A 70-year-old diabetic woman with a 6 months history of angina on moderate exertion is presenting with increased frequency of her symptoms in the past 48 hours and is now occurring at rest. She is admitted to the coronary care unit:

• Sinus rhythm
• Abnormal Q waves and mild ST elevation in the inferior leads in keeping with probably recent inferior myocardial infarction, age undetermined
• T wave abnormality (negative T waves) in V4-V6, consider lateral ischemia

The cardiac enzymes were not elevated. Coronary angiography revealed a 90% proximal stenosis of the right coronary artery, that was successfully treated with angioplasty and stenting. The left coronary artery and its branches showed no significant abnormalities.