American Board of Internal Medicine (ABIM) Certification Practice Exam

Which stress test is best for patients with COPD who cannot exercise?

1. Treadmill stress test

2. Dobutamine stress test

3. Adenosine stress test

4. Nuclear stress test

The correct answer is: Dobutamine stress test

In patients with chronic obstructive pulmonary disease (COPD) who are unable to exercise, the dobutamine stress test is the most suitable option. This test is particularly beneficial for those who cannot perform physical activities due to their respiratory limitations. Dobutamine is an inotropic agent that stimulates the heart to increase its rate and force of contraction, mimicking the effects of exercise, without requiring the patient to physically exert themselves. It allows for the assessment of cardiac function in a controlled setting, making it possible to evaluate the heart's response to increased demand, which is crucial for diagnosing underlying cardiovascular conditions. In contrast, other stress tests may not be appropriate for patients with severe COPD. A treadmill stress test relies on the patient's ability to walk or run, which is clearly infeasible in this population. Adenosine stress tests, while also effective for non-exercising patients, are generally more suitable for those who need perfusion imaging rather than direct cardiac functional assessment. Nuclear stress tests typically involve exercise or pharmacological agents that may not be as well tolerated in severely compromised pulmonary patients. Therefore, the dobutamine stress test stands out as the optimal choice for evaluating cardiac health in patients with COPD who are unable to perform traditional exercise-based stress tests.