What complication can arise from untreated significant coronary artery stenosis during stress testing?

In the context of untreated significant coronary artery stenosis during stress testing, the most pertinent complication that can arise is a myocardial infarction. When the coronary arteries are significantly narrowed, the heart muscle may not receive adequate blood supply, especially during times of increased demand, such as during stress testing. This lack of sufficient oxygenated blood can lead to ischemia or insufficient blood flow to the heart muscle.

As the demand for oxygen increases during exertion, the existing stenosis can become critically limiting. If the demand exceeds the supply due to this blockage, it can result in damage to the heart tissue, ultimately leading to a myocardial infarction. This condition is characterized by the death of heart muscle cells due to prolonged ischemia.

While hypertension, heart failure, and arrhythmias can all be associated with coronary artery disease, they are less immediate complications that are directly related to the acute stress of testing in the presence of significant stenosis. Hypertension may occur as a response to stress, heart failure may be a consequence of chronic ischemia over time, and arrhythmias can develop from various factors, including ischemia but are not as directly linked to the acute scenario posed by the stress test with significant stenosis.