TRANSESOPHAGEAL ECHOCARDIOGRAPHIC STUDY OF RIGHT ATRIAL MYOCARDIAL-INFARCTION AND MYOCARDIAL VIABILITY

In Order to determine the effects of dobutamine on right atrial wall m ovement, two groups were studied using transesophageal echocardiograph y. Group A included six patients without ischemic heart disease. Group B included six patients with infarction of the inferior wall of both ventricles and abnormal wall movement of the right atrium. In group A, an increase in. the amplitude of right atrial movement was observed w ith dobutamine at doses of 5 and 10 mu g/kg per minute. In, group B, i nfusion of dobutamine did not modify, wall akinesis in three patients with right atrial infarction; in the remaining three, alterations of s egmental atrial movement were evident, and their responses to dobutami ne were related to the patency of right atrial coronary branches. The following conclusions were reached: (1) dobutamine has a positive inot ropic effect on atrial myocardium; (2) right atrial ischemia appears i n the echocardiogram as altered segmental or global wall movement; (3) dobutamine can be used in the evaluation of atrial myocardial viabili ty.