What is the recommended echocardiographic approach to assess right ventricular function in patients with non‑valvular cardiac disease?

Echocardiographic Evaluation of Right Ventricular Function in Non-Valvular Cardiac Diseases

A comprehensive RV assessment requires a multiparametric approach using multiple acoustic windows, combining at least one measure of RV size (basal and mid-cavity linear dimensions) with multiple functional parameters including fractional area change (FAC), tricuspid annular plane systolic excursion (TAPSE), tissue Doppler-derived tricuspid lateral annular systolic velocity (S'), and when available, RV free wall longitudinal strain by speckle-tracking echocardiography. 1

Essential Imaging Windows

The evaluation must utilize multiple standardized views 1:

• RV-focused apical four-chamber view (mandatory - provides better visualization of the entire RV free wall than standard four-chamber view)
• Standard apical four-chamber view
• Modified apical four-chamber view
• Left parasternal long- and short-axis views
• Left parasternal RV inflow view
• Subcostal views

The RV-focused view is specifically recommended for measurements because it centers on the right ventricle rather than the left, avoiding underestimation of RV size 1.

RV Size Assessment

Linear Dimensions (2D Measurements)

Measure at end-diastole in the RV-focused view 1:

• Basal RV diameter (RVD1): Maximal transversal dimension in basal one-third of RV inflow
  • Abnormal if ≥41 mm
• Mid-cavity RV diameter (RVD2): Transversal diameter at mid-level, approximately halfway between base and apex at papillary muscle level
  • Abnormal if ≥35 mm

Important caveat: These linear dimensions are simple and fast but may underestimate RV size due to its crescent shape and are dependent on probe rotation 1.

RV Systolic Function Assessment

Mandatory Parameters (Choose At Least One)

The guidelines emphasize that no single parameter is sufficient - you must report multiple indices 1, 2:

1. Fractional Area Change (FAC)

   • Strongest correlation with MRI-derived RVEF (r=0.77-0.80) 3, 4
   • Abnormal if <35%
   • Most validated 2D parameter

2. Tricuspid Annular Plane Systolic Excursion (TAPSE)

   • M-mode measurement
   • Abnormal if <17 mm
   • Simple but angle-dependent

3. Tissue Doppler S' velocity (lateral tricuspid annulus)

   • Abnormal if <10 cm/s
   • Less load-dependent than TAPSE

4. RV Index of Myocardial Performance (RIMP/Tei index)

   • Can be calculated by pulsed Doppler or tissue Doppler

Advanced Parameters (Nice to Have)

RV free wall longitudinal strain by speckle-tracking echocardiography is the most accurate predictor of RV dysfunction 2, 5, 3:

• Shows strongest correlation with MRI-derived RVEF (r=-0.86) 3
• Abnormal if less negative than -17% (i.e., >-17%)
• Highest diagnostic accuracy (AUC 0.92) with 96% sensitivity and 93% specificity for detecting RVEF <45% 3
• More sensitive for detecting subclinical dysfunction than conventional parameters 5
• Particularly valuable in cardiomyopathies, especially arrhythmogenic RV cardiomyopathy 2

3D echocardiography for RV volumes and ejection fraction 2:

• Extensively validated against cardiac MRI 2
• Recommended when standard longitudinal function indices are globally reduced
• Requires good acoustic windows and proper laboratory experience

Critical Pitfall: Discordant Parameters

A major pitfall is relying on a single parameter - studies show that S' and FAC are discordant in up to 58% of patients (only concordant in 42% when abnormal) 6. This strongly supports the guideline recommendation for multiparametric assessment 1, 6.

Among less validated criteria, isovolumic acceleration (IVA) ≤1.8 m/s² has good diagnostic value and is least load-dependent, while 2D strain appears afterload and preload dependent 6.

Additional Mandatory Assessments

• RV systolic pressure: Calculate using tricuspid regurgitation jet velocity plus estimated RA pressure based on IVC size and collapsibility (report when complete TR Doppler envelope is present) 1
• Right atrial size: Part of comprehensive RV evaluation 1

Reporting Structure

The echocardiographic report should 1, 2:

• Present both qualitative and quantitative assessments
• Include multiple parameters (never rely on single measurement)
• Use RV-focused views for measurements
• Consider 3D volumes when feasible in patients with good windows
• Include RV strain in cardiomyopathy patients for incremental prognostic value 2

The strength of this multiparametric approach is that it accounts for the RV's complex crescent geometry and provides complementary information about longitudinal function (TAPSE, S'), global function (FAC), and regional mechanics (strain), maximizing diagnostic accuracy while minimizing the risk of misclassification from any single parameter's limitations.