Left systolic atrioventricular plane displacement in the assessment of myocardial viability in patients with previous myocardial infarction.

UNLABELLED

In order to detect myocardial viability in coronary artery disease patients (CAD) with a previous myocardial infarction and dysfunction of the left ventricle (LV), the reliability of the left atrioventricular plane displacement (LAVPD) during low dose dobutamine stress echocardiography (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-mode echocardiography, at four sites corresponding to the septal, lateral, anterior and inferior walls of the LV, prior and during the DSE (5-10 micrograms/kg/min). All patients underwent exercise SPECT Thallium-201 with four-hour redistribution and rest-reinjection, in order to determine tissue viability. Intraobserver and interobserver variability for the LAVPD was insignificant (5.8% and 7.2%, respectively). Healthy subjects 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 during DI, at all asynergic sites in which viable tissue was found (p < 0.001). However, in the asynergic sites without viable tissue the LAVPD did 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 found to be 80% and 87% respectively. The proportion of agreement between 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 the LAVPD was also prospectively examined in a similar group of 35 CAD patients exhibiting myocardial dysfunction as a result of a previous myocardial infarction (sensitivity 85% and specificity 90%, respectively).

CONCLUSIONS

1. The assessment of left LAVPD during DI is a new quantitative, accurate method with a low intraobserver and interobserver variability, in detecting viable myocardium. 2) Combination of this method and DSE proved good diagnostic markers of myocardial viability.