American Board of Internal Medicine (ABIM) Certification Practice Exam

In patients with a normal baseline electrocardiogram and intermediate pretest probability of coronary artery disease, what is the initial test of choice?

1. Cardiac MRI

2. Exercise electrocardiographic testing

3. CCTA (Coronary CT Angiography)

4. Echocardiography

The correct answer is: Exercise electrocardiographic testing

In patients who have a normal baseline electrocardiogram and an intermediate pretest probability of coronary artery disease (CAD), exercise electrocardiographic testing is the initial test of choice because it offers a balance between availability, cost-effectiveness, and diagnostic accuracy in this clinical scenario. Exercise electrocardiographic testing involves assessing the patient's heart response to physical exertion, which can reveal ischemic changes that may not be apparent at rest. Given that the patient already has a normal baseline electrocardiogram, observing their heart's electrical activity during exercise provides valuable additional information about the cardiovascular system under stress. Moreover, in patients with an intermediate pretest probability of CAD, the likelihood of a positive result on the stress test can guide further management decisions effectively. Exercise electrocardiographic testing has been well-studied and is a widely accepted initial evaluation tool before considering more advanced imaging modalities, which may not be necessary if the exercise test is normal. Other tests like CCTA or cardiac MRI are typically reserved for cases where the exercise test results are abnormal or inconclusive, or if the patient cannot exercise adequately. This makes exercise electrocardiographic testing the preferred first-line approach in this particular context.