Misplacement in myocardial contrast echo during alcohol septal ablation in hypertrophic obstructive cardiomyopathy indicates intraseptal collateralization.

Abstract

A 42-year-old patient with HOCM was submitted for percutaneous transluminal septal myocardial ablation (PTSMA). Coronary angiography (Panel A) identified the first septal branch (SB) (yellow arrow) as estimated target vessel and a second SB (white arrow). Compared with intraprocedural baseline transthoracic echocardiography (TTE) (Panel B), myocardial contrast echocardiography (MCE) with injection of 1.5 mL cold gelafundin 4% through an inflated over the wire balloon catheter (OTW-BC) in the first SB (Panel C) identified a correct septal depot (orange arrow), but also opacification at the left ventricle apex (dotted orange arrow). Contrast dye injection through the OTW-BC (dotted yellow arrow) showed collateralization from the first (yellow arrow) into the second SB (yellow arrow) and drainage into the left anterior descending (LAD) (red arrow) as reason for the misplacement (Panel D). We placed a second OTW-BC in the collateralized second SB (dotted white arrow; Panel E). Contrast injection through both inflated OTW-BC showed only distal first (yellow arrow) and second SB (white arrow) without further collaterals and without drainage into the—in the meantime wired—LAD (red arrow). MCE (Panel E) showed only opacification of the targeted septal area (orange arrow) as TTE (Panel F) does after injection 1.5 cc of alcohol through each balloon. After deflation and retraction of the BCs, 10 min after alcohol injection, haemodynamic measurements ensured elimination of resting and provocable gradients. Final coronary angiography (Panel G) showed occluded SBs (arrows) and unchanged LAD.