This patient with atypical chest pain and indeterminate results on exercise stress testing should undergo stress echocardiography. Baseline abnormalities on the resting electrocardiogram (ECG) can limit the ability to interpret the ECG during exercise. Specific abnormalities on the resting ECG preclude the use of ECG stress testing because of difficulty in accurately interpreting changes that may occur with stress. These abnormalities include the presence of left ventricular hypertrophy with repolarization abnormalities (ST-segment depressions) greater than 0.5 mm, preexcitation, left bundle branch block, and a paced rhythm. In these settings, exercise stress testing with imaging, either with echocardiography or perfusion imaging, is required. Although patients without these exclusionary findings may undergo stress ECG, baseline changes need to be considered in interpreting the test. This patient had ST-segment depressions less than 0.5 mm at baseline; if there were no further changes with exercise testing, these findings could be interpreted as normal. However, a positive stress test is defined as greater than 1-mm ST-segment depression in two contiguous leads during exercise testing. In this patient, the 1-mm ST-segment depression that developed during exercise is a less reliable predictor of ischemia given the ST-segment baseline abnormalities. Therefore, these changes on stress testing are not definitive and her test result is considered indeterminate. She should therefore undergo repeat stress testing with imaging in order to establish a diagnosis of coronary artery disease (CAD).

The patient does not yet have a diagnosis of CAD and her hypertension is adequately treated on her current regimen; adding treatment with a β-blocker to treat myocardial ischemia would not be indicated.

Cardiac catheterization should be reserved for patients with high-risk features on exercise stress testing, such as a high-risk Duke treadmill score (below −11), hypotension, severe ST-segment depression, and early-onset angina. This patient has atypical chest pain, and cardiac catheterization should be deferred until a diagnosis of CAD is made and the extent and severity of disease are evaluated with stress imaging.

Cardiac magnetic resonance (CMR) imaging is best utilized for diagnoses of the aorta, pericardium, and myocardium, including viability and extent of myocardial fibrosis. Stress CMR imaging can be performed, but its availability is limited.