Atrial fibrillation is the most common heart irregularity, but there are four different recognised types of the condition.
Previously, Atrial Fibrillation (AF) was classified as either chronic or acute, but in 2014 new guidelines from the American College of Cardiology and American Heart Association changed the classification of AF from two, to four, types.
AF is an irregular and often very rapid heart rhythm (arrhythmia) that causes the upper and lower chambers of the heart to beat out of sync, fast, and erratically.
It can lead to blood clots in the heart and increases the risk of stroke, heart failure and other heart-related complications.
The heart rate in AF can range from 100 to 175 beats a minute, compared to the normal range of 60 to 100 beats a minute.
The four types of Atrial Fibrillation are: Paroxysmal, Persistent, Long-standing persistent, and Permanent. In addition, one type of AF can become another type as the condition progresses.
Paroxysmal atrial fibrillation: This type of AF can come and go and begin and end without warning with the irregular heartbeat lasting for a period that may range from as little as a few seconds to up to a week. In most cases, paroxysmal AF, which often has no clear symptoms, can resolve itself within 24 hours and may be addressed with lifestyle changes, such as eliminating caffeine and reducing stress.
Persistent atrial fibrillation: Persistent AF also begins spontaneously and can last for a week or even longer and may not end unless there is medical intervention. That could include having the heart shocked back into its natural rhythm, medication, or changes to lifestyle.
Long-standing persistent atrial fibrillation: This is a more serious form of AF and can last as long as a year. Often linked with structural heart damage, this form of the condition can be challenging to treat and may need more than medication, with treatment approaches including electrical cardioversion, catheter ablation or even the implantation of a pacemaker.
Permanent atrial fibrillation: When treatment for long-standing persistent AF is not effective in restoring the normal rhythm of the heart, it can become permanent atrial fibrillation and mean that the patient’s heart is constantly in a state of atrial fibrillation. In these cases, physicians my suggest ending efforts to control the arrhythmia, though may still prescribe medication that aims to control the heart rate and prevent blood clots.
Valvular and nonvalvular AF
While there are four types of atrial fibrillation, the notable difference within them is the length of time the episode lasts.
Additionally, the symptoms for each type, and the duration, can change and while some people can be asymptomatic for a lengthy period, others experience symptoms more quickly. But overall, the longer time period that AF occurs for, the greater likelihood that a patient will notice the symptoms.
The broad goal for all types of AF, however, is for treatment to restore the normal rhythm of the heart; slow the heart rate; and prevent the blood clots that may lead to stroke, which may see doctors prescribe anticoagulants.
AF can be nonvalvular – meaning it does not stem from a problem with a heart valve or a replacement valve – or it can be valvular AF, having resulted from an issue with a patient’s heart valve, such as mitral valve stenosis.
Any type of AF can be valvular or nonvalvular, but it is important to determine whether a valve issue is responsible, as this will influence the course of treatment as physician may prescribe.
The heart has two upper chambers (atria) and two lower chambers (ventricles). Within the upper right chamber (right atrium) is a group of cells called the sinus node, which produce the signal for each heartbeat.
In a regular heart rhythm, the signal travels from the sinus node through the atria, whereas in AF the signals in the upper chambers are chaotic.
Remote monitoring devices, such as the CART-I ring cardio tracker from Sky Labs, can help in the detection of AF. As the world’s first ring-type smart wearable heart rhythm monitoring medical device, it measures heart rate from screening the bloodstream through the wearer’s finger.