Continuous hands-free monitoring of echocardiographic exercise test using probe fixation device

Stress echocardiography has been widely used in clinical practice for decades and has recently gained even more importance in diagnostic approaches to ischemic heart disease. However, it still has numerous limitations. Despite advantages of physical exercise as most physiologic stressor, it is impossible to continuously monitor the cardiac function during treadmill test and difficult to maintain an optimal acoustic window during cycle ergometer exercise tests. The aim herein, is to assess the feasibility of probe fixation for use during exercise echocardiography.

Forty-eight subjects (47 men, mean age 42 ± 17 years, 25 healthy volunteers, 23 patients with suspected coronary artery disease) were included in this study. All subjects underwent exercise stress test on treadmill (32 cases) or cycle ergometer (16 cases). Both sector and matrix probes were used (in 17 and 31 tests, respectively). The semi-quantitative quality of acquired apical views were assessed at each stage using a four-point grading system.

The mean time required for probe fixation was 9 ± 2 min. At baseline, 10 patients had at least one apical window of quality precluding reliable analysis. Twenty-five patients required probe repositioning during exercise (more often on a treadmill). During peak exercise quality of images in all views declined, but for diagnostic purposes it remained sufficient in 29 patients. Thus, 76% of performed tests (60% study population) had sufficient image quality.

Probe fixation offers the possibility of continuous acquisition of echocardiographic images during physical exercise. The device is suitable almost exclusively for male patients and in some patients requires repositioning.