Question 1 of 6
Cardiothoracic
A 65-year-old man with exertional chest tightness and severe three-vessel coronary disease undergoes adenosine stress cardiac MRI. Stress perfusion shows circumferential subendocardial hypoperfusion in all three territories. The defect is several pixels wide, begins with myocardial contrast arrival and persists beyond peak enhancement. Rest perfusion is normal, with no myocardial late gadolinium enhancement. What is the most likely explanation?