RETROGRADE CORONARY VENOUS INFUSION OF ETHANOL FOR ABLATION OF CANINEVENTRICULAR MYOCARDIUM

Introduction: Permanent cure of reentrant ventricular tachycardia (VT) associated with coronary artery disease is difficult to achieve. Retr ograde coronary venous infusion of ethanol for ablation of ventricular myocardium associated with reentrant tachyarrhythmias has several pot ential advantages, including use of physiologic mapping techniques and production of deeper, wider necrotic zones. Methods and Results: Nine anesthetized dogs had baseline hemodynamic measurement, left ventricu lography, coronary arteriography, occlusive coronary venography, and p rogrammed electrical stimulation of the right ventricular apex and out flow tract. A balloon-tipped infusion catheter was advanced into a dis tal coronary venous branch, the balloon slowly inflated, and pure etha nol infused at volumes of 1.5, 3, or 5 cc. Hemodynamic measurements, a ngiography, ventriculography, and programmed electrical stimulation we re repeated immediately and 1 week following ablation, Formalin-perfus ed hearts were serially sectioned and lesion volumes determined. Histo logic examination of ablation beds then was performed. No significant difference was found in any hemodynamic measurement before or after ab lation, Coronary arteriograms and left ventriculograms were unchanged after ablation. Nonsustained VT occurred in eight dogs during ethanol infusion; however, VT was not inducible in any dog before or after abl ation, Infusion volumes of 3 cc or more were required to produce trans mural lesions. Conclusion: Retrograde coronary venous infusions of eth anol using a balloon-tipped infusion catheter were effective in ablati ng ventricular myocardium. Retrograde chemical ablation did not itself result in inducible VT or adversely affect hemodynamic measurements o r coronary arteries. Transmural myocardial necrosis, necessary in the ablation of VT associated with coronary artery disease, can be produce d by higher infusion volumes.