Right Atrial Adaptation to Precapillary Pulmonary Hypertension: Pressure-Volume, Cardiomyocyte, and Histological Analysis.

Background: Precapillary pulmonary hypertension (precPH) patients have altered right atrial (RA) function and right ventricular (RV) diastolic stiffness.

Objectives: This study aimed to investigate RA function using pressure-volume (PV) loops, isolated cardiomyocyte, and histological analyses.

Methods: RA PV loops were constructed in control subjects (n = 9) and precPH patients (n = 27) using magnetic resonance and catheterization data.