A pacemaker is indicated when electrical impulse conduction or formation is dangerously disturbed. The pacemaker rhythm can easily be recognized on the ECG. It shows pacemaker spikes: vertical signals that represent the electrical activity of the pacemaker.

What are the causes for a pacemaker rhythm?

This typically results in the appearance of too many pacing spikes, as seen on ECG (Fig. 3). The main causes of undersensing are pacemaker programming problems (improper sensing threshold), insufficient myocardial voltage signal, lead or pacer failure (fibrosis, fracture, etc.), or an electrolyte abnormality.

What rhythms do Pacemakers treat?

• Slow heart rhythm (bradycardia)
• Fainting spells (syncope)
• Heart failure.
• Hypertrophic cardiomyopathy.