[Usefulness of Doppler echocardiography in the diagnosis of complications in the acute phase of myocardial infarct].

Doppler echocardiography, providing objective data on heart anatomy and cardiac function, is a diagnostic method of unquestionable value in the acute phase of myocardial infarction. In what concerns myocardial infarction complications; echocardiography permits: a) evaluation of ventricular function, by quantifying heart failure and establishing the diagnosis of ventricular aneurysm; b) it is the most reliable method in the diagnosis of thrombi, and c) it constitutes a fundamental diagnostic tool in mechanical complications: rupture of the heart structures and evaluation of valvular competence. a) Evaluation of ventricular function. The analysis of ventricular dimensions and segmentary wall motion abnormalities permits the quantification of the infarct size and its repercussion upon the cardiac function. Otherwise, left ventricular proto and end diastolic filling rates give an idea about ventricular diastolic function alterations. b) Ventricular thrombi. The incidence of ventricular thrombi in AMI is variable, depending on the site of infarction and the number of segments with wall motion abnormalities. By echocardiography it has been demonstrated that 40% of the anterior transmural myocardial infarctions and 10% of the inferior ones disclosed thrombi, although the incidence of systemic embolism is scarce and similar on both anterior and inferior infarctions: nearly 2% during the first month after infarction. The criteria that identify the embolic risk include: thrombus size over 2 x 2 x 2 cm, pediculated and mobile thrombi. On the other hand, right intraventricular thrombi incidence is rare nearly 5% of right ventricular infarctions and post-infarction pulmonary embolism is probably more related to peripheral venous thrombus than to an intraventricular one. c) Mechanical complications. Echocardiography enables the direct diagnosis of interventricular septum and papillary muscles rupture in about 80% of the cases and although ordinary does not provide direct data on free ventricular wall rupture, the detection of pericardial effusion with high density echoes, together with finding of free right ventricular and atrial wall collapse, gives 80% of sensibility and over 90% of specificity in the diagnosis of free ventricular wall rupture. Finally, Doppler echocardiography permits the diagnosis and quantification of mitral and tricuspid regurgitation secondary to a rupture of even a simple disfunction of the atrioventricular subvalvular apparatus.