40 APD nactivated stimulus -40 open 80 ERP rest APD +20 2 0 20 RRP I 0 SNP ERP 60 100 50100150200250300350 Action potential Duration (APD) and effective refractory period (ERP)
Action potential Duration (APD) and effective refractory period (ERP) APD APD ERP
Resting Activated Inactivated Extracellular Nat m( 40 40 0 8-40 Threshold 三60 Recover A schematic representation of Nat channels cycling through different conformational states during the cardiac action potential. Transitions between resting, activated, and inactivated states are dependent on membrane potential and time. the activation gate is shown as m and the inactivation
A schematic representation of Na+ channels cycling through different conformational states during the cardiac action potential. Transitions between resting, activated, and inactivated states are dependent on membrane potential and time. The activation gate is shown as m and the inactivation
A. Electrophysiological basis of arrhythmias 0 2. Slow and fast response cells u slow response cells: pacemaker cells u fast response cells: conduction and contraction cells Fast response Slow response phase 4 potential -90 mV 70 mv depolarization Na,, 120 m V, 1-2 ms Ca+, 70 mV,7ms automaticity low(0.02 V/s) high(0.1 V/s) conduction fast( 200-1000 V/s) slow( 10 V/s) effects conduction icemaker
2. Slow and fast response cells slow response cells: pacemaker cells fast response cells: conduction and contraction cells Fast response Slow response phase 4 potential －90 mV －70 mV depolarization Na+ , 120 mV, 1-2 ms Ca2+, 70 mV, 7 ms automaticity low（0.02 V/s） high（0.1 V/s） conduction fast（200-1000 V/s） slow（10 V/s） effects conduction pacemaker A. Electrophysiological basis of arrhythmias
0「窦房结 Slow response 40H0 膜 心室 电 2 Fast response 0 0 位 4 V)-90 Action potentials of slow and fast response cells
Action potentials of slow and fast response cells Slow response Fast response
Interatrial sinoatrial(SA)node (AV) node Threshold potental Faster rate of Internodal Len depolarization branch Time (msec) br△nch atrioventricular(Av) node ventricle Threshold Slower rate depolarization Time(mse Slow response pacemakers in sinoatrial (SA) node and atrioventricular (AV) node
Slow response pacemakers in sinoatrial (SA) node and atrioventricular (AV) node sinoatrial (SA) node atrioventricular (AV) node