What Happens During Atrial Fibrillation?

What Happens During Atrial Fibrillation?

The human heart contracts and relaxes in an orderly manner and regularly beats to pump blood throughout the whole body. Actually, what happens during atrial fibrillation? This article will explain briefly what happens during atrial fibrillation. For more info, you may visit DoctorOnCall’s Health Centre page.

Generally, in atrial fibrillation, the electrical impulses in the top two chambers of the heart, called atria,  fire chaotically when they should be regular and steady that cause them to twitch or quiver (fibrillation). If this happens to you, you might feel an irregular and sometimes rapid, heartbeat or pulse. Some patients say it feels like their heart is fluttering or racing, also known as palpitations.

On the other hand, atrial fibrillation might also come and go, which is what is called paroxysmal atrial fibrillation, however, sometimes it does not go away at all. This temporary condition is not life-threatening, but it is considered serious as it could cause blood clotting in the heart that may lead to a stroke. About 15 to 20 percent of people who have strokes have atrial fibrillation.  This clot risk is why patients with atrial fibrillation are given blood thinners medication. Although untreated atrial fibrillation doubles the risk of deaths related to heart disease, and is associated with a  five fold increased risk for stroke, many patients still are unaware that this type of cardiac arrhythmia is a serious condition.

  • Mechanisms Of Atrial Fibrillation Development

Besides, there are a wide variety of pathophysiological mechanisms of atrial fibrillation development.  Nevertheless, it is the cardiac remodeling that accounts for most of the mechanisms. Cardiac remodeling, specifically of atria, eventually results in electrical and structural changes in the heart that may lead to deranged rhythm in atrial fibrillation. Structural remodeling is caused by the changes in myocytes ( muscle cells; in this case means the muscles of the heart) and the extracellular matrix, as well as the fibrous tissue deposition also plays a major role in some causes or etiologies. On top of that, tachycardia (rapid heartbeat) and shortening of the refractory period lead to electrical remodeling in the heart.

Furthermore, some research has shown evidence of genetic reasons for this condition involving chromosome 10 (10q22-q24) that consists of a mutation in the gene, which is known as alpha-subunit of the cardiac Ik5, that is responsible for pore formation. Following the function mutation, it allows more pores, increasing the activity within the heart ion channels, and finally affecting the stability of the heart membrane.

History and physical examination are important for diagnosing and risk stratifying patients with atrial fibrillation. Other than a detailed history and examination, the electrocardiogram (ECG) is crucial in making the diagnosis of this condition. On ECG, atrial fibrillation presents with the typical narrow complex pattern of “irregularly irregular” that will be detected by doctors. Besides, fibrillary waves may be seen or absent. The ventricular rate often ranges between 80 and 180 per minute.


In short, heart quiver is actually what happens in atrial fibrillation. There are also certain physiological mechanisms explanations regarding the development of atrial fibrillation. Most patients notice that the heartbeat feels strange and sometimes very fast, even when they are not exercising. Concurrently, sometimes people do not experience any symptoms and atrial fibrillation gets detected when having an examination or check up.

You should consult a doctor for diagnosis but you may also detect it by feeling your pulse at your wrist. A normal heart rate is usually steady that ranges between 60 and 100 beats per minute when you are at rest.  If you have atrial fibrillation, your pulse will have no regular pattern and the beats might have different or strange strengths.  Some people have atrial fibrillation which comes and goes, which means their pulse may feel normal at times but at other times it will be irregular.