According to the Centers for Disease Control and Prevention, heart disease is the leading killer of men and women in the United States. With over 47 percent of heart attack victims dying before they reach emergency medical facilities, proper diagnosis and quick action is imperative to save lives. One of the most accurate means of diagnosing heart disease is angiography.
A Primer on Heart Disease
The leading form of heart disease in the United States is coronary artery disease. The heart receives its blood supply through two major arteries called coronary arteries. Beginning in one's early 20s, the coronary arteries begin accumulating cholesterol from diets high in saturated fat and cholesterol. Over time, the cholesterol calcifies and can eventually occlude the blood supply to the heart. When this occurs, the patient may suffer from angina, or a shortage of blood to the heart. If the blood supply is completely cut off, it can cause a heart attack.
Diagnosing Heart Disease
There are many methods to diagnose heart disease, once symptoms begin to appear. The first test may be as simple as a blood test for total cholesterol, low-density lipoproteins, high-density lipoproteins and triglycerides. These help your doctor to determine your risk for heart disease and help him to rule out other diseases. If the results point toward heart disease, he may order an exercise stress test. During a stress test, your doctor--using an electrocardiogram--monitors your heart's response to increasing physical demands while you walk on a treadmill. Electrocardiograms can pinpoint problems with blood supply to your coronary arteries but are not definitive tools. For that type of accuracy, doctors depend on angiograms.
Angiography
Angiography was developed by Portugese physician Egas Moniz in 1927. Although the process has evolved over the years, it basically involves injecting a contrast agent into the suspected arteries and taking X-ray pictures of the area to determine if there are circulation blockages in the heart. Angiography can also be used in other areas, such as the brain or extremeties. In the case of the coronary arteries, the patient is lightly sedated but kept awake throughout the procedure. A cardiologist inserts a small diameter catheter into the groin through an artery up to the heart. The cardiologist injects a small amount of contrasting dye through the catheter into the artery in question and takes X-rays of the suspected area. Blockages in circulation appear as an absence of dye. Armed with this specific information, the cardiologist can formulate a plan for the next level of treatment--balloon angiography, stenting or coronary bypass surgery.
Balloon Angiography
If traditional angiography determines that there are significant obstructions in the coronary arteries that limit the amount of blood flow to the heart, the next step could be Percutaneous Transluminal Coronary Angioplasty, or PCTA. PCTA is often called balloon angiography. The procedure is similar to standard angiography, with one major difference. A guide wire is inserted through a narrow sheath about the diameter of spaghetti. A cardiologist slides a balloon catheter over the guidewire until it reaches the site of occlusion. To clear the obstructed area, the cardiologist inflates the balloon at the end of the catheter from one to eight times the normal atmospheric pressure in an attempt to compress the area where cholesterol and plaque has shut off blood to the heart. After 30 seconds to two minutes, the balloon is deflated and the process is repeated. The goal is to compresses the area that is cutting off blood supply to the heart.
Coronary Stents
If traditional balloon angiography fails to return adequate blood flow to the coronary arteries, the cardiologist may elect to introduce a stent into the affected area during the angioplasty procedure. A stent is a narrow piece of stainless steel material that is "crimped" before being inserted into the artery. When the stent is correctly positioned, the cardiologist uses a balloon catheter to inflate the stent to its permanent diameter. The purpose of the stent is to maintain a larger diameter for blood flow that was previously occluded by cholesterol and plaque.
Coronary Bypass Surgery
When PCTA and stenting fail to open the coronary arteries enough to provide adequate circulation to the heart, coronary artery bypass surgery may be the next option. During bypass surgery, the patient's chest is opened and veins are harvested from other areas of their body. The harvested veins are sewn onto to the coronary arteries and bypass the occluded areas, returning blood to the heart.
