Substrate Ablation by Multivein, Multiballoon Coronary Venous Ethanol for Refractory Ventricular Tachycardia in Structural Heart Disease.

BACKGROUND: Ablation of ventricular tachycardia (VT) in the setting of structural heart disease often requires extensive substrate elimination that is not always achievable by endocardial radiofrequency ablation. Epicardial ablation is not always feasible. Case reports suggest that venous ethanol ablation (VEA) through a multiballoon, multivein approach can lead to effective substrate ablation, but large data sets are lacking. METHODS: VEA was performed in 44 consecutive patients with ablation-refractory VT (ischemic, n=21; sarcoid, n=3; Chagas, n=2; idiopathic, n=18). Targeted veins were selected by mapping coronary veins on the epicardial aspect of endocardial scar (identified by bipolar voltage <1.5 mV), using venography and signal recording with a 2F octapolar catheter or by guidewire unipolar signals. Epicardial mapping was performed in 15 patients. Vein segments in the epicardial aspect of VT substrates were treated with double-balloon VEA by blocking flow with 1 balloon while injecting ethanol through the lumen of the second balloon, forcing (and restricting) ethanol between balloons. Multiple balloon deployments and multiple veins were used as needed. In 22 patients, late gadolinium enhancement cardiac magnetic resonance imaged the VEA scar and its evolution. RESULTS: Median ethanol delivered was 8.75 (interquartile range, 4.5-13) mL. Injected veins included interventricular vein (6), diagonal (5), septal (12), lateral (16), posterolateral (7), and middle cardiac vein (8), covering the entire range of left ventricular locations. Multiple veins were targeted in 14 patients. Ablated areas were visualized intraprocedurally as increased echogenicity on intracardiac echocardiography and incorporated into 3-dimensional maps. After VEA, vein and epicardial ablation maps showed elimination of abnormal electrograms of the VT substrate. Intracardiac echocardiography demonstrated increased intramural echogenicity at the targeted region of the 3-dimensional maps. At 1 year of follow-up, median of 314 (interquartile range, 198-453) days of follow-up, VT recurrence occurred in 7 patients, for a success of 84.1%. CONCLUSIONS: Multiballoon, multivein intramural ablation by VEA can provide effective substrate ablation in patients with ablation-refractory VT in the setting of structural heart disease over a broad range of left ventricular locations.

Advanced Techniques for Ethanol Ablation of Left Ventricular Summit Region Arrhythmias.

BACKGROUND: Coronary venous ethanol ablation (VEA) can be used as a strategy to treat ventricular arrhythmias arising from the left ventricular summit, but collateral flow and technical challenges cannulating intramural veins in complex venous anatomies can limit its use. Advanced techniques for VEA can capitalize on collateral vessels between target and nontarget sites to improve success. METHODS: Of 55 patients with left ventricular summit ventricular arrhythmia, advanced techniques were used in 15 after initial left ventricular summit intramural vein mapping failed to show suitable targets for single vein, single-balloon VEA. All patients had previous radiofrequency ablation attempts. Techniques included: double-balloon for distal protection to block distal flow and target the proximal portion of a large intramural vein where best signal was proximal (n=6); balloons in 2 different left ventricular summit veins for a cross-fire multivein VEA (n=4); intramural collateral vein-to-vein cannulation to reach of targeted vein via collateral with antegrade ethanol and proximal balloon block (n=2); prolonged ethanol dwell time for vein sclerosis of large intramural vein and subsequent VEA (n=3); and intramural collateral VEA (n=1). RESULTS: Fifteen (8 females) patients (age 60.6±17.6 years) required advanced techniques. Procedure time was 210±49.9 minutes, fluoroscopy time was 25.3±14.1 minutes, and 113±17.9 cc of contrast was utilized. A median of 7 cc of ethanol was delivered (range, 4-15 cc). Intraprocedural radiofrequency ablation was delivered before ethanol in 9 out of 15 patients but failed. Ethanol achieved acute success in all 15 patients. Ethanol was used as the sole treatment in two patients. At a median follow-up of 194 days, one patient experienced recurrence. CONCLUSIONS: Advanced techniques capitalizing on venous anatomy can enable successful VEA and selective targeting of arrhythmogenic sites, by blocking distal flow, utilization of collaterals between nontarget and target veins and multivein VEA. Understanding individual anatomy is critical for VEA success.