Stress echocardiography (ECHO) has a slightly higher specificity compared with stress nuclear testing and stress electrocardiography (ECG), according to Hossam El-Gendi, MD, Essex Cardiothoracic Centre, Essex, United Kingdom. A retrospective review that he conducted of 1000 patients showed that stress ECHO better defined the probability of coronary artery disease than exercise treadmill testing [Hopkinson SA, El-Gendi H. 2012].

Exercise ECG is no longer performed in the United Kingdom because it is seen as more harmful than beneficial, he stated. Exercise ECG compared with coronary angiography had a wide variability in its mean sensitivity (68%; range, 23 to 100) and mean specificity (77%; range, 17 to 100) in a meta-analysis of 147 consecutive studies with 24 074 patients conducted in the late 1980s.

Stress ECHO is limited to wall motion analysis, which captures only 30% of myocardial function, but determining the rate of strain between 2 points in the myocardium provides complementary data to determine the overall myocardial function. Longitudinal strain is an effective tool to evaluate the true systolic function of patients, for example in hypertrophic cardiomyopathy, which is characterized by a normal ejection fraction and decreased (by ≤ 20%) global longitudinal strain. Prof El-Gendi stated that speckle tissue tracking is reproducible, has less intraobserver and interobserver variability, and is a useful approach to judge ventricular function and rate of strain.

Automated function imaging, based on 2D strain technology, has been documented to quantify myocardial motion and deformation under rest conditions and is the subject of global collaborative research to determine its best use to enhance clinical decision making. Automated function imaging provides a rapid, reproducible, quantitative tool for the assessment of segmental and global wall motion, said Prof El-Gendi.

Furthermore, using speckle tissue tracking with stress ECHO is simple and can be used in daily practice to answer common clinical questions, stated Prof El-Gendi. In patients with cardiac resynchronization therapy, it provides more information about left ventricular synchrony and performance, and atrioventricular timing, to better manage hemodynamics in patients with heart failure. It can be used to assess coronary arteries, ischemia in the left anterior descending artery and inferior of the myocardium, left ventricular hypertrophy (LVH), hypertrophic obstructive cardiomyopathy, nonischemic cardiomyopathy, and cardiac amyloid. The strain presentation in LVH is characterized by a decrease in the basal strain segments, normal apical segments, and a strain bulls-eye “donut.”

Stress ECHO with speckle tissue tracking is an emerging tool that should be used in clinical practice to master it, urged Prof El-Gendi, because it has opened the window to evaluate the myocardium from the inside to the outside.