[How to assess dysfunction of the left ventricle after myocardial infarction with Doppler echocardiography]

Doppler echocardiography is one of the most useful non-invasive methods of cardiac imaging in patients who have suffered myocardial infarction because it provides important information such as the immediate identification of the infarct, its size, possible mechanical complications and an assessment of its effects on global ventricular function, all in a single procedure. Several mathematical formulae have been proposed to quantify global left ventricular function from two-dimensional imaging; the most commonly used are the surface-length method based on the parasternal short axis view (V = 5/6 A.L) and reconstruction by Simpson's method based on two orthogonal apical views. Hemodynamic data may be obtained by Doppler studies, especially of the ejection phase (transaortic velocities and cardiac output determination) and left ventricular filling. The effects of left ventricular dysfunction on the right heart may be evaluated when tricuspid regurgitation is present as right ventricular and pulmonary artery systolic pressures can be determined. The non-invasive nature of Doppler echocardiography enables documentation of these parameters of ventricular function as often as the patient's clinical status requires during follow-up, or to assess the effects of treatment in the post-infarction period.