Cardiac pacemakers treat bradyarrhythmias by allowing the heart to reestablish functional circulation and hemodynamics. Pacemakers provide an appropriate heart rate and heart rate response.
When evaluating for a pacemaker, the clinician must consider whether the patient has significant symptoms of bradyarrhythmia, the location of the abnormality, and whether there are any reversible causes.
Bradyarrhythmias cause frequent dizziness, lightheadedness, fatigue, and poor exercise tolerance. The abnormality is usually pinpointed to SA node or AV node conduction. When there is a direct correlation between symptoms and the bradyarrhythmia, the clinician can recommend pacemaker therapy for clinical improvement. On the other hand, when a clinician is unable to correlate the patient’s symptoms with a bradyarrhythmia, pacemaker placement should not be a consideration for therapy.
Various types of pacemakers have emerged over the years. The “on-demand” device senses a spontaneous rhythm. The double-chamber pacemaker allows AV sequential pacing. The rate-responsive device accelerates the pacing rate after analyzing the patient’s exercise activity and respiratory rate.
Some devices switch automatically between two-chamber pacing and ventricular pacing after atrial fibrillation. Some devices provide rapid atrial stimulation as well as recordings of sleep and telemetry. A particular type of pacemaker is selected based on the patient’s clinical presentation of bradyarrhythmias.