HOLE IN THE HEART

Here you are at 4 weeks gestation - safely inside your mum.  You already have a pulse, at least since Day 21 if not earlier - possibly Day 18 and probably before Mum even knew you were there.

The first functional organ of your body, your 4-chambered heart, is now developing but like ALL babies…. believe it or not!...... you are going to be born with a HOLE IN THE HEART, in fact a TRIPLE SHUNT.  No kidding!                             

            

(Of course, how safe you are depends on people deciding whether you’re a legally protected baby or no better than a benign tumour that can be legally disposed of.)

As your inactive lungs developed and filled with fluid, to avoid cardiac stress a primitive shunt formed during the 4^th week in the wall (septum) between the upper chambers (atria) of your heart, allowing oxygenated umbilical blood to circulate directly through your body. In time, a second wall formed between the atria with a one-way valve known as the ‘foramen ovale’. 
(This opening was complemented by 2 other shunts - the ‘ductus arteriosus’ between the pulmonary artery and the aortic arch – also bypassing the lungs, plus the ‘ductus venosus’ between the umbilical vein and the inferior vena cava - bypassing the liver.)

As soon as you took your first lungful of air and the umbilical cord was cut, the pressure changes experienced by your heart caused the foramen ovale to close and eventually seal. Failure to seal is known as Atrial Septal Defect or ASD (similar to Ventricular Septal Defect) which often requires surgical intervention.   

So….why are we kept unaware that we were all born with a hole in the heart?

Is it because this temporary multiple-shunt arrangement is just too ingenious?

 

Acknowledgements: wikipedia.com                                                                                                          

Photo credits: ebru.ca            skippy.org.uk             health.howstuffworks.com