How do you trace the flow of blood through the heart?

The flow of blood through the heart can be traced by injecting a dye into the arteries through a procedure known as an angiogram. Another procedure, cardiac catheterization, involves using a catheter to inject the dye. Magnetic resonance angiography or MRA, uses MRI technology.

X-ray images reveal the narrow spots or blockages in the arteries, which are highlighted by the dye. CT coronary angiograms involve injecting a contrast dye into the arteries intravenously during a computerized tomography, or CT scan. The details obtained through MRA are not as clear as those provided by cardiac catheterization. If there is a blockage that requires treatment, a mesh tube or stent is used to keep the artery open.