Feasibility of Early Myocardial Infarction Detection in the Emergency Department Using Maximum Principal Strain

Myocardial Infarction (MI) is the leading cause of death across most demographic lines in the United States, and one of the leading causes of death worldwide [1]. Early detection, as well as understanding of the extent of the damage done are imperative to survival and recovery. MI can be clinically characterized by identifying abnormalities in the muscle function of the cardiac muscle, which can be quantified by calculating strain of the muscle. Myocardial Elastography (ME) is a strain estimation technique using a 1-D cross-correlation algorithm in a 2-D search, then a least-squares strain estimator, on RF data acquired at 300 Hz. ME has been shown to be able to detect radial strain abnormalities resulting from blockages of the main arteries which supply blood to the ventricular myocardium [6]. In this study, ME was applied to echocardiographic beamformed RF signals acquired from patients presented with chest pain (angina) in the Emergency Room. ME strain calculations were compared to clinical findings in a pilot study in order to assess performance of ME in informing on presence and stage of heart disease at the point-of-care cardiac imaging. The findings of the pilot study demonstrate that patients experiencing MI have maximum principal strains significantly (p<0.01, Mann-Whitney) lower (19.0%+/-2.0%) compared to patients experiencing angina due to other co-morbidities (23.6%+/-5.1%).