Estimating mean pulmonary wedge pressure in patients with chronic atrial fibrillation from transthoracic Doppler indexes of mitral and pulmonary venous flow velocity.

OBJECTIVES

We sought to obtain a noninvasive estimation of mean pulmonary wedge pressure (MPWP) in patients with chronic atrial fibrillation (AF).

BACKGROUND

It has previously been demonstrated that MPWP can be reliably estimated from Doppler indexes of mitral and pulmonary venous flow (PVF) in patients with sinus rhythm. Doppler estimation of MPWP has not been validated in patients with AF.

METHODS

MPWP was correlated with variables of mitral and pulmonary venous flow velocity as assessed by Doppler transthoracic echocardiography in 35 consecutive patients. The derived algorithm was prospectively tested in 23 additional patients.

RESULTS

In all patients the mitral flow pattern showed only a diastolic forward component. A significant but relatively weak correlation (r = -0.50) was observed between MPWP and mitral deceleration time. In 12 (34%) of 35 patients, the pulmonary vein flow tracing demonstrated only a diastolic forward component; a diastolic and late systolic forward flow was noted in the remaining 23 patients (66%). A strong negative correlation was observed between MPWP and the normalized duration of the diastolic flow (r = -0.80) and its initial deceleration slope time (r = -0.91). Deceleration time > 220 ms predicted MPWP < or = 12 mm Hg with 100% sensitivity and 100% specificity. When estimating MPWP by using the equation MPWP = -94.261 PVF deceleration time -9.831 Interval QRS to onset of diastolic PVF -16.337 Duration of PVF + 44.261, the measured and predicted MPWP closely agreed with a mean difference of -0.85 mm Hg. The 95% confidence limits were 4.8 and -6.1 mm Hg.

CONCLUSIONS

In patients with chronic AF, MPWP can be estimated from transthoracic Doppler study of PVF velocity signals.