Atrial Fibrillation

Every human heart has four partitions namely Left Auricle, Left Ventricle, Right Auricle and Right Ventricle. Auricles are chambers that carry oxygenated blood to all parts of the body and ventricles are one that transports deoxygenated or impure blood from various parts of your body to the heart. All the four chambers will contract and expand rhythmically to pump blood. This in turn produces heartbeat.

What Happens During Heartbeat?

There is an inbuilt timer in your right auricle called sinoatrial node which creates new electrical impulse at defined intervals. The generated impulse would make the auricles to contract which in turn forces the blood to ventricles via one way valve. The same impulse will spread across AV node found in the lower end of right auricle. Here the impulse will be slightly delayed. Again the impulse will be transported to the ventricles through Atrioventricular node called AV bundle. Subsequently, the ventricles will contract pushing the blood to arteries through valves.

There is a continuous sequence of these events that maintains predefined rhythm. And the contraction and expansion of auricles and ventricles in systemic pattern gives you the heartbeat. Your heart beat is 60-96 per minute normally which goes up when you are doing exercise or emotionally disturbed. If the normal rhythm of the heartbeat is disturbed it would cause rapid heartbeat and both the auricles (RA and LA) would beat irregularly which subsequently would disturb the normal motion of ventricles causing atrial fibrillation.

Atrial fibrillation would cause palpitation and shortness of breath. The auricles receive erratic electrical impulse and accordingly beat in disorganized fashion causing abnormal heartbeat. Any irregular heartbeat would definitely affect the normal blood flow to the body causing weakness. It is quite common for all of us to get palpitation for few seconds. But if atrial fibrillation is frequent you need to seek medical help. This can be treated with medications and implanting devices to control electric impulses.

Symptoms :

Not all the atrial fibrillation would produce obvious symptoms. There are some people who may not feel any signs of abnormal heartbeat and the condition would be found during physical examination. Atrial fibrillation can produce signs of palpitation (racing/irregular heartbeat), fatigue, dizziness and confusion. Since normal blood flow from the auricles is affected it would cause general weakness and fatigue. For some people it can cause tightness in chest and shortness of breath.

Types :

  • Atrial fibrillation that is rare and occasional is known as paroxysmal type. The symptoms would last for few minutes/seconds and the heartbeat switches over to normal.
  • For some people, irregular heartbeat is persistent. The chaotic heart rhythm would not stop on its own requiring medical intervention. This type of atrial fibrillation is called persistent.
  • In severe cases, the abnormal heartbeat becomes permanent causing permanent fibrillation. The person will have to depend on medications till the end of his life to manage heartbeat.

Causes :

The auricles would receive irregular electrical signals due to some reason that causes abnormal heartbeat and atrial fibrillation. The AV node receives high input of signals resulting in irregular heartbeat. Normal heartbeat (65-100) per minute is altered resulting in 125-175 beats in a minute or even more leading to palpitation.

Several reasons can influence the normal electrical impulse. Some of them are sudden high blood flow to heart, high blood pressure, abnormality in the valves of the heart, heart attack, congenital heart attack and coronary heart problem. If your thyroid gland becomes overactive it can cause atrial fibrillation. Lung disease like pneumonia and sleep apnea can cause irregular heartbeat. If the pacemaker of the heart does not function properly it can produce erratic heartbeat. In some cases the reasons are unknown.

Risk Factors :

As one grows old, it increases the risk of getting atrial fibrillation. 1 person out of 200 people in age group (55-65) is diagnosed with AF. A person is heart valve problem congenitally (by birth) or having coronary heart problem or undergone heart surgery has increased chance of developing AF. High blood pressure, obesity, family history of heart problem, having chronic diseases and drinking alcohol can cause AF.

Complications :

Not all the AF is serious. But atrial fibrillation that is persistent can be life threatening. Irregular rhythm of your heart can lead to blood clot formation which can subsequently travel to brain causing stroke. A person with subsequent episodes of AF can develop heart failure.

Diagnosis :

Your doctor will listen to the above symptoms, and request for ECG and echo test to get a clear picture of your heart. Nowadays holter monitor is used to measure heartbeat and function which gives the activity of your heart for 24 hours. It gives a better picture of your heart’s function when you are at work and stressed. Portable ECG device can also be used to check heartbeat when you have palpitation. In addition your doctor may order for blood test and chest X-ray.

Treatment :

Treatment for AF depends on the type of AF you are experiencing. Your doctor will consider factors like your age and health condition before starting any treatment. The aim of any treatment for AF is to prevent formation of blood clot and to control the rhythm of heart.

Cardioversion is a procedure used for resetting the rhythm of your heart. A mild electric shock is sent to your heart through paddles attached on your chest, which would stop the electrical impulse for a while. When the heart begins to function again, it would resume normal rhythm. Anti arrhythmic drugs are also used to manage rhythm of your heart. The person will be given blood thinners like Coumadin before the procedure so that he does not get a stroke or develop blood clots.

Depending on the case of the patient, the doctor may prescribe anti arrhythmic drugs like tikosyn or rhythmol permanently. Medications like digoxin can control the heart rate effectively. In some cases, calcium channel blockers are also given.

  • Surgery :

This is the last option for people with AF where medications and other procedures are ineffective. Catheter ablation is done the surgeon sends in a long catheter (thin tube) to your heart and using radiofrequency high power heat or cold is generated to scar the tissue that causes erratic electrical impulse. This in turn could correct the heartbeat producing normal heart rate.

Sometimes, the surgeon would create multiple incisions on the upper chamber of the heart resulting in scar tissue. This is known as surgical maze which is highly successful in correcting AF. AV node ablation can also be done by sending high powered radiofrequency waves in the pathway of auricles and ventricles. Anticoagulant drugs (blood thinners) are prescribed for people who have undergone treatments for AF. Your doctor will closely monitor the thickness of blood periodically. Some people have to take these drugs all through their life.

Changes in Lifestyle :

  • Once you are diagnosed with AF you need to make certain changes in your diet and start healthy living.
  • Eat balanced diet free of fats and oils.
  • Practice regular exercise.
  • Quit smoking and drinking.
  • If you have blood pressure, follow the instructions of your doctor in taking medications.
  • Practice yoga and meditation to manage stress.
  • By following healthy lifestyle and controlling your weight, you can prevent AF to large extent.

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