Coronary artery disease (CAD), also known as coronary heart disease (CHD) is a medical condition where there is gradual narrowing of the coronary arteries owing to the deposition of fatty materials (atherosclerotic plaques) on the wall of the arteries. The coronary arteries supply oxygen and nutrients to the heart muscles. Worldwide CAD is the one of the most common causes of sudden death. Early stage CAD usually does not produce any symptoms but with gradual progression of disease symptoms appear. In many cases the first symptom is often sudden heart attack (myocardial infarction). Life style modification, drugs and interventional therapy are the treatment options.
In the initial stages, coronary artery disease may not produce any symptoms because the degree to which the blood flow interrupted is not sufficient to injure or damage the heart muscle. However, as the narrowing worsens the heart muscle is compromised and symptoms become evident especially during strenuous activity and psychological stress. These symptoms are :
- Chest pain (angina) occurring after heavy meal, exercise or emotional stress. The pain is described typically as crushing or squeezing pain, usually felt on the left side of the chest sometimes radiating towards upper arm, back even upper abdomen. Angina can be of various types stable angina pain usually subsides with rest and nitroglycerines. Unstable angina is characterized by change in frequency, duration and pattern of the pain.
- Breathlessness like anginamay occur with exertion (physical and mental).
- Associated symptoms are fatigue, lethargy, profuse sweating and apprehension.
Narrowing of the coronary arteries occur due to damage to the inner wall of the arteries and subsequent deposition of fatty materials (plaque) on them (atherosclerosis). There are some factors responsible for fatty plaque deposition on the walls of the coronary arteries such as :
- Family history of CAD
- High blood pressure
- High cholesterol
- Long-term smoking
Under stressful conditions, the workload on the heart increases thereby requiring more oxygen for the heart muscles. The already narrowed coronary arteries only partially meet the need of the heart muscles leading to ischemia of the heart muscle characterized by intense chest pain, sweating and shortness of breathing.
Sometimes the fatty plaques rupture, attract platelets and form blood clots that may dislodge and block other segment of coronary arteries. This will cause complete obstruction of blood flow to a specific portion of the heart muscle supplied by that coronary artery, leading to a heart attack (myocardial infarction).
- Age: men > 60 years, women > 65 years
- Sex: men and women after menopause
- Family history
- High blood pressure (systolic pressure)
- High cholesterol (high LDL, lipoprotein a, low HDL)
- Lack of exercise
- Diet rich in saturated fat
Treatments is based on three approaches – lifestyle modification, drugs and surgery.
- Cessation of smoking and moderate alcohol consumption.
- Diet rich in unsaturated fatty acids.
- Weight reduction.
- Antihypertensive (to lower high blood pressure)
- Hypoglycemic agents (to lower blood sugar)
- Cholesterol-lowering drugs
- Low dose aspirin (to prevent clot formation)
- Beta blockers (to reduce cardiac workload)
- Nitroglycerines (to reverse narrowing of coronary arteries)
- ACE inhibitors, angiotensin receptor blockers
- Balloon angioplasty to dilate the narrowed artery and stenting to maintain the dilation.
- Bypass surgery: using vessel from other part of the body to bypass the narrowed artery.