Left ventricular apex-dimension loops in acute myocardial infarction.

Apex-dimension loops may provide useful information in patients with acute myocardial infarction because incoordinate contraction and relaxation can be demonstrated. The method could allow assessment of the effects of therapeutic interventions. Fifty consecutive patients with AMI in the coronary care unit within 48 hours after the onset of their symptoms were studied. Simultaneous recordings of the echocardiogram and apexcardiogram, which were of an adequate quality for analysis, were obtained in only 7 patients (success rate 14%). In all these patients, incoordinate relaxation was demonstrated. A major practical drawback of the method is the time needed for recording the basic data requiring 2 investigators. Therefore, because of the low success rate and difficulties in obtaining simultaneous recordings, apex-dimension loops are not practical in most patients with acute myocardial infarction.