Flashcards: Cardiac Electrical Physiology and Arrhythmias — 10 cards

Refractory periods — purpose?

Prevent premature contractions and re-entry arrhythmias.

Conduction pathway order?

SA node, atria, AV node, bundle of His, bundle branches, Purkinje fibers, ventricles.

Conduction pathway — sequence?

SA node → atria → AV node → Bundle of His → bundle branches → Purkinje fibers.

SA node — role?

Heart's natural pacemaker, initiates impulses.

Cardiac action potential — phase 2?

Plateau phase due to Ca²⁺ influx balancing K⁺ efflux.

Atrial conduction — function?

spreads electrical activity through atria.

AV node — delay purpose?

Allows atrial contraction before ventricles.

Bundle of His — function?

Transmits impulses from AV node to bundle branches.

Purkinje fibers — role?

Distribute impulses rapidly to ventricles.

Cardiac action potential — phase 0?

Na⁺ influx causes rapid depolarisation.