I was wondering if it's left to right shunt that would make it a volume overload condition in the right side of the heart and thus dilation but also considering that maybe left chambers are also enlarged due to increased flow through the lungs?
The Ventricular Septal Defects represent 30% of all the congenital cardiac defects.
Important is to underline that the interventricular septum has a membranosus part (superior) and a muscular part (inferior).
There are also 4 types of VSD:
Perimembranosus: under aortic valve. gives a aortic insufficiency due to the prolapse of the right coronaric cuspid or of the non coronaric cuspid
In-let: in the upper-posterior part of the septum, under atrio-ventricular valves
Out-let: under aortic and pulmunar valvolar rings; this give a aortic insufficiency
Muscular-trabecular: (known also as swiss-cheese), because has more holes and is far from conduct pathways.
The shunt is always left to right, due to pressures of the venticulus. This creates a big difference between pulmonary and sistemic resistances, so the right ventricle is enlarged, but not the right atrius
EKG: not specific signs of ventricular hypertrofy. The cild can be completely asintomatic, and have symptoms when make phisical activity
- Heart Ultrasound: is the gold standard. This shows the discontinuity of the septum and with a flow examination it shows the left-to-right direction
I've read that you want references, and this is great. This is from my sudies and is actually on every Pediatric Manual. Also on Pubmed.
-my personal noted during internship
With the Ventricular Septal Defects prior to Eisenmenger Syndrome the left to right shunt occurs because left atrial pressure exceeds right atrial pressure in systole and blood gets ejected directly into the Right Ventricular Outflow Tract and Pulmonary artery instead of the Right Ventricle. For this reason Right Ventricle does not dilate. However, increased flow through lungs does create a volume loading condition in the Left atrium and Left Ventricle. Hence the volume loading of the left side with the dilation and preserved integrity of the right side, as noted per the American College of Cardiology guidelines. http://www.acc.org/guidelines#sort=%40foriginalz32xpostedz32xdate86069%20descending&f:@fdocumentz32xtype86069=[guidelines]