Abstract 1061: Pattern and Extent of Systolic Intraventricular Dyssynchrony in Patients with Hypertrophic Cardiomyopathy: Comparison with Hypertensive and Athlete Hearts Using Tissue Doppler Imaging
Differentiating hypertrophic cardiomyopathy (HCM) from athletes heart and hypertensive left ventricular hypertrophy (LVH) has important diagnostic and prognostic implications. The objective of this study was to evaluate the discriminatory value of systolic intraventricular dyssynchrony (S-dy) parameters using tissue Doppler imaging (TDI) in distinguishing HCM from other variants of LVH. Twenty one patients with HCM and preserved systolic function were compared with athletes (n=14) and 19 patients with hypertensive LVH. For TDI, color Doppler cine loops were obtained using a 3.5-MHz probe at frame rates of ≥120 fps (standard long-axis, two-chamber and four-chamber images). Digitized images were analyzed off-line (Echo Pac 7.0; Vingmed-General Electric) and time-velocity profile reconstituted in 6 basal and 6 mid LV segments. The extent of S-dy was represented as the standard deviation of the time to peak systolic contraction of the 12-LV segments (dyssynchrony index). The pattern of S-dy was assessed from time delay between peak systolic (S′) velocities in opposing walls, namely, antero-inferior (AI), septal-lateral (SL) and anteroseptal-inferolateral (ASIL) of the left ventricle, compared between groups and also correlated to QRS width (surface ECG). Systolic dysynchrony parameters were most deranged in the HCM cohort, with inferolateral segments exhibiting the longest activation delay. On receiver operating curve analysis, dyssynchrony index (AUC 0.77, p<0.001), and S-Dy in only ASIL (AUC 0.78, p<0.001), or AI (AUC 0.68, 0.02), but not SL (AUC 0.61, 0.16), were able to discriminate HCM from athletes or hypertensive LVH. Dyssynchrony analysis may serve as an adjunctive diagnostic tool for differentiating HCM from other forms of LVH in patients with preserved systolic function.