The heart pumps about 70 times in a minute. This beating occurs at a regular interval. An irregularity in the rhythm is called Arrhythmia. An irregular heartbeat is called a cardiac arrhythmia. The heart may beat irregularly, beat too fast, or beat too slowly.
Nearly everyone has felt their heart skip a beat, race, or flutter inside their chest. Occasional heart palpitations are common and harmless, even though they’re considered arrhythmias. They may just occur, or they may be produced by something that stimulates your heart, such as stress, tobacco, alcohol, caffeine, appetite suppressants, or cold and cough medicines that contain caffeine or other stimulants. If you have an otherwise normal heart, occasional heart palpitations are rarely the cause of alarm, and most don’t require medical treatment. If they’re bothersome, limiting or avoiding what prompted them may eliminate the problem.
Electrical System of the heart:
Our heart is the most wonderful and complex Pumping machine – probably the best pump in the world. It has to keep on pumping the blood for years at the rate of 100,000 times per day.
It’s not a simple pump – just receiving and pumping the blood. It has to receive the blood – send it to the lungs for purification, receive it back, and then again pump it to the body. So, it’s a double pump.
Structure wise, it has two receiving chambers – upper chambers (Atria) and two pumping chambers which can be called lower chambers (ventricles). The two upper chambers will receive the blood from the body and the lungs respectively. Then both pump the received blood to the two lower chambers (Right and Left Ventricles). These ventricles have to pump impure blood to the lungs and the pure blood to the body. Now all the chambers cannot pump together – then there will be no flow. First, the upper chambers will pump and fill the lower chambers – then the lower chambers will have to pump. The speed of the chambers also has to be the same.
To synchronize these pumping actions – one after another – the heart is fitted with an electrical system. This system starts with the Original Pacemaker (medically called S A Node) – which is a highly active nerve cell of the size of a pinhead. This generates the electrical impulses which start the pumping actions. This usually sends signals of 70-72 per minute – this governs the heart rate or pulse rate.
First to get the SA node electrical signal to pump are the upper chambers (Atria – Right and Left). They pump the blood to the ventricles. The electrical signal now pauses for microseconds at another Pacemaker called AV node – which is situated little away just near the ventricles. Once the pumping of upper chambers is complete and the lower chambers are filled up completely – the AV Node starts sending electrical signals to Both lower chambers to contract. This is done by a Y shaped nerve called “Bundle of His” which has two branches for the two lower chambers. These branches are called Left and Right Bundle Branch. Now, the Lower chambers contract sending the blood to body and Lungs. This completes one cycle – called the cardiac Cycle. This Whole cycle takes 0.8 seconds or 800 million seconds. Now the SA Node starts another cycle by sending signals to upper chambers again.
To make a gist – this electrical system has four parts – 1. SA Node 2. Nerves from SA node to Upper chambers 3. AV Node and 4. Bundle of His with left and right branches.
Hope you liked this blog!
For more health related blogs, please click here.