Pacemakers are implantable cardiac devices used in the treatment of bradycardia and heart failure. They monitor electrical signals in the heart and deliver electrical stimuli to cause contraction in the targeted heart chamber. Permanent pacemaker therapy is recommended in patients with symptomatic bradycardia or asymptomatic infranodal atrioventricular block to improve symptoms and quality of life. Biventricular pacemakers can also be used in cardiac resynchronization therapy, which corrects dyssynchrony between the ventricles. In patients who have symptomatic heart failure with reduced ejection fraction, left bundle branch block, and prolonged QRS duration, cardiac resynchronization therapy improves outcomes, including mortality. Medical procedures such as electrocautery or magnetic resonance imaging may interfere with a patient's pacemaker; family physicians should coordinate with cardiologists to ensure appropriate care for patients in whom these procedures are indicated.