|
Normal impulse conduction pathway |
|
This illustration shows the normal pathway through which electric activities needed for cardiac excitation (impulse conduction pathway) are transmitted.
First generated at the site called the sinus node in the atrium, the electric impulse is transmitted via the atrioventricular node to the ventricle, which causes the ventricular contraction to pump blood to the entire body.
|
What is atrial fibrillation? |
A healthy person may have a regular heart beat of 50-80 beats per minute.
During atrial fibrillation, however, a ventricle is electrically excited, which results in an irregular and very fast heart beat (300600 beats per minute), which prevents the heart from effectively performing the pumping function.
A patient with atrial fibrillation may be aware of palpitations, and have the risk of acute heart failure and cerebral infarction to 510 times that of persons with a regular heart beat.
|
Mechanism of onset of atrial fibrillation
|
|
The cardiac chamber known as the left atrium is connected by four pulmonary veinsN vessels that deliver oxygen-rich blood from the lungs back to the heart. Approximately 90% of paroxysmal atrial fibrillations are caused by cardiac muscle that generates rapid twitching (excitation) in these vessels, which causes the transmission of frequent electric impulses to the atrium (left illustration) and results in atrial fibrillation (right illustration).
The remaining 10% of paroxysmal atrial fibrillations occur in another atrium.
This understanding of the mechanism responsible for atrial fibrillation has led to the development of the procedure known as atrial fibrillation ablation. |
Types of atrial fibrillation |
Atrial fibrillation can be classified into three types:
1) Paroxysmal atrial fibrillation: atrial fibrillation that occurs suddenly and stops spontaneously without any particular treatment.
|
| 2) Persistent atrial fibrillation: atrial fibrillation that does not stop unless treated with medication, drip infusion, or electric shock. |
| 3) Chronic atrial fibrillation: atrial fibrillation that does not stop even after the use of medication or electric shock or resumes soon after it stops temporarily. |
How to cure atrial fibrillation
|
1)
Medicinal treatment (symptomatic therapy): prevents events and reduces the risk of thrombosis through the use of an antiarrhythmic drug to inhibit atrial fibrillation , a beta-blocker to prevent an increase in the pulse rate, a calcium antagonist, digitalis, the blood-thinner warfarin, etc. |
| 2)
Catheter ablation (permanent therapy): involves cauterization of the area around the pulmonary vein ostia with the use of a catheter to prevent atrial fibrillation while maintaining a normal heart beat. |
| 3)
Catheter ablation + a heart pacer treatment (symptomatic therapy): involves electric isolation of the atrium and the ventricle via cauterization of the normal impulse conduction pathway and the simultaneous implantation of a heart pacer. This method is usually used in older patients |
|
