Abstract 2242: Hypertrophic Cardiomyopathy is Associated With More Severe Left Ventricular Dyssynchrony Compared to Hypertensive Heart Disease: Demonstration by 2-Dimensional Speckle Tracking Imaging
Background: 2D speckle tracking imaging allows the measurement of radial and circumferential strain in multiple LV short axis views, thus resulting in new modality for assessing LV dyssynchrony. The aim of this study was to evaluate LV dyssynchrony in patients with LVH, and to compare abnormalities between hypertrophic cardiomyopathy (HCM), and hypertensive heart disease (HHD) using 2D speckle tracking imaging.
Methods: Basal, middle and apical LV short-axis harmonic images were acquired in 43 patients with LVH ( HCM: n=20, 6±14 years, HHD: n=23, 64±11 years) and 15 age-matched normal volunteers (64±8 years). Using commercially available software, peak radial and circumferential strain, and the time interval between the onset of the R wave on the ECG and peak radial strain (Trs), time to peak circumferential strain (Tcs) were measured from 3 LV short-axis images. At each level, 6 equidistant segments were analyzed. To assess LV dyssynchrony, the standard deviation (SD) of Trs and Tcs in 18 segments (Tps-18SD, Tcs-18SD) was calculated.
Result: Radial strain in the apical segments was significantly decreased in patients with HCM (16.8±8.3 ) compared to those in HHD (27.9±15.7, p<0.001). Circumferential strain in the apical segments was also significantly decreased in patients with HCM (−11.9±5.7) compared to those with HHD ( −18.9±5.2, p<0.001 ). Trs-18SD and Tcs-18SD were significantly prolonged in patients with HCM compared to those with HHD patients and normal volunteer (Trs-18SD: HCM; 83.4±30.6 ms, HHD; 50.7±19.8 ms, normal volunteer; 45.4±11.6 ms, p<0.0001, Trc-18SD: HCM; 74.0±28.5 ms, HHD; 45.7±13.8 ms, normal volunteer; 45.5±13.7 ms , p<0.0001). If we defined Trs-18SD> 69 msec (mean + 2SD in age-matched normal volunteer) as LV dyssynchrony, 15 of 20 HCM patients and 4 of 23 HHD patients showed LV dyssynchrony (p<0.001). If we defined Tcs-18SD> 74 msec (mean + 2SD in age-matched normal volunteer) as LV dyssynchrony, 11 of 20 HCM patients and none of HHD patients showed LV dyssynchrony (p<0.001).
Conclusion: The presence of LVH is not always associated with LV dyssynchrony. However, more reduction of apical strain value and exaggerated LV dyssynchrony in HCM than in HHD suggests the development of LVH in HCM reflects more pathological meanings.