Alcohol Septal Ablation for Hypertrophic Cardiomyopathy Guided by Intracoronary Myocardial Contrast Echocardiography to Reduce Myocardial Damage

Septal reduction therapy (SRT) is indicated for drug-refractory hypertrophic obstructive cardiomyopathy (HOCM). SRT includes surgical myectomy and alcohol septal ablation (ASA). The outcome between SRTs are similar except complete atrioventricular (AV) block. Intracoronary myocardial contrast echocardiography is used to minimize myocardial damage by ASA. We report a case of 40-year-old male who was diagnosed of HOCM with progressed symptoms under optimal medication. Echocardiography revealed peak velocity cross left ventricular outflow tract (LVOT) 5.3 m/s, systolic anterior motion (SAM) of mitral valve with eccentric mitral regurgitation (MR) and interventricular septal thickness 16 mm. Alcohol (99.5%) 1.5 mL was injected into the first small branch of the first septal artery, under precise localization by intracoronary myocardial contrast echocardiography. The pressure gradient of apex-LVOT-aorta reduced from 90 to 20 mmHg after ASA. No AV block was noted after the procedure and echocardiography revealed improved peak velocity cross LVOT and interventricular septal thickness. No more SAM or eccentric MR was observed. Previous studies recommended ASA reserved for patients with higher surgical risk and severe comorbidities. However, a recent study showed that young adults had better long-term survival and only one-half pacemaker implantation rate than older group following ASA. Under the guidance of intracoronary myocardial contrast, target vessel could be precisely localized to small branch from a septal artery to decrease myocardial damage. Therefore, ASA may be considered as the first-line SRT for symptomatic HOCM due to minimal invasiveness and effective outcome.