[Peradine]

A pulse oximiter measures the oxygen content of arterial blood in the peripheries. A heart attack is caused by a localised blockage of the arteries to the heart, causing reduced oxygen and nutrient delivery to an area of heart muscle. A heart attack alone would not affect peripheral oxygen content unless it was severe enough for a complication such as heart failure to develop, but by that stage it's much too late.

Indeed the vast majority of patients with an acute heart attack would have completely normal pulse oximetry findings, the only way to properly diagnose a heart attack is with an electrocardiogram (EKG) and/or blood tests to look for markers of heart muscle damage