Risks of the procedure are cardiac arrhythmias , cardiac tamponade , trauma to the vein or artery, low blood pressure , infection, embolism from blood clots at the tip of the catheter, reaction to contrast medium, hemorrhage, stroke , and heart attack . It may be performed in people with unstable angina , atypical chest pain , aortic stenosis , and unexplained heart failure . There may also be other indications. Normal blood supply to the heart is normal. Depending on the degree of blocked blood flow in the coronary arteries, there is an increased risk for a heart attack .
Cardiac catheterization is used to study the various functions of the heart.
Using different techniques, the coronary arteries can be viewed by injecting dye or opened using balloon angioplasty. The technique can even be performed in small, newborn infants.