What is the primary cause of myocardial ischemia?

Choice A rationale
Reducing the overall contractility of the heart muscle is not the primary reason for performing Coronary Artery Bypass Surgery (CABG)4. In fact, reducing the contractility of the heart muscle could potentially decrease the heart’s ability to pump blood effectively.
Choice B rationale
Reducing plaque buildup in the carotid artery is not the primary reason for performing CABG4. While plaque buildup in the carotid artery can lead to serious conditions such as stroke, CABG is specifically performed to bypass blocked coronary arteries, not carotid arteries.
Choice C rationale
Increasing the oxygen supply to the heart muscle is the primary reason for performing CABG4. When coronary arteries become blocked or narrowed due to plaque buildup, the heart muscle may not receive enough oxygen-rich blood. CABG is performed to create a new route, or bypass, around the blocked artery, which improves blood flow and oxygen supply to the heart muscle.
Choice D rationale
Increasing the myocardial workload is not the primary reason for performing CABG4. In fact, increasing the workload of the heart could potentially exacerbate heart disease and lead to complications such as heart failure.

Choice A rationale
While palpating the liver edge can provide information about liver health and potential fluid accumulation, it is not typically a priority assessment for a patient taking Digoxin (Lanoxin), Furosemide (Lasix), and Captopril.
Choice B rationale
A serum potassium level of 3.0 mEq/L is low (hypokalemia). This is a critical finding because both Digoxin and Furosemide can cause hypokalemia. Hypokalemia increases the risk of digoxin toxicity, which can lead to serious cardiac arrhythmias.
Choice C rationale
While weight gain may indicate worsening heart failure, a gain of 2 pounds over 3 days is not typically considered significant. However, any sudden or unexplained weight gain should be reported to the healthcare provider.
Choice D rationale
Presence of 1+ to 2+ edema in the feet and ankles could indicate worsening heart failure, but it is not as immediately concerning as hypokalemia in a patient taking Digoxin and Furosemide.