Introduction

The heart has three coronary arteries and they supply your heart with blood, oxygen and nutrients. The coronary arteries due to build up of fatty deposits becomes obstructed and this is known as coronary artery disease.

The gradual buildup of fatty deposits in your coronary arteries (atherosclerosis) narrow your coronary arteries.Eventually; diminished blood flow may cause chest pain (angina), shortness of breath or other symptoms. A complete blockage can cause a heart attack.

Coronary artery disease often develops over many years; it can go virtually unnoticed until it produces a heart attack. But action may be taken to prevent coronary artery disease.

Signs and symptoms

• Chest pain
  The pain is usually triggered by physical or emotional stress. It typically goes away within minutes after stopping the stressful activity. Pain usually is on the left side of the chest. It can radiate to the left arm, lower jaw or the neck.
  
  
• Shortness of breath
  If your heart can't pump enough blood to meet your body's needs, you may develop shortness of breath, fatigue with exertion, and swelling in your feet and ankles.
  
  
• Heart attack
  Complete blockage of a coronary artery leads to a heart attack. The classic symptoms of a heart attack include crushing pain in your chest, pain in your shoulder or arm, and shortness of breath. Sometimes a heart attack occurs without any apparent signs or symptoms.

Causes

Coronary artery disease is thought to begin with injury to the inner layer of a coronary artery. The damage leads to deposition of fatty material inside the blood vessel called atherosclerosis. The damage may be caused by various factors, including:

• Smoking
  
  
• High blood pressure
  
  
• High cholesterol
  
  
• Diabetes mellitus

Risk factors

Men are generally at greater risk of coronary artery disease than are women. However, the risk for women increases after menopause. Other risk factors for coronary artery disease include:

• Smoking
  
  
• High blood pressure
  
  
• High cholesterol
  
  
• Diabetes
  
  
• Obesity
  
  
• Family history
  
  
• Physical inactivity
  
  
• Stress

Sometimes coronary artery disease develops without any of the risk factors. Researchers are studying other possible factors, including:

• C-reactive protein
  CRP is a general sign of inflammation, which plays a central role in atherosclerosis. The liver produces C-reactive protein (CRP) in response to injury or infection. CRP is also produced by muscle cells within the coronary arteries.
  
  
• Homocysteine
  Homocysteine is an amino acid the body uses to make protein and to build tissue. But excessive levels of homocysteine may increase your risk of coronary artery disease.
  
  
• Fibrinogen
  Fibrinogen is a protein in your blood that plays a main role in blood clotting. But too much may promote excessive clumping of platelets leading to clotting of blood which can lead to a heart attack or stroke.
  
  
• Lipoprotein (a)
  This substance forms when a low-density lipoprotein (LDL) cholesterol particle attaches to a specific protein. The protein that carries lipoprotein (a) may disrupt your body's ability to dissolve blood clots. High levels of lipoprotein (a) may be associated with coronary artery disease and heart attack.

When to seek medical advice

If you have risk factors for coronary artery disease, or signs or symptoms of narrowed arteries. Even if you don't have evidence of coronary artery disease, your doctor may recommend aggressive treatment of your risk factors. Early diagnosis and treatment may stop progression of coronary artery disease and help prevent a heart attack.

Screening

After a detailed medical history and physical examination certain routine blood tests would be done. One or more diagnostic tests may be done as well.

• Electrocardiogram (ECG)
  This is a trace of the electrical activities of the heart. An ECG can often reveal evidence of a previous heart attack or one that's in progress.
  
  
• Echocardiogram
  An echocardiogram uses sound waves to produce images of your heart. During an echocardiogram, it is possible to determine whether all parts of the heart wall are contracting normally. Parts that move weakly may have been damaged during a heart attack .The heart valves and its function may also be seen.
  
  
• Exercise Stress test
  If your signs and symptoms occur most often during exercise, your doctor may ask you to walk on a treadmill. This is known as an exercise stress test. Sometimes medication is used to stimulate your heart and an echo is used to visualize the heart. These are known as stress echos. Another stress test known as a nuclear stress test helps measure blood flow to your heart muscle at rest and during stress. It's similar to a routine exercise stress test but with images in addition to an ECG. Trace amounts of radioactive material — such as thallium or a compound known as sestamibi — are injected into your bloodstream. Special cameras can detect areas in your heart that receive less blood flow.
  
  
• Coronary Angiogram
  To view blood flow through your heart, your doctor may inject a special dye into your arteries before a chest X-ray. This is known as an angiogram. The dye outlines narrow spots and blockages on the X-ray images.
  
  
• Multislice CT Angiogram
  This test, can detect narrowing or blockage of coronary arteries. It can also show calcium within fatty deposits that narrow coronary arteries. If a substantial amount of calcium is discovered, coronary artery disease is likely. This is an x-ray test.

Treatment

Lifestyle changes can promote healthier arteries. Quitting smoking is the most important thing you can do. Eat healthy foods, and exercise regularly. Sometimes medication or procedures to improve blood flow are recommended as well.

Medications:

Many drugs can be used to treat coronary artery disease, including:

• Aspirin
  Used daily to reduce the tendency of your blood to clot, which may help prevent obstruction of your coronary arteries. If you've had a heart attack, aspirin can help prevent future attacks.
  
  
• Cholesterol medications
  Aggressively lowering your low-density lipoprotein (LDL), or "bad," cholesterol can slow; stop or even reverse the build-up of fatty deposits in your arteries. Statins and fibrates are the most commonly used.
  
  
• Beta blockers
  These drugs slow your heart rate and decrease your blood pressure. If you've had a heart attack, beta blockers reduce the risk of future attacks.
  
  
• Nitro-glycerine
  Nitro-glycerine tablets spray and patches can control chest pain by opening up your coronary arteries.
  
  
• Angiotensin-converting enzyme (ACE) inhibitors
  These drugs decrease blood pressure and may help prevent progression of coronary artery disease. If you've had a heart attack, ACE inhibitors reduce the risk of future attacks.
  
  
• Calcium channel blockers
  These medications relax the coronary arteries muscles and cause the vessels to open, increasing blood flow to your heart. They also reduce the blood pressure.

Procedures to improve blood flow

Sometimes more aggressive treatment is needed to restore blood flow.

• Angioplasty and stent deployment
  In this procedure, a long, thin tube (catheter) is introduced into the coronary artery and a wire with a deflated balloon is passed through the catheter to the narrowed area. The balloon is then inflated opening up the narrow artery. A mesh tube (stent) is then deployed to keep the artery open. Some stents slowly release medication to help keep the artery open.
  
  
• Coronary artery bypass surgery
  A surgeon creates a graft to bypass blocked coronary arteries using a vessel from another part of your body. This allows blood to flow around the blocked or narrowed coronary artery. Because this requires open heart surgery, its most often reserved for cases of multiple narrowed coronary arteries.

Control of Risk factors:

Lifestyle changes can help you prevent or slow the progression of coronary artery disease.

• Stop smoking
  Smoking is a major risk factor for coronary artery disease. Nicotine constricts blood vessels and forces your heart to work harder, and carbon monoxide reduces oxygen in your blood and damages the lining of your blood vessels.
  
  
• Blood pressure control
  Blood pressure must be well controlled. Medication should be taken for life. Normal blood pressure is below 120 systolic/80 diastolic as measured in millimetres of mercury (mm Hg).
  
  
• Cholesterol control
  if you've already had a heart attack or have diabetes, for exam: Most people should aim for an LDL level below 130 mg/dL. If you have other risk factors for heart disease, your target LDL may be below 100 mg/dL. If you're at very high risk for heart disease — you may need to aim for an LDL level below 70 mg/dL.
  
  
• Diabetes under control
  If you have diabetes, tight blood sugar control can help reduce the risk of heart disease.
  
  
• Regular exercise
  Exercise helps you achieve and maintain a healthy weight and control diabetes, elevated cholesterol and high blood pressure — all risk factors for coronary artery disease. Aim for 30 to 60 minutes of physical activity at least five days of the week.
  
  
• Eat healthy food
  A diet low in saturated fat, cholesterol and sodium — can help you control your weight, blood pressure and cholesterol. One or two servings of fish a week are also beneficial.
  
  
• Maintain weight
  Being overweight increases your risk of coronary artery disease. Weight loss is especially important for people who have large waist measurements — more than 40 inches for men and more than 35 inches for women.
  
  
• Avoid stress
  Reduce stress as much as possible. Practice healthy techniques for managing stress, such as muscle relaxation and deep breathing.