Chapter 1 Electrophysiology Gail Walraven, Basic Arrhythmias, Seventh Edition ©2011 by Pearson Education, Inc., Upper Saddle River, NJ

EKGs are graphic representations of electrical activity within the heart. Gail Walraven, Basic Arrhythmias, Seventh Edition ©2011 by Pearson Education, Inc., Upper Saddle River, NJ

EKG EKGs reflect electrical activity, not mechanical activity. To evaluate mechanical function, assess blood pressure and peripheral pulses. Gail Walraven, Basic Arrhythmias, Seventh Edition ©2011 by Pearson Education, Inc., Upper Saddle River, NJ

EKG EKG can tell about electrical function: Rhythm disturbances Conduction disturbances Gail Walraven, Basic Arrhythmias, Seventh Edition ©2011 by Pearson Education, Inc., Upper Saddle River, NJ

EKG EKG cannot tell about mechanical function: Structural disorders Perfusion disorders Gail Walraven, Basic Arrhythmias, Seventh Edition ©2011 by Pearson Education, Inc., Upper Saddle River, NJ

The Sodium Pump Chemical Basis for Impulse Formation Gail Walraven, Basic Arrhythmias, Seventh Edition ©2011 by Pearson Education, Inc., Upper Saddle River, NJ

Initiation of Electrical Flow Polarization “Ready” state Depolarization “Discharge” state Repolarization “Recovery” state Gail Walraven, Basic Arrhythmias, Seventh Edition ©2011 by Pearson Education, Inc., Upper Saddle River, NJ

Electrical Conduction System Gail Walraven, Basic Arrhythmias, Seventh Edition ©2011 by Pearson Education, Inc., Upper Saddle River, NJ

Inherent Rates Sinus Node 60-100 beats/min AV Junction 40-60 beats/min Ventricles 20-40 beats/min Gail Walraven, Basic Arrhythmias, Seventh Edition ©2011 by Pearson Education, Inc., Upper Saddle River, NJ

Pacemaker Rule Pacemaker site with the fastest rate will generally control the heart. Gail Walraven, Basic Arrhythmias, Seventh Edition ©2011 by Pearson Education, Inc., Upper Saddle River, NJ

Irritability A site along the conduction pathway becomes irritable and speeds up, thus overriding higher pacemaking sites for control of the heart. Gail Walraven, Basic Arrhythmias, Seventh Edition ©2011 by Pearson Education, Inc., Upper Saddle River, NJ

Escape Mechanism The normal pacemaker slows down or fails, and a lower pacing site assumes pacemaking responsibility. Gail Walraven, Basic Arrhythmias, Seventh Edition ©2011 by Pearson Education, Inc., Upper Saddle River, NJ

Autonomic Nervous System Gail Walraven, Basic Arrhythmias, Seventh Edition ©2011 by Pearson Education, Inc., Upper Saddle River, NJ