Chapter 30 Antiarrhythmic Drugs
Chapter 30 Antiarrhythmic Drugs
A normal rhythm Rs premature ventricular beat 人人人入人 C paroxysmal supraventricular tachycardia (PSVT) D atrial fibrillation arrhythmias E atrial flutter with variable Av conduction ++++++++++++++++ F atrial flutter with 1: 1 AV conduction G monomorphic ventricular tachycardia H Torsades de Pointes 从M从 √
arrhythmias
A. Electrophysiological basis of arrhythmias D 1. Normal cardiac electrophysiology I Excitability: ability to produce action potentials maximal diastolic potentials(MDP) thresold levels D Automaticity: pacemaker phase 4 slope D Conductivity conduction pathways, phase 0 amplitude
A. Electrophysiological basis of arrhythmias 1. Normal cardiac electrophysiology Excitability: ability to produce action potentials maximal diastolic potentials (MDP) thresold levels Automaticity: pacemaker phase 4 slope Conductivity: conduction pathways, phase 0 amplitude
inward outward 0 nase Na+ current Action Ca2+L-type current T-type potential transient ITO1 (4-AP-sensitive) and ion outward current To2 (Ca2+-activated) transport delayed rectifiers cI or lKp inward rectifier, Ik1 Fast response cell pacemaker current, If (…, see above Na*-Ca2+ exchange Na′,K+ ATPase
Action potential and ion transport Fast response cell
膜电位+20 mv 2 -20 RRP 40 SNP ERP 60 80 100 50 100150200250300350 Action potential and effective refractory period
Action potential and effective refractory period
房间束 窦房结 前结间束 中结间束 后结间束 Kent旁路柬 房室结 Ma haim旁路纤维 James旁路纤维 左束支间隔分支 Kent旁路束 左束支前分支 房室束 左束支后分支 右束支 浦顷野网 Pacemaker and conduction systems in the heart
Pacemaker and conduction systems in the heart
atria ventricles node conducting system Impulse generation and conduction in the heart QRS
Impulse generation and conduction in the heart
A. Electrophysiological basis of arrhythmias I 2. Slow and fast response cells I Slow response cells: pacemaker cells L 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 pa 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 2 40F0 Isi、If、lst Action 膜 -80 potentials 心室 Fast response 电 of slow 0 and fast 位 4 4 response mV)-90 cels 心电图 10 R ECG 0.5 0
Action potentials of slow and fast response cells Slow response Fast response ECG
A. Electrophysiological basis of arrhythmias D 3. Abnormal generation ofimpulse D ()Augmented automaticity D Augmented automaticity in the myocardial cells other than the sinoatrial node cells will produce arrhythmias I Maximal diastolic potential (MDP)in phase 4: ischemia, digitalis, sympathetic excitation, imbalance of electrolytes I Fast spontaneous depolarization in phase 4:fast response cells->slow response cells
3. Abnormal generation of impulse (1) Augmented automaticity Augmented automaticity in the myocardial cells other than the sinoatrial node cells will produce arrhythmias Maximal diastolic potential (MDP) in phase 4: ischemia, digitalis, sympathetic excitation, imbalance of electrolytes Fast spontaneous depolarization in phase 4：fast response cells → slow response cells A. Electrophysiological basis of arrhythmias