Causes of Aortic and Pulmonary Regurgitation
Aortic Regurgitation Causes
Aortic regurgitation results from disease affecting either the aortic valve leaflets themselves or the aortic root, which distorts the leaflets and prevents proper coaptation 1, 2.
Valve Leaflet Pathology (Primary AR)
The most common leaflet abnormalities include:
- Degenerative/calcific valve disease - the leading cause in developed countries, often accelerated in bicuspid aortic valves where patients present earlier 3
- Bicuspid aortic valve - the most common congenital abnormality causing AR 1, 4
- Infective endocarditis - causes acute severe AR through leaflet perforation or destruction 1, 5
- Rheumatic heart disease - remains a major cause in low- to middle-income countries, typically causing chronic progressive AR 1, 4
- Myxomatous degeneration - leads to leaflet prolapse 1
Aortic Root Pathology (Secondary AR)
Root diseases that cause AR include:
- Idiopathic aortic root dilatation (annulo-aortic ectasia) - common in older patients 1, 5
- Marfan syndrome - causes progressive root dilatation 1, 5
- Aortic dissection - causes acute severe AR, a surgical emergency 1, 2
- Systemic hypertension - chronic pressure leads to root dilatation 1, 2
Less Common Causes
Additional etiologies to consider:
- Traumatic aortic valve injury 1
- Ankylosing spondylitis 1, 2
- Rheumatoid arthritis 1
- Syphilitic aortitis 1
- Ehlers-Danlos syndrome 1
- Reiter's syndrome 1
- Ventricular septal defects with aortic cusp prolapse 1
- Discrete subaortic stenosis 1
- Anorectic drugs 1
Pulmonary Regurgitation Causes
Mild pulmonary regurgitation is physiologic and found in 40-78% of normal individuals, but severe PR is uncommon and typically iatrogenic or associated with specific pathologies 5.
Acquired Causes (Most Common)
- Post-surgical or post-balloon valvuloplasty for pulmonary stenosis - PR is an almost unavoidable consequence, occurring in 87% of patients after intervention 1
- Post-repair of Tetralogy of Fallot - the most common cause of severe PR, with many patients developing significant RV dilatation and dysfunction over decades 1
- Pulmonary hypertension with pulmonary artery dilatation - causes mild-to-moderate PR through annular dilatation 5
Congenital Causes
Other Pathologies
- Infective endocarditis - rare but causes valve destruction 5
- Carcinoid syndrome - results in leaflet shortening and thickening 5
- Rheumatic heart disease - uncommon for isolated PR 5
- Idiopathic pulmonary artery dilatation - causes annular dilatation preventing leaflet coaptation 1
- Connective tissue disorders - associated with pulmonary artery and annular dilatation 1
Clinical Context
The distinction between acute and chronic presentation is critical for AR management. Acute AR (from endocarditis, dissection, or trauma) presents as a medical emergency with sudden hemodynamic collapse, while chronic AR allows gradual LV adaptation through eccentric remodeling over years 1, 2. For PR, the clinical significance depends heavily on RV adaptation - long-standing severe PR after Tetralogy of Fallot repair can lead to progressive RV dilatation, dysfunction, and ventricular arrhythmias requiring pulmonary valve replacement 1.