Available online 19 September 2022

Patients with obstructive hypertrophic cardiomyopathy (HCM) often experience symptoms of heart failure upon exertion despite having a normal left ventricular (LV) ejection fraction. Longitudinal strain may be a more sensitive marker of systolic dysfunction in patients with LV hypertrophy. We aimed to characterize segmental and global LV longitudinal strain (LV GLS) at rest and during exercise, and to assess if first-line treatment with beta-blockers improves LV systolic performance.

Twenty-nine patients with obstructive HCM and New York Heart Association (NYHA) class ≥ II symptoms were enrolled in a double-blind, placebo-controlled, randomized crossover trial. Patients received metoprolol 150 mg or placebo for two consecutive two-week periods in random order. Echocardiographic assessment with speckle-tracking derived longitudinal strain (LS) was performed at rest and during peak exercise at the end of each treatment period.

During placebo treatment resting values of segmental LS showed an apical-basal difference of -10.3% (95% confidence interval (CI): -12.7 to -7.8; p < 0.0001), with severely abnormal values of the basal segment -9.3 (4.2) %. Treatment with metoprolol was associated with more negative LS values of the apical segment (-2.8 %; 95% CI: -4.2 to -1.3; p < 0.001) and the mid segment (-1.1%; 95% CI: -2.0 to -0.3; p = 0.007). During peak exercise there was a deterioration in LV GLS, yet treatment with metoprolol was associated with a more negative peak exercise LV GLS (-1.3 %; 95% CI: -2.6 to -0.1; p = 0.03).

Systolic performance assessed by LV GLS showed impaired values at rest and during exercise, with severely depressed values of the basal and mid segments. Treatment with metoprolol improved LV GLS upon exercise, indicating a beneficial effect of beta-blocker treatment on LV systolic function.

2022 Published by Elsevier Inc. on behalf of the American Society of Echocardiography.