Diastolic Abnormalities Detected by Velocity Vector Imaging in the Presence of Coronary Ischemia: A Pilot Stress Echocardiographic Study

BACKGROUND: The ischemic cascade has long been known to begin with diastolic dysfunction before detectable systolic abnormalities. The advent of speckle-tracking imaging and velocity vector imaging (VVI) has provided accurate and reproducible interpretation of systolic abnormalities in numerous disease processes; however, this imaging tool has been only recently been proposed for detecting diastolic abnormalities. METHODS: We analyzed pre and poststress echocardiography images of ten patients using VVI. We calculated normalized strain time (NST) as the duration strain was at least 90% of the measured peak and subtracted pre and poststress NST to calculate prolongation of NST as a sign of diastolic dysfunction. These intervals were measured from left ventricular longitudinal cine images obtained from two and 4-chamber in five patients not only with a positive stress echocardiographic response but also anatomy confirmed by coronary angiography. They were then compared to five patients without coronary artery disease (CAD). RESULTS: Differences in pre and poststress NST measured in the apical 4-chamber view were greater in CAD patients than without (40 ± 16 vs. 12 ± 19; P = 0.04). CONCLUSIONS: Significant diastolic abnormalities were detected using a semi-automated VVI analysis in the poststress recovery period. A prospective study is now required in a larger number of patients to correlate the development of diastolic strain abnormalities with extent and location of CAD.