Some causes related to cardiovascular disease: The sensation of an irregular heart rhythm is usually related to either premature atrial complexes (PACs), premature ventricular complexes (PVCs), or, most commonly, atrial fibrillation.
Some causes related to other disorders: Occasionally, non-cardiac disorders such as thyroid disease or anxiety conditions can produce the sensation of irregular heart beats.
Significance: Because palpitations may occasionally indicate a significant cardiac arrhythmia, they should always be evaluated by a physician.
