Heart after heart attack. Coloured computer- enhanced Gamma Scan of a human heart (in inferior sagittal section) which has suffered myocardial infarction or heart attack. During a heart attack, heart muscle is starved of oxygen and necrosis (tissue death) occurs in places. Here, pink areas show healthy myocardial tissue which in a normal heart is continuous in a semi-circle around the left ventricle. Due to myocardial infarction the pink areas are separated, with scar tissue occur- ring at centre right between the pink areas. Gamma scanning (scintigraphy) involves introducing a radioactive tracer into the blood, which is taken up by the heart and detected by a gamma camera.