American Association of Critical-Care Nurses (AACN) Certification Practice Test

Which scenario is a common cause of cardiogenic shock?

1. Severe dehydration

2. Pulmonary embolus

3. Acute myocardial infarction (MI)

4. Neurogenic shock

The correct answer is: Acute myocardial infarction (MI)

Cardiogenic shock is primarily characterized by the heart's inability to pump effectively, leading to inadequate blood flow to meet the body's needs. One of the most common causes of this condition is acute myocardial infarction (MI). During an MI, obstruction of blood flow to a portion of the heart muscle can cause significant damage, impairing the heart's pumping ability. When a large enough area of the heart is compromised, the result can be cardiogenic shock, as the heart struggles to maintain adequate circulation, leading to symptoms such as hypotension, tachycardia, and organ dysfunction. In contrast, severe dehydration leads to hypovolemic shock due to reduced blood volume, while pulmonary embolism can result in obstructive shock as it blocks blood flow to the lungs. Neurogenic shock is caused by a loss of sympathetic tone often due to spinal cord injuries. Each of these conditions has a different underlying mechanism, but in the context of cardiogenic shock, acute myocardial infarction is particularly significant as it directly impairs the heart's ability to function effectively, leading to a critical reduction in cardiac output.