An arrhythmia is an abnormaliy of the heart rhythm. It can be too fast (tachycardia) or too slow (bradycardia). It could mean a lack of coordination between different heart chambers. It could come and go (be paroxysmal or intermittent) or be present all of the time (persistent or permanent). It could last for a few seconds (non-sustained) or minutes or hours (sustained). It could cause symptoms or be asymptomatic. Finally, it could be benign or potentially dangerous.
To understand arrhythmias it is important to first understand how the normal heart beat works.
Click on the rhythms below to learn more about their mechanisms and consequences
Regular, efficient, speeds up and down with the body's demands. Most people don't feel their natural heart beat. Click on the button to learn more.
Single extra beats, also called premature beats, that feel like a skip, jump or missed beat or a sudden lurch in the chest. Come and go. May be more common at rest and at night. Click on the button to learn more.
A chaotic, irregular pulse. May be fast or a normal speed. May be asymptomatic and discovered by chance, cause vague symptoms of fatigue and breathlessness or even cause palpitations, chest pain and dizzy spells. May come and go or be there all the time. Increases the risk of stroke. Click on the button to learn more.
Often regular and rapid, typically 150 beats per minute. Can be there all the time or come and go. May cause palpitations and breathlessness, dizzy spells or chest pains but may also be mild or asymptomatic. Increases the risk of stroke. Click on the button to learn more.
SVT is usually very fast and regular. It starts suddenly. In some people it stops on its own, in others it requires treatment in an Emergency Department. Typical symptoms include palpitations, breathlessness, dizziness and chest tightness. Can happen at any age, young or old. Different varieties include Wollf-Parkinson-White syndrome and AV nodal reciprocating tachycardia (AVNRT). Click on the button to learn more.
VT is usually very fast and regular. It starts suddenly. It may be brief or go on until treated in an Emergency Department. Typical symptoms include palpitations, breathlessness, dizziness, blackouts and chest tightness. Some types in otherwise normal hearts are benign. Other types, particularly if the heart is damaged or abnormal, can be life-threatening. Click on the button to learn more.