The relationship between abnormal echocardiographic septal motion and myocardial perfusion in patients with significant obstruction of the left anterior descending artery.

Abstract

This study assesses the relationship between segmental myocardial function and coronary perfusion in patients with high-grade stenosis of the left anterior descending artery. Twenty-five patients with critical lesions (> 70%) were divided into two groups according to the absence or presence of normal echocardiographic septal motion. Twelve patients had abnormal echocardiographic septal motion (AESM) and 13 patients had normal septal motion. Septal perfusion was evaluated by intracoronary injections of radiolabeled macroaggregated albumin (MAA) particles. Of the parameters analyzed abnormal septal perfusion was best related to AESM. Among the 12 patients with AESM, ten had absent resting septal perfusion. Of the 13 patients with normal septal ECHOCARDIOGRAPHY HAS NOW BECOME a useful and accepted noninvasive procedure for evaluating left ventricular performance.' Although the procedure has been most helpful in assessing left ventricular function when the ventricle is diffusely diseased, the echocardiogram is also of proven benefit in defining abnormal contractility in patients with coronary artery disease.8 '0 However, since all segments of the ventricle are not accessible by echocardiography and since coronary disease may produce segmental ventricular dysfunction, it is not always possible to detect all diseased segments of the ventricle. On the other hand, the echocardiogram can provide useful information regarding the interventricular septum, a structure which is not easily evaluated by conventional angiographic techniques."' 12 An important and common cause of abnormal echocardiographic septal motion (AESM) is high grade obstruction of the left anterior descending artery.5' 10, 13 This abnormality of the septum when seen in the presence of significant obstruction of the left anterior descending would seem to imply myocardial ischemia and/or infarction or fibrosis of the septum. A recent report which includes pathological studies related septal thinning to scarring of the septum.'2 Some authors have further suggested that AESM implies not only a critical left anterior descending lesion, but that the lesion is proximal to the first septal perforator branch.10 13Despite the usefulness of coronary angiography in defining the presence of significant obstruction of the major coronary arteries, the procedure does not allow visualization of small vessels and therefore does not provide complete information concerning resting myocardial perfusion. motion, only two had abnormal septal perfusion. Septal width was also significantly thinner in patients with AESM. When angiographic collateralization was associated with septal perfusion as detected by injection of MAA into the right coronary artery, normal septal motion was present (five patients). When no septal perfusion resulted from right coronary injection, even though collaterals were seen angiographically, AESM was found (four patients). Thus, in patients with severe left anterior descending stenosis the presence of abnormal echocardiographic septal motion strongly sug...