心脏电生理及射频消融基础.ppt

1、电生理相关资料,Cardiac vein stenosis,PTCA with 3.5 mm balloon,Final result,Modified Seldinger technique for percutaneous catheter sheath introduction,Sequence of P Wave Generation,Sinus Node,SA Junction,Atrium,(P wave),Non-visible process on the EKG,SUMMARY Mechanisms of SVT,Atrial Tachycardia,AVNRT,AVRT,F

2、P,SP,Differential Diagnosis of NCT,Short RP AVRT AT Slow-Slow AVNRT,Long RP AT Atypical AVNRT PJRT,P buried in QRS Typical AVNRT AT JET,SUMMARY,Obtain a 12 lead ECG. The location of the P wave will dictate the differential diagnosis If hemodynamically unstable (chest pain, heart failure, hypotension

3、)- CARDIOVERSION If hemodynamically stable -AV NODAL AGENT Long term therapy depends on mechanism and can be conservative, pharmacologic or invasive EP study often needed for definitive characterization of mechanism and can cure most SVTs with 90% success rate,AVNRT,Atrial flutter sawtooth or picket

4、 fence,Atrial flutter with rapid response,Arrhythmias: SA Block,P,QRS T,Arrhythmias: Atrial Flutter,Steps to reading ECGs,What is the rate? Both atrial and ventricular if they are not the same. Is the rhythm regular or irregular? Do the P waves all look the same? Is there a P wave for every QRS and

5、conversely a QRS for every P wave? Are all the complexes within normal time limits? Name the rhythm and any abnormalities.,Rate,Look at complexes in a 6-second strip and count the complexes; that will give you a rough estimate of rate Count the number of large boxes between two complexes and divide

6、into 300 Count the number of small boxes between two complexes and divide into 1500 Estimate rate by sequence of numbers (see next slide),Bundle branch blocks Look at the QRS morphology in V1 and V6,AVNRT,Acute treatment ATP or Verapamil Cardioversion if BP Long term Drugs, verapamil or b-blocker EP

7、S and RFA,AVRT,WPW or concealed accessory pathway acute and chronic treatment similar to AVNRT avoid b-blocker and verapamil in known WPW,Atrial Flutter,Marcoreentrant circuit in RA terminate by cardioversion with high success rate poorly controlled by medical therapy EPS + RFA,“Typical isthmus depe

8、ndent atrial flutter” is due to a macro reentrant circuit around the tricuspid valve,This rhythm can be stopped by pacing and cured with ablation Embolic risk may be less than in fibrillation, but same recommendations apply,Electrophysiology II Supraventricular Arrhythmias,Atrial Flutter,Ventricular

9、 rate 150 bpm,“Saw tooth” p waves,Atrial Flutter,Electrophysiology II Supraventricular Arrhythmias,Atrioventricular Nodal Reentrant Tachycardia (AV Node Reentry or AVNRT),Most common cause of paroxysmal SVT in the young adult Occurs over a small reentrant circuit located near the AV node The circuit

10、 consists of a fast and slow pathway connected by a common top and bottom pathway,Electrophysiology II Supraventricular Arrhythmias,AV Node Reentry Tachycardia,Rate of 145 bpm,(Short RP tachycardia),Electrophysiology II Supraventricular Arrhythmias,RP = 60 msec,Ectopic Atrial Tachycardia (Long RP ta

11、chycardia),Uncommon cause of paroxysmal SVT in the young adult ( 5%) Occurs in a small region of either the right or left atrium,Electrophysiology II Supraventricular Arrhythmias,Frequently due to an automatic mechanism making it difficult to reproduce in EP Lab,Rate = 160 bpm,RP = 220 msec,Atrial t

12、achycardia,(Long RP tachycardia),Electrophysiology II Supraventricular Arrhythmias,Wolff-Parkinson-White Syndrome,Relatively common cause of paroxysmal SVT in children and young adults Due to an “extra” muscular bridge that connects the atrium and ventricle and allows the ventricle to be “excited” b

13、efore the signal passing through the AV Node,Electrophysiology II Supraventricular Arrhythmias,Accessory Pathway Mediated Tachycardias (AV Reentry),95% of infants,95% of adults,AVNRT,Manolis, Ann IM, 1994,AVRT(WPW),Heart Disease,Arrhythmias = abnormal heart rhythms. Bradycardia = slower Tachycardia

14、= faster (exercise!) Flutter: extremely rapid Fibrillation: Contractions of different groups of myocardial cells at different times. Ventricular fibrillation is life-threatening.,Train your eyes,Train your eyes for Rate: Check the computer Train your eyes for Rhythm: Check the rhythm strip Check I,

15、II, avF Train your eyes for Axis: Check I, II Train your eyes for Intervals: PR: check II QT: check the computer QRS: check I, V1,Train your eyes,Train your eyes for LVH: Look atin order avL V3 V1 V5,V6 Check your cheat sheet Read the computer Train your eyes for MI: Look at all T waves Look at all

16、ST segments Check for Q waves Check for R waves in V1-2,Arrhythmias,Ventricular fibrillation rapid, uncoordinated depolarization of ventricles,Tachycardia rapid heartbeat,Atrial flutter rapid rate of atrial depolarization,15-71,Brugada Algorithm,Supraventricular Tachycardia,Wavy baseline,Sinoatrial

17、(SA) node,Internodal and interatrial tracts,Atrioventricular (AV) node,Bundle of His,Bundle branches,Purkinje fibers,Electrocardiography,Figure 18.16,Salvo of pvcs,Multifocal pvcs,PAC premature atrial contraction,RP - PR relationship,Torsade de pointes turning of the points or torsion,Junctional rhy

18、thm,You have lost your P wave or it is inverted,Primary Atrial Junctional Tachycardias,Sinus Tach,EAT,A Flutter,AVNRT,JET,Vulnerable t wave refractory period,Why ventricular? Why tachy?,Fig 12 a summary of heart blocks.,a summary of other arrhythmias,Causes of SA Exit Block and Sinus Pauses/Arrest,I

19、ncreased vagal tone (very intense for sinus arrest) Drugs: beta blockers, calcium channel blockers, amiodarone, digoxin (indirect effect) Myocardial ischemia/infarction Sick sinus syndrome Sequela of open heart surgery,Wolff-Parkinson-White Syndrome Tachycardias,CC5,CM5,ML,QRS电轴简单计算方法,、aVR、aVL、aVF六个

20、导联 哪一个导联上的QRS波正向波幅最高，则该导联的正极方向即代表QRS电轴方向。2。上述六个导联中，哪一个导联的QRS波负向波幅最大，则该导联的正极方向即背离QRS电轴方向。3。上述六个导联中，如在某导联出现正负等相图形（即正相波振幅与负相波振幅相等），则该导联的正极与负极均与QRS电轴呈直角。,Warfarin for Atrial Fibrillation Limitations Lead to Inadequate Treatment,Samsa et al. Arch Intern Med. 2000;160:967-973.,INR above target6%,Subtherap

21、eutic INR 13%,INR intarget range15%,No warfarin65%,Adequacy of Anticoagulation inPatients with AF in Primary Care Practice,Regional anatomy relevant to percutaneous femoral arterial and venous catheterization,Left Atrial Appendage (LAA),inside,outside,特发性室性心动过速的射频消融,特发性室性心动过速的射频消融,折返的条件,QRS波群起始部的切迹、

22、顿挫,0.05mV负向波,梗死部位对QRS波的影响,右心房起搏导线常用位置右心耳,起搏系统,房室旁路的解剖分布,左游离壁 前间隔 希氏束 冠状窦口 右游离壁 后间隔,正常的房室传导系统,左侧房室旁路的定位标准,V1导联QRS波主波方向向上（多呈Rs型） V1导联P波和QRS波不融合，两者间可有等电位线，PR0.09s 预激波额面电轴右偏（90120度）,右侧房室旁路的定位标准,V1导联QRS波主波方向向下（多呈rS型） V1导联P波和QRS波融合，二者间无等电位线，PR0.07s 预激波额面电轴左偏（3060度）,右后、右侧游离壁： 、aVL、V5、V6导联预激波正向， 、aVF导联预激波负向

23、或正负双向。 右前游离壁： 、aVF导联预激波正向或正负双向。,前间隔房室旁路的定位标准,V1导联QRS波主波方向向下（多呈rS型） V1导联P波和QRS波融合，二者间无等电位线，PR0.07s 预激波额面电轴正常，aVL导联预激波正向提示右前隔，反之为左前隔,左后间隔房室旁路定位标准,V1导联P波和QRS波虽不融合，但二者之间无等电位线 预激波额面电轴左偏，V1预激波一定正向，预激波在、aVL导联正向， 、aVF导联负向 QRS波主波在胸导联均为正向，、aVL导联QRS主波正向， 、aVF导联QRS主波负向 额面QRS电轴左偏,右后间隔房室旁路定位标准,V1导联P波和QRS波不融合，因该导联

24、预激波为等电位故使二者间似有等电位线 预激波额面电轴左偏，V1预激波等电位或负向，预激波在、aVL导联正向，在 、aVF导联均负向 QRS波主波在V1为负向，其余胸导联均正向，、aVL导联QRS主波正向， 、aVF导联QRS主波负向 额面QRS电轴左偏,房室旁路定位诊断步骤,第一步：V1导联QRS波形态（Rs、rS抑或RS）及额面QRS电轴（左、右、不偏） 第二步：从PR段及PR间期进一步印证（PR间期长或者短） 第三步：根据预激波在下壁导联（ 、aVF ）及左侧导联（ 、aVL、V5、V6 ）的方向确诊,房室旁路的精确定位,房室旁路的精确定位依赖于心内电生理检查，是经导管射频消融术的必要及关

25、键步骤。,心内电生理示意图,二尖瓣环 房室旁道 CS电极 冠状窦口 HIS束电极 RV电极,Welcome to our department,In summary.,The (relatively) good: Mobitz I AV block, or Wenckebach block,The bad: Mobitz II AV block, and.,The ugly: Complete heart block,Torsades de Pointes,Rate in beats/min = 60/interval between two beats in seconds A handy

26、shortcut is: Heart rate (beats/min) = 1500/R-R interval (mm),1500/20 = 75 b/min,First degree - prolonged PR interval only. The normal PR interval is 0.12 to 0.21 seconds. A PR interval 0.21 would be classified as first degree block. Usually this block is above His bundle,Second degree - some P waves

27、 are not followed by QRS. Often has a regular sequence, i.e., 2:1 or 3:2. The first number is the number of P waves present and the second is the number of QRSs. What is this?,Mobitz I (Wenckebach) the PR progressively lengthens with one P wave for every QRS until a beat is dropped. Usually the bloc

28、k is above His bundle. This is common in coronary patients and is caused by increased vagal tone and usually eventually disappears with no problems,Mobitz II the PR is constant but with occasional dropped beats. This is a more serious arrhythmia because the injury is probably in fast conducting tiss

29、ue below the His bundle which is not under vagal control.,This is unambiguously Mobitz II It is a dangerous arrhythmia because the heart may suddenly start beating very slowly or even stop.,Complete heart block. Since there is no conduction down the AV node pathway atria and ventricles beat regularl

30、y but at different rates.,Slow ventricular rate Usually treated with pacemaker May be temporary or intermittent. Can be induced by drugs that cause increased vagotonia,WPW: Normally conducting cardiac muscle bridges the gap between atria and ventricles.,The accessory pathway activates the ventricle

31、before normal activation via the AV node.,The PR interval is 0.12 sec,Delta waves are usually present,Can get retrograde conduction causing reentry and a tachyarrhythmia.,If accessory pathway has short antegrade refractory period, can have serious arrhythmias, especially with atrial fibrillation,Sin

32、us Tachycardia 100b/min 1. Normal P waves 2. Normal or shortened PR interval 3. QRS and T vectors are normal 4. ST segments are normal 5. RR interval short 15mm 1500/100 = 15,Sinus Bradycardia 25mm 1500/60 = 25,Premature ventricular contraction (PVC) 1. Arises from ectopic focus in ventricles 2. Ear

33、ly QRS not preceded by a P wave (see fig 4) 3. Will have an unusual QRS shape a) odd vector b) prolonged QRS duration,Premature ventricular contraction (PVC) 1. Arises from ectopic focus in ventricles 2. Early QRS not preceded by a P wave (see fig 4) 3. Will have an unusual QRS shape a) odd vector b

34、) prolonged QRS duration 4. A compensatory pause,Multifocal PVCs. Two separate foci are originating PVCs Irritable ventricle IF all PVC are identical it is from one ectopic site (Unifocal).,Premature atrial contraction (PAC) 1. Arises from an ectopic focus in the atria. 2. Will have an identifiable

35、P wave but the shape of the P wave may be altered 3. May have a normal QRS 4. May have a compensatory pause,The QRS may be altered if some of the ventricle is still in its refractory period.,The compensatory pause is lacking because the SA node was reset. The rhythm has been shifted.,Atrial fibrilla

36、tion 1. Irregularly irregular 2. No P waves,The AV node keeps the ventricular rate low May be treated with drugs to depress AV conduction and slow the ventricular rhythm: Beta blockers, calcium channel blockers,Common: will occur in about 1/3 of the population Not a serious arrhythmia unless in WPW,

37、Electrical reentry can cause fibrillations and tachycardias.,Ventricular tachycardia (Fig 9) 1. Regularly occurring rhythm originating from a regular ventricular ectopic focus. 2. QRS morphology is usually like a PVC,Because the cardiac output is very low it usually produces myocardial ischemia and

38、often progresses to ventricular fibrillation,Ventricular fibrillation (VF) 1. Thought to be a reentrant excitation of the ventricles; premature impulse may arise during vulnerable period 2. Irregular baseline with no identifiable waves,3. No cardiac output. Usually the cause of sudden death 4. May b

39、e the result of ischemia, lightning strike, electrocution, chest trauma, or drugs 5. Requires CPR and electrical difibrillation. Patients do not spontaneously recover.,Extended phase two cause long QT syndrome.,Q-T interval is rate- dependent and is an index of the duration of phase 2 in the ventric

40、ular AP 12 x 40 = 480 ms,12 blocks,Long QT syndrome Prolonged duration of phase 2 causes an early afterdepolarization. That can trigger an early action potential causing a reentrant tachycardia Patients may experience attacks of VT with torsades de pointes - a waxing and waning of the QRS morphology

41、 (as if circling around a point).,3. Long QT is induced by some drugs and can be due to genetic abnormalities in some potassium and calcium channels. At present 5 separate genetic defects have been identified which cause long QT,14 STEPS TO ASSURE A SUCCESSFUL READING AND UNDERSTANDING OF AN UNKNOWN

42、 ECG 1. Is the ventricular rhythm regular?2. Are there P waves?3. Is the atrial rhythm regular?4. Is there one P wave for each QRS?5. What are the atrial and ventricular rates?6. What is the P-R interval?7. Is the P-R interval constant?8. Are there extra or premature beats?9. What is the QRS duratio

43、n?10. Does the QRS morphology indicate presence of a conduction defect?11. What is the mean electrical QRS axis?12. What is the mean electrical P wave axis?13. Is there S-T segment deviation?14. Are there pathologic Q waves?,Fig 12 a summary of heart blocks.,a summary of other arrhythmias,RA,LA,LV,R

44、V,Types of Supraventricular Tachyarrhythmias,Sinus Node Reentry Atrial Flutter Automatic Atrial Tachycardia Reentrant Atrial Tachycardia Atrioventricular NodalReentry (AVNRT) AV Reentry via an AccessoryAV Connection (AVRT) Atrial Fibrillation (Not Shown),Types of Paroxysmal Supraventricular Tachycardia,AV NodalReentry,AV ReciprocatingTachycardia,Sinus Nodal Reentry,Intra-atrial Reentry,Automatic AtrialTachycardia,Mechanisms of Paroxysmal Supraventricular Tachycardias,Enhanced Au