Coronary Artery Disease

What is Coronary Artery Disease?

The foremost effect of coronary artery disease is the loss of oxygen and nutrients to myocardial tissue because of diminished coronary blood flow. Fatty fibrous plaques or calcium plaque deposits, or combinations of both, narrow the lumens of coronary arteries, reducing the volume of blood that can flow through them.

Coronary artery disease is more prevalent in men, whites, and middle-aged and elderly people than in women or in people of other races and ages.

Causes of Coronary Artery Disease

Coronary artery disease is thought to begin with damage or injury to the inner layer of a coronary artery, sometimes as early as childhood. The damage may be caused by various factors, including:

• Family history of coronary heart disease (especially before age 50)
• Blood pressure
• Serum cholesterol levels
• Smoking
• Lack of physical activity or exercise
• Obesity
• Stress
• Menopause in women
• Diabetes mellitus

Signs & Symptoms of Coronary Artery Disease

While symptoms of CAD will vary with each individual, in general they may include "chest pain" or angina. Angina is a painful or uncomfortable feeling in the chest, neck, back, shoulders, arms, and/or jaw. This can be described as tightness, aching, burning and/or pain in any of the previously mentioned areas. Other symptoms of CAD can include nausea, vomiting, weakness, and/or shortness of breath (SOB).

Diagnostic Tests

Many tests will help cardiac specialists to confirm the diagnosis of CAD.

These may include blood tests, a 12-lead electrocardiogram (EKG), a chest x-ray, stress testing, echocardiogram and ultimately a cardiac catheterization (angiography).

Treatment

The goal of treatment in patients with angina is to reduce myocardial oxygen demand or increase the oxygen supply and reduce pain. Activity restrictions may be required to prevent onset of pain. Rather than eliminating activities, performing them more slowly often averts pain. Stress reduction techniques are also essential, especially if known stressors precipitate pain.

Pharmacologic therapy consists primarily of nitrates, such as nitroglycerin, isosorbide dinitrate, or betaadrenergic blockers or calcium channel blockers.

Obstructive lesions may necessitate atherectomy or coronary artery bypass graft surgery, using vein grafts. Percutaneous transluminal coronary angioplasty (PTCA) may be performed during cardiac catheterization to compress fatty deposits and relieve occlusion. In patients with calcification, PTCA may reduce the obstruction by fracturing the plaque.

ALERT: PTCA carries certain risks but causes fewer complications than surgery. Complications after PTCA can include circulatory insufficiency, death (rarely), myocardial infarction, restenosis of the vessels, retroperitoneal bleeding, sudden coronary occlusions, or vasovagal response and arrhythmias.

PTCA is a viable alternative to grafting in elderly patients or in those who otherwise can't tolerate cardiac surgery. However, patients with a left main coronary artery occlusion, lesions in extremely tortuous vessels. or occlusions older than 3 months aren't candidates for PTCA.

PTCA may be done in combination with coronary stenting, or stents may be placed alone. Stents provide a framework to hold an artery open by securing flaps of tunica media against an artery wall. Intravascular coronary stenting is done to reduce the incidence of restenosis. Prosthetic intravascular cylindrical stents made of stainless steel coil are positioned at the site of the occlusion. To be eligible for this procedure, the patient must be able to tolerate anticoagulant therapy and the vessel to be stented must be at least 3 mm in diameter.

Laser angioplasty corrects occlusion by vaporizing fatty deposits with the excimer or hottip laser device. Percutaneous myocardial revascularization (PMR) is an investigational procedure that uses a laser to create channels in the heart muscle to improve perfusion to the myocardium. A carbon dioxide laser is used to create transmural channels from the epicardial layer to the myocardium, extending into the left ventricle. This technique is also known as transmyocardial revascularization (TMR) and appears to be up to 90% effective in treating severe symptoms.

Rotational ablation (or rotational atherectomy) removes atheromatous plaque with a high-speed, rotating burr covered with diamond crystals. Another method recently approved is an angiojet system septa to remove clots in symptomatic coronary arteries and coronary artery bypass grafts. It's an alternative to thrombolytic therapy and involves a jet stream of saline solution and a catheter to seek out clots. After the clot is removed, the patient can undergo angioplasty.

Prevention Tips

• Don't smoke.
• Regular exercise can make your heart stronger and reduce your risk of heart disease.
• Keep blood pressure under control.
• Eat a low fat, low cholesterol diet.
• Inquire about what vitamin supplements may be helpful in the prevention of CHD.
• Reduce stress as much as possible. Practice healthy techniques for managing stress, such as muscle relaxation and deep breathing.