Abstract 13069: Left Atrial Mechanics in Patients With Hypertrophic Cardiomyopathy

Background: Patients with hypertrophic cardiomyopathy (HCM) frequently have diastolic dysfunction (DD) characterized by elevated filling pressures. Speckle-tracking analysis of the left atrium (LA) is an imaging tool for quantifying DD, however, its value in HCM is not well established. Methods. Transthoracic echocardiographic images of consecutive HCM patients with a septal thickness ≥15 mm and no aberrant loading conditions at an academic tertiary care center were evaluated. Peak atrial longitudinal strain (PALS) was determined by averaging the atrial strain over all segments in the 4- and 2-chamber views ( Figure ). Results. Among 205 HCM patients, 108 patients (52 years, 40% female) had sinus rhythm and sufficient image quality to be included. The median interventricular wall thickness was 20 mm (IQR 17-23), the relative wall thickness ratio was 0.65 mm (IQR 0.46-0.87), and the LV mass index was 164.0 g/m 2 (IQR 131.5-188.5). The mean PALS was 18.5% (± 8.8%) and did not differ between men and women. PALS significantly (all p <0.05) correlated with septal thickness (r=-0.31), LA volume index (r=-0.60), E/A ratio (r=-0.25), E/E’ (r=-0.63), systolic pulmonary pressure (r=-0.31), and high sensitivity troponin-T levels (r=-0.43). Moreover, PALS correlated with resting gradients in patients with relevant LV outflow tract obstruction (n=53 [49%]; r=-0.29). Among patients who underwent cardiac magnetic resonance imaging (81%), PALS was significantly correlated with LA ejection fraction (r=0.59) and late gadolinium enhancement of the total LV mass (r=-0.42). In addition, PALS was the only echocardiographic parameter reflecting DD that was significantly associated with the presence of LGE (Odds Ratio 0.93, 95%CI 0.88-0.99). Conclusion. PALS is a useful tool for quantifying DD in HCM patients and is associated with the presence of LGE. Future research will need to evaluate its significance in early identification of HCM patients at risk of sudden cardiac death.