Measurements of RV on Echocardiography

Major Echocardiographic Views and Normal Dimensions of the Right Ventricle (RV) and Right Atrium (RA)

Right heart assessment is essential in pulmonary hypertension, congenital heart disease, RV infarction, cardiomyopathy, and advanced left-sided heart disease. Accurate chamber quantification should follow the recommendations of the American Society of Echocardiography (ASE) and the European Association of Cardiovascular Imaging (EACVI).

Right heart measurements are ideally obtained at end-diastole (for RV size) and end-systole (for RA area), using RV-focused views whenever possible.

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1. Apical 4-Chamber View (RV-Focused View)

This is the most important view for quantitative RV and RA assessment.

Technique: • Optimize by centering and enlarging the RV

• Avoid LV foreshortening

• Measure RV at end-diastole

• Measure RA at end-systole

Right Ventricle – Normal Dimensions (End-Diastole)

• RV Basal Diameter (RVD1): 25–41 mm

• RV Mid Cavity Diameter (RVD2): 19–35 mm

• RV Longitudinal Length (RVD3): 59–83 mm

RV Enlargement: • Basal diameter > 41 mm

• RV/LV basal ratio > 1

Right Atrium – Normal Dimensions (End-Systole)

• RA Major Dimension: ≤ 53 mm

• RA Minor Dimension: ≤ 44 mm

• RA Area: ≤ 18 cm²

RA Enlargement: • RA area > 18 cm²

Clinical relevance: RA enlargement correlates with chronic pressure overload, pulmonary hypertension, and adverse prognosis.

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2. Parasternal Long Axis (RV Inflow View)

Used for: • Tricuspid valve morphology

• RV inflow tract

• RV free wall thickness

RV Wall Thickness

Measured in subcostal view (preferred) or PLAX at end-diastole.

Normal: • ≤ 5 mm

RV Hypertrophy: • > 5 mm (suggests chronic pressure overload e.g., pulmonary hypertension)

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3. Parasternal Short Axis View

Provides complementary assessment.

Mid-ventricular level: • Compare RV size to LV

• Assess septal flattening

Septal flattening: • Systolic flattening → Pressure overload

• Diastolic flattening → Volume overload

• Persistent D-shaped LV → Severe pulmonary hypertension

RVOT Measurements

Measured in PLAX and PSAX.

Normal Values: • Proximal RVOT (PLAX): 20–30 mm

• Distal RVOT (PSAX): 17–27 mm

Enlargement suggests pulmonary hypertension or congenital heart disease.

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4. Subcostal View

Best for: • RV free wall thickness

• RA size

• IVC assessment

Although not a primary view for chamber quantification, it is particularly useful in patients with poor parasternal windows.

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Practical Approach to Right Heart Size Assessment

Step 1: Start with RV-focused apical 4-chamber

Step 2: Measure RVD1, RVD2, RVD3

Step 3: Measure RA area at end-systole

Step 4: Assess RV/LV ratio

Step 5: Confirm with parasternal and subcostal views

Step 6: Integrate with functional parameters (TAPSE, S′, FAC)

Right ventricular size alone is insufficient; always interpret in clinical context.

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Key Reporting Cutoffs (Quick Reference)

RV Dilatation: • RVD1 > 41 mm

• RV/LV basal ratio > 1

RA Dilatation: • RA area > 18 cm²

RV Hypertrophy: • Wall thickness > 5 mm

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Important Clinical Correlations

RV Dilatation Causes: • Pulmonary hypertension

• Pulmonary embolism

• Severe TR

• Congenital shunts

• RV cardiomyopathy

RA Enlargement Causes: • Chronic pulmonary hypertension

• Long-standing TR

• Atrial arrhythmias

• Right-sided volume overload

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Final Take-Home Points

• Use RV-focused apical 4-chamber for accurate measurement

• Measure RV at end-diastole, RA at end-systole

• RV basal diameter > 41 mm indicates enlargement

• RA area > 18 cm² indicates enlargement

• Wall thickness > 5 mm suggests RV hypertrophy

• Always interpret size with RV function and clinical scenario

Accurate right heart quantification improves diagnostic precision and prognostic stratification in cardiology practice.