Cardiac action potential chart covering ventricular vs pacemaker cell phases, ion movement, automaticity, and EKG correlations for anesthesia boards.
Review the core table first, then launch practice to convert recognition into faster recall.
| Phase | Non-pacemaker (ventricular / atrial / Purkinje) | Pacemaker (SA / AV node) | Ion movement | EKG correlation |
|---|---|---|---|---|
| 4 | Stable resting membrane potential near -90 mV | Slow spontaneous depolarization (automaticity) | Ventricular: IK1 K+ leak; Pacemaker: funny current (If), declining K+ efflux, late T-type then L-type Ca2+ entry | Diastolic interval / TP segment |
| 0 | Rapid depolarization | Slow upstroke depolarization | Ventricular: fast Na+ influx; Pacemaker: L-type Ca2+ influx | QRS corresponds mainly to ventricular phase 0 |
| 1 | Initial repolarization | Not prominent / absent | Transient outward K+ current | Early repolarization |
| 2 | Plateau | Absent | Ca2+ influx balanced by K+ efflux | ST segment |
| 3 | Repolarization | Repolarization | K+ efflux; Ca2+ channels close | T wave |
This tool is for educational purposes only. Always verify clinical values against current authoritative sources before patient care.