An abnormal heart rhythm caused by a disturbance in the formation or conduction of the heart’s electrical signals.
Arrhythmias may cause the heart to beat too quickly, too slowly, or irregularly. Some are harmless or cause few symptoms, while others can impair the heart’s ability to pump blood effectively and may be life-threatening.
Symptoms can include palpitations, dizziness, fainting, chest discomfort, or shortness of breath, although some arrhythmias cause no noticeable symptoms.
QUICK FACT
An arrhythmia does not necessarily mean that the heart is beating too fast; abnormal rhythms can also be unusually slow or irregular.
COMMONLY CONFUSED WITH
Heart attack (myocardial infarction): caused by interrupted blood supply to heart muscle; an arrhythmia is a problem with the heart’s electrical rhythm.
SEE ALSO