1. Antiarrhythmic drugs [,æntiə'riðmik] 抗心律失常药

2. 1 Introduction Definition：
Cardiac arrhythmia [ə'riðmiə]心律失常 is any of a group of conditions in which the electrical activity of the heart is irregular, faster, or slower than normal, thus the heartbeat may be too fast or too slow, or may follow an irregular rhythm.
Tachycardia [,tæki'kɑ:diə]: heart beat above 100 beats per minute;
Bradycardia [,brædi'kɑ:diə]: heart beat below 60 beats per minute.

3. Electrical conduction system of the heart
Atrium [‘eɪtrɪəm] 心房; Ventricle ['ventrikl] 心室

5. Resting membrane potential of cardiomyocytes

6. Action potential and transmembrane ion flow

7. Schematic diagram of the ion permeability changes and transport processes that occur during an action potential and the diastolic period following it. Yellow indicates inward (depolarizing) membrane currents; blue indicates outward (repolarizing) membrane currents. Multiple subtypes of potassium and calcium currents, with different sensitivities to blocking drugs, have been identified. The right side of the figure lists the genes and proteins responsible for each type of channel or transporter.

8. ICaL
阈电位
K +外流进行性衰减
进行性增强
主要为Na+ 内流
Na+-Ca2+交换
形成的净内向电流

9. Schematic representation of the heart and normal cardiac electrical activity (intracellular recordings from areas indicated and ECG). Sinoatrial (SA) node, atrioventricular (AV) node, and Purkinje cells display pacemaker activity (phase 4 depolarization). The ECG is the body surface manifestation of the depolarization and repolarization waves of the heart. The P wave is generated by atrial depolarization, the QRS by ventricular muscle depolarization, and the T wave by ventricular repolarization. Thus, the PR interval is a measure of conduction time from atrium to ventricle, and the QRS duration indicates the time required for all of the ventricular cells to be activated (ie, the intraventricular conduction time). The QT interval reflects the duration of the ventricular action potential.

10. Electrocardiograph (ECG,心电图)

11. Feature
Description
P wave
reflects atrial depolarization
PR interval
reflects the time the electrical impulse takes to travel from the sinus node through the AV node and entering the ventricles. The PR interval is, therefore, a good estimate of AV node function.
QRS complex
reflects the rapid depolarization of the right and left ventricles.
ST segment
represents the period when the ventricles are depolarized. It is isoelectric等电位的.
T wave
represents the repolarization (or recovery) of the ventricles.
QT interval
a prolonged QT interval is a risk factor for ventricular tachyarrhythmias and sudden death..

12. 2 Mechanisms of tachyarrhythmia
2.1 Enhanced automaticity [ɔ:,tɔmə'tisəti]自律性:
Sites: sinus, AV nodes, His-Purkinje system, sites ordinarily lack spontaneous pacemaker activity (e.g., ventricular cells);
Causes: Adrenergic or acetylcholine stimulation, hypokalemia, ischemia, mechanical stretch of cardiac muscle cells.

13. 2. 2 Afterdepolarizations and triggered automaticityB C
Early afterdepolarization (EAD) 早后除极 interrupting phase 3 repolarization. Under some conditions, triggered beat(s) can arise from an EAD (black arrow, right).

14. A B
1000 ms
60/min
750 ms
80/min
Delayed afterdepolarization (DAD) 迟后除极 arising after full repolarization. A DAD that reaches threshold results in a triggered upstroke.

15. Cause of DAD: intracellular Ca2+ overload (e. g
Cause of DAD: intracellular Ca2+ overload (e.g., myocardial ischemia, adrenergic stress, digitalis intoxication, or heart failure); Cause of EAD: inward current through Na+ or Ca2+ channels.

16. 2.3 Re-entry 折返激动
A: Normally, electrical excitation branches around the circuit, is transmitted to the ventricular branches, and becomes extinguished at the other end of the circuit due to collision of impulses. B: An area of unidirectional block develops in one of the branches, preventing anterograde impulse transmission at the site of block, but the retrograde impulse may be propagated through the site of block if the impulse finds excitable tissue; that is, the refractory period is shorter than the conduction time. This impulse then reexcites tissue it had previously passed through, and a reentry arrhythmia is established.

17. Brief review 室上性心律失常 supraventricular arrhythmia 室性心律失常
Sites
窦房结 SA node
Arrhythmias
窦性心律失常 sinus arrhythmia
Causes
abnormal automaticity
Drugs
Atropine 阿托品
β receptor blockers
普萘洛尔
Mechanism
Affect the efferent nerve system
Brief review
窦性心动过缓 sinus bradycardia
窦性心动过速 sinus tachycardia
房性心律失常 Atrial arrhyttmia
心房 atrium
1 abnormal automaticity
2 triggered automaticity
3 abnormal conduction
室上性心律失常
supraventricular arrhythmia
阵发性房性心动过速
paroxysmal atrial tachycardia
胺碘酮 amiodarone
维拉帕米
verapamil
1 inhibit the efflux of K+；
2 block Na+ and
Ca2+ channels;
房性早搏
atrial premature beats
block Ca2+ channels;
心房扑动 atrial flutter
心房颤动 atrial fibrillation
房室结 AV node
传导阻滞 conduction block
abnormal
conduction
Atropine 阿托品
Pacemaker起搏器
Affect the efferent nerve system
一度房室传导阻滞
first degree atrioventricular block
二度1型房室传导阻滞
Type 1 second-degree AV block
二度2型房室传导阻滞
Type 2 second-degree AV block
正常心律
normal rhythm
三度房室传导阻滞
Third-degree AV block
1 slightly block Na+ channels;
2 slightly promote K+ efflux
室性心律失常
ventricular arrhythmia
心室 ventricle
室性心律失常 ventricular arrhythmias
利多卡因
Lidocaine
苯妥因钠
phenytoin sodium
胺碘酮 amiodarone
1 abnormal automaticity
2 triggered automaticity
3 abnormal conduction
室性早搏 ventricular premature beat
多源室性早搏
multifocal ventricular premature beat
1 slightly block Na+ channels;
2 slightly promote K+ efflux
室早二联律
ventricular premature beat (bigeminy)
室早三联律
ventricular premature beat (trigeminy)
1 inhibit K+ efflux；
2 block Na+ and
Ca2+ channels;
心室扑动 ventricular flutter
心室颤动 ventricular fibrillation

18. 心脏射频消融术
植入型体内自动除颤器（ICD）

19. 大纲要求
熟悉抗心律失常药的分类，各类代表药的抗心律失常作用及作用机理。
掌握各类药物的抗心律失常方面的用途。
了解各类药物的主要不良反应。