American Board of Internal Medicine (ABIM) Certification Practice Exam

What should be the closing criterion for a ventricular septal defect (VSD)?

1. A significant shunt and left ventricular volume overload

2. Only a significant shunt

3. Only left ventricular volume overload

4. No criterion is necessary

The correct answer is: A significant shunt and left ventricular volume overload

The appropriate closing criterion for a ventricular septal defect (VSD) involves assessing both the presence of a significant shunt and the resulting left ventricular volume overload. This is important because a VSD can cause increased blood flow to the left side of the heart, leading to volume overload and potential heart failure if left untreated. A significant left-to-right shunt indicates that there is a substantial amount of blood flowing from the left ventricle into the right ventricle, which can have detrimental effects on heart function over time. The consequence of this shunting is typically an increase in volume load on the left side of the heart, especially the left atrium and left ventricle, which can lead to dilatation and eventually heart failure. Therefore, both the shunt and the volume overload must be considered when determining the need for closure of the defect. This dual criterion ensures that both the physiological impact of the defect and the clinical manifestation of heart failure or other complications are accounted for, guiding the decision-making process for intervention. In contrast, focusing only on a significant shunt or volume overload separately would not provide a complete picture of the defect's impact on cardiac health and may miss important aspects of the management strategy.