Section Electrophysiology of the heart
2 Section 2 Electrophysiology of the Heart
CARDIAC ELECTROPHYSIOLOGY R ST P-R- QRS Q-T-
3 CARDIAC ELECTROPHYSIOLOGY
Two kinds of cardiac cells The conduction system of the heart Interatrial septum Right and left bundle branches 1. The working cells Sinoatrial node (SA node) Atrioventricular pecial property node(Av node) contractility Atrioventricular bundle of His Purkinje fibers Interventricular septum Apex of heart
4 1, The working cells. Special property: contractility Two kinds of cardiac cells
2, Special conduction system including h The conduction system of the heart Sinoatrial nodes Interatrial septum Atrioventricular Right and left bundle branches node Sinoatrial node. (SA node) Atrioventricular Atrioventricular node(Av node) TU N bundle(bundle of Atrioventricular bundle His) (bundle of His and Purkinje Nancy Marshburn system Purkinje fib Interventricular septum Apex of heart Special property automaticity
5 including the Sinoatrial node, Atrioventricular node, Atrioventricular bundle (bundle of His), and Purkinje system. Special property: automaticity 2, Special conduction system
I. Transmembrane Potentials of Myocardial eels
6 I. Transmembrane Potentials of Myocardial Cells
ACTION POTENTIALS FROM DIFFERENT AREAS OF THE HEART Fast and Slow response ATRIUM Ⅴ ENTRICLE 0 90mv 90mv SA NODE 80mv 7 time
7 ACTION POTENTIALS FROM DIFFERENT AREAS OF THE HEART Fast and Slow Response mv 0 -90mv mv 0 -90mv mv 0 -80mv ATRIUM VENTRICLE SA NODE time
ELECTROPHYSIOLOGY OF THE FAST VENTRICULAR MUSCHE +20 AMP 2 0 3 Cardiac cell 90 0 300 t(msec)
8 ELECTROPHYSIOLOGY OF THE FAST VENTRICULAR MUSCLE t (msec) -90 0 +20 0 300 0 1 2 3 4 Cardiac Cell AMP
General description Phase 0: rapid Resting potential :-9omv depolarization mS Action potential Phase 1: early rapid +20 repolarization. 10 ms 2 Phase 2: plateau, slow 0 repolarization the 0 3 potential is around o 日 mV.100-150ms Phase 3, late rapid 0 repolarization. 100 50 ms 0 300 t(msec) Phase 4 resting potentials 9
9 t (msec) -90 0 +20 0 300 0 1 2 3 4 Phase 0: rapid depolarization, 1-2ms Phase 1: early rapid repoarization, 10 ms Phase 2: plateau, slow repolarization, the potential is around 0 mv. 100 – 150ms Phase 3, late rapid repolarization. 100 – 150 ms Phase 4 resting potentials General description Resting potential: -90mv Action Potential
lon Channels in Working Muscle Essentially same in atrial and ventricular muscle Best understood in ventricular cells 10
10 Ion Channels in Working Muscle ➢ Essentially same in atrial and ventricular muscle ➢ Best understood in ventricular cells
Ion Channels in Ventricula Cells Voltage-gated Nat channels Inward rectifier K+ channels L-type Ca2+ channels Several voltage-gated K+ channels
11 Ion Channels in Ventricular Cells ➢ Voltage-gated Na+ channels ➢ Inward rectifier K+ channels ➢ L-type Ca2+ channels ➢ Several Voltage-gated K+ channels
