Evaluating left ventricular systolic dysfunction: Stress echocardiography

Dyspnea is a common complaint in clinical practice. It has been shown to be a strong predictor of mortality in patients referred for stress testing to evaluate the cardiac reasons for symptoms. 1 Echocardiography and commonly stress echocardiography are high-yield initial tests in evaluation of patients with unexplained dyspnea. In one study, stress echocardiography provided a potential explanation for dyspnea in[50% of referred patients 2 ; this study did not include assessment of post-exercise diastolic function or novel techniques to assess myocardial mechanics which may provide incremental diagnostic information. 3 The patient in question presents with chronic exertional dyspnea (8 months duration) without chest pain. She has strong cardiovascular risk factors (type 2 diabetes mellitus and hypertension). Her QRS complex duration is presumably narrow. Baseline echocardiogram shows mildly enlarged left ventricle and moderate systolic left ventricular dysfunction with diffuse hypokinesis (left ventricular ejection fraction of 35%). There is no significant valvular abnormality, right ventricular function is preserved, and estimated resting pulmonary artery systolic pressure is borderline (35 mm Hg). Resting echocardiogram can provide important clues to the cause of the left ventricular systolic dysfunction and may further assist in risk stratification. Presence of regional wall motion abnormalities concordant with coronary distribution and echo-bright areas of myocardial thinning may help with differential diagnosis but absence of these findings in this patient does not rule out ischemic cardiomyopathy. Additional resting echocardiographic information that should be obtained in this patient includes estimated resting left ventricular filling pressures and global longitudinal strain. In parallel with initiating guideline-directed medical therapy, the important question is how to proceed with work-up for the cause of her systolic left ventricular dysfunction in a way that is accurate, safe, cost-effective, and prognostically relevant. We believe stress echocardiography is the best initial test for this patient.