Bradyarrhythmias and AV Block

Abstract

Bradyarrhythmias may be due to disorders of impulse origination in the sinus node and disorders of atrioventricular conduction. These abnormalities can be asymptomatic or result in symptoms such as fatigue, lightheadedness, syncope, exertional dyspnea, or chest discomfort. In almost all cases, diagnosis can be made by obtaining a surface 12-lead electrocardiogram. If asymptomatic, bradyarrhythmias often do not require treatment except for second-degree atrioventricular block Mobitz type II, high-grade atrioventricular block, and complete heart block. If symptomatic, the importance of establishing a temporal symptom correlation with the bradycardia cannot be over-emphasized. Hemodynamically unstable patients may require treatment with medications such as atropine, dopamine, or temporary transcutaneous or transvenous cardiac pacing if available. In the long term, a permanent pacemaker is often indicated in symptomatic patients except if the etiology is considered to be reversible such as medication induced.