LONG RP TACHYCARDIA MAPPING AND RF ABLATION

Transcription

1 LONG RP TACHYCARDIA MAPPING AND RF ABLATION Dr. Hayam Eldamanhoury Ain shams univeristy Arrhythmia is a too broad topic SVT is broadly defined as narrow complex ( unless aberrant conduction ) Requires atrial tissue or AVN as an integral part of the arrhythmia substrate 1

2 Subcategorizing SVT (P wave) No P or P in QRS Short RP Long RP Helps to focus the differential diagnosis AVNRT Atrial Flutter AT with first degree AV block Junctional Tachycardia Much less likely AVRT 2

3 Short RP AVRT (87% ) AVNRT (90%) AT with first degree AV conduction delay Junctional Tachycardia 3

4 Long RP Tachycardia 4

5 Long RP Atrial tachycardia Sinus tachycardia AVNRT ( atypical form ) Junctional Tachycardia Uncommonly in AVRT Atrial tachycardia Along the crista terminalis in the right atrium and near the pulmonary veins in the left atrium Less frequently from the coronary sinus, CS os, parahisian region, the appendages Rarely along the tricuspid or mitral annulus The long expected RP relation may not hold 5

6 Atypical AVNRT fast/slow When RP of the fast pathway is shorter than the slow pathway Unidirectio nal block occurs in the slow pathway But activation continues orthodromi cally through the fast pathway Ant. Cond. Curves mostly discontinuo us Ret. St. curves may demonstrat e jump Atypical AVNRT fast / slow The pattern of conduction as will as the incessant nature seen in patients with this tachycardia can also be seen in AVRT due to concealed septal AP with decremental properties 6

7 Reciprocating AVRT using retrograde AP with decrementel conduction PJCT Orthodromic AVRT with a slowly conducting AP most commonly in the posteroseptal area (right side) Almost completely incessant and occurs at a slower rate than other forms of AVRT Does not usually present by sudden onset of rapid palpitations Differentiation Between Atypical AVNRT AT Analysis of conventional intracardiac electrograms during tachycardia Response of arrhythmia to stimulation maneuvers. ORT 7

8 DIFFERENTIATION OF LONG RP TACHYCARDIA Ats originating away from the AV valve annuli or CS ostium, atrial activation is usually inconsistent with AVRT or AVNRT If there is 1:1conduction and atrial activation sequence suggests an annular location differentiation from AVNRT and AVRT can be more difficult. DIFFERENTIATION OF LONG RP TACHYCARDIA Spont. termination of the tachycardia with an atrial depolarization not followed by a ventricular depolarization makes AT unlikely Variable AV conduction with more atrial than ventricular signals favors AT (AVN reentry with block in the lower common pathway) 8

9 Ventricular pacing during tachycardia with 1:1 VA conduction V-A-A-V sequence Diagnosis AT V-A-V sequence Suggests AVNRT or ORT 9

10 10

11 TACHYCARDIA REPRODUCIBLY TERMINATED BY V EXTRA STIMULUS NOT REACHING ATRIUM EXCLUDES AT HIS SYNCHRONOUS VENTRICULAR EXTRA STIMULATION Extra stimulus introduced when His bundle is refractory during tachycardia If atrium to be captured by this extra stimulus it should be an extra nodal capture (through AP ) This may advance or delay subsequent atrial activation in septal decremental pathway 11

12 AVNRT 12

13 ORT ATRIAL TACHYCARDIA 13

14 AVNRT VS ORT MAPPING OF AT Activation mapping Pace mapping 3-D mapping 14

15 TARGET SITES FOR ABLATION Atrial electrogram preceding p wave onset by at least 15 to 60 ms Early fractionated electrograms Perfect pace map Earliest site identified by 3-D mapping 15

16 16

17 MAPPING AND ABLATION OF AVNRT Elimination of retrograde 1:1 slow AV pathway conduction is the primary goal Ablation is directed to the site of the earliest retrograde atrial activation (during tachycardia or V pacing ) Pts with atypical AVNRT frequently lack retrograde conduction over the fast AV nodal pathway 17

18 MAPPING AND ABLATION OF ORT Most AP with decremental conduction are right sided RF current targetting right posteroseptal area or the proximal coronary sinus 18

19 ABLATION OF LEFT SIDED AVNRT Left posterior nodal extension may form the slow pathway Extensive ablation from the right atrium and CS may fail to eliminate slow pathway function Ablation at the posterior mitral annulus At ablation site tachycardia may be reset by LA extra stimulus indicating proximity to reentrant circuit Conclusion Long RP tachycardias are special entity of SVT Differentiation between types of long RP tachycardia may be challenging Different electrocardiograp hic and electrophysiologic al criteria can be used for differentiation In clinical practice, not all maneuvrs can be universally applied and multiple criteria have to be used for differential diagnosis of narrow complex tachycardia with atypical ch.ch. 19

20 Most long RP tachycardias are amenable to RF catheter ablation using different mapping techniques Conclusion In difficult cases of atypical AVNRT ablation from left side should be attempted During RF ablation of atypical AVNRT, goal should be elimination of 1:1 retrograde slow pathway conduction Thank you for Attention 20