Use of strain imaging in detecting segmental dysfunction in patients with hypertrophic cardiomyopathy

Background: The distribution and magnitude of left ventricular hypertrophy are not uniform in patients with hypertrophic cardiomyopathy (HCM). Previous echocardiographic studies have focused on global left ventricular function. Recently, myocardial Doppler strain (ε) imaging, a newly developed technique, has allowed the quantification of regional myocardial motion. The aim of this study was to characterize regional left ventricular systolic function by myocardial Doppler ε imaging in patients with HCM. Methods: Included in this study were 31 patients with asymmetric septal hypertrophy and HCM, and 41 age-matched healthy patients. Regional longitudinal axial systolic ε was assessed at the basal, mid, and apical segments of the septal and lateral walls and compared between both groups. Results: Patients with HCM had reduced ε at the ventricular septum (-10.3 ± 5.7%) compared with control patients (-19.4 ± 3.3%, P < .001). In the HCM group, ε in the midseptum (-1.3 ± 8.2%) was significantly less than at the basal (- 12.2 ± 8.7%, P < .01) and apical septum (-17.3 ± 10.4%, P < .01), and was also less than at the midlateral wall (-9.4 ± 5.3%, P < .05). There was a significant correlation between midseptal ε and intraventricular septum to posterior wall thickness ratio (r = 0.81, P < .001). Conclusion: Midseptal longitudinal ε was markedly decreased, even reversed in patients with HCM (paradoxic longitudinal systolic expansion), which was directly related to the degree of septal hypertrophy. Myocardial Doppler ε imaging could offer a unique approach to quantify regional systolic dysfunction in these patients.