Heart after heart attack. Three-dimensional models based on gamma scanning used to assess a 74-year- old man's heart after a heart attack (myocardial infarction). The top row shows a relaxed heart and the bottom row shows a contracted heart ejecting blood. From left to right, there are three views of the heart: the front (anterior), side (lateral) and the pointed base (apex). The ejection fraction (EF) of the heart (the amount of blood it pumps) is an adequate 55%. These and others tests allowed a diagnosis of ischaemia (reduced blood flow) for areas of this heart. Radioactive tracers were used to label the blood and track its uptake by heart muscle by detecting its emissions of gamma rays.