1.Objectives
The untoward effects and clinical uses of antiarrhythmic
drugs. The influence of antiarrhuthmic drugs on the membrane
potential of cardiac cells.
2.Teaching content
(1)Review elementary knowledge related to myocardium physiology:
action potential phases and ions across membrane. Automaticity,
conductivity, excitability, absolute refractory period,
effecitive refractory period, action potential duration,
reentry, mechanism of arrhythmias.
(2)The classification of antiarrhythmic drugs:
Na+ channel blocking drugs(Ⅰa): quinidine: decrease membrane
permeability to Na+, also decrease membrane permeability
to K+, Ca2+, decrease automaticity, conduction speed,
prolong effective refractory period, decrease cardiac
contractity, ECG changes, used to treat atrial fibillation,
atrial flutter, side effects: syncope, precautions in
using qunidine. Procainamide: the difference with quinidine.
Ⅰb: lidocaine, promote K+ efflux, and inhibit Na+ influx,
mainly affect on purkinje’s system, decrease automaticity,
enhance the conduction speed of damaged fiber, shortening
refractory period and duration of action potential. Used
to treat ventricular arrhythmias. Pharmacokinetics and
side effects. Phenytoin: characteristics of action, compared
with lidocaine.
Ⅰc: flecainide: propafenone, encainide: pharmacological
characteristics.
Ⅱ: βadrenergic blocking drugs: propranolol: the relationship
of antiarrhythmic effects with βreceptor blocking action
and membrane stabilizing effects, clinical uses, untoward
effects and contraindications. Uses of other β adrenergic
blocking drugs.
Ⅲ: prolongation of APD drugs: amiodarone, sotalol, bretylium:
pharmacological effects, clinical uses and untoward effects.
Ⅳ: Ca2+ blockers: verapamil, diltiazem: pharmacological
effects, clinical uses and untoward effects.
Teaching hours: 4
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