Elevated frame rates during exercise echocardiography improve speckle-tracking success rate and augment deformation values.

Abstract

Although two-dimensional (2-D) speckle-tracking echocardiography (STE) is important for the clinical quantification of myocardial function, it remains unknown whether increased frame rates during exercise STE augment tracking success and absolute deformation values. Overall, 19 participants (15 males and 4 females; aged 26.7 ± 4.8) underwent stepwise exercise testing on a recumbent bicycle. Exercise started at 50 W, increasing by 30 W every 3 min until a target heart rate (HR) of 130-140 beats/min was reached. During the last 90 s of each exercise stage, echocardiographic sequences for offline quantification of longitudinal strain (LS), peak twist, untwisting velocity, basal rotation, and apical rotation were acquired with high [high frames per second (HFPS)], medium [medium frames per second (MFPS)], and low-frames per second (LFPS)]. Differences in tracking success were determined by using Chi-square test, and the impact of different frame rates on absolute deformation values was compared by using mixed-model analysis. Utilization of HFPS significantly improved tracking success for parasternal short-axis images. LS acquired at HFPS was the highest at baseline and across all the exercise stages. Similar trends were observed for twist, peak untwisting velocity, and apical rotation, whereas basal rotation showed no differences. Mixed-model analysis revealed a significant impact of frame rate setting on LS (P < 0.05) and untwisting velocity (P < 0.05). In contrast to recommendations by leading organizations advocating for frame rates between 40 and 80 frames per second (fps) during resting conditions, with a proportional increase as heart rate rises, our findings suggest that consistently maintaining the frame rate at the highest feasible level is preferable for achieving optimal-tracking success and accuracy in STE.NEW & NOTEWORTHY This study demonstrates the benefits of high frame per second (HFPS) rate settings in speckle-tracking echocardiography, achieving superior-tracking success and higher deformation values, including longitudinal strain and untwisting velocity, compared with lower frame rates. These advantages, particularly evident at elevated heart rates, highlight the importance of high temporal resolution for accurate cardiac imaging under stress conditions. The findings support prioritizing HFPS in clinical and research settings to improve tracking reliability and data accuracy.