Understand the heart's electrical conduction system
The heart's electrical activity is managed by a specialized conduction system that triggers contractions. Key structures include:
- Sinoatrial (SA) Node: The natural pacemaker located in the upper right atrium. It initiates the heartbeat with a normal rate of 60-100 bpm.
- Atrioventricular (AV) Node: Located in the lower interatrial septum. It delays the impulse to ensure the atria contract fully before the ventricles. Backup rate: 40-60 bpm.
- Purkinje System: Comprising bundle branches and Purkinje fibers, this network rapidly transmits impulses to the ventricular muscle (speed: 2-4 m/s). Backup rate: 20-40 bpm.