Question

What is pathophisiology for Atrial Fibrillation, causes, symptoms, and treatment

Answer 1

Atrial fibrilation - is a condition in which the atria contracts irregularly in a quick manner or we can say it doesnot contract in a synchronised way.So the atria get fibrillates.In this case the heart rate is more than 350.It is classified into three different categories,such as paroxysmal atrial fibrillation ( stays for less than 7 days),persistant atrial fibrilation ( stays more than 7 days)permanent atrial fibrilation(cannot treat and revert)

Pathophysiology of atrial fibriltion

In the normal heart the electrical impulse which generated in the S A node (pacemaker of the heart) pass through the atrial myocardium and enters the atrioventricular node (AV node) and it passes to the ventricle in a regular manner and allow the ventricle to contract.But in case of atrial fibrillation the impulses are generated from the other parts (not from the SA node),this can be from the ectopic foci,(are the pacemaker cells that produce impulse other than the SA node )which is present in the pulmonary veins also it can be seen near the inferior and the superior venacava at the right atrium. This ectopic foci produce impulses to th eatrial myocardium which are capable to cancell the normal electrical impulse that is produced by the SA node.As a result the AV node receive the irregular and the rapid impulse and cause the very rapid heart rate.

Other way is the presence of the reentry circuit that is developed  in the atrial myocardium due to the conditions such as the ischemic heart disease,hypertension and the age there willm be change in the atrial myocardial morphology and the there will be change in the shape of the atrium.This cells in th reentry circuit has the different level of conductivity and the excitability.This areas are slow conducting area and has small refractory period.Asa result the impulses from the SA node gets reexcited in this area and the neighbouring calles also gets reexcited this can form a reentry circuit.The impulses produced in this area collide with the impulse from the SA node and the impulse get cancelled.And the AV node receive rapid and the irregular impulse from these reentry area and causes the rapid ventricular rate.

Causes

Hypertension,coronary artery disease,congetital heart disease,diabetes mallitus,cardiomyopathy,structural heart disease,valvular heart disease,sleep apnea,obesity,untreated atrial flutter,lung diseases,family history of AF, use of tobacco and alcohol,viral infections,

symptoms

palpitaion,weakness,lethargy,dizziness,chest pain,difficulty in breathing,

Treatment

The treatment goals include to reduce the heart rate and rhythm and to prevent the complication that can be occures due to the formation of the blood clot which is formed in the atrium due to the improper contraction.

we use certain medications to control the heart rate.The medications such as betabloker,calcium channel bloker and digoxin are used to control the heart rate below 110 beats per minute.

Use the anticoagulation therapy to prevent the complications that can occur due to the formation of blood clot in the atrium.

There are another remedy called electrical cardioversion by using the synchronised current and cardioversion by means of medication(anti arrythmic drugs)

Invasive procedures such as catheter ablation,maze procedure,A V node ablations are used.In these three methods the doctor distroy the tissue that produce the abnormal impulses.

The other remedy that includes the change in the life style to prevent or to reduce the obesity and to prevent the progress of the heart disease.