ABSTRACT
This is a report of a patient who had documented coronary artery disease and was admitted with chest pain, nausea, vomiting and headache. She was immediately taken to coronary angiography and underwent percutaneous coronary intervention with stent implantation. After the operation, she was coincidentally diagnosed to have Carbon Monoxide (CO) poisoning. We discuss if percutaneous intervention (PCI) was an overtreatment and briefly review the mechanisms of the cardiovascular effects of CO toxicity which is an insidious pathology and diagnosed only if it is suspected.