol ablation was performed on the 10th day of hospitalization. A 0.014 inch guidewire and microcatheter were advanced into the target coronary septal branch, and the myocardial septum was mapped. The guidewire-assisted transcoronary mapping showed a potential 43 ms ahead of QRS onset during VT. The coronary septal artery branch was considered the target artery, and 0.5 mL of ethanol was injected. No further VT was observed for 12 months after the transcoronary ethanol ablation.

Discussion

Transcoronary ethanol ablation is considered in cases where a deep intramural substrate is suspected or when early activation at the interventricular septum is identified. Guidewire-assisted transcoronary mapping allows mapping of VT with deep intramural substrates and may be useful in selecting target coronary arteries while performing transcoronary ethanol ablation.

Chemical Ablation of Ventricular Tachycardia Using Coronary Arterial and Venous Systems

Radiofrequency catheter ablation (RFCA) is the first-line therapy for treatment of drug refractory ventricular arrhythmias (VAs), however, creating a safe, transmural lesion can be difficult. Ethanol in the arterial system has been used as an adjunctive therapy to RFCA since 1986, but with limited use due to technical and efficacy limitations. Venous ethanol is emerging as powerful alternative.