The heart weighs about 350 to 450 grams in an average adult.

It pumps about 80 cc of blood per heart beat. At average heart beat of 70 per minute, in a day, the heart would have pumped 8 thousand liters of blood around the body.

It is on automatic. Via specialised group of cells, the heart has a natural pacemaker that will regulate the heart rate.

Some specialised muscle cells act as a conducting pathway, much like electrical circuit. Signals from the pacemaker is transmitted to heart muscle in orderly fashioned.

Cardiac valves separate the various chambers and great blood vessels. Acting like a door, it allows blood flow only in one direction. There are four valves in a normal heart.

Coronary arteries are special blood vessels running on the surface of the heart. They supply nutrient-rich blood to the hardworking heart muscle. A narrowing or blockage of these arteries causes heart attacks and coronary artery disease.

Major risk factors for coronary artery disease are:

• Smoking
• High cholesterol level
• High blood pressure
• Diabetes mellitus
• Family history

Exercises increase the demand on circulatory system and condition it in the long run to work more efficiently. Walking, light jogging, swimming or cycling for 30 to 40 minutes at least three times per week is recommended.

Heart disease could be silent in the early stage. It may be worthwhile to undergo routine physical examination and stress test, especially if you are above 45.

Prudent and healthy lifestyles are important preventive measures. Regular exercise, keeping optimal body weight, good balanced diet and stress reduction are important.