Alcohol septal ablation for hypertrophic obstructive cardiomyopathy

Abstract

Since its original description in 1994, alcohol septal ablation (ASA) has emerged as a minimally invasive modality for treatment of hypertrophic obstructive cardiomyopathy compared to surgical myomectomy. This catheter-based intervention relies on the injection of absolute alcohol into the septal perforator to induce a controlled infarction of the hypertrophied septum and consequently abolish the dynamic outflow obstruction. This gradient reduction has been correlated with a significant clinical improvement in the patient's symptomatology and with left ventricular remodeling. The procedure has been refined throughout the years, especially with the introduction of myocardial contrast echocardiography for localization of the area at risk of infarction and the reduction in the amount of alcohol used. Major complications of ASA are uncommon in large referral centers but conduction system disturbances has been the most commonly reported complications of ASA with 10% of patients necessitating permanent pacemaker implantation for complete heart block. ASA has not been compared to the gold standard surgical myomectomy in a randomized prospective study. We review the clinical aspects of this procedure and provide some historical background.

Keywords: Hypertrophic cardiomyopathy; alcohol ablation.; left ventricular outflow obstruction.

Fig. (1)

Apical four-chamber views illustrating the use of myocardial contrast echocardiography to determine area at risk during ASA: injection into the first septal perforator results in enhancement of the proximal basal septum. (adapted with permission from Nagueh, S. F., et al. J Am Coll Cardiol 1998; 32: 225-229).

Fig. (2)

Transthoracic echocardiogram in hypertrophic obstructive cardiomyopathy: continous wave Doppler across the LVOT (A) before ASA indicating severe obstruction with a dynamic gradient of 96 mmHg and (B) 6 months after ASA with resolution of the obstruction.