Myocardial Infarction and Coronary Angioplasty Treatment, Animation.
Myocardial infarction, commonly referred to
as heart attack, is the sudden death of part of the heart muscle due to loss of blood flow.
This occurs when one of the coronary arteries — the arteries that supply blood to the heart
— is blocked. The blockage is commonly due to atherosclerosis – cholesterol plaques/fat
deposits on the wall of blood vessels. As the plaque builds up, the vessel becomes narrow
restricting blood flow. Under stress, the plaque may rupture. This triggers formation
of blood clot on top of the plaque leading to complete blockage of blood flow. When this
happens in a coronary artery, the downstream patch of the myocardium dies from lack of
oxygen. Weaken heart muscle may disrupt electrical activity of the heart and subsequently cause
cardiac arrest. Coronary angioplasty is a non-surgical procedure
used to open narrowed or blocked coronary arteries. It can also be performed as an emergency
treatment for myocardial infarction. The first part of the procedure is to localize the site
of blockage. This part is called cardiac catheterization. A guiding catheter is inserted through the
femoral artery at the groin and threaded all the way to the aorta. The tip of the catheter
is placed at the beginning of the coronary artery to be investigated. A radio-opaque
dye is injected through the catheter into the coronary artery. This enables real-time
visualization of the artery using X-ray imaging. A narrowed part of an artery would appear
as a bottle neck on an x-ray image. After the location of narrowed artery is identified,
angioplasty can begin. A guidewire with a deflated balloon is inserted and pushed to
the location of blockage. The balloon is inflated to crush the plaque. At the end of procedure,
the balloon is again deflated and removed together with all catheters and guidewire.
In some cases, a stent is inserted together with the balloon, inflated and left on place
of the plaque to keep the artery open permanently.