Determinants of altered left ventricular suction in pre-capillary pulmonary hypertension

Although the left ventricular (LV) dysfunction in pre-capillary pulmonary hypertension (PH) has been recently recognized, the mechanism of LV dysfunction in this entity is not completely understood. We thus aimed to elucidate the determinants of intraventricular pressure difference (IVPD), a measure of LV suction, in pre-capillary PH.

Right heart catheterization and echocardiography were performed in 86 consecutive patients with pre-capillary PH (57 ± 18 years, 85% female). IVPD was determined using colour M-mode Doppler to integrate the Euler equation. In overall, IVPD was reduced compared to previously reported value in normal subjects. In univariable analyses, QRS duration (P = 0.028), LV ejection fraction (P = 0.006), right ventricular (RV) end-diastolic area (P < 0.001), tricuspid annular plane systolic excursion (P = 0.004), and LV early-diastolic eccentricity index (P = 0.009) were associated with IVPD. In the multivariable analyses, RV end-diastolic area and LV eccentricity index independently determined the IVPD.

Aberrant ventricular interdependence caused by RV enlargement could impair the LV suction. This study first applied echocardiographic IVPD, a reliable marker of LV diastolic suction, to investigate the mechanism of LV diastolic dysfunction in pre-capillary PH.