INTRODUCTION
Catheter ablation is an effective therapy for ventricular tachycardia
(VT) in patients with structural heart disease. Endocardial ablation was
often supplemented by epicardial ablation in 15-30% of patients to
achieve success.(1-3) Percutaneous epicardial mapping and ablation was
first attempted by Sosa and his colleagues.(4) Since then, this
technique has been widely used in patients with non-ischemic
cardiomyopathy (NICM), arrhythmogenic right ventricular cardiomyopathy
(ARVC) and some focal VTs originating epicardially.(5-7) Unfortunately,
some VTs are still refractory to combined endocardial and epicardial
ablation. These challenging VTs often progress to electrical storm
causing frequent implantable cardioverter defibrillator (ICD) shocks and
significantly increase the mortality. (8-9) The intramural or
subepicardial VT substrate may cause the ablation failure. Percutaneous
epicardial ablation frequently was limited by poor contact force or fat
tissue. Some non-conventional ablation strategies for intramural
ventricular arrhythmias have been reported recently including bipolar
ablation, needle ablation, half-normal saline irrigated ablation.
(10-12) However, these techniques required specific devices or equipment
which have not been available in most of centers. Transvessel ethanol
ablation has also been reported as an effective alternative strategy for
VTs with previously failed radiofrequency ablation.(13, 14) However, its
success was limited by the anatomy of coronary branches. Surgical
epicardial ablation has been reported as a feasible alternative strategy
for VTs.(15-17) Meanwhile, intramyocardial ethanol injection has been
proved effectively in animal models. (18) There have been no reports on
effects of intramyocardial ethanol injection for the treatment of VTs in
human. We hypothesized that surgical catheter ablation supplemented by
direct ethanol injection might be a powerful treatment in those
challenging VTs, especially when concomitant surgical interventions were
needed.