Atrial fibrillation (AF) is the most common arrhythmia, it occurs when the upper chambers (atria) of the heart experience chaotic electrical signals. The result is a rapid and irregular rhythm. The heart rate of atrial fibrillation may reach 100 to 175 beats per minute.
Our heart consists of four chambers – two upper chambers (atria) and two lower chambers (ventricles). In the right superior chamber of the heart (the right atrium), there is a group of cells called the sinoatrial node. This is the natural pacemaker for the heart. The electrical signal generated by the sinoatrial node (SA node) usually activates every heartbeat. A signal is first sent from the SA node, passes through the upper chambers of the heart, through a channel called the atrioventricular node, then reaches the lower chambers. The passage of signal causes the heart to contract in a coordinated manner, sending blood to the body.
During atrial fibrillation, the signal in the upper chamber of the heart is chaotic. As a result, the upper chambers begin to shake. Atrioventricular node, the electrical connection between the atrium and the ventricle, is bombarded by pulses trying to pass through the ventricles, but not all signals pass through. As a result the lower chambers also beat very fast, but not as fast as the upper chambers. There is no coordination between the heart chambers, consequently the heart cannot pump enough blood to your lungs and body, making you feel tired or dizzy, you could also experience heart palpitation or chest pain.
Blood also pools within the upper chambers of the heart, over time this could lead to the formation of blood clots. The clot could circulate from the heart through the body, and end up in the brain where the vessels are too small to pass through, this results in a blockage of the blood supply into the brain tissues, causing a stroke.
On the surface, atrial fibrillation may seem to be a small disease, but patients must remain vigilant, because the formation of a blood clot is unpredictable, and the resulting stroke is one of the highest causes of disability and death across the world.
The incidence rate of atrial fibrillation increases with age, for people over 75 years, the incidence rate could reach 10%, research have shown that atrial fibrillation increases an individual’s risk of stroke by 4 to 6 times on average.1
If untreated, symptoms for Atrial Fibrillation worsen over time, causing permanent irreversible damage to the heart.
Over 1/3 of patients do not experience any symptoms. Therefore you might not be feeling any effect of atrial fibrillations, but it may have already crept into your heart, threatening your health.
Early diagnosis is important for atrial fibrillation. At the early stages, damage to the heart can be reversed through therapeutic intervention. The main diagnostic methods are:
Electrocardiogram (ECG) – Which records the electrical signals of your heart, however an early stage atrial fibrillation may occur randomly, for short periods of time, ECG may not be able to capture patients affected by this disease at an early stage.
Holter Monitor – A Holter monitor is a wearable device that can record the heart’s rhythm for 24–72 hours. Doctors can access the data remotely and perform a diagnosis. Due to the longer tracking time, there is a higher probability of capturing patients affected by atrial fibrillation at an early stage.
Studies have shown that 90% of atrial fibrillation is related to pulmonary veins.1
Through minimally invasive surgery a radiofrequency ablation catheter can be inserted in to the heart, and release radiofrequency energy at the junction of the left atrium and pulmonary vein, forming a layer of isolation. This way, the abnormal signals related to pulmonary veins can be limited in the isolation belt, and only the correct signal can be transmitted to the atrium and ventricle.
Research have shown that the 1 year success rate for using radiofrequency ablation in treating patients with atrial fibrillation is greater than 90%.2