American Board of Internal Medicine (ABIM) Certification Practice Exam

Acute ventricular free wall rupture typically occurs how many days after a myocardial infarction (MI)?

1. 1 to 2 days

2. 3 to 7 days

3. 8 to 14 days

4. More than 2 weeks

The correct answer is: 3 to 7 days

Acute ventricular free wall rupture is a serious complication that can occur following a myocardial infarction (MI), particularly with ST-elevation MIs. It tends to happen during a specific time frame following the event. The rupture usually occurs 3 to 7 days post-MI and is most likely when the myocardial tissue is weakened following cell death and necrosis due to a lack of blood supply. During this timeframe, inflammation and the healing process can lead to structural instability in the cardiac wall, predisposing it to rupture, especially in cases involving large infarcts. As for the other possible timeframes: 1 to 2 days post-MI is often too early for the rupture to occur, as the myocardial tissue is still undergoing acute necrosis. If it were to occur at this time, it would generally be associated with severe and massive infarcts. Ruptures occurring 8 to 14 days later or more than 2 weeks post-MI are less common because, after approximately one week, the tissue begins to heal and there is typically a stabilization of the heart wall structure due to fibrosis. Therefore, the window of highest risk for free wall rupture is indeed within the 3 to 7 day mark following an MI.