Split of second heart sound in Ventricular Septal Defect (VSD)
- First you can review the Mechanism of normal split in second heart sound
- In case of small ventricular septal defect, the blood flow through it is not large enough to cause a significant increase in right ventricular ejection time
- Hence there is a normal split
- But in case of large VSD, both the right ventricle and left ventricle act as a single chamber
- The blood flow from both the ventricle occur for the same duration
- Also because of the presence of pulmonary hypertension, hangout interval becomes negligible
- Hence there is a single second heart sound with absent split in case of large VSD
