Cardiovascular Disease Update: Bradyarrhythmias.

Bradyarrhythmia (bradycardia) is a heart rate lower than 60 beats/min. It can be due to sinus, atrial, or junctional bradycardia or to a problem with the conduction system (eg, an atrioventricular block). Asymptomatic bradycardia is common, especially among trained athletes or during sleep. Bradycardia symptoms can include syncope, dizziness, chest pain, dyspnea, or fatigue. It is important to determine during the evaluation if bradycardia is the cause of the patient's symptoms. In the acute setting, symptomatic patients should be treated with atropine. Percutaneous pacing can be used as a bridge to definitive treatment. The only therapy for persistent bradycardia is placement of a permanent pacemaker. Symptomatic patients with sick sinus syndrome and high second- or third-degree atrioventricular blocks require placement of permanent pacemakers.