Right heart flow hemodynamic assessment using 4D flow CMR: a systematic review

Area of Science:

• Cardiovascular Imaging
• Medical Physics
• Hemodynamics

Background:

• Right heart dysfunction significantly impacts cardiovascular disease outcomes.
• Detailed assessment of right atrial (RA) and right ventricular (RV) hemodynamics is crucial.
• Four-dimensional flow cardiovascular magnetic resonance (4D flow CMR) offers advanced physiological evaluation.

Purpose of the Study:

• To systematically review studies utilizing 4D flow CMR for assessing RA and RV hemodynamics.
• To synthesize findings on flow dynamics, kinetic energy (KE), and energy loss (EL) in health and disease.
• To evaluate the utility of 4D flow CMR in understanding right heart function.

Main Methods:

• Systematic literature search of the Scopus database (up to March 2025).
• Inclusion of observational studies on adult right heart function assessed by 4D flow CMR.
• Narrative synthesis of data on RA/RV flow dynamics, KE, EL, and hemodynamic parameters; quality assessment using the AXIS tool.

Main Results:

• 17 studies (894 participants) met eligibility criteria, including healthy individuals and patients with pulmonary hypertension (PH).
• RA flow dynamics showed a dominant vortex in health, disrupted in disease; RV flow components demonstrated reduced direct flow and increased residual volume with disease.
• Alterations in atrial and ventricular KE were observed based on age, sex, and disease. Increased EL was noted in PH.

Conclusions:

• 4D flow CMR is a potent tool for evaluating novel right heart hemodynamic parameters.
• Quantification of flow patterns, components, and energetics provides a comprehensive assessment of right heart function.
• This approach holds promise for enhanced diagnosis, management, and prognostic stratification of right heart diseases.