Pacemakers are indicated primarily for the management of bradyarrhythmias, where the heart's natural pacing is insufficient to maintain an adequate heart rate and cardiac output. The two main indications for pacemaker implantation are:
- Sinus Node Dysfunction: This condition involves the sinus node, the heart's natural pacemaker, failing to generate impulses at a sufficient rate, leading to bradycardia. Patients with symptomatic sinus node dysfunction, such as fatigue, dizziness, or syncope, may require a pacemaker to maintain an appropriate heart rate.
- Atrioventricular (AV) Block: In this condition, the electrical signals generated by the sinus node are delayed or blocked as they travel through the AV node to the ventricles. This can result in a slow heart rate or pauses in heart activity. A pacemaker is used to ensure that the ventricles contract at an adequate rate by bypassing the blockage and delivering impulses directly to the ventricles.
In both conditions, the pacemaker ensures that the heart maintains an adequate rate to support normal physiological function, reducing symptoms and preventing complications associated with severe bradycardia.
