抗心律失常药物的离子流机制和临床应用进展（英文）.ppt

抗心律失常药物的离子流机制和临床应用进展 Gan-Xin Yan, MD, PhD, F.A.C.C Main Line Health Heart Center Jefferson Medical College Case 1 (病例1) A 45 year-old female is referred to your office because of symptomatic paroxysmal atrial fibrillation. She also has a history of asthma. She tried Ca++ blockers and dofetilide before, but none of them suppressed atrial fibrillation. She has not been on any medications for a couple of weeks. Her recent echocardiogram and stress test were normal. In your office, 12 lead ECG shows atrial fibrillation with ventricular responses at 80 beats per minute. She states that she always knows the onset of atrial fibrillation that occurs when she takes a nap or is hungry. Question for Case 1 (病例1) Which of the following antiarrhythmic drugs is the best choice for the patient? Question Lidocaine (利多卡因) and mexiletine are Class Ib antiarrhythmic drugs. Which of the following arrhythmias is most likely suppressed by the Class Ib antiarrhythmic drugs? Why? Major Ionic Currents in Ventricular Action Potential The States of Voltage-Dependent Ionic Channel Relationship between Volatge-dependent Ion Channel Statuses and Action Potential INa-mediated action potentials (钠通道介导的动作电位, resting membrane potential -70 mV): fast phase 0 upstroke and conduction velocity that is suppressed by INa blockers. Atria, His-Purkinje conduction tissues, ventricles, accessory pathways; ICa,L-mediated action potentials (钙通道介导的动作电位, resting membrane potential -60 mV ): slow phase 0 upstroke and conduction velocity that is suppressed by ICa,L blockers. Sinus and AV nodes. Heart Electrical System and Action Potential Features Ionic Currents and Diseases Genesis of Cardiac Arrhythmias Abnormal Impulse Formation Automaticity: enhanced pacemaker; Triggered Activity: early afterdepolarization (EAD) and delayed afterdepolarization (DAD) Reentry (Circus Movement ) Electrical Obstacle (such as scar tissue due to MI) Functional Block (relative larger dispersion of repolarization)