Abstract 16081: Diastolic Function and Left Atrial Volume Improve Following Septal Myectomy for Obstructive Hypertrophic Cardiomyopathy
Background: Septal myectomy is an established therapy for obstructive hypertrophic cardiomyopathy (HCM) patients with symptoms refractory to maximal medical therapy. Although reduction in left ventricular (LV) outflow tract gradient is well documented, little data exists regarding changes in left atrial (LA) volume and LV diastolic parameters following myectomy.
Methods: We investigated changes in LA size and LV diastolic function in patients with HCM following septal myectomy with or without mitral valve repair/replacement or MAZE surgery from 2004 to 2011. Patients who had serial echocardiograms at baseline and at most recent follow up, at least 6 months following myectomy, were included. Patients with aortic valve replacement were excluded, and those with mitral valve replacement (MVR) or annuloplasty were excluded from diastolic function analysis. Baseline and follow up clinical and echocardiographic parameters were compared using paired t-tests and Fisher’s exact test for continuous and categorical variables respectively.
Results: We studied 25 patients (age 49.2 ± 13.1, 48% female) followed for a mean of 527 days after surgery. Three patients (12%) underwent MAZE and 13 (52%) underwent mitral valve surgery, of whom 5 had a MVR or annuloplasty. LA volume index significantly decreased (from 47.2 ± 17.6 to 35.9 ± 17.0 ml/m2, p=0.001) and LV diastolic function improved with an increase in lateral e’ velocity (from 7.3 ± 2.9 cm/sec to 9.8 ± 3.1 cm/sec, p=0.01) and a decrease in E/e’ (from 14.8 ± 6.3 to 11.7 ± 5.5, p=0.051). As expected, septal thickness and LVOT gradient decreased, and symptoms of dyspnea and heart failure improved.
Conclusions: These data indicate that relief of LVOT obstruction in HCM by septal myectomy results in improved LV diastolic function and concomitant reduction in LA volume with improved dyspnea and NYHA functional class. Whether decreased LA volume leads to decreased atrial fibrillation in longer term follow up needs further evaluation.
- © 2013 by American Heart Association, Inc.