Uncertainty of Myocardial Perfusion Imaging in Chest Pain Risk Stratification

Chest pain is a common presenting symptom in the emergency department (ED). Although the diagnostic workup for chest pain is well established, the best time to perform invasive cardiac catheterization in patients with low to moderate risk of coronary artery disease is still unclear, particularly if noninvasive tests such as the electrocardiogram (ECG) and nuclear myocardial perfusion scan show nonsignificant findings.

We present the case of a 52-year-old female who presented to the ED with acute-onset chest pain that had started early in the morning while she was sleeping. She had presented to the ED 2 weeks prior with chest pain, but her ECG and transthoracic echocardiogram were normal, and her myocardial perfusion scan revealed no significant perfusion defect, so she was discharged. During her second ED visit, the patient developed an arrhythmia, diagnosed as supraventricular tachycardia, that was rapidly converted to sinus rhythm with one dose of intravenous adenosine. Because of her persistent chest pain and the arrhythmia, she underwent cardiac catheterization that revealed coronary artery disease with 80% middle left anterior descending artery stenosis. Percutaneous coronary intervention was performed, and the patient's symptoms resolved.

Chest pain evaluation is challenging for ED physicians, hospitalists, and cardiologists. Although the nuclear myocardial perfusion scan has excellent sensitivity and specificity in ischemic detection, the clinical examination remains the primary determinant of further management.