Correlation of left ventricular diastolic filling characteristics with right ventricular overload and pulmonary artery pressure in chronic thromboembolic pulmonary hypertension.

Objectives: This study was designed to determine a quantitative relationship between right ventricular (RV) pressure overload and left ventricular (LV) diastolic filling characteristics in patients with chronic thromboembolic pulmonary hypertension (CTEPH).

Background: Right ventricular pressure overload in patients with CTEPH causes abnormal LV diastolic filling. However, a quantitative relationship between RV pressure overload and LV diastolic function has not been established.

Methods: We analyzed pre- and postoperative diastolic mitral inflow velocities and right heart hemodynamic data in 39 consecutive patients with CTEPH over the age of 30 (55 +/- 11 years) with mean pulmonary artery pressure >30 mm Hg who underwent pulmonary thromboendarterectomy (PTE).

Results: After PTE, mean pulmonary artery pressure (mPAP) decreased from 50 +/- 11 to 28 +/- 9 mm Hg (p < 0.001) while cardiac output (CO) increased from 4.4 +/- 1.1 to 5.7 +/- 0.9 l/m (p < 0.001). Mitral E/A ratio (E/A) increased from 0.74 +/- 0.22 to 1.48 +/- 0.69 (p < 0.001). E/A was < 1.25 in all patients pre-PTE. After PTE, all patients with E/A >1.50 had mPAP <35 mm Hg and CO >5.0 l/min. E/A correlated inversely with mPAP (r = 0.55, p < 0.001) and directly with CO (r = 0.53, p < 0.001).

Conclusions: E/A is consistently abnormal in patients with CTEPH and increases post-PTE. Moreover, E/A varies inversely with mPAP and directly with CO. Following PTE, E/A >1.5 correlates with the absence of severe pulmonary hypertension (mPAP >35 mm Hg) and the presence of normal cardiac output (> 5.0 l/m).