Septal Reduction Therapy for Obstructive Hypertrophic Cardiomyopathy and Sudden Death

T here is a subset of patients with hypertrophic cardiomy- opathy and left ventricular outflow tract obstruction who have severely limiting symptoms despite optimal medical therapy. 1 Septal reduction therapy, consisting of a surgical procedure (septal myectomy) or a catheter-based therapy (alcohol septal ablation), has been used to treat this subset of patients.A successful procedure will abolish the left ventricular outflow tract obstruction and result in dramatic relief of symptoms, allowing these patients with severe debilitation to return to a near-normal lifestyle. Article see p 97For most of these medication-refractory patients, septal myectomy has been considered the "gold standard" for treatment.2 Since its first introduction in the 1960s, there has been a continued decrease in operative mortality and an increase in overall success rate primarily due to improvements in operative technique and myocardial protection.In the hands of experienced surgeons, the mortality for an isolated septal myectomy is Ͻ1%, and Ͼ90% of patients are able to achieve sustained clinical improvement.Modern data also support that survival is equivalent to the general population after successful septal myectomy.3 Alcohol septal ablation emerged in the mid-1990s as a percutaneous alternative to septal myectomy.4 There was a high initial enthusiasm for alcohol septal ablation because early results demonstrated that relief of obstruction and improvement of symptoms could be accomplished with a low procedural complication rate.5 Although surgical myectomy was limited to a few tertiary referral centers, many catheterization laboratories across the world began to perform alcohol septal ablation.However, after the introduction of alcohol septal ablation, case reports emerged describing the occurrence of potentially lethal arrhythmias on follow-up.6,7 MRI scanning with gadolinium enhancement demonstrated a large "scar" in the myocardium at the site of the alcohol ablation, signifying aThe opinions expressed in this article are not necessarily those of the editors or of the American Heart Association.