Altered left ventricular diastolic indices as an iscremic response to dipyridamole stress echocardiography: a comparative study with exercise ECG and coronary angiography

ABSTRACT

The most commonly used provocative test for IHD remains treadmill exercise testing. Echocardiography is one of the several techniques which have been used in conjunction with that test to enhance its diagnostic accuracy. In this study we used a pharmacological stressor [dipyridamole] rather than exercise to overcome the difficulty to maintain adequate views during exercise. Thirty patients coming for coronary angiography were subjected to both exercise EGG and dipyridamole echo before angigraphy. By dipyridamole echo, regional wall motion, wall motion score index [WMSI] and LV diastolic indices by Doppler were assessed before and after dipyridamole infusion [high dose]. According to the result of coronary angiography, the patients were classified to group I [nine patients with normal coronaries] and group II [21 patients with CAD]. The overall sensitivity and specificity of exercise ECG in patients with CAD were 71% and 78%, respectively while the sensitivity and specificity of dipyridamole echo were 86% and 100%. respectively. Our study revealed a significant increase in mean WMSI in group II with a positive correlation to the extent of CAD. Dipyridamoie echo also had the ability to predict LAD and RCA lesions with good sensitivity *86% and 83% respectively] but less for LCX [70%]. All patients with CAD arid positive dipyridamole echo showed a significant change in LV diastolic indices denoting acute relaxation abnormality during ischemia. We concluded that dipyridamole echo is more sensitive than the exercise ECG in the diagnosis and detecting the extent of CAD