Objective: our goal was to characterize left ventricular regional systolic function using speckle tracking echocardiography (STE) in spontaneously hypertensive rats (SHR).
Background: Conventional ultrasonic parameters reflect indirectly myocardial function through the change of ventricular volume over a cardiac cycle, which is not quite sensitive and accurate. Angle-independent speckle tracking echocardiography has been proposed as sensitive tools to detect early regional systolic function abnormalities. Methods: Echocardiographic examinations were performed in 8 SHR and 6 normotensive Wistar-Kyoto rate (WKY). Two-dimendional acquisitions were anlyzed off-line to measure circumferential and radial strain and strain rate in parasternal short-axis view at the level of papillary muscle.
Results: Despite apparently normal left ventricular (LV) eject fraction(EF) and fractional shortening(FS), inferial and septal segmental circumferential strain, posterior, inferial and septal segmental circumferential strain rate, and almost all segmental and average radial strain rate but lateral and postal segments were reduced significantly in SHR (p<0.05). Anterier segmental circumferential strain rate is significantly lower than that of infereral and septal segments in WKY.
Conclusions: Hypertensive rats may have regional LV systolic function impairment despite having normal EF and FS. The EF and FS were not the decisive factors of myocardial systolic function in the present study. STE can be used to accurately recognize and quantify abnormalities of regional myocardial deformation.