Quantification of Left Ventricular Systolic Function by Tissue Doppler Echocardiography Added Value of Measuring Pre- and Postejection Velocities in Ischemic Myocardium

TLDR: It is indicated that peak ejection velocity is an inappropriate measure of function in severely ischemic myocardium, and therefore IVC and IVR velocities are better markers of function.

Abstract: Background— Tissue Doppler imaging (TDI) is a potentially powerful method for diagnosing myocardial ischemia. This study was designed to investigate how velocity patterns in ischemic myocardium relates to regional function, and to determine whether timing of velocity measurements relative to ejection and isovolumic phases may increase the diagnostic power of TDI. Methods and Results— In 17 open-chest anesthetized dogs we measured pressures by micromanometers, myocardial longitudinal segment lengths by sonomicrometry, and velocities by TDI. Myocardial longitudinal strain rate was calculated as velocity divided by distance to the left ventricle apex. Moderate ischemia (left anterior descending coronary artery stenosis) caused parallel reductions in regional systolic shortening by sonomicrometry (P<0.05) and in peak systolic velocities by TDI (P<0.05). Severe ischemia (left anterior descending coronary artery occlusion), however, induced systolic lengthening by sonomicrometry (P<0.001), whereas peak TDI velo...