What are Cardiac Arrhythmias?
Cardiac arrhythmias, also commonly called arrhythmias, are irregularities of the heart beat. For the most part, the normal, constant rhythm of the heartbeat that ensures essential blood flow throughout the body goes unnoticed.
But for some people, problems arise as the electrical impulses that synchronize the heart beat don’t function properly, causing the heart to beat out of rhythm - too quickly, too slowly or with an irregular pattern.
Arrhythmias are fairly common. Most people have had at least one experience where it feels as if the heart has skipped a beat, or has given an unexpected flutter. For many, the experience is usually not cause for concern. However, while many arrhythmias are harmless, some can be extremely dangerous and require medical treatment.
What are the Different Types of Cardiac Arrhythmias?
There are a number of different types of arrhythmias, differing in severity, point of origin and the speed at which they cause the heart to beat. There are three main categories according to rate:
- Tachycardia - A fast heartbeat (greater than 100 beats a minute)
- Bradycardia - A slow heartbeat (less than 60 beats a minute)
- Premature heartbeats - an extra beat between two normal heartbeats
Not all of these arrhythmias are dangerous, and some are quite normal. For example, a heart rate greater then 100 beats per minute may be the normal response to exercise, anxiety or fear. However, when arrhythmias occur unexpectedly, there may be cause for concern.
Where Can Cardiac Arrhythmias Occur?
Arrhythmias also occur in different chambers of the heart. In general, arrhythmias that start in the lower chambers of the heart (the ventricles) are more serious than those that start in the upper chambers (the atria).
- Arterial fibrillation: occurring in the atria, this arrhythmia causes the heart to beat too fast and irregularly. A potentially dangerous condition.
- Sick sinus syndrome: This occurs when the SA node (usually responsible for regular electrical impulses in your heart) is not working properly, causing the heart to beat too fast, too slowly, or both.
- Paroxysmal atrial tachycardia: this causes the heart to have periods where it beats regularly but very fast. While it may
sometimes feel uncomfortable, this condition is usually not harmful.
- Ventricular tachycardia: this arrhythmia originates in the ventricles and causes the heart to beat too fast. As a result, the body doesn’t get enough blood and the consequences are very serious. This type of arrhythmia needs immediate medical attention.