RESUMEN
<b>[Background] </b>Surgical septal myectomy is the gold-standard therapy for hypertrophic obstructive cardiomyopathy (HOCM) in Europe and America. However, few cases underwent surgical septal myectomy in Japan. We have performed the surgical transaortic extended left ventricular myectomy (LV myectomy) as a first choice in HOCM patients unresponsive to pharmacologic therapy. We report the short and medium term clinical outcomes. <b>Methods</b> : From May 2012 to September 2014, 9 patients underwent extended LV myectomy without other accompanying procedures. All cases were symptomatic and peak left ventricular outflow tract pressure gradients (LVOTG) were 50 mmHg or more. We assessed clinical and echocardiographic outcomes at the short and medium term, intra-operative findings and cardiomyocyte pathological findings. <b>Results</b> : All patients (mean age 64.3 years, 56% female) underwent transaortic LV myectomy with no obvious complications. Postoperative LVOTG were controlled within 10 mmHg or less. SAM disappeared completely in all patients and MR decreased to mild or less. LVOTG sustained good control of 10 mmHg or less under low-dose dobutamine stress echocardiography at the medium term. <b>Conclusion</b> : Our transaortic extended LV myectomy procedure is effective in decreasing LVOTG, SAM and MR with low operative morbidity and mortality.