Acute changes in systolic and diastolic events during clinical coronary angioplasty: A comparison of regional velocity, strain rate, and strain measurement

Ultrasound-derived natural strain rate and strain are new Doppler myocardial imaging (DMI) parameters, which can measure local deformation independently of overall heart motion and thus could better characterize local contractility than DMI velocities alone. This study was undertaken to evaluate the relative benefits of regional velocity, strain rate, and strain measurements in detecting the range of acute changes in regional myocardial function in the at-risk zone during coronary angioplasty. Sixty-one patients (aged 63 12, 18 women) with stable angina pectoris were studied before, at the end of, and during recovery from a 60-second percutaneous transluminal coronary angioplasty (PTCA) balloon occlusion. High frame rate (147 fps) color DMI regional velocity data were derived from basal posterior (parasternal view) and mid, apical septal (apical view) at-risk segments as welt as from the corresponding segments in healthy subjects and analyzed offline for velocity (VEL), strain rate (SR), and strain (E) measurements. Coronary occlusion resulted in the reduction in VELSYS, SRSYS, and epsilon(SYS) values for both radial (RCA/CX occlusion) and longitudinal data (LAD occlusion) in all segments analyzed. Velocity parameters alone failed to distinguish between baseline and occlusive measurements in the at-risk segments with visually abnormal baseline function. SRSYS and epsilon(SYS) had a higher diagnostic accuracy (sensitivity 75%, 80% and specificity 80%, 82%, respectively) than VELSYS velocity alone (sensitivity 68%, specificity 65%,) for identifying acute ischemia in either baseline normal and abnormal segments. DMI-derived indexes can identify and quantify the spectrum of acute systolic and diastolic ischemic changes induced during clinical PTCA. The quantitation of regional deformation rather than motion would appear to be more appropriate in detecting and quantifying acute ischemic changes in myocardial function, especially in segments with pre-existing abnormal function.