Three-dimensional echocardiography to evaluate right atrial volume and phasic function in pulmonary hypertension

Area of Science:

• Cardiology
• Pulmonary Hypertension Research
• Cardiac Imaging

Background:

• Pulmonary hypertension (PH) significantly impacts right ventricular (RV) systolic and diastolic function.
• Compensatory changes in right atrial (RA) function occur in response to RV dysfunction, but their exact role is debated.
• Understanding RA function's contribution is key to managing PH progression and patient outcomes.

Purpose of the Study:

• To investigate the role of right atrial (RA) function in compensating for right ventricular (RV) dysfunction in patients with pulmonary hypertension (PH).
• To determine if RA function is more critical in compensating RV dysfunction than in preventing clinical failure in PH.
• To evaluate specific RA volumetric and functional parameters using 3D echocardiography (3DE).

Main Methods:

• Studied 54 patients with PH and 23 healthy controls.
• Utilized 3D echocardiography (3DE) to assess RA volumes (maximum, minimum, pre-atrial systole).
• Calculated RA indices: maximum volume index (VmaxI), total emptying volume index (TotEVI), passive emptying volume index (PassEVI), and active ejection fraction (ActEF).
• Employed ROC curve analysis to predict World Health Organization functional class (WHO-FC) IV.

Main Results:

• Patients with PH exhibited higher RA maximum volume index (RAVmaxI) compared to controls.
• RA total emptying volume index (TotEVI) was significantly higher, while passive emptying volume index (PassEVI) was lower in PH patients.
• Active ejection fraction (ActEF) increased in WHO-FC III but decreased in WHO-FC IV PH.
• 3D RA ActEF demonstrated superior predictive value for WHO-FC IV compared to other 2D and 3D RA parameters.

Conclusions:

• Right atrial (RA) function plays a significant compensatory role in right ventricular (RV) dysfunction associated with pulmonary hypertension (PH).
• The active ejection fraction (ActEF) of the RA is a critical indicator, showing adaptive increases then declines in advanced PH.
• RA function's importance extends beyond merely preventing clinical failure, actively contributing to RV compensation in PH.