560 Quantification of left ventricular function in patients with hypertrophic cardiomyopathy: an ultrasound based regional strain and strain rate imaging study

Background: The echocardiographic evaluation of myocardial systolic function in pts with hypertrophic cardiomyopathy (HCM) is still unsatisfactory. This disease has been shown to exhibit LV relaxation and filling abnormalities despite normal LV ejection fraction (EF). However, EF only detects radial motion and the normal value of systolic function described in HCM pts may be due to a relative insensitivity of the used technique. Strain (S) and Strain Rate (SR) imaging is a new technique able to quantify both radial and longitudinal regional myocardial deformations and potentially is more sensitive compared to 2D grey scale imaging. Methods: We studied 25 HCM pts (aged 16±3 yrs) using standard grey scale echocardiography and S/SR imaging. Regional peak systolic longitudinal function was assessed from the apical views while regional peak systolic radial function was evaluated from the parasternal views. We studied also the time to peak systolic deformation (from the onset of ECG Q wave to the peak systolic S) for both radial and longitudinal function, in the mid segment of posterior wall from the apical 3 chamber view and the parasternal view, respectively. Data were compared with that of 33 age comparable healthy subjects. Results: All pts showed a normal LVEF. Radial peak systolic S and SR in HCM pts were comparable to healthy subjects. Conversely, regional longitudinal function was significantly reduced when compared to healthy subjects (S [%]: HCM=10±6 vs healthy subjects =25±5, p