1、心律失常发生机制及导管消融适应症 （Electrophysiological Mechanisms of Cardiac Arrhythmias and Indication of Radiofrequency Catheter Ablation),吉林大学第二医院 心内科 李树岩,Indications for Radiofrequency Catheter Ablation,Wolff-Parkinson-White Syndrome (WPW) Atrioventricular Nodal Reentrant Tachycardia (AVNRT) Atrial Flutter Atri
2、al Fibrillation (AF) Ventricular Tachycardia (VT) Atrial Tachycardia (AT) Others,Risks and Complications With RF Ablation,Hypotension - secondary to drugs or vagal reaction Vascular injury Ischemia/Infarction Venous/ Arterial Thrombosis Cardiac perforation Damage to the AV conduction system Life thr
3、eatening arrhythmias,Arrhythmia Mechanisms,Automaticity Triggered Activity Reentry,Automatic tachycardia (AT, VT, AF) is identified by the presence of the following characteristics:Can be initiated by an isoproterenol infusionPES cannot initiate or terminate the tachycradiaCan be gradually supressed
4、 with overdrive pacing, but then resumes with a gradual increase in the rateCan be terminated by propranololThese episodes have a “warm up” and/or “cool down phenomenonCannot be terminated by adenosine, but transiently slows or suppresses, especially when it can be induced with isoproterenol,(Zipes
5、DP, Jalife J. Cardiac Electrophysiology: From cell to bedside, 4th edition. 2004; pg. 500-501),Arrhythmia Mechanisms,Triggered activity (AT, VT, AF) is identified by the presence of the following characteristics:Triggered arrhythmias can be initiated with rapid pacing or exstrastimuli dependant on r
6、eaching a certain range of pacing cycle lengthsNo entrainment is observed, but overdrive suppression or termination occursDelayed afterdepolarizations can be recorded near the origin using a monophasic action potential catheter before the onset, but not at sites remote from the tachycardiaIs termina
7、ted by adenosineRarely requires isoproterenol to induce itIs terminated by dipyridamole, propranolol, verapamil, edrophonium, Valsava maneuvers and carotid sinus pressure,(Zipes DP, Jalife J. Cardiac Electrophysiology: From cell to bedside, 4th edition. 2004; pg. 500-501),Arrhythmia Mechanisms,Micro
8、reentry (AT, AVNRT, VT)/Macroreentry (AT, AVRT, Atrial Flutter) is identified by the presence of the following characteristics:Can be reproducibly initiated and terminated by pacing and extrastimuliNo delayed afterdepolarizations can be recorded using a monophasic action potential catheterManifest a
9、nd concealed entrainment observed while pacing during the tachycardiaFrequently terminated by verapamil and adenosine, but adenosine usually has no effectThe interval between the initiating premature beat and first beat of the AT are inversely related,(Zipes DP, Jalife J. Cardiac Electrophysiology:
10、From cell to bedside, 4th edition. 2004; pg. 500-501),Arrhythmia Mechanisms,Sequence of the Flow in a Typical EP Study,Preparation of the Patient Insertion of sheaths and Electrode catheters Basic EPS study to get the basic data Induction of the Arrhythmia Diagnosis of the Arrhythmia Ablation of the
11、 Arrhythmia (if indicated) Confirmation of Therapy Success,WPW,Occurrence of dysrhythmias 1,2,2Fitzgerald, et al., J Electrocardiol., Vol. 29, No.1, Jan. 1996, p. 1-10.,1Fogoros, Electrophysiologic Testing, 2nd ed. 1995, p 104-107,ANTI 10%,ORTHO 90%,WPW tachycardia circuits,Orthodromic Tachycardia,T
12、hese terms are only applicable when the patient is in their tachycardia, i.e. during the intrinsic rhythm this patient may be manifest or concealed, but during the tachycardia we define this patient as either antidromic or orthodromic. Antidromic means antegrade conduction (from the atrium to ventri
13、cle) occurs down the AP and retrograde conduction (from the ventricle to the atrium) up the normal conduction system (AV node). Orthodromic means antegrade conduction occurs down the normal conduction system and retrograde conduction up the AP.,Antidromic Tachycardia,Bypass Tract Locations,Anywhere
14、except here (fibrous trigone),Bypass Tract Locations,Types of Accessory Pathways,A = atriofascicular B = nodofascicular C = nodoventricular* D = fasciculoventricular E = atrioventricular*first described by Mahaim,Types of Accessory Pathways,Preexcitation Syndromes,Wolff - Parkinson - White “Mahaim”
15、Fibers - now separated into: Atriofascicular Nodoventricular Nodofascicular Fasciculoventricular,Wolff, Parkinson and White, and their Syndrome,Published in American Heart Journal in August, 1930 findings on 11 patients with a syndrome of signs and symptoms Clinical significance May confuse physicia
16、ns Delta Wave may be interpreted as an infarct Marked preexcitation in atrial tachycardias may look like VT Pt has paroxysms of SVT May bypass the protective nature of the AV node and expose the ventricles to extremely high heart rates.,Kastor, Arrhythmias, 2nd ed., 2000, p.12,Fogoros, Electrophysio
17、logic Testing, 2nd ed. 1995, p 132,Diagnosis and Localization,Surface lead evaluation Understanding Bundle Branch Block “Patterns” as applied to interpreting Delta Wave polarity Delta Wave Polarity interpretation The use of algorithms for evaluating preexcited 12 leads Functional Bundle branch block
18、 during ORT Electrophysiology study Catheter mapping,Delta Wave Polarity,Use the first 20-40 mSec of the Delta wave to determine polarity The QRS usually follows the polarity of the Delta wave Use algorithms to locate the AP Of primary concern- is the pathway right or left sided? (Transseptal proced
19、ure or not?) Determine Delta wave polarity in V1 - V1 positive = left sided V1 negative = right sided,The delta wave,Clinical manual of electrophysiology Singer and Coopersmith ch 9 pg 125,Delta Wave Polarity,Fitzpatrick, et al., JACC, Vol. 23, No. 1, Jan. 1994, p. 110,Pre-excitation,Fusion of the Q
20、RS occurs because there is simultaneous conduction down the AV node and accessory pathway,WPW Baseline,Note the pre-excitation as evidenced by the delta wave, resulting in a short PR interval,Delta Wave,Short PR Interval,Normal ECG with no delta wave and a normal PR interval and QRS,Evaluating a pre
21、excited 12 lead,Leads I and aVL Indicates impulse travel as right to left (positive) or left to right (negative) Leads II, III, and aVF Indicate impulse travel as superior to inferior (positive) or inferior to superior (negative) The QRS axis will be directed away from the ventricle being preexcited
22、 V Lead transition Helps differentiate septal or lateral sites.,Algorithm - Arruda (a),Arruda, et.al., JCE Vol 9 #1 Jan 1998, pp. 2-12,Algorithm - Arruda (b),Arruda, et .al., JCE Vol 9 #1 Jan 1998, pp. 2-12,More examples,Electrophysiology study,Goals of the EP study Identify the function and threat
23、of the AP Locate the AP to determine approach for ablation Methods Atrial Pacing Ventricular Pacing Catheter mapping Additional Maneuvers Para-Hisian pacing Pharmacologic conduction block,Atrial pacing,Initiated after baseline recordings Often used with isoproteronol to induce tachycardia and shorte
24、n refractory periods Progressive AV node delay encourages conduction over the accessory pathway Look for delta wave to become more noticeable Find the antegrade and retrograde refractory periods of the AVN and AP,Ventricular Pacing,Look for the earliest retrograde A “Advance” the atria during tachyc
25、ardia Differentiate between AVRT, AVNRT and atrial tachycardias.,Paced PVC During His Refractory Period,Para-Hisian pacing- Retro AVN conduction; no BPT,Narrow QRS,Wide QRS,His and V capture,V capture only,Variable Stim -A,Zipes & Jalife, Cardiac Electrophysiology: From Cell to Bedside, 2nd ed,. 199
26、5, p. 623,Para-Hisian pacing- Retro conduction through BPT,Narrow QRS,Wide QRS,His and V capture,V capture only,Fixed Stim - A,Zipes & Jalife, Cardiac Electrophysiology: From Cell to Bedside, 2nd ed,. 1995, p. 623,Pharmacologic Block,Block AV node conduction with adenosine or verapamil. Should show
27、continued V-A conduction during V pacing. Adenosine can break some non - WPW tachycardias Adenosine does not work in every patient,房室折返性心动过速（AVRT）适应证,明确适应证：反复发生AVRT首选射频消融房颤或其他房性心律失常伴旁道前传所致快速心室率 相对适应证：无关旁道,Ablation,Objectives- Eliminate the abnormal conduction Preserve the normal conduction Indicator
28、s of success- Disappearance of Delta Wave (in WPW only) Increase in V-A conduction time during V pacing (WPW or concealed APs) Tachycardia not inducible Caveats “bumping” the pathway before ablation Complications (A-V block during RF of anteroseptal pathways, transseptal risks, perforation, vascular
29、 ablation, others),Ablation,Rickerd, The New EP Techs Book, 3rd ed., 2002, p. 102 - 103,More examples,AVNRT,Basics of AVNRT,Most common form of SVT treated by ablation More common in females than males Otherwise healthy individuals Usually adolescent to mid-30s, but can occur at any age, including i
30、nfancy,Types of AVNRT,Three Main TypesTypical; common; usual; slow-fastAtypical; uncommon; unusual; fast-slowSlow-slow,Distribution of Types of AVNRT,Kuck KH, Cappato R. Catheter Ablation in the Year 2000. Current Opinion in Cardiology 2000;15:29-40.,AVNRT Circuit,The reentrant circuit involves the
31、Fast Pathway (FP), which enters the compact AV node from the anterior septal region close to the compact AV node, and the Slow Pathway (SP), which is located in the posterior septal region. There are 3 types of AVNRT. In common type AVNRT antegrade conduction is down the SP and retrograde up the FP.
32、 In the uncommon type, antegrade conduction is down the FP and retrograde up the SP. In the slow slow type, antegrade conduction is down one SP (a certain bundle of fibers) and retrograde up another SP (a different bundle of fibers). For all three types ablation is performed by ablating the SP, beca
33、use FP ablation has the risk of complete AV block necessitating pacemaker implantation due to its close proximity to the compact AV node.,- Dual pathway physiology; one fast and one slow- Typical (common) AVNRT: antegrade slow, retrograde fast- Atypical AVNRT (uncommon): antegrade fast, retrograde s
34、low-Slow slow AVNRT: antegrade certain slow fibers, retrograde other slow fibers- Jump in AH interval 50 msec during a 10msec decrement in extrastimulus testing,Common (Typical) AVNRT,In common AVNRT, antegrade conduction is down the slow pathway and retrograde up the fast pathway. The earliest atri
35、al activation would be recorded in the anteroseptal region where the fast pathway is located. Also since conduction to the ventricle is down the slow pathway, the AH interval will be prolonged.,Uncommon (Atypical) AVNRT,In uncommon AVNRT, antegrade conduction is down the fast pathway and retrograde
36、up the slow pathway. The earliest atrial activation would be recorded in the posteroseptal region where the slow pathway is located. Also since conduction to the ventricle is down the fast pathway, the AH interval will be normal.,Slow Slow AVNRT,In Slow Slow AVNRT, antegrade conduction is down some
37、slow pathway fibers and retrograde up other slow pathway fibers. The earliest atrial activation would be recorded in the posteroseptal region where the slow pathway is located. Also since conduction to the ventricle and back to the atrium is via the slow pathway, both the AH & HA intervals will be p
38、rolonged.,Dual AV Nodal Physiology,Patients with AVNRT usually demonstrate dual-nodal physiology.,Dual AV Nodal Physiology cont,Complex structure of AVN Displays discontinuous Conduction Properties Peri-nodal tissue behaves functionally as two parallel pathways Differentiated by electrophysiologic p
39、roperties Exhibits non-uniform anisotropic properties Both Capable of Antegrade and retrograde conductionExhibits longitudinal dissociation Results in Reentry around, or within, the AVN,Slow and Fast Pathways,Slow Pathway Perinodal tissue possessing conduction properties of slow depolarization and r
40、elatively rapid repolarization Fast Pathway Perinodal tissue possessing the conduction properties of relatively rapid depolarization and relatively slow repolarization,Dual AV Nodal Physiology cont,Dual AV nodal physiology - a “jump” in the A-H interval of greater than, or equal to, 50 msec in respo
41、nse to a 10 msec decrement in the S1S2 interval; during atrial extra-stimulus testing as the extra-stimulus is introduced (decremented).,Sinus Rhythm with Dominant Fast Pathway Conduction,Sinus Rhythm with Dominant Slow Pathway Conduction,Criteria for A-V Nodal SVT cont.,Typical A-V Nodal ReentryRet
42、rograde atrial activation caudocephalic with electrogram in the A-V Junction earliest (V-A -42 to +70msec) Retrograde P wave within the QRS with distortion of terminal portion of the QRS. Atrium, His bundle, and ventricle not required Vagal manuevers slow and then terminate SVT.,Clinical Cardiac Ele
43、ctrophysiology: techniques and interpretations,2nd. EdLea and Febiger, 1993.page224,Differentiate AVNRT from: AVRTAVNRTAtrial tachycardiasPJRT,Differential Diagnosis,Differential Diagnosis,PVC when His bundle is refractory Para-Hisian Pacing Adenosine Administration A-V Wenckebach periodicity or Dis
44、sociation V-A Wenckebach periodicity or dissociation,PVCs on the His,Performed during tachycardia Pace RV when AV node is refractory Look for retrograde atrial conduction V-A conduction while the AV Node is refractory is diagnostic of an accessory pathway not AVNRT,Pharmacological block,Block AV nod
45、e conduction with adenosine or verapamil Continued V-A conduction is diagnostic of an accessory pathway Adenosine can break some non-WPW tachycardias Adenosine does not work on every patient,Objective,Modify the slow pathway of the AV node in order that it will no longer conduct.,Slow Pathway Modifi
46、cation,Ablation catheter is positioned “anatomically” on the tricuspid valve annulus posterior and inferior to the His bundle at the level of the CS ostium. If unsuccessful, the catheter is moved anterior and superior in a stepwise fashion until successful.,RAO,LAO,Slow Pathway Modification,Inabilit
47、y to reinduce tachycardiaLoss of dual AVN physiologyProlongation of AH intervalComplete heart block *,RF Ablation Endpoints,* Not a desirable endpoint for slow-pathway ablation.,Potential Complications,Potential Complications,3rd degree AV block-rare when targeting slow pathway 10% when targeting fast pathwayOther EP study related complications,房室结折返性心动过速（AVNRT）适应证,明确适应证：反复发生AVNRT首选射频消融 相对适应证：心脏电生理检查发现房室结双径路但未诱发AVNRT，病史中疑有AVNRT发作的病人,Conclusions,Easy to diagnose Easy to treat High success rate with RFA,Thank You,
