Primary Causes of Severe Aortic Regurgitation
Aortic regurgitation (AR) can arise from primary disease of the aortic valve leaflets, abnormalities of the aortic root geometry, or a combination of both mechanisms. 1
Valve-Related Causes (Primary AR)
Bicuspid aortic valve - The second most common cause of AR in Western countries, with accelerated valve degeneration leading to earlier presentation of severe disease 1
Degenerative valve disease - The most common etiology of chronic AR in the general population 1
Infective endocarditis - Can cause acute severe AR through valve leaflet destruction or perforation 1
Rheumatic heart disease - Historical cause that remains significant in certain regions 1, 2
Congenital valve anomalies - Including quadricuspid valves and other malformations 1
Carcinoid syndrome - Results in shortening and thickening of valve leaflets 1
Aortic Root Causes (Secondary AR)
Aortic root dilatation - Increasingly observed as the primary cause of pure AR in Western countries, can be idiopathic or associated with aging 1, 3
Aortic dissection - Causes acute severe AR requiring urgent intervention 1
Marfan syndrome and other connective tissue disorders - Lead to aortic root dilatation and subsequent AR 2, 4
Hypertension - Can contribute to aortic root dilatation over time 1, 5
Iatrogenic and Traumatic Causes
Complications of transcatheter procedures - Including TAVI (Transcatheter Aortic Valve Implantation) with improper valve sizing or positioning 1
Post-valvuloplasty - Following balloon aortic valvuloplasty procedures 1
Blunt chest trauma - Can cause acute AR 1
Post-surgical - May occur following septal myectomy, particularly in children and young adults 1
Clinical Implications
Acute severe AR is a medical emergency characterized by pulmonary congestion and hypotension, requiring urgent surgical intervention 1, 5
Chronic severe AR leads to combined left ventricular volume and pressure overload, with progressive LV dilation and eventual systolic dysfunction 6, 5
The pattern of AR mechanism influences management decisions, particularly when valve repair is being considered 1, 4
Generalized aortic root dilatation is associated with more severe ventricular dilatation, hypertrophy, and dysfunction compared to localized dilatation 3
Understanding the specific cause of AR is essential for determining appropriate treatment strategies, including surgical repair versus replacement options 2, 4