LEFT SYSTOLIC ATRIOVENTRICULAR PLANE DISPLACEMENT IN THE ASSESSMENT OF MYOCARDIAL VIABILITY IN PATIENTS WITH PREVIOUS MYOCARDIAL-INFARCTION

In order to detect myocardial viability in coronary artery disease pat ients (CAD) with a previous myocardial infarction and dysfunction of t he left ventricle (LV), the reliability of the left atrioventricular p lane displacement (LAVPD) during low dose dobutamine stress echocardio graphy (DSE), was validated. The study population consisted of 70 CAD patients and 35 age and sex matched healthy subjects. From the apical four and two chamber views the LAVPD was recorded and measured by M-mo de echocardiography, at Sour sites corresponding to the septal, latera l, anterior and inferior walls of the LV, prior and during the DSE (5- 10 mu g/kg/min). All patients underwent exercise SPECT Thallium-201 wi th four-hour redistribution and rest-reinjection, in order to determin e tissue viability. Intraobserver and interobserver variability for th e LAVPD tvas insignificant (5.8% and 7.2%, respectively). Healthy subj ects exhibited a significant and equally distributed maximal increase of the LAVPD, at all sites during dobutamine infusion (DI) (p<0.001). Patients also, showed a significant maximal increase of the LAVPD duri ng DI, at all asynergic sites in which viable tissue was found (p<0.00 1). However, in the asynergic sites without viable tissue the LAVPD di d not significantly change (p<0.05). Selecting a LAVPD increase of > 2 mm to detect viable myocardium at any asynergic site of LV, resulted in a sensitivity of 91% and specificity of 89%. When DSE was used for the detection of viable myocardium, sensitivity and specificity were f ound to be 80% and 87% respectively. The proportion of agreement betwe en the two above mentioned methods was 82%. When the two methods were in agreement, the positive and negative predictive values were 94% and 97%, respectively. The validity of the above mentioned increase of th e LAVPD was also prospectively examined in a similar group of 35 CAD p atients exhibiting myocardial dysfunction as a result of a previous my ocardial infarction (sensitivity 85% and specificity 90%, respectively ). Conclusions: 1) The assessment of left LAVPD during DI is a new qua ntitative, accurate method with a low intraobserver and interobserver variability, in detecting viable myocardium. 2) Combination of this me thod and DSE proved good diagnostic markers of myocardial viability.