What does a slight prominence of the sinus of Valsalva at 3.5 cm on an echocardiogram (echo) indicate?

Sinus of Valsalva at 3.5 cm: Clinical Interpretation

A sinus of Valsalva measurement of 3.5 cm on echocardiography is within the upper range of normal for most adults and requires comparison to age- and body surface area (BSA)-adjusted reference values to determine if true dilatation exists.

Normal Reference Values

The interpretation of your 3.5 cm measurement depends critically on patient-specific factors 1:

• Normal adult men: 3.4 ± 0.3 cm (range approximately 3.1-3.7 cm)
• Normal adult women: 3.0 ± 0.3 cm (range approximately 2.7-3.3 cm)
• Indexed values: Should be 1.7 ± 0.2 cm/m² for men and 1.8 ± 0.2 cm/m² for women 1

Assessment Algorithm

Step 1: Calculate BSA and determine age-specific expected diameter 1

The measurement must be plotted against BSA-adjusted nomograms using age-stratified equations:

• Adults 20-39 years: y = 0.97 + 1.12x
• Adults >40 years: y = 1.92 + 0.74x (where x = BSA in m²) 1

Step 2: Determine if dilatation exists 1

Aortic root dilatation is defined as a diameter above the upper limit of the 95% confidence interval for the patient's age and BSA 1. For a 3.5 cm measurement:

• This would be normal or mildly prominent in a larger male (BSA >2.0 m²)
• This would represent mild dilatation in a smaller female (BSA <1.7 m²)
• This would be at the upper limit of normal for most average-sized adults 1

Step 3: Calculate the aortic root index 1

Divide the observed diameter (3.5 cm) by the expected diameter from the equation above. A ratio >1.0 suggests the measurement exceeds predicted normal values 1.

Clinical Significance

If Within Normal Range

• No immediate concern for aortic pathology 1
• Routine follow-up as clinically indicated
• Ensure measurement was obtained correctly at end-diastole using leading-edge to leading-edge convention 1

If Mildly Dilated (Above 95% CI)

• Evaluate for underlying aortopathy: bicuspid aortic valve, connective tissue disorders, hypertension 1
• Assess for aortic regurgitation: dilatation is associated with progression of AR and risk of dissection 1
• Serial imaging recommended if diameter >4.0 cm, with annual imaging if >4.5 cm 1

Critical Measurement Considerations

Common pitfalls to avoid 1:

• Incorrect measurement plane: Must be perpendicular to the long axis of the aorta at end-diastole 1
• Measuring within the sinuses: Attempting to measure between what appear to be hinge points typically measures within the sinuses and overestimates the annulus 1
• Not accounting for BSA and age: A 3.5 cm measurement has vastly different implications for a 25-year-old woman versus a 60-year-old man 1

When Additional Imaging is Needed

Consider CT or MRI angiography if 1:

• The ascending aorta cannot be fully visualized beyond 4.0 cm from the valve plane on echo
• There is concern for bicuspid aortic valve with associated aortopathy
• Serial monitoring is needed for documented dilatation
• The measurement is borderline and clinical decision-making requires precise characterization

Note: CT/MRI measurements are typically 1-2 mm larger than echo due to inclusion of the aortic wall and different timing in the cardiac cycle 1.

Risk Stratification for Complications

While 3.5 cm itself is not associated with high dissection risk, be aware that 1:

• Sinus of Valsalva diameter <3.0 cm is associated with increased risk of coronary occlusion during TAVI procedures 1
• Progressive dilatation requires monitoring as dissection risk increases with diameter, though some dissections occur at diameters <5.0 cm 1