Electronic reading of the hearts electrical activity.

 Sinoatrial Node (SA)  Atrioventricular Node (AV)  Bundle of His (BOH)  Purkinje Fibers (PF)

 The first little hump is known as the P wave. It occurs when the atria depolarize (i.e. trigger).  The next three waves constitute the QRS complex. They represent the ventricles depolarizing. These three are lumped together because a normal rhythm may not have all three.

 T-WAVE- Re-polarization of the ventricles.  QUESTION:  Why can’t we see the re-polarizaton of the Atria?

A B C

 A = Tachycardia  B= Bradycardia  C= Arrhymthmia