Physiological Adaptation Q 127
After an anterior wall myocardial infarction, which of the following problems is indicated by auscultation of crackles in the lungs?
A. Left-sided heart failure
B. Pulmonic valve malfunction
C. Right-sided heart failure
D. Tricuspid valve malfunction
Correct Answer: A. Left-sided heart failure
The left ventricle is responsible for the most cardiac output. An anterior wall MI may result in a decrease in left ventricular function. When the left ventricle doesn’t function properly, resulting in left-sided heart failure, fluid accumulates in the interstitial and alveolar spaces in the lungs and causes crackles.
Option B: Pulmonic valve malfunction may cause right-sided heart failure. Pulmonary regurgitation (PR, also called pulmonic regurgitation) is a leaky pulmonary valve. This valve helps control the flow of blood passing from the right ventricle to the lungs. A leaky pulmonary valve allows blood to flow back into the heart chamber before it gets to the lungs for oxygen.
Option C: Right-sided heart failure can be caused by a pulmonic valve or tricuspid valve malfunction. This is the narrowing of the pulmonic valve that limits blood flow out of the right ventricle.
Option D: Tricuspid valve malfunction causes right-sided heart failure. The tricuspid valve doesn’t close properly. This causes blood in the right ventricle to flow back into the right atrium.