We all know what the function of our heart is and how important it is. Without heart we cannot live. Just today, I read in the news paper about an operation performed on a baby girl of 15 minutes old, to fix a pacemaker on her heart because her heart beat was well below the rate (of the order of 45 per minute where it should have been 120 to 130 for a new born baby of the same age). It is not the age that matters but its condition that matters. Therefore to know about how we should take care of our heart, we must know how it works and what are the dos and don’ts to keep it running in top condition.

Our heart can be considered like a mechanical pump which pumps water. In any mechanical pump, it is possible for some choking due to mud and other dirt particles within itself as well as the pipe line that carries water so that its efficiency is reduced over a period of time. We will then do some repair to remove the blockade and the pump will start working well once again. Similarly, the functioning of the heart is also depending upon its own health and the condition of the veins and arteries carrying blood. Death due to heart diseases is increasing day by day. In some cases we know well in advance about the problems related to our heart, thereby we are able to do proper treatment and keep up the good working condition. But there are many cases where it is all of a sudden that the death happens and no one has a clue about the cause of death. That particular person might not have shown any symptoms of problems with respect to the heart.

Let us see how the heart works and learn some simple steps to keep it up and running. The position of the heart between the lungs and it is behind our breast bone. It is aligned 2/3rd to the left and only 1/3rd of it is towards the right side of our body. We all know that the heart consists of some important parts like Aorta, Pulmonary trunk, Left Atrium, Pulmonary veins, Left ventricle, Inferior vena cava, Right ventricle, Right atrium and Superior vena cava.

There are three layers for our heart called endocardium, myocardium and pericardium. Endocardium is the smooth inside lining. Pericardium which is almost like a sac filled by a fluid surrounding the middle layer which is the myocardium. The heart can be considered as having four chambers. There are two chambers on the right and two on the left and these chambers are known as Atrium and Ventricle. Left and Right sides of the heart have two chambers each – one Atrium and one Ventricle.

Atria receive the blood flowing back to the heart and Ventricles pump blood out of the heart.

There are four valves regulating and controlling the flow of blood into and out of the heart. They are Tricuspid valve, Pulmonic or Pulmonary valve, Mitral valve and the Aortic valve. They are located within the heart chambers and very much critical to the proper flow of blood. They are normally one-way valves, which allow blood to flow from one chamber to other and/or allowing blood to flow out of the heart. They open and close thus controlling the flow during the contractions of the heart. There will be pressure difference within the heart while it is in working condition. The difference in pressure as well as other muscles within the heart controls the closing and opening of these valves.

The veins in our body carry blood to the heart and they reach the right atrium – the right atrium is the receiving chamber – which is at the right side of our heart. When the blood fills the right atrium, the tricuspid valve opens and blood flows to the right ventricle. This is de-saturated or impure blood that enters the heart. The pressure in the right atrium and the right ventricle changes closing the tricuspid valve. Now the blood is in the right ventricle. As the tricuspid valve closes, right ventricle starts contracting and it is ready to pump the blood into the lungs. The pulmonary valve opens, which was in a closed state while the right ventricle was filling. The pulmonary artery carries this blood to the lungs. Pulmonary valve closes then to prevent blood from entering back into the right ventricle.

When the blood passes through the lungs, it gets refreshed with fresh supply of oxygen. In effect the carbon dioxide which gets added to the blood by various body organs gets replaced by fresh oxygen while the blood passes through the lungs. The refreshed blood then flows to the left chamber of the heart. Here the receiving chamber is the left atrium. The mitral valve in the left atrium will be in a closed state while the left atrium is filling. Once the pressure changes in the left atrium and left ventricle, the oxygenated blood flows into the left ventricle by the opening of the mitral valve. The mitral valve closes once the left ventricle is filled with oxygenated blood and the left ventricle starts contracting. The mitral valve prevents the blood going back to the lungs.

The blood pressure is generated by the left ventricle which is normally called the pumping chamber of the left side of our heart. The normal blood pressure of a grown up man is 120 over 80. The refreshed blood supply leaves the left ventricle when it contracts. The aortic valve controls the flow of blood from the heart to different parts of our body. The main artery of the body then gets fresh, oxygenated blood. This main artery is known as aorta. Once the left ventricle gets empty the aortic valve closes. This will prevent the blood being pushed back to the heart.

The functioning of these four valves of our heart – the systematic sequential opening and closing – is very much important for the normal functioning of our heart. There are two general conditions where the valves operate abnormally. They are known as Regurgitation and Stenosis. The condition by which the valve narrows is known as Stenosis. When the valve is unable to close completely, it is either called Insufficiency or Regurgitation. There are various other conditions that can affect the normal functioning of the valves. These problems are rectified by doing surgery and in certain irreparable conditions; these valves may have to be replaced.

The heartbeat is produced by the tricuspid and mitral valves when blood reaches the heart and the pulmonic and aortic valves when blood flows out of the heart.

The average heartbeat rate per minute is called the Pulse, which changes according to the age. For a new born baby the heart beats within 120 to 130 times. Hearts beat is about 140 when the baby is 3 months old. At one year, it is around 120 and reduces as the baby grows. The pulse rate is about 85 at the age of 12 and for an adult it varies between 60 and 100. The average heartbeat of an adult is 72 per minute.

How does the heart beat automatically? Our body has a built-in electrical system. These are special groups of cells which can on themselves generate an electrical activity. Sinoatrial Node is a natural pacemaker within our heart which is located in the right atrium. The cells which having ability to generate electrical signals produce impulses in the Sinoatrial Node. The heart also contains some special fibers which can conduct these electrical signals from the pacemaker to various parts of the heart. Other nerves in the heart can change the rate of firing of the pacemaker cells and can also control the contraction of our heart. They are known as Autonomic Nervous System and have two parts called Sympathetic Nerves and Parasympathetic Nerves. The sympathetic nerves increase the rate at which the heart beats and the amount of contraction of the heart. It is the opposite with the parasympathetic nerves.

These electrical activities can be measured. This is what we measure using ECG. Some of these electrical system malfunctions like minor premature beats are not that serious, which normally do not need treatment. We need an artificial pacemaker to correct the slow or irregular beats.

The heart, which is just another organ in our body, requires blood and oxygen supply for its normal working. The heart cannot extract oxygen on its own from the blood flowing inside it and there comes the coronary artery which supplies fresh blood to the heart. We must keep our coronary arteries in good condition, without any blockade by following a healthy diet. If the arteries are blocked, we will have a heart attack. The heart also has various veins which carry impure blood from the heart muscles. The major veins of the heart open into the right atrium.

The average heart pumps about 2.4 ounces – which is 70 ml - during one heartbeat. This is about 1900 gallons or 7200 liters of blood in a day if the heart beats 72 times per minute. So, our heart is a very important organ in our body and we must keep its good health.

We shall see more about heart and heart diseases and how we can detect them early and take required precautions before it is too late.

I love my heart do you?