Septal Myectomy for Isolated Midventricular Obstruction After Alcohol Septal Ablation for Obstructive Hypertrophic Cardiomyopathy.

BACKGROUND

Alcohol septal ablation is an alternative to surgical myectomy for septal reduction in obstructive hypertrophic cardiomyopathy, particularly in high-risk surgical patients. However, alcohol septal ablation can sometimes result in residual left ventricular obstruction, typically in the subaortic area and, much more rarely, in the midventricular region.

METHODS

This report presents 3 unique cases of isolated midventricular obstruction without systolic anterior motion that required surgical myectomy after alcohol septal ablation.

RESULTS

Three patients presented with persistent or recurrent symptoms of left ventricular outflow obstruction after alcohol septal ablation. Surgical myectomy, performed through a transapical approach alone or in combination with a transaortic approach, successfully reduced intracavitary gradients and septal thickness in all 3 patients. One patient underwent cardiac transplantation 2 years after septal myectomy due to diastolic heart failure without obstruction.

CONCLUSIONS

This case series highlights concerns about the use of alcohol septal ablation for patients with long-segment subaortic obstruction and midventricular involvement, suggesting that surgical myectomy may be a more suitable treatment option for this anatomic subtype.