Your heart consists of four chambers, the upper two are called atria, and the lower two are called ventricles, which contract at a regular rhythm to supply blood to the body. This rhythm is generated and controlled by a special electrical system present in your heart consisting of the SA node, AV node, and bundle of Hiss. Any problem occurring in the conductivity of this electrical system can cause abnormal rhythms known as arrhythmias. The ultimate initiating event of atrial fibrillation is still unknown. However, it is linked to changes in electrical conductivity and structural remodeling. Factors like neurochemical derangements, hemodynamic stress, atrial inflammation, atrial ischemia, and metabolic stress can influence the normal structural and electrical processes in the heart and lead to atrial fibrillation. These impulses can also be transferred to the lower chambers, causing premature ventricle beats.
Atrial fibrillation may occur in a healthy person or people with concurring diseases, particularly high blood pressure, coronary artery disease, and valvular heart disease. The factors that can trigger an Afib may include;
· Previous or current heart disease such as heart attack, rheumatic heart disease, mitral valve prolapse, pericarditis, heart failure, Wolff-Parkinson-White syndrome
· Chronic lung disease or pneumonia,
· Excessive intake of caffeine or alcohol
· Drug abuse including methamphetamine and cocaine
· Pregnancy
· Smoking
· Thyroid disease
· Digoxin toxicity
· Some medications, such as dobutamine and the chemotherapy agent cisplatin.
According to the duration of the attack, Afib has been classified into three main patterns;
Around 2.7 to 6.1 million people are affected by atrial fibrillation in the USA. Its incidence increases with age, and it is more prevalent in men.
Some of the conditions that can predispose you to an Afib include;
· Age: more than 45 years
· Excessive alcohol, tobacco, or caffeine use
· Family history for some types of Afib
· Strenuous exercise
· Sedentary lifestyle and obesity
· Long-standing Diabetes mellitus or hypertension
· Heart or lung disease
· Obstructive sleep apnea
Some people may not show any symptoms while others may exhibit the following;
To diagnose, your doctor will inquire about symptoms and previous medical records. They will examine you with particular emphasis on heart examination using a stethoscope for hearing heart sounds and murmurs. The following tests can be used;
· Electrocardiogram (ECG): Electrical impulses in the heart are recorded during this simple test. Many cardiac disorders, such as irregular heartbeats and clogged arteries, can be diagnosed with an ECG. ECG is sometimes taken when you work out, usually on a bike or treadmill. A stress test is a name for this approach. The typical findings in the ECG of Afib are irregularly spaced QRS complexes and the absence of P waves.
· Ambulatory monitoring: It makes use of sensors that monitor your heart rate. A Holter monitor is a device worn for one or more days to record the activity of your heart.
· Event recorder: This device can be worn even for a month for detecting infrequent arrhythmias. You are needed to press a button whenever you feel the symptoms.
· Electrophysiology (EP): During this procedure, a long, narrow, flexible tube is placed into a blood channel generally in the pelvis and directed to the heart to detect the electrical activity of the heart through sensors located at the tip of the catheter. It can help a doctor to locate the accessory pathways.
· Echocardiogram: In this test, ultrasound waves create an image of your heart. This test would be suggested by your physician to check how your heart's structures work.
· Transesophageal echocardiography: It is a type of echocardiogram that is performed through the esophagus. A transesophageal echocardiogram may be recommended if more precise pictures of your heart are required. A thin pipe holding the sensor is directed down your throat and into the tube that connects your mouth and stomach(esophagus). The procedure is carried out when you are anesthetized.
· Blood tests: Various blood tests, such as those to assess your kidneys, liver, and thyroid function and digoxin levels, may be ordered.
· Cardiac enzymes: Increased amounts of specific proteins or enzymes found in cardiac muscle may be detected by blood testing. Any person with chest pain and risk factors should be checked for myocardial infection using a blood test for enzymes.
· X-ray of the chest. A chest X-ray can reveal the state of the lungs, the size and form of the heart, and the main blood channels. A chest X-ray can also reveal lung disorders such as pneumonia or a collapsed lung, which can predispose to SVT.
Some other disorders may present like atrial fibrillation and need to be excluded to make an efficient diagnosis;
If you suspect having atrial fibrillation, you must contact your healthcare provider as untreated Afib can lead to some complications, particularly stroke which can be prevented by simple measures. Due to improper and irregular beating of the atrium, the blood tends to stagnate, predisposing to the formation of a blood clot called thrombus that can go into the brain and cause stroke. The treatment goal is to control the rate and rhythm of the heart to prevent hemodynamic collapse and provide medications to reduce the risk of stroke. The following treatment is usually performed;
Medications
To control rate: Your doctor will prescribe medication to decrease your heart rate like Beta Blockers (Atenolol, Propranolol), and Calcium Channel Blockers (Amlodipine, Diltiazem ).
To control rhythm: These are given to enable your heart to maintain a normal rhythm. For example; procainamide, flecainide acetate, , sotalol, propafenone, or amiodarone.
Blood-thinning drugs: These are given to prevent thrombus formation in the atria and reduce the risk of stroke. They include heparin and warfarin. Aspirin can be used too, as it also functions as a blood-thinning agent. The side effects of using these medicines include bleeding episodes, so their levels in the blood need to be closely monitored to prevent hemorrhages. The parameter used to monitor them is called INR. Its value should remain between 2-3.
Procedures
Electrical cardioversion: It is the first choice for unstable patients. During this procedure, an electric current is delivered to your chest using special paddles to restore electrical activity.
Pacemaker: Some people are given a pacemaker device that is implanted under the skin. It is connected to the heart and generates a heartbeat.
An Implantable Cardioverter-defibrillator (ICD): This equipment measures your heart rate and, if necessary, gives electric shocks to correct irregular heart rhythms. It monitors and manages aberrant arrhythmias.
Surgeries
Catheter ablation: In this procedure, radiofrequency ablation, or cryoablation is used in which heat or cold energy is applied to the heart tissue to destroy the connections causing aberrant electrical conductivity. This area is often the atrioventricular nodes, so this procedure is sometimes known as Atrioventricular (AV) node ablation. It involves using a catheter which is a long, narrow, flexible tube that is placed into a blood channel and directed to the heart, generally in the pelvis or forearm.
Surgical ablation: This procedure is also called the Maze procedure. In this procedure, electrical barriers or blocks are created in the atria using open surgery.
Treatment of Afib is very important to prevent strokes. It is linked to a 1.5- to 1.9-fold higher risk of death due to strokes. It also increases the risks of heart failure, coronary artery disease, dementia, and kidney disease. Women tend to have the worst outcomes.
Adopting the following lifestyle changes may prevent you from developing atrial fibrillation.
Our clinical experts continually monitor the health and medical content posted on CURA4U, and we update our blogs and articles when new information becomes available. Last reviewed by Dr.Saad Zia on May 12, 2023.
https://www.heart.org/en/health-topics/atrial-fibrillation/what-is-atrial-fibrillation-afib-or-af
Atrial fibrillation (Afib) refers to the condition of the heart associated with a fast and irregular heartbeat (abnormal heart rhythm) occurring due to problems of electrical activity in the upper chambers (atria) of the heart. It is one of the most common types of heart arrhythmias. A normal heart beats at the rate of 60 to 100 beats per minute. An episode of atrial fibrillation can make the heart beat at the rate of over 140 beats per minute. Sometimes, there may be no symptoms; in other cases, you may feel palpitation, lightheadedness, faintness, shortness of breath, sweating, fatigue, and/or chest pain. Once the condition is diagnosed, treatment should be provided as it can lead to stroke, heart failure, and dementia.