Valutazione non invasiva del profilo emodinamico nel paziente con scompenso cardiaco: Stima della portata cardiaca

In patients with chronic heart failure the estimation of cardiac output represents a valuable tool in assessing both prognosis and therapy. The thermodilution method during right heart catheterization remains the standard method, even if some echo-Doppler methods have been demonstrated to be feasible and accurate in determining cardiac output. Using echo-Doppler it is also possible to determine right atrial pressure (evaluating respiratory changes in the diameter of the inferior vena cava), the right ventricular-atrial pressure gradient (using the continuous wave Doppler of the tricuspid regurgitant jet) and, consequently, systolic pulmonary artery pressure. Diastolic pulmonary artery pressure can be calculated from the continuous wave Doppler of the pulmonary regurgitant jet, so mean pulmonary artery pressure can be calculated. Pulmonary capillary wedge pressure can be calculated by echo-Doppler using a few methods proposed in the literature. All these parameters allow for the calculation of the transpulmonary gradient and (with determination of cardiac output) of pulmonary vascular resistance. The main purpose is the assessment of prognosis after heart transplantation. Due to the fact that chronic heart failure patients need serial evaluations when awaiting for transplantation, echocardiography could became an alternative, safe and feasible procedure in these cases.