Chemical ablation by subendocardial injection of ethanol via catheter--preliminary results in the pig heart.

This study was set up to discover how a subendocardial application of ethanol administered via a catheter would affect an animal model. A 7 F bipolar catheter with a lumen, through which a 2 mm needle was inserted, was placed in the left ventricle of 11 pigs. Altogether, 33 subendocardial injections into the left ventricular myocardium were performed under fluoroscopic control using a mixture of 0.5-1.5 ml ethanol and 0.5-1 ml iopamidol as contrast medium. The mixtures were injected into the apical, lateral and septal walls of the left ventricle. After 25 days, the hearts were removed and the lesions examined pathologically. The calculated volume of the lesions was about 60 mm3, the area in projection to the endocardium about 35 mm2, the depth relative to the endocardium about 1.5 mm and the maximum diameter about 8 mm. Perforation of the myocardial wall by pericardial injection occurred twice without further complications. Subendocardial application of concentrated ethanol by catheter caused a controlled local necrosis. This technique may become a new approach with which to treat ventricular tachycardia by chemical ablation.