Table 4.

Correlates of strain and early diastolic strain rate in the healthy population

	Peak Systolic Strain
	Longitudinal Four-chamber			Longitudinal Two-chamber			Circumferential			Radial
R2	0.13			0.19			0.05			0.04
Constant term*	−22			−22			−16			18
	β	SE	S-β	β	SE	S-β	β	SE	S-β	β	SE	S-β
Frame rate (fps)	−0.002	0.060	−0.001	−0.034	0.049	−0.032	0.001	0.034	0.001	−0.281	0.140	−0.088†
Sub-optimal image (vs. Optimal)	0.624	0.222	0.121†	0.669	0.285	0.113†	0.597	0.286	0.091†	−1.042	1.192	−0.038
Age (years)	0.028	0.027	0.046	0.025	0.033	0.039	−0.015	0.033	−0.021	0.056	0.138	0.019
Female (vs. Male)	−0.948	0.207	−0.209‡	−1.200	0.245	−0.250‡	−0.812	0.252	−0.150†	0.274	1.049	0.012
White (vs. Black)	−0.593	0.233	−0.122†	−0.978	0.276	−0.188‡	−0.261	0.283	−0.045	−1.377	1.180	−0.058
Educational years	0.002	0.041	0.002	−0.012	0.049	−0.013	−0.003	0.050	−0.002	0.363	0.209	0.082
Body mass index (Kg/m2)	0.021	0.036	0.028	0.054	0.045	0.063	0.007	0.043	0.008	0.056	0.180	0.015
Heart rate (bpm)	0.037	0.010	0.153‡	0.058	0.012	0.226‡	0.009	0.013	0.033	−0.129	0.052	−0.109†
Systolic blood pressure (mmHg)	0.023	0.009	0.120†	0.015	0.010	0.073	0.014	0.011	0.060	0.107	0.046	0.112†

	Early-Diastolic Strain Rate
	Longitudinal Four-chamber			Longitudinal Two-chamber			Circumferential			Radial
R2	0.10			0.14			0.06			0.02
Constant term*	2.10			1.7			1.0			−1.4
	β	SE	S-β	β	SE	S-β	β	SE	S-β	β	SE	S-β
Frame rate (fps)	−0.012	0.007	−0.077	0.005	0.006	0.039	−0.007	0.004	−0.074	0.017	0.015	0.049
Sub-optimal image (vs. Optimal)	−0.020	0.024	−0.036	0.015	0.032	0.022	−0.024	0.033	−0.031	−0.034	0.128	−0.012
Age (years)	−0.011	0.003	−0.162‡	−0.015	0.004	−0.200‡	0.000	0.004	−0.004	0.006	0.015	0.017
Female (vs. Male)	0.101	0.023	0.206‡	0.134	0.028	0.253‡	0.056	0.029	0.088	−0.172	0.113	−0.071
White (vs. Black)	0.043	0.025	0.082	0.012	0.031	0.021	−0.010	0.033	−0.014	0.450	0.127	0.175‡
Educational years	−0.002	0.004	−0.019	0.004	0.006	0.037	0.011	0.006	0.088	−0.067	0.022	−0.141†
Body mass index (Kg/m2)	−0.004	0.004	−0.054	−0.012	0.005	−0.124†	−0.011	0.005	−0.107†	−0.005	0.019	−0.012
Heart rate (bpm)	0.001	0.001	0.028	−0.002	0.001	−0.057	0.003	0.001	0.081	0.000	0.006	−0.003
Systolic blood pressure (mmHg)	−0.002	0.001	−0.077	0.000	0.001	−0.008	−0.002	0.001	−0.065	−0.004	0.005	−0.038

Multivariate linear regressions to evaluate association of strain and strain rate with demographics, anthropometrics, hemodynamic variables and technical parameters.

R² = coefficient of determination. S-β=standardized beta-coefficient. SE=standard error.

^*Constant term = Y intercept derived from multivariable linear regression.

^†p<.05

^‡p<.001