A 35-year-old woman from rural Uttar Pradesh presents with dyspnea on exertion and orthopnea. Echocardiography shows severe aortic regurgitation with aortic root dilatation. What is the most common underlying cause of aortic regurgitation in this clinical context?

Explanation

## Most Common Cause of Aortic Regurgitation in India **Key Point:** Rheumatic heart disease (RHD) is the most common cause of aortic regurgitation in India and other developing nations, accounting for 60–70% of cases. The patient's demographics (rural India, young woman, aortic root involvement) are classic for RHD. ### Pathophysiology of Rheumatic Aortic Regurgitation 1. Post-streptococcal inflammation of the aortic valve 2. Valve leaflet thickening, retraction, and fibrosis 3. Inability of leaflets to coapt → central regurgitation 4. Secondary aortic root dilatation due to chronic volume overload 5. Progressive left ventricular dilatation and dysfunction ### Clinical Features in RHD-Related AR - Young to middle-aged patients (20–50 years) - Female predominance (especially in mitral disease, but AR also common) - History of acute rheumatic fever or recurrent sore throats - Symptoms: dyspnea, orthopnea, palpitations (due to LV dilatation) - Signs: wide pulse pressure, early diastolic murmur, bounding pulses - Echocardiography: thickened, retracted valve leaflets; aortic root dilatation ### Differential Diagnosis: Why Other Causes Are Less Common in This Context | Cause | Frequency in India | Key Features | Why Not This Case | |-------|-------------------|--------------|-------------------| | **Rheumatic heart disease** | 60–70% | Young, rural, female; leaflet thickening; aortic root dilatation | **BEST FIT** — matches all clinical features | | **Marfan syndrome** | <1% | Tall stature, lens dislocation, aortic root dilatation, family history | No mention of skeletal features or family history; Marfan is rare in India | | **Infective endocarditis** | 10–15% | Acute presentation, fever, emboli, vegetation on echo | Subacute/chronic presentation here; no acute fever or septic features | | **Syphilitic aortitis** | <1% | Tertiary syphilis; ascending aortic dilatation; aortic root involvement | Rare in modern India; would require positive serology and ascending aorta findings | **Clinical Pearl:** In a young Indian woman with AR and aortic root dilatation, RHD should be the first diagnosis. Look for a history of ARF, other valve involvement (mitral stenosis is often coexistent), and signs of chronic volume overload. **High-Yield:** RHD commonly affects **multiple valves**—mitral stenosis + aortic regurgitation is a classic combination. Always examine for other valve lesions in suspected RHD. **Mnemonic:** **RHDAR** = Rheumatic Heart Disease causes Aortic Regurgitation in rural India.