[Non-invasive evaluation of the hemodynamic profile in patients with heart failure: estimation of left atrial...

The management of patients with heart failure requires an accurate and non-invasive estimation of left ventricular filling pressures. This is essential in order to optimize unloading treatment, interpret equivocal symptoms, assess disease severity (and prognosis), and follow up the hemodynamic effect of long-term treatments. Since Doppler technique was implemented, several non-invasive methods to estimate left ventricular filling pressures were developed. Among these, a method based on the calculation of the left ventricular-atrial pressure gradient and its subtraction from systolic arterial blood pressure can be used in patients with significant mitral regurgitation and well-defined continuous wave Doppler signal of the regurgitant flow. Mitral and pulmonary venous flow velocities, as assessed by pulsed Doppler, are closely related to left atrial pressures, and several derived indices can be used to qualitatively estimate left ventricular filling pressures in patients with heart failure due to left ventricular systolic dysfunction who are in sinus rhythm. Furthermore, the combination of these indices in multivariable equations can improve this relationship and allows for a quantitative estimation of filling pressures, even in patients with significant mitral regurgitation and atrial fibrillation. There are, however, several groups of patients with heart failure in whom pulsed Doppler of mitral and pulmonary venous flow provides limited hemodynamic information. These include those with a) sinus tachycardia and/or prolonged P-R interval; b) normal left ventricular systolic function (and "pure" diastolic heart failure); c) primarily abnormal left atrial dysfunction (such as patients who had undergone heart transplantation), and d) technically inadequate Doppler recordings of pulmonary venous flow. To assess left ventricular filling pressures in these patients, two new methods which combine pulsed Doppler mitral flow indices with load-independent indices of left ventricular relaxation (either early diastolic velocity of mitral annulus, as assessed by tissue Doppler, or propagation velocity of mitral inflow, as assessed by color M-mode) can be used.