Palpitations: what is the mechanism, and when should we treat them?

Palpitation is an unpleasant awareness of an abnormal beating of the heart. This symptom may be brought on by a variety of cardiac disorders, such as cardiomyopathy, valvular heart disease, and coronary artery disease, but the most common cause is primary cardiac arrhythmias. Several noncardiac disorders may also cause palpitations, and in this case are an effect of the disease upon cardiac rhythm. Palpitations occur frequently in women at all ages, especially during the luteal phase of the menstrual cycle, during pregnancy, and during the perimenopausal period. Palpitations occurring at young age and associated with fast heart rate are frequently due to Wolff-Parkinson-White syndrome or other forms of re-entrant tachycardia, and may require catheter ablation. A correlation between ovarian hormones and occurrence of paroxysmal supraventricular tachycardia has recently been reported in female patients with normal menstrual cycles; palpitations are frequently reported in cases of mitral valve prolapse, whereas episodes of paroxysmal supraventricular tachycardia reported during pregnancy may be due to mechanical stimuli or to a suggested arrhythmogenic effect of pregnancy. Palpitations during the perimenopausal period are usually benign and seem to be related to the increased sympathetic activity caused by the menopause. Although the vast majority of palpitations are benign and need not be treated, an electrophysiological study is indicated for those patients who have a documented episode of palpitation associated with syncope or with a pulse that is inappropriately rapid during symptoms. The treatment of palpitations due to cardiac arrhythmias is dependent upon the kind of arrhythmia detected during either invasive or noninvasive electrophysiological studies.