Pathophysiology in VSD
depends on the size of VSD. There are two types of
VSD based on the size of defect.
Restrictive VSD (Small /
moderate sized )
Non restrictive VSD
Pathophysiology of
restrictive VSD
In restrictive VSD there
is resistance to left to right shunt at the site of defect. Here the right
ventricular systolic pressure is less than left ventricular systolic pressure.
Small VSD
Right ventricular
systolic pressure is normal and pulmonary vascular resistance is also normal.
So there is predominant left to right shunting during systole. These type of
VSD usually closes spontaneously .
Moderate VSD
Right ventricular
systolic pressure is elevated but it is less than left ventricular systolic
pressure. Pulmonary vascular resistance is low. There is left to right shunt
during systole and diastole occurs. Here predominantly left ventricular volume
overload is seen. These type of lesions may occasionally undergoes spontaneous
closure. The incidence of Eisenmenger syndrome is rare. Left ventricular
failure is the main complication.
Pathophysiology of
non-restrictive VSD
In non-restrictive VSD
the systolic pressure in left ventricle and right ventricle is equal so both
act as a common chamber and shunt depends on pulmonary and systolic vascular
resistance. Here the pulmonary vascular resistance is high. There is large left
to right shunt and left ventricular volume overload is seen. Eisenmenger
syndrome is common.
When the patient develops
pulmonary hypertension in non-restrictive VSD the left ventricular volume
overload decreases. Left to right shunt also decreases and right to left shunt
increases. Right ventricular pressure overload develops
Read related topics
Development of ventricular and outflow tract separation
Anatomical classification of Ventricular septal defect
Heart sounds in ventricular septal defect
Murmur in Ventricular Septal Defect (VSD)
Development of ventricular septum
What are the clinical features of ventricular septal defect (VSD)?
Pathophysiology of ventricular septal defect (VSD)
