Cardiac Medicine Certification (CMC) Practice Exam

What can lead to increased risk of left ventricular dysfunction following an anterior wall MI?

1. Increased peripheral resistance

2. Scar tissue formation

3. Coronary artery spasm

4. Electrolyte imbalances

The correct answer is: Scar tissue formation

Scar tissue formation is a significant factor that can lead to increased risk of left ventricular dysfunction following an anterior wall myocardial infarction (MI). After an MI, particularly in the anterior wall, the heart muscle sustains damage due to loss of blood supply, leading to necrosis of myocardial tissue. As the damaged area heals, it is replaced by scar tissue, which does not possess the same contractile properties as healthy myocardial tissue. This lack of contractility can impair the overall pumping ability of the left ventricle, leading to heart failure and reduced cardiac output. Healthy myocardial tissue can contract and relax effectively, contributing to normal diastolic and systolic functions. In contrast, scar tissue reduces the heart's efficiency and can lead to complications such as ventricular dilation and progressive heart failure. This is particularly relevant in anterior wall MIs, where the affected area of the heart has a substantial impact on overall cardiac function, given that the left ventricle is responsible for pumping oxygenated blood to the rest of the body. Increases in peripheral resistance, coronary artery spasm, and electrolyte imbalances can influence the heart's function, but the primary concern in the context of post-MI risk is the direct impact of scarring and loss of viable myocardial