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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 infusion PES cannot initiate or terminate the tachycradia Can be gradually supres
4、sed with overdrive pacing, but then resumes with a gradual increase in the rate Can be terminated by propranolol These episodes have a “warm up” and/or “cool down phenomenon Cannot be terminated by adenosine, but transiently slows or suppresses, especially when it can be induced with isoproterenol,(
5、Zipes 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 dependa
6、nt on reaching a certain range of pacing cycle lengths No entrainment is observed, but overdrive suppression or termination occurs Delayed afterdepolarizations can be recorded near the origin using a monophasic action potential catheter before the onset, but not at sites remote from the tachycardia
7、Is terminated by adenosine Rarely requires isoproterenol to induce it Is 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 Mech
8、anisms,Microreentry (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 extrastimuli No delayed afterdepolarizations can be recorded using a monophasic action potential cath
9、eter Manifest and concealed entrainment observed while pacing during the tachycardia Frequently terminated by verapamil and adenosine, but adenosine usually has no effect The interval between the initiating premature beat and first beat of the AT are inversely related,(Zipes DP, Jalife J. Cardiac El
10、ectrophysiology: 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 Arrhythmi
11、a Ablation of the 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,Orthodro
12、mic Tachycardia,These 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
13、 atrium to ventricle) 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 Lo
14、cations,Anywhere 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
15、 - White “Mahaim” 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 Ma
16、y confuse physicians 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,Fogo
17、ros, Electrophysiologic 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 B
18、undle branch block 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? (
19、Transseptal procedure 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-excitati
20、on,Fusion of the QRS 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 QR
21、S,Evaluating a preexcited 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 ventricl
22、e being preexcited 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 fu
23、nction and threat 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 tach
24、ycardia and shorten 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 a
25、tria during tachycardia 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 Bed
26、side, 2nd ed,. 1995, 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 verap
27、amil. Should show 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
28、 conduction Indicators 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,
29、perforation, vascular 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
30、 any age, including infancy,Types of AVNRT,Three Main Types Typical; common; usual; slow-fast Atypical; uncommon; unusual; fast-slow Slow-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 reentra
31、nt circuit involves the 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 a
32、nd retrograde up the FP. 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
33、by ablating the SP, because 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): an
34、tegrade fast, retrograde slow -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 fas
35、t pathway. The earliest atrial 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
36、fast pathway and retrograde 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, antegr
37、ade conduction is down some 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
38、 AH & HA intervals will be prolonged.,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 Differenti
39、ated by electrophysiologic properties Exhibits non-uniform anisotropic properties Both Capable of Antegrade and retrograde conduction Exhibits longitudinal dissociation Results in Reentry around, or within, the AVN,Slow and Fast Pathways,Slow Pathway Perinodal tissue possessing conduction properties
40、 of slow depolarization and relatively 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,
41、or equal to, 50 msec in response 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.
42、,Typical A-V Nodal Reentry Retrograde 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 termi
43、nate SVT.,Clinical Cardiac Electrophysiology: techniques and interpretations,2nd. EdLea and Febiger, 1993.page224,Differentiate AVNRT from: AVRT AVNRT Atrial tachycardias PJRT,Differential Diagnosis,Differential Diagnosis,PVC when His bundle is refractory Para-Hisian Pacing Adenosine Administration
44、A-V Wenckebach periodicity or Dissociation 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,P
45、harmacological block,Block AV node 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 lo
46、nger conduct.,Slow Pathway Modification,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,S
47、low Pathway Modification,Inability to reinduce tachycardia Loss of dual AVN physiology Prolongation of AH interval Complete 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 pathway Other 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,
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