抗心律失常课件.ppt

1、抗心律失常药抗心律失常药Anti-Arrhythmic Drug抗心律失常课件正常心脏电生理正常心脏电生理抗心律失常课件Cardiac electrical activity and ECG抗心律失常课件 Cardiac electrical activity抗心律失常课件Heterogeneous APs in heart抗心律失常课件Ion channels and AP01234INaICa.LIKrIKsIK1IK1ITo1INa-Ca抗心律失常课件Ion currents underlying AP in ventricleInward currentsInward currents

2、I INaNaI ICaCaI INaNa/CaCaOutward currentsOutward currentsI IK1K1I Ito1to1I IKrKrI IKsKsI Ito2to2I ITOOSCN5ASCN5ADHP receptorDHP receptorNCX1NCX1Kir2Kir2.x xKv4Kv4.x x?HERGHERG/MiRP1MiRP1KvLQKvLQT11/minminKKPossible clonePossible cloneTTX X,S STX X,lidocaine lidocaineDHPDHP,Cd Cd22+,Co Co22+NiNi+,NC

3、X1 NCX1-antibodantibodyBaBa22+44-APAPDIDSDIDS,9-ACACDofetilideDofetilide,sotalol sotalolChromanol 2Chromanol 293B3BBlockersBlockers抗心律失常课件窦房结细胞动作电位时程中的参与电流窦房结细胞动作电位时程中的参与电流（Currents underlying depolarization in SA nodal cells）抗心律失常课件心律失常发生机制心律失常发生机制折返折返自律性升高自律性升高后除极后除极 早后除极早后除极 迟后除极迟后除极基因缺陷基因缺陷抗心律失常

4、课件折返形成机制折返形成机制(Unidirectional block and reentry)抗心律失常课件预激综合症中房室预激综合症中房室折返环路的形成折返环路的形成Atrioventricular reentry in the Wolff-Parkinson-White syndrome抗心律失常课件心肌细胞的早后除心肌细胞的早后除极和迟后除极极和迟后除极(Two forms of abnormal activity,early and delayed afterdepolarizations)抗心律失常课件抗心律失常药物作用抗心律失常药物作用降低自律性降低自律性减少后除极减少后除极消除

5、折返消除折返抗心律失常课件降低自律性的降低自律性的四种方式四种方式(Four ways to reduce the rate of spontaneous discharge in automatic tissues)抗心律失常课件心律失常类型心律失常类型抗心律失常课件Atrial flutter 抗心律失常课件Atrial fibrillation抗心律失常课件Atrial fibrillation抗心律失常课件Ventricular beat抗心律失常课件Ventricular fibrillation抗心律失常课件Cardiac arrhythmias Tachy-cardiac arr

6、hythmias-Atrial-premature beats-Atrial flutter-Atrial fibrillation(AF)-Ventricular-premature beats(contractions)-Ventricular-tachycardia(VT)-Ventricular fibrillation(VF)Brady-cardiac arrhythmias-Bundle branch blocks-Sinus bradycardia(Sick Sinus Syndrome)抗心律失常课件抗心律失常药物分类抗心律失常药物分类抗心律失常课件Summary of ant

7、iarrhythmic drugsClassDrug exampleActions UsesIaIbIcQuinidine,ProcainamideLidocaine,MexiletineFlecainide,EncainideBlock of INa,IK,and ICa,ADP,ERP,Velocity,ContractilityBlock of INa(fast dissociation),APD,ERPBlock of INa(slow dissociation),Velocity,ContractilityVT,AFVP VTIIPropranolol,MetoprololBlock

8、 of-adrenoceptor ContractilityAT,VTIIIDofetilide,IbutilideAmiodaroneBlock of IKr,ADPBlock of INa(Inac),IKr,ADPAF,ATIVVerapamil,Diltiazem Block of Ca2+channelsAPD,A-V velocityAFflutter抗心律失常课件End!抗心律失常课件Problems to be solved Pro-arrhythmias of antiarrhythmic drugsi.e.lack of selectivity when they are

9、used to treat atrial fibrillation.No effective drugs for arrhythmias in patients with heart failure.No drugs available for Sick Sinus Syndrome.抗心律失常课件Pro-arrhythmia of antiarrhythmic drugs抗心律失常课件Arrhythmogenic action in rabbit heartQuinidine(5 M)E-4031(0.5 M)Asono et al.(1997)JMCC,29:831 抗心律失常课件Lack

10、 of IKur in human ventricleAtrial cellVentricular cellA ControlD ControlB 4-AP 50 MC 4-AP-sensitiveE 4-AP 50 MF 4-AP-sensitive+50 50 mV200pA30 ms Li et al(1996):Circ Res 78:689抗心律失常课件Ion currents in human atrium&ventricleInward currentsOutward currentsINaICaINa/CaIK1Ito1IKurIKrIKsAtriumVentricle抗心律失

11、常课件Human atrial IKur-A target for developing selective anti-atrial fibrillation drug抗心律失常课件Atrial Fibrillation(AF)AF is the most common arrhythmia in elderly persons AF is a potent risk factor for ischemic stroke,increasing the risk of stroke 5-fold and accounting for about 15%of all strokes in USA.

12、Symptomatic AF may also reduce quality of life,functional status,and cardiac performance.It is associated with higher medical costs as well as an increased risk of death.抗心律失常课件Go,A.S.et al.JAMA 2001;285:2370-2375.Projected Number of Adults With Atrial Fibrillation in the United States Between 1995

13、and 2050抗心律失常课件A population-based study of the long-term risks associated with atrial fibrillation 20-year follow-up of the Renfrew/Paisley study Stewart et al.Am J Med.2002;113:359-64抗心律失常课件It is important to develop selective anti-atrial fibrillation drugs抗心律失常课件Life-threatening VF in heart failur

14、e抗心律失常课件Heart failure-mortality15%Within 1 year after diagnosisKannel,et al.Br Heart J 1994;72:S3-S9抗心律失常课件80%In 6 years after diagnosisHeart failure-mortalityKannel,et al.Br Heart J 1994;72:S3-S9抗心律失常课件Of deaths,up to 50%are sudden or unexpected50%Heart failure-mortalityTendera&Ochala Curr Opin Car

15、diol 2001;16:180 抗心律失常课件Lethal arrhythmias:VT or VFVFVT抗心律失常课件Prolongation of ECG Q-T interval in HF patients Choy et al.Am Heart J,1998;136:664-71抗心律失常课件Cellular mechanisms of arrhythmias in HFVTVTVFVFEADsControlHFDADsHF抗心律失常课件APs and Ito,IKs in dog ventricleLiu et alLiu et al.Circ Circ.Res Res.1 1

16、993;72:6713;72:671,1 1995;76:3515;76:351抗心律失常课件Question How the heterogeneous electrophysiology of the transmural ventricular wall is remodeled in heart failure?抗心律失常课件Dog HF model and human HFHuman explanted heart抗心律失常课件Regional ventricular cells抗心律失常课件EndoM cellEpiEADsEADsEADsEADs in regional cell

17、s from dog HF抗心律失常课件No change of ICa in cells from dog HF AControlHeart failure-50 mV0 mV500 pA100 msTP(mV)-3003060ICa(pA/pF)-9-6-30EndoMEpimV-40-200204060ICa(pA/pF)-9-6-30EndoMEpiBCControlHeart failure抗心律失常课件IK1 reduction in dog HFControlHeart failure 2 nA 100 ms-40-110 mVAB抗心律失常课件Reduction of regi

18、onal IK1 in dog HFControlTP(mV)-80-70-60-50-40-30Current(pA/pF)02468*HF-110-90-70-50-30-30-20-10010HFControl*TP(mV)Current(pA/pF)AB抗心律失常课件Reduction of regional Ito1 in dog HFTP(mV)-3003060246810Epi M Endo ATP(mV)-3003060246810EpiMEndoControlHeart FailureB抗心律失常课件Down-regulation of IKs in dog HFEpiMEn

19、doIKs.tail(+30mV)BCurrent(pA/pF)02468AControlEpiMEndoDEpiMEndo 400 pA 2 sec-60+50mV-30IKs.tail(+30 mV)Current(pA/pF)02468EpiMEndoHeart failureC 400 pA 2 sec抗心律失常课件No change of IKr in dog HF+40 mVControlE-4031E-4031-sensitive+20 mV0 mV*I=0A170 pA 1.3 sec+40 mV-60-30 TP(mV)-20-10010203040IKr(pA/pF)0.0

20、0.20.40.60.81.0Epi M EndoEpi MEndoBControl:HF:抗心律失常课件抗心律失常课件No change of ICa in human HFTP(mV)-40-200204060Current(pA/pF)-12-10-8-6-4-20ControlHFABControlHF抗心律失常课件IK1 reduction in human HFControlHeart failureCurrent(pA/pF)BTP(mV)-100-80-60-40-20-18-15-12-9-6-303Control FH*ATP(mV)-80-60-40-200.00.51.

21、01.52.02.5*抗心律失常课件Reduction of Ito1 in human HFATP(mV)-3003060pA/pF246810ControlFH*ControlHFB抗心律失常课件AControlHF250 pA1.2 sec-50+50-30BTP(mV)-30-20-10 010 20 30 40 500.00.20.40.60.8ControlHF*Down-regulation of IKs in human HF抗心律失常课件SummaryIKsIK1Ito1抗心律失常课件SummaryFibrillationVT0EADs抗心律失常课件IK1,IKs activ

22、atorsFuture perspectiveEADs抗心律失常课件Sick Sinus Syndrome抗心律失常课件 Cardiac electrical activity抗心律失常课件ECGSick Sinus SyndromeBradycardiac and tachycardia are seen in Sick Sinus Syndrome抗心律失常课件Atriaficial pacemaker抗心律失常课件 Threshold potential Diastolic potential(60 mV)034Pacemaker cell action potentials ICaIK

23、If Pacemaker potentialSinoatrial node(SA node)抗心律失常课件Pacemaker potential and If 35 mV35 mV85 mV85 mV5 mV5 mVFrom Difrancesco:Cardiovasc Res 1995;29:449-456抗心律失常课件Modulation of IfA ACCB BFrom Difrancesco:Cardiovasc Res 1995;29:449-456抗心律失常课件If and cloned HCN channelsFrom Ludwig et al.:Nature 1998;393:587-591HCN:HCN:Hyperpolarization-activated,cyclic nucleotide-gated channels,the HCN family includes the members HCN1-HCN4.抗心律失常课件