Types of Arrhythmia

There are a few common types of arrhythmia:

Premature (Extra) Beats

Premature extra heart beats are often harmless and usually do not cause any symptoms.

When symptoms do occur, however, they usually feel like fluttering in the chest or a feeling of a skipped beat. Most of the time, premature beats need no treatment, especially in healthy individuals.

Premature beats that occur in the atria are called premature atrial contractions, or PACs. Premature beats that occur in the ventricles are called premature ventricular contractions, or PVCs.

In most cases, premature beats occur naturally, not due to any heart disease. But certain heart diseases can cause premature beats. They also can happen because of stress, too much exercise, or too much caffeine or nicotine.

Supraventricular Tachycardia Arrhythmias

Supraventricular tachycardia (SVT) is any rapid heart rhythm originating in the upper chambers of the heart. Some forms are called paroxysmal atrial tachycardia (PAT) or paroxysmal supraventricular tachycardia (PSVT).
Common types of SVT include atrial fibrillation (AF), atrial flutter, paroxysmal supraventricular tachycardia (PSVT), and Wolff-Parkinson-White (WPW) syndrome. SVT is generally not life threatening, though it may cause worsening heart function if it is sustained for hours.​

Atrial Fibrillation

Atrial fibrillation (AF) is the most common type of serious arrhythmia. It's a very fast and irregular contraction of the atria.

In AF, the heart's electrical signal doesn't begin in the SA node. Instead, the signal begins in another part of the atria or in the nearby pulmonary veins and is conducted abnormally. When this happens, the electrical signal doesn't travel through the normal pathways in the atria. Instead, it spreads throughout the atria in a fast and disorganized manner. This causes the walls of the atria to quiver very fast (fibrillate) instead of beating normally. As a result, the atria aren't able to pump blood into the ventricles the way they should.