内科学课件07-心律失常-8年制.ppt

1、Dr.Wei Meng,MD,FACCDepartment of cardiology,affiliated 6th peoples hospital,Shanghai Jiao Tong UniversitylProperty of cardiac elctrophysiology兴奋性（兴奋性（Excitability)自律性自律性(automaticity)传导性传导性(Conductivity)lExcitability indicates that myocardial cell has electrical activity when it is stimulatedlElectr

2、ical activity of single myocardial cell is called action potential(AP)lElectrical activity of whole heart makes ECG0-60-90+20Threshold voltagemv01234ARPERPRRPSuper-conductive periodARP:Absolute Refractory period;ERP:Effective Refractory period;RRP:Relative Refractory periodlElectrical impulse can co

3、nduct in myocardial tissue bidirectionallylNormal conduction pathway：sinus nodeintranode bundle atrioventricula node and intraatrial bundleHis bundleright and left bundle branch(including left anterosuperior and posteroinferior)Purkinje fibermyocardiumlCells spontaneously discharging(spontaneous AP,

4、diastolic depolarization)lAutomaticity increases from high to low as follows:Physiological status：SN、AVN、HIS、Purkinjepathological：diseased myocardial and conductive tissue,etc.lImpulse from SNlHeart rate is within 60100/minlRegular rhythm，PP interval0.12slPR interval is between 0.120.20s，QRS complex

5、 duration0.10slFrontal axis within-30110It is considered as arrhythmia if any item above is not matchedlEnhanced automaticity lTriggered activitylAutomatic cells diminish or malfunction,Dysfunction of conductive tissueslReentryEnhanced automaticity lEndogenous or exogenous catecholamine increasinglA

6、bnormality of acid,basic,electrolyte balance lIschemia,hypoxia lMechanical stretch ldrugslDisturbance of nerve and liquid modulationTriggered activitylDepolarizing oscillations of membrane voltage induced by abnormal inward Na+current(one or more preceding AP)during earlier or later reporlarization,

7、ie,After depolarizationEarly depolarizationDelayed depolarizationlAutomatic cells diminish or malfunction,such as sick sinus syndromelDysfunction of conductive tissues,such as sinoatrial block,atrioventricular block or bundle branch block as well as abnormal pathwayReentryprerequisite of reentry lCo

8、nduction inconsistency of anatomy or physiology lSingle directional conduction blockinglDelayed conductionlInitial blocking area recovers excitability(reentry cycle length great than refractory period of the blocking)lClassified on property of electrical activityAbnormality of impulse and conduction

9、lClassified on heart rate,rapid or slowRapid or slow arrhythmiaslClassified on clinical manifestation,mild or severFatal or nonfatalHigh risk or low risklClassified on origin of arrhythmiasl Symptom Caused by abnormal contractile：palpitation,discomfort,beating stop,etc.Induced by cardiac output decr

10、easing：chest compressing and pain,dizziness,presyncope,syncope,short of breathlessFactors related to symptom:medications,diet,emotion,infection,etc.lSignSignChanging of rhythm:slow or Changing of rhythm:slow or fast,regular or irregularfast,regular or irregularIntensity of heart soundIntensity of he

11、art sound：S1 S1 muffle or loudmuffle or loud，cannon soundcannon soundRelation between carotid vein Relation between carotid vein wave pulse and heart rate,and wave pulse and heart rate,and changing of blood pressurechanging of blood pressurelElectrocardiogramMost valuable:evaluating arrhythmia type,

12、property,prognosis,etc.lDynamic Electrocardiogram(Holter)Most valuable:assessing arrhythmia type,numbers,distribution,property,prognosis.Evaluating clinical significance,effects of treatment,etc.lEsophagus electrocardiogramEsophagus electrocardiogramDifferentiating SVT from VTDifferentiating SVT fro

13、m VT，understanding mechanism of SVT.understanding mechanism of SVT.Semi-invasiveSemi-invasive.lElectrophysiologic study(EPS)Electrophysiologic study(EPS)Classical way of researching arrhytnmias.Classical way of researching arrhytnmias.InvasiveInvasiveAssessing function of SNAssessing function of SNl

14、Sinus node recovery time,SNRTSinus node recovery time,SNRTlSinoatrial conduction time,SACTSinoatrial conduction time,SACTAssessing AV conduction Assessing AV conduction Analyzing mechanisim of tachyarrhythmiasAnalyzing mechanisim of tachyarrhythmiasEvaluating unknown syncopeEvaluating unknown syncop

15、elExercise ElectrocardiogramExercise ElectrocardiogramSuitable for some of arrhythmias,Suitable for some of arrhythmias,such as VTsuch as VTlOtherslRapid arrhythmias Premature contractionlAtrial,junctional,ventricularTachyarrhythmias lSinus,atrial,supraventricular,junctional,ventricular,atrial flutt

16、er and fibrellationlBradyarrhythmiasDisease of sinus,AV node or bundle branchlTwo syndromes Preexciting syndromelRelated with rapid arrhythmiasSick sinus syndrome(SSS)lRelated with slow arrhythmiasFeatures of ECG(1)lSerious persistent bradycardia(often 2s,or slow and persistent AFAFL,or slow escape

17、rhythmEtiology lIntrinsic：sinus node itself is involved,e.g.ischemia,regressive degeneration,infiltration of other cells or tissues lExtrinsic：high vagal tone,hyperkalemia,antiarrhythmics most frequent etiology are regressive degeneration and CHD Symptoms lIschemia of brain,heart,kidneylAdams-Stokes

18、 syndromeDiagnosis lTypical ECG patternslSymptoms is related with ECG changingslHolter,provoking test,treadmill and finally electrophysiological study for the suspected.Holter is most valuableFeatures lPP interval elongates abruptly,basically at sinus bradycardia,which is not common multiples of bas

19、ic PP intervallEscape beat or rhythm is common seenlSymptoms is depend on duration of standstill lSymptomatic treatment,pacemaker is ultimate choice Classification of ECGlFirst degree SAB cant be seen on ECGlThird degree SAB cant be differentiated from sinus standstilllSecond degree SAB is divided i

20、nto two subtype,i.e.type I and type II second degree SAB lSymptoms and therapy are same as sinus standstillFeatures of ECGlPP interval progressively shortens until next P wave fails to occurlThe long PP interval that 200 bpm less seenlP wave is not as same as sinus one,PR interval changing with slig

21、htly irregular rhythmlAV block with different ratio can be seen l“Warm-up”can be seen at its initial attacklEtiological or symptomatic treatment,RF also plays a role Features lRare,most having basic diseaselHR is between 100-130 bpm,at lest two kind P wave can be seenlPR and PP interval are changing

22、,P not conducting sometimes,isoelectrical line between PP interval can be seen,precursor of atrial fibrillationlEtiological or symptomatic treatment，antiarrhythmics with caution Features of ECGlP wave disappears,substituted by regular saw-like F wave with its rate between 220350 bpmlVentricular resp

23、onse(AV ratio)is usually 2:1,sometimes 4:1 or irregularlStimulation of vagus nerve or exercise may decrease or increase AV ratio with multiplelUsually AFL is due to reantry around tricuspid ring,and tend to become AFClinical featureslHR is usually around 150 bpm which represents AV ratio is 2:1，may

24、having underlying diseaseslTiny and rapid jugular pulses can be seen with its rate beyond 300 bpmlSimilar manifestation to it in atrial fibrillation(AF)lRate or rhythm control depends on clinical presentationFeatures of ECGlNo P wave,replaced by rapid,chaotic and tiny atrial waves with its rate of 3

25、50600 bpmlVentricle response is irregularly due to AV delay,irregular rates with normal QRS complex,but individual QRS complex may slightly different lCardiacDegeneration,ischemic,myocarditis,enhanced load due to variety of heart diseases,hypertension,post CABG,preexciting syndrome,lone AFlNon cardi

26、acAlcohol abuse,hyper-or hypothyroidism,alteration of vagal or sympathetic tone,COPD,pulmonary embolism,diabetes,sepsis Clinical featureslCommon with aging as well as those with underlying diseases lSymptomatic severity depends on HR,AF duration,underlying heart diseaselTend to embolism because of t

27、hrombosis in atrialMay have long cardiac arrest after paroxysmal AF stopsl lClinical featuresWith stethoscope,palpating artery pulse and watching jugular pulse,near all most of AF can be diagnosed with confidenceAmphasisng prevention embolismRate or rhythm control depends on clinical presentationlNe

28、w classificationFirst-detected episodeRecurrent paroxysmal(self-terminating,7 d)permanentlOld classification paroxysmal,persistent and permanent AF Features of ECGlPremature retrograde P wave(may not seen)lThe P usually in front of QRS complex(may follows QRS one),PR0.10s，RP0.20slMost of them with c

29、omplete compensatory pause,QRS complex normal or in aberration Clinical features lRather common.Most occurred with organic heart diseaselSimilar findings to atrial one on auscultationlSymptom is similar to that of atrial oneslTreatment is not necessary unless obvious symptomFeatures lLess common.Mos

30、t have underlying diseases,digitalis side effect lAttack gradually,AV dissociation common,QRS complex usually normallHR between 70-130 bpm,hemodynamics relatively changing less lEiological treatment,antiarrhythmics is not recommended Features of ECGlHR between 160250bpm,absolute regular,QRS complex

31、narrowing(exception of aberration)lOccasionally,retrograde P wave seenlReentry(AV node,AV)is majority of mechanismClinical featureslMost without organic heart disease,common seenlAttack with sudden initiation and termination,maintaining short for minutes or long for hours.Palpation is mainstream of

32、symptomlHypotension,collapse is far less than VT lGood reaction to treatment,e.g.vagal maneuvers,antiarrhythmics.Radiofrequace is best way for radical cureFeatures of ECGlPR interval 0.12 s or normal,wave in onset of QRS complex which result in widened QRS complex followed by secondary ST-TchangelPR

33、 interval is 0.12 s，but QRS complex is normal(short PR syndrome or LGL(lown-Ganong-Levine syndrome)Features of Preexcitation syndrome P-R=0.12s,wave Secondary ST-T change STV often seen Clnical featureslPart of patients have onset of SVT,AF,AFL,its mechanism is reentrylThere are several types of pre

34、excitation,e.g.persist,intermittent,latent,concealedlIt is predisposed to sudden death if refractory period of accessory pathway is 0.20s in adults or 0.18s in children lMost of it is in 0.210.35sFeatures of ECGlProgressive PR interval prolongation occurs,resulting in a nonconduction P wave(the paus

35、e),the duration of the pause is ventricular ratelQRS complex is broad if pace site distal to His,otherwise it is nearly normallAdvanced AVB refer to that only a few P wave conducts to the ventricles,getting its same clinical significant as it in III AVB first degree AVBlSeen at inflammation(myocardi

36、tis,AMI),drugs,trauma,fibrosis,increased vagus tone,etc.lNo symptoms Second degree typeAVBlSeen at high vagal tone,drugs myocarditis,AMI,etc.lNo remarkable hemodynamics change,may have wild symptomslA few cases may progress worse into severe AVBSecond degree type II AVBlAlmost has underlying heart d

37、iseaseslHR is slow and sometimes unstablelThose whose blocking level is distal to His bundle are predisposed to progress into third AVBlSymptoms are prominent Third degree AVBlAlmost has underlying heart diseaseslHR is slow and unstablelThose whose blocking level is distal to His bundle are predispo

38、sed to turn into cardiac asystole or TDP,which could cause recurrent syncope or Adams-Stokes syndrome Third degree AVBlOn auscultation,intensity of S1 varies due to loss of AV synchrony,cannon sound(wave),S3，S4 can be heardlSyncope,presyncope,chest compression heart failure,etc.are seen frequently.W

39、ith high risk of sudden death lFirst or second degree type I AVBAim for etiology and symptoms,follow up AV conduction changing lSecond degree type AVBAim for etiology and symptoms,close investigation of clinical manifestationlPatients with symptomatic bradyarrhythmia should receive a permanent pacem

40、akerThird degree AVBlThere is evidence that pacing can improve prognosis in these patient no matter symptomatic or asymptomatic,in acute stage,temporary pacemaker,chronic permanent lRight BBB(complete,incomplete)lLeft BBB(complete,incomplete)lLeft anterior fascicular blocklRBBB plus Left anterior fa

41、scicular blocklIntraventricular block(nonspecific intraventricular conduction defect)lLeft posterior fascicular blockFeatures of ECGlDuration of QRS complex 0.12slVAT(ventricle activity time)at right precordial leads 0.07slQRS complex in lead V1 is in pattern of rSR，in V5 with a blunt,prolonged and

42、shallow S wave,with secondary ST-T changinglQRS complex measured is 0.12slVAT(ventricle activity time)at left precordial leads 0.07slQRS complex in lead V1 is in pattern of rS，in V5 is a high,blunt,widen R wave,with secondary ST-T changinglQRS complex measured is 0.12s is recognized as incomplete LB

43、BBlBBB per se have no significant effect on hemadynamicslBBB may not deteriorate at long term follow-up in patients who have no underlying heart diseaseslNew BBB in AMI or myocarditis signifies clinical deteriorationlMost of bilateral BBB will develop complete heart blocklNo particular treatment unl

44、ess there is indication of pacing lMedicationlNon medicationCatheter based lAblation(electric,radiofrequecy,cryoablation,Chemo-ablation,laser)lProgrammed electric stimulationlNon medicationpacemakerlFor bradycardialFor tachycardiaSurgical operationlCut off,excision,Fox operation,CABG,etc.otherslDC c

45、ardioversion,stimulation of vagus nerve,transesophageal pacinglEvaluating risk of arrhythmiaslDeciding to Treating it or not lWhich therapy should be chosenlWhat is the endpoint of therapy Recognition of malignant arrhythmiaslVentricular flutter or fibrillationlSustained or non sustained VTlAdvanced

46、 or complete AVBRecognition of malignant arrhythmiaslAF or AFL with rapid ventricle response lVPC are Multilocal,polymorphic,couplet,triplet and R on TlSevere SSSSerious heart diseaseslAMI、serious myocarditis,myocardiopathy,hear failure,taking digitalis Hemodynamics unstablelBlood pressure decrease,

47、shock,heart failure or heart failure deterioration when on onset of arrhythmiaslLife quality is decreased,which is caused by arrhythmiaslSuggest worse prognosis when the arrhythmiaKEmergency KUrgent KactiveKPalliative Fatal arrhythmiaslSustained VT,VFL,VFlExtremely slow and unstable bradycardia,asys

48、tole will happen at any timeHemodynamics deterioration or shocklVT,rapid AF or AFL,extreme and/or bradycardias,etc.lWith serious heart diseases(myocarditis,myocardiopathy)lWith acute coronary ischemialWith remarkable depressed cardiac function or decompensate heart failurelOn digitalislAbnormality o

49、f acid,basic,electrolyte balancelToo much complain,life quality decrease,may induce complication,but relatively normal heartSuch as frequent premature contraction,AF,SVTlAsymptomatic arrhythmias with normal or relatively normal heartAim for removal of provocative factorslCorrection of anoxia,ischemi

50、a,disturbance of elctrolyte,acid and basic lControl of heart failure,infection,inflammation,diminishing side-effects of drugs relevant to arrhythmiasMedication lIV administration in emergencylCombination of antiarrhythmics in necessary,in which effect would be good，but possible side effects also inc