Table 3. Evaluation of heart failure with preserved ejection fraction with speckle tracking echocardiography.

Study	Sample size with description	Imaging modality with vendor name	Objective	Outcomes
Phan et al. [48]	HfPEF (n=47) vs. young (n=27) vs. old controls (n=26)	2D-ECHO, 2D-STE (EchoPAC-GE)	Comparing strain profiles: HfPEF vs. age related changes	Increased TS seen with ageing. CS increase (-24.7% vs. -20%) differentiates HfPEF from old controls
Phan et al. [28]	HfPEF (n=38) vs. controls (n=33)	2D-ECHO and 2D-STE (EchoPAC-GE)	Dyssynchrony assessment in HfPEF	Systolic and diastolic dyssynchrony observed. LS impairment (-17.6% vs. -19.9%) and higher LV dyssynchrony (LS delay index-14.4% vs.-10.7%) noted
Donal et al. [39]	HfPEF (n=21) vs. controls (n=15)	2D-ECHO, exercise stress testing and 2D-STE (EchoPAC-GE)	To characterize resting and exercise induced strain changes	GLS impaired at rest [Rest: (-16% vs. -20%) and aggravated by stress: (-17% vs. -23%); similar trend with global CS
Kraigher-Krainer et al. [27]	HfPEF (n=219) vs. controls (n=50) and Hypertensive Heart Disease (n=44)	Vendor independent STE Software	Strain parameters in HfPEF	Lower LS and CS in HfPEF (-14.6±3.3 vs.. 20.0±2.1 in controls); Lower LS values co-related with higher NT-ProBNP

2D, 2 dimensional; CS, circumferential strain; ECHO, echocardiography; GLS, global longitudinal strain; HfPEF, heart failure with preserved ejection fraction; LS, longitudinal strain; RS, radial strain; STE, speckle tracking echocardiography; TS: torsional strain; BNP: Brain Natiuretic Peptide.