Aortic regurgitation complicating VDS is an important clinical entity in congenital heart disease.It is also a popular case for the cardiology fellows in their final clinical examinations . AR is a late manifestation of VSD (usually in early adolescent or adult hood) .This develops due to loss of aortic valvular support provided by the inter ventricular septum.
In fact , IVS can be termed as a foundation stone on which a part of aorta (Mainly its anterior part) rests . So, it is not surprising VSD patients are prone to develop AR especially, as they grow when aorta tires to outgrow the septal support . Further, the hemodynamics of VSD has a crucial impact on the AR progression.(See image below)
Pulse /Blood pressure
Large volume pulse, may be collapsing
Peripheral signs of Aortic run off usually present
Apical impulse
Shifted down and out Hyperdynamic
Murmur
To and fro murmur (To -Systolic , Fro -Diastolic )
It is differentiated from continuous murmur by a distinct reduction in the intensity of murmur towards the end systole and a different murmur appear in diastole . While , a continuous murmur is a single murmur that peaks around sound heart sound , overlaps the second heart sound and spills well into diastole.
Other useful diagnostic clues
- Usually the VSD is restrictive .Left to right shunt is often below 2:1
- With the onset of AR ,there is further reduction in the left to right shunt of VSD
- Hence,progressive pulmonary arterial hypertension is uncommon and Eisenmenger is reaction is very rare in VSD with AR.
- Presence of AR makes LV dilatation disproportionate to VSD shunt (LV size is not useful to assess the hemodynamic significance of VSD)
- LV dilatation invariably means significant AR rather than VSD. VSD induced LV enlargement is usually less conspicuous as it is represents physiological flow across mitral inflow . While , AR is a high gradient leak from a non-physiological chamber (Aorta)
- ECG volume overload of LV is evidenced by more prominent * q waves in V5 V6
*Double dose of volume overload (AR +VSD)
Management
- If AR is mild ,only VSD closure is advocated *
- If AR is moderate , repair of aortic valve is considered along with VSD closure.
- For severe AR , Aortic valve replacement or repair with VSD closure mandatory.
- Device closure of VSD and percutaneous aortic valve replacement not feasible at the moment .May be a future possibility.
* If both VSD and AR are very small , simple follow up , and observation (Leaving the patient happy!) could be a distinct option !
Pathogenesis of AR in VSD : The landmark article from Japan in 1973 by Tatsuno and Sakakibara
http://circ.ahajournals.org/cgi/content/short/48/5/1028
Thanks to circulation .Such articles are made available .
Dr.S.Venkatesan MD 