Septal reduction therapies in hypertrophic cardiomyopathy: comparison of surgical septal myectomy and alcohol septal ablation

Abstract

Left ventricular outflow tract obstruction, either resting or labile, occurs in approximately 70% of patients with hypertrophic cardiomyopathy and is a major cause of symptoms. In patients with obstructive physiology and medically refractory symptoms, septal myectomy and alcohol septal ablation reduce the left ventricular outflow tract gradient and improve symptoms. Myectomy is more effective at gradient reduction compared with ablation, with lower need for subsequent pacemaker implantation. However, cohort studies and meta-analyses have shown short-term mortality and post-procedural functional classes are similar between procedures. In many centers alcohol septal ablation case volumes have surpassed myectomy. There remains significant controversy regarding choice of myectomy or ablation. This review describes the two septal reduction procedures, examines the available comparative data for clinical outcomes and discusses clinical considerations when selecting myectomy or ablation.

Editorial: Cibenzoline for left ventricular outflow tract obstruction in tako-tsubo cardiomyopathy and hypertrophic cardiomyopathy

“…The papillary muscles are anteriorly malpositioned and can be inserted directly onto the mitral leaflet. These geometric papillary muscle changes, in combination with mitral leaflet elongation, lead to less posterior leaflet tethering and thus provide sufficient leaflet mobility to result in SAM 10 , 11 , 12 . Although the mechanism of the outflow tract gradient in HCM was initially thought to be caused by systolic contraction of the hypertrophied basal ventricular septum encroaching on the LVOT, most recent studies have demonstrated that given the mitral anatomy in HCM, the predominant mechanism of SAM is related to drag on the mitral valve leaflet, generated by blood flow acceleration across the septum during ventricular systole, ‘pushing’ the leaflets into the LVOT 10 , 11 , 12 .…”

“…As opposed to a fixed stenosis in aortic stenosis, subvalvular obstruction is dynamic and fluctuates significantly based upon changes in numerous clinical factors, including fluctuations in volume status, autonomic nervous activity, diurnal variation, pharmacotherapy, exercise, and physical position during assessment 10 , 11 , 12 .…”