9. Role of strain rate imaging in the detection of significant coronary artery stenosis

Abstract

Clinical Research. Oral Presentation. Nowadays, there are many methods for detection of significant coronary artery stenosis and myocardial ischemia either by imaging the coronaries or detecting myocardial perfusion abnormalities, but the majority of these methods needs either stress imaging or injection of contrast especially in patients with stable coronary artery disease (SCAD) where there is no resting electrocardiogram (ECG) changes or resting echocardiography wall motion abnormalities. With the development of tissue Doppler imaging, new methods like strain and strain rate imaging were developed followed by the development of the speckle tracking imaging. Strain and strain rate imaging can detect myocardial deformation which is the basis of myocardial function, thus with impaired myocardial perfusion the amount and rate of deformation decreases. Thirty patients with SCAD and significant single vessel left anterior descending (LAD) coronary artery stenosis, diagnosed by invasive coronary angiography, undergoing elective percutaneous coronary intervention (PCI) of the LAD lesion with no significant lesions in the other coronary vessels, left circumflex (LCX) and right coronary artery (RCA). Patients with diabetes, regional wall motion and reduced left ventricular systolic function were excluded. Regional systolic strain and strain rate was measured in the ischemic LAD segments which are six, apicoseptal, mid anteroseptal, basal anteroseptal, apicoanterior, mid anterior and basal anterior, and measured in the non-ischemic LCX and RCA segments, before elective PCI of LAD and three months later. By comparing the strain and strain rate of the ischemic segments before and after PCI there was significant improvement of the systolic strain while there were non-significant changes in the non-ischemic segments. Tissue Doppler strain and strain rate imaging during resting echocardiography can be used to detect regional myocardial ischemia in patients with significant coronary artery stenosis.