Ventricular Tachycardia Ablation in Patients With Severely Decreased Left Ventricular Ejection Fraction.

BACKGROUND

Ablation of ventricular tachycardia (VT) is often performed in patients with structural heart disease. Procedural and delayed enhancement cardiac magnetic resonance imaging (DE-CMR) characteristics among patients with very severe cardiomyopathy (CM) and without left-ventricular assist devices (LVAD) have been incompletely described.

OBJECTIVES

To examine procedural and imaging characteristics of patients with very severely decreased ejection fractions undergoing VT ablation procedures.

METHODS

Consecutive patients with a left ventricular ejection fraction (EF) < 20% and without LVADs who underwent VT ablation were included. A composite outcome of survival free from VT, LVAD, or transplant was examined.

RESULTS

Twenty-seven patients were included (64.1 ± 7.76 years; male n = 23, 88.5%; EF 12.8 ± 3%, LV end diastolic diameter 74 ± 11 mm, ischemic CM (n = 16, 60%), Nonischemic CM (n = 9, 52%), mixed CM (n = 2, 7%)). Twenty-five (93%) patients had failed amiodarone, 9 (33%) had a prior VT ablation, and 13 (48%) underwent ablation for VT storm. Scar was present in 22/23 patients with DE-CMR (intramural [n = 13], endocardial [n = 8], epicardial [n = 2], mixed components [n = 12]). DE-CMR scar corresponded to VT sites of origin in 18/22 patients (82%), excluding one patient with right ventricular VT, two with bundle-branch-reentry VT, and one-non-inducible patient. After 22 ± 19 months, VT occurred in 15/27(56%) patients, death 8/27(30%) and the composite outcome occurred in 22/27(82%) patients.

CONCLUSION

Patients with very severe cardiomyopathy undergoing VT ablation represent a high risk population, experiencing high rates of VT recurrence and death on midterm follow up. Despite severe remodeling, DE-CMR provides localizing information on the arrhythmia site of origin.