Transthoracic and transesophageal echocardiography in the hemodynamic assessment of patients with congestive heart failure

All methods for estimating the severity of heart failure, such as clinical and radiographic examination, measures of ventricular performance, and exercise capacity, when used independently, have major limitations. Echocardiography can be used, not only to assess left-ventricular ejection fraction but also other determinants of prognosis (i.e., left-ventricular size and shape, estimation of left atrial and pulmonary artery pressures, right side involvement). The availability of continuous-wave Doppler has permitted us to evaluate pulmonary artery systolic pressure from tricuspid regurgitation, and this contributes to additional powerful data. In long-standing heart failure, pulmonary artery wedge pressure is a predictor of survival, and aggressive therapy to reduce wedge pressure improves survival. Noninvasive estimation of left-atrial pressure and left-ventricular filling pressure have been attempted by continuous-wave Doppler echocardiography in patients with heart failure and mitral regurgitation and by tissue Doppler imaging at the mitral annulus level. A significant relation has been reported between profiles of pulmonary venous flow and left-atrial pressure, but pulmonary venous flow indexes can be better assessed by transesophageal echocardiography (TEE) in terms of detection rate. It has recently been recognized that TEE can provide valuable information on intracardiac hemodynamics and ventricular function. Two-dimensional evaluation of ventricular function and pulsed- and continuous-wave Doppler recordings from the pulmonary artery, pulmonary vein, and mitral inflow are combined to provide these data, which are both qualitative and quantitative, and permit estimation of ventricular ejection fraction, left-atrial pressure, and cardiac output. It would be important to be able to stratify patients with congestive heart failure according to groups with the highest risk for early death because heart transplantation or aggressive medical treatment could be specifically applied to this population. Serial echocardiographic evaluations of the classic variables of systolic left-ventricular function as well as Doppler transmitral flow may be useful in monitoring the progression of the disease and the effects of medical treatment. The degree of pulmonary hypertension is independently associated with the restrictive left-ventricular diastolic filling pattern and with the degree of functional mitral regurgitation. Future studies on the impact of these hemodynamic variables on the outcome of patients with left-ventricular dysfunction are desirable.