NREMT Paramedic Practice

What increases the risk of cardiac rupture in blunt myocardial injuries?

1. Severe head trauma

2. Signs of myocardial infarction

3. Muffled heart sounds

4. Cardiogenic shock

The correct answer is: Signs of myocardial infarction

The risk of cardiac rupture in blunt myocardial injuries is notably increased by the presence of signs indicative of myocardial infarction. This condition suggests that there is underlying damage to the heart muscle, which can predispose it to rupture, especially when combined with the physical trauma from an impact. In the case of blunt trauma, the myocardium may develop necrosis or other significant structural abnormalities, and if a coronary artery is compromised, it can increase the likelihood of rupture due to weakened tissue integrity. While severe head trauma, muffled heart sounds, and cardiogenic shock may indicate serious medical conditions, they do not directly correlate with an increased risk of cardiac rupture as myocardial infarction does. Severe head trauma may lead to different complications, muffled heart sounds can suggest fluid accumulation or other issues but are not direct indicators of myocardium integrity, and cardiogenic shock is a consequence of heart dysfunction rather than a causative factor for rupture in blunt injuries. Understanding the mechanisms of myocardial ischemia and how it affects tissue vulnerability is key to grasping why signs of myocardial infarction are critical in evaluating the risk of cardiac rupture following blunt trauma.