Vorticity is a marker of right ventricular diastolic dysfunction

Area of Science:

• Cardiology
• Fluid Dynamics
• Medical Imaging

Background:

• Right ventricular diastolic dysfunction (RVDD) is a key prognostic factor in pulmonary arterial hypertension (PAH).
• The role of right ventricular (RV) vortex dynamics, measured by vorticity, in RVDD remains unclear.
• Vorticity quantifies fluid's local spinning motion and may offer sensitive insights into RV function.

Purpose of the Study:

• To investigate the relationship between right heart vorticity and echocardiographic indicators of RVDD in PAH patients.
• To explore the potential of four-dimensional (4D) flow cardiac magnetic resonance imaging (CMR) for assessing RV fluid mechanics.

Main Methods:

• Thirteen PAH subjects and 10 controls underwent same-day 4D flow CMR and echocardiography.
• RV diastolic function was assessed using trans-tricuspid valve (TV) early (E) and late (A) velocities, E/A ratio, and tissue Doppler velocities (e', a').
• Integrated mean vorticity in the RV and right atrium (RA) was calculated for E- and A-wave filling periods.

Main Results:

• A-wave vorticity was significantly increased in the RV and RA of RVDD subjects compared to controls.
• RA E-wave vorticity was significantly decreased in RVDD subjects.
• E-wave vorticity correlated with TV e', E, and E/A; A-wave vorticity correlated with TV A and E/A.

Conclusions:

• RVDD in PAH is associated with significant alterations in RV and RA vorticity during diastolic filling.
• Vorticity measurements correlate with established echocardiographic markers of RVDD.
• Vorticity shows promise as a noninvasive research tool for investigating RV fluid and tissue interactions in PAH.