What does an echo finding of concentric remodeling and anterobasal septal hypertrophy indicate?

Echocardiographic Findings of Concentric Remodeling and Anterobasal Septal Hypertrophy

Concentric remodeling with anterobasal septal hypertrophy on echocardiography indicates cardiac adaptation to pressure overload, most commonly due to hypertension, with localized thickening of the basal septum that may represent early hypertensive heart disease or a variant of hypertrophic cardiomyopathy. 1

Understanding Concentric Remodeling

Concentric remodeling is defined by:

• Normal left ventricular mass (≤115 g/m² in men, ≤95 g/m² in women)
• Increased relative wall thickness (RWT ≥0.42)
• Normal or small left ventricular cavity size 1

This pattern represents an early adaptive response to pressure overload, typically from hypertension, where the heart walls thicken without increasing overall mass. It's a geometric pattern that precedes the development of frank left ventricular hypertrophy.

Anterobasal Septal Hypertrophy

Anterobasal septal hypertrophy refers to:

• Localized thickening of the basal portion of the interventricular septum
• Often asymmetric compared to other ventricular segments
• May be an early sign of hypertrophic cardiomyopathy or a variant of hypertensive heart disease 1, 2

Clinical Significance

Cardiovascular Risk

• Concentric remodeling, even with normal LV mass, is associated with:
  • 2.56-fold increased risk of cardiovascular events compared to normal geometry 3
  • Poorer cardiovascular outcomes despite normal LV mass 3
  • Reduced myocardial function (lower midwall shortening) 4

Functional Implications

• Reduced stroke volume compared to patients with normal geometry 4
• Impaired myocardial deformation (strain) compared to normal geometry (-12.8% vs -17.5%) 5
• Early diastolic dysfunction may be present 1

Differential Diagnosis

When evaluating anterobasal septal hypertrophy, consider:

1. Hypertensive heart disease - most common cause of concentric remodeling 1, 6
2. Hypertrophic cardiomyopathy - especially if there's asymmetric septal hypertrophy 1, 2
3. Infiltrative disorders - such as amyloidosis (though typically more diffuse) 1
4. Athlete's heart - though typically more eccentric pattern 1

Management Implications

The finding of concentric remodeling with anterobasal septal hypertrophy should prompt:

1. Evaluation for hypertension - Aggressive blood pressure control is essential as this is the most common cause 6
2. Assessment for other cardiovascular risk factors - Including hypercholesterolemia, diabetes 6
3. Consideration of further imaging - Cardiac MRI may provide better tissue characterization if the diagnosis is unclear 1, 2
4. Regular follow-up - Echocardiography every 1-2 years to monitor for progression to frank LVH 6

Pitfalls to Avoid

• Measurement errors - Ensure proper alignment of M-mode cursor perpendicular to LV long axis 6
• Single measurements - Obtain at least two consecutive measurements before making management decisions 6
• Failure to normalize for body size - Particularly important in smaller patients and women 6
• Overlooking localized hypertrophy - Contrast echocardiography may be needed to better visualize the apex or lateral wall 1

Conclusion

Concentric remodeling with anterobasal septal hypertrophy represents an important finding that warrants attention due to its association with increased cardiovascular risk. While often related to hypertension, this pattern may also represent early or variant forms of hypertrophic cardiomyopathy, requiring careful clinical correlation and potentially further imaging for definitive diagnosis.