+20 ROH 4 00 绝对不应期 有效不应”1 动作电位时间 图224不应期与动作电位时间 局部去极化(局部性兴奋) 全面去极化(扩布性兴奋) Action potential and effective refractory period
Action potential and effective refractory period
atna ventricles 人- node conducting system Impulse generation and conduction in the heart endocardium ORS
Impulse generation and conduction in the heart
A. Electrophysiological basis of arrhythmias 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 Ca+, 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
◼ 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
Schematic representation of the heart and normal cardiac electrical activity (intracellular recordings from areas indicated and eCg). hase SA node Slow response AV node Phase Fast Tricuspid Purkinje Resting potential response Ventricle Action potential phases 1: Early-fast repolarization 2: Plateau 3: Repolarization ECG ECG
Schematic representation of the heart and normal cardiac electrical activity (intracellular recordings from areas indicated and ECG). Slow response Fast response ECG
Interatrial pathway Cell A Atrioventricular (AV) nod Sinoatrial (SA)node atrum annum Faster rate of Intermodal Left depolarization pathway brar of bundle of His branch of bund! of His Len ventre ventrcle Purkinje Cell B Threshod Slower rate of depolarization Time (msec)