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| CHIEF DISORDERS OF THE HEART |
Coronary Artery Disease
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Coronary Artery Disease (CAD) is blockage of the arteries that feed the heart muscle. If the blockage is complete, areas of the heart muscle may be damaged and/or die from lack of oxygen. This can lead to a heart attack, otherwise known as a Myocardial Infarction.
Coronary Artery Disease is the most common form of heart disease.
CAUSES
* Thickening of the walls of the arteries feeding the heart muscle
* Accumulation of fatty plaques within the coronary arteries
* Sudden spasm of a coronary artery
* Narrowing of the coronary arteries
* Inflammation within the coronary arteries
* Development of a blood clot within the coronary arteries that blocks blood flow
- Clot formation at the site of a narrowed artery (rather than progressive arterial narrowing to the point of blockage) is the precipitating cause of CAD events.
- Clots may also occur silently without a clinical event and lead to progressive plaque enlargement and further narrowing of the artery.
* There has also been debate about the role of infection (by Chlamydia pneumoniae ) in causing CAD. But trials of antibiotics targeting this infection showed no evidence of an effect on CAD.
RISK FACTORS
Major risk factors include:
* Sex: male (men have a greater risk of heart attack than women)
* Age: 45 and older for men, 55 and older for women
* Heredity: strong family history of heart disease
* Obesity and being overweight
* Smoking
* High Blood Pressure
* Sedentary Lifestyle
* High blood cholesterol (specifically, high LDL cholesterol, and low HDL cholesterol)
* Diabetes
Other risk factors include:
* Stress
* Excessive alcohol use
* Metabolic Syndrome : combination of high blood pressure, abdominal obesity, and insulin resistance.
SYMPTOMS
CAD may progress without any noticeable symptoms.
Symptoms include:
* Angina — intermittent chest pain that often has a squeezing or pressure-like quality, that may radiate into the shoulder(s), arm(s), or jaw. Angina usually lasts for about 2-10 minutes and is often relieved with rest. Angina can be triggered by:
- Exercise or exertion
- Emotional stress
- Cold weather
- A large meal
Angina unrelieved by rest or Nitroglycerin, severe angina,angina that begins at rest (with no activity), or angina that lasts more than 15 minutes are warning signs of unstable angina or a heart attack. Accompanying symptoms may include:
* Shortness of breath
* Sweating
* Nausea
* Weakness
Immediate medical attention is needed for Unstable Angina.
CAD in women may cause less classic chest pain and be heralded by shortness of breath on exertion and fatigue.
DIAGNOSIS
BLOOD TESTS — to look for certain substances in the blood called Troponins which help the doctor determine if you are having an acute heart attack.
ELECTROCARDIOGRAM(ECG, EKG)— records the heart's activity by measuring electrical currents through the heart muscle, and can reveal evidence of past heart attacks, acute heart attacks, and heart rhythm problems.
ECHOCARDIOGRAM — uses high-frequency sound waves (ultrasound) to examine the size, shape, and motion of the heart, giving information about the structure and function of the heart.
EXERCISE STRESS TEST — records the heart's electrical activity during increased physical activity.
NUCLEAR STRESS TEST — radioactive material is injected into a vein during exercise or pharmacologic stress and observed as it is absorbed by the heart muscle. This can help tell your doctor whether there is impaired blood flow suggesting an obstructed coronary artery.
CORONARY CALCIUM SCORING — a type of X-ray called a CAT scan that uses a computer to make pictures of the heart. The presence of calcium in the heart arteries suggests that atherosclerosis or hardening of the arteries is occurring.
CORONARY ANGIOGRAPHY — X-rays taken after a dye is injected into the arteries to allows the doctor to look for abnormalities in the arteries. This can be done invasively through a puncture into the large artery in the groin or noninvasively with new CAT Scan technology.
TREATMENT
NITRATE MEDICATIONS
Nitroglycerin is usually given during an acute attack of angina. It can be given as a tablet that dissolves under the tongue or as a spray. There are also longer-lasting types that can be used to prevent angina before you participate in an activity known to cause it. These may be given as pills or applied as patches or ointments.
BLOOD-THINNING MEDICATIONS
A small, daily dose of aspirin has been shown to decrease the risk of heart attack. Warfarin (Coumadin), ticlopidine (Ticlid), and clopidogrel (Plavix) are also used for some patients.
BETA BLOCKERS,CALCIUM CHANNEL BLOCKERS and ACE INHIBITORS
These may help prevent angina and, in some cases, lower the risk of heart attack.
MEDICATIONS TO LOWER CHOLESTEROL
These medication may prevent the progression of coronary artery disease and may even improve existing coronary artery disease.
REVASCULARIZATION
Patients with severe blockages in their coronary arteries may benefit from procedures to improve blood flow to the heart muscle:
* Percutaneous Coronary Interventions (PCI) — catheter-based procedures done through a small puncture into the large artery in the groin. These include balloon angioplasty where a small balloon is inflated in a coronary artery to widen and compress plaque out of the way. In some cases, a wire mesh stent is placed to hold the artery open. Some newer stents are coated with a medication (drug eluting stents) to prevent recurrent narrowing due to clot formations.
* Coronary Artery Bypass Grafting (CABG) — done surgically through an incision in the chest. Segments of arteries taken from the chest wall and wrist or veins taken from the legs are sewn into the heart arteries to reroute blood flow around blockages.
OPTIONS FOR REFRACTORY ANGINA
For patients who are not candidates for revascularization procedures but have continued angina despite medication, options include:
* Enhanced External Counterpulsation (EECP) — large air bags like blood pressure cuffs are inflated around the legs in sequence with the patient’s heart beat. The patient receives 5 one-hour treatments per week for seven weeks. This has been shown to reduce angina frequency and may improve symptom-free exercise duration.
* Transmyocardial Revascularization (TMR) — surgical procedure done with laser to reduce chest pain
PREVENTION
* Maintain a healthy weight.
* Begin a safe exercise program with the advice of the doctor.
* If smoking, quit.
* Eat a healthful diet, low in saturated fat and rich in whole grains, fruits, and vegetables.
* Treat high blood pressure and/or diabetes.
* Treat high cholesterol or triglycerides.
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| Last Modified :
Tuesday, May 12, 2009 |
Compiled and edited by the Editorial team and
approved by Expert panel of h4heart.com
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