Predictive value of Myocardial Acceleration During Isovolumic Contraction During Dobutamine Stress Echocardiography: Pulsed Wave Tissue Doppler Study

Background: Tissue Doppler echocardiography (DTE) can improve the diagnostic accuracy of dobutamine stress echocardiography (DSE) for detection of coronary artery disease, myocardial acceleration during isovolumic contraction or isovolumic acceleration (IVA) derived from tissue Doppler echocardiography may predict significant coronary stenosis.Aim of study: Comparing the regional response IVA to dobutamine stress echocardiography to coronary angiographic findings.Methods: 30 patient with chest pain suggestive of coronary artery disease (CAD) subjected to dobutamine stress tissue Doppler echocardiography prior to coronary angiography. Patients were classified according to the angiographic findings into group I (20 patients) with significant CAD and group II (10 subjects) with normal coronaries. IVA was analyzed at rest and peak stress in 360 segments distributed according the angiographic findings into 108 ischemic segments suppliedby culprit coronary artery distal to the site of stenosis (group IA), 132 non ischemic segments supplied by non diseased part of the culprit vessel or by non affected vessel (group IB) and 120 normal segments from control subjects. The diagnostic, accuracy of IVA to predict coronary stenosis was determined using cut-off values.Results: Regional IVA increased in dose dependent manner during dobutamine infusion. The response was blunted in the ischemic segments where the magnitude of change in IVA from rest to peak was significantly lower in group IA compared to group IB and group II. Globally the magnitude of change in IVA also significantly lower in group I than in group II. Increased IVA velocity by 60% from rest to peak stress predict significant coronary artery stenosis with 98% specificity.Conclusion: Regional changes of isovolumic acceleration during dobutamine stress echocardiography reflect regional wall motion and can be used specifically to predict coronaryartery stenosis with high accuracy.