1. Advanced AVNRT and AVRT
With differentiation
Advanced EP Training
(中華民國心律醫學會)
謝敏雄 醫師
台北醫學大學醫學系副教授
萬芳醫院心臟內科主任
April 24, 2011 於台北國際飯店

2. Supraventricular tachycardia (SVT)
• Etiology: (臺北榮總十三年經驗)
1. AVNRT (n=1452): 50%
Typical (slow-fast) 90%
Atypical (fast-slow) 7%
Variant (intermediate) 9%
2. AVRT (n=1221): 42%
orthodromic (fast AP 90% or
slow AP 10%)
3. AT (n=245): 8%

3. 12-lead ECG for
differential diagnosis
of SVTs (important!)

4. Retrograde P wave in SVT
(Tai CT et al. JACC 1997)

5. Short RP SVT
1. Slow-Fast AVNRT:
No apparent retrograde P wave: 50%
Pseudo R’ in V1 or pseudo-S in inferior
leads: 50%
2. Orthodromic AVRT: 70 ms<RP<PR
The presence of delta wave in NSR.
3. AT with PR prolongation: the presence of
AV block favors AT.

6. S-F AVNRT
Pseudo-R’
Pseudo-S

7. NSR after IV adenosine
No pseudo-R’ and pseudo-S

8. S-F AVNRT
No apparent P wave

9. S-F masked by QRS
P wave
AVNRT

10. S-F AVNRT
Pseudo-R’ and pseudo-S

11. S-F AVNRT
Pseudo-R’ and pseudo-S

12. Orthodromic AVRT
RP>70 ms, favor LL AP

13. MWPW (LL or LAL AP)

14. Long RP SVT
1. Fast-Slow AVNRT:
Positive p wave in V1 and negative p
wave in inferior leads.
2. Orthodromic AVRT using decremental
(slow) APs.
3. AT with normal PR interval.

15. EP study for
differential diagnosis
of SVTs

16. Favors AVNRT
1. The presence of dual AVN physiology:
upper or lower common pathway.
2. The critical prolongation (jump) of AH
interval during the initiation of SVT.
3. The concentric atrial activation:
especially a straight line from ECG-A-V
or A before V (SF AVNRT)

17. AVNRT
• Antegrade SAVN: AH jump > 50 ms
• Continuous curve AVNRT
• Retrograde SAVN:
1.Long VA interval
2.CSO-A earliest.
• Retrograde intermediate AVN:
1.Intermediate VA interval
2.His-A and CSO-A both earlier
• AVNRT with retrograde eccentric
activation

18. Continuous curve AVNRT
(Tai CT et al. Circulation 1997)

19. Initiation of S-F AVNRT
Progressive AH prolongation with jump

20. Lower common of VA interval
Progressive prolongation
pathway
V A V AV AV A

21. AVNRT with eccentric A activation
(Ong M. et al. IJC 2007)

22. Favors AVRT
1. No decremental conduction during
pacing (except slow AP).
2. The eccentric atrial activation with short
VA interval (>70 ms)
3. VA interval increases >30 ms with
functional BBB.

23. LT AP with LBBB
(Josephson ME. P237)

24. Single VPC reset SVT

25. His refractory VPC
• 35-55 ms before the His deflection.
• Advance the following A: AVRT
• VPC without conducting to atrium but
terminate the SVT: rule out AT.
• VPC from the sites other than RVA:
LV: for left side APs
RVOT: for septal APs

26. Ventricular Overdrive
Pacing (VOP) (10-40 ms
shorter than tachycardia)
during SVT

27. VOP entrains the SVT
• VOP could not entrain SVT: AT
• The same atrial activation sequence:
AVNRT or AVRT
The different atrial activation sequence: AT
• The presence of lower common pathway:
AVNRT is more likely.
• The presence of V-A-A-V response: AT
• The presence of V-A-V response: favors
AVNRT or AVRT.

28. VOP during SVT
A A
V
V
AT
1. The retrograde A sequence is different during tachycardia and VOP
2. The presence of V-A-A-V response during VOP
(Veenhuyzen G. et al. PACE 2011)

29. Para-Hisian pacing
Hirao, K. et al. Circulation 1996;94:1027-1035

30. Ablation Strategy of AVNRT
• Make a correct diagnosis!!!
• Ablation of slow or intermediate AVN
1. Anatomic approach: P M A
2. Electrogram approach: small A, large V
3. JT during RF
• How to avoid AV block?
1. ablation during A pacing
2. avoid ablation during SVT or V pacing.
3. You have only one second to stop RF!!!

31. JT under during RF

32. Transient second degree AVB

33. Flat and horizontal Koch’s Triangle
RAO LAO
(Lee PC et al. Curr Opin Cardiol. 2009)

34. Ablation Strategy of AVRT
• Make a correct diagnosis!!!
• Localization of the APs: 12-lead ECG
algorithm and intracardiac recordings.
• Antegrade approach: for RT AP
• Retrograde approach: for LT AP
1. V site (subvalvular): small A, large V, stable
ablation catheter
2. A site (ante- or retro-grade): larger A, unstable
ablation catheter

35. Delta Wave in NSR
(Chiang CE et al. AJC 1996)

36. What’s on the other side
背面是啥米碗糕

37. 這是真的呀

38. Cases Discussion

39. Case 1
VT, PSVT with RBBB or preexcitated tachycardia?

40. RA burst + Isuprel induce SVT
What’s the mechanism of SVT?
AVNRT with Wenkebach AV block then 1:1 conduction

41. S-F AVNRT

42. PSVT with LBBB

43. RVS1S2 induced PSVT
500 270

44. Retrograde-intermediate AVN or AP?
AH=188 ms HA=158 ms

45. VPC terminate SVT: AVN or AP?
347 ms 347 ms 293 ms

46. V pacing during SVT: AVN or AP?
372 ms
350 ms Lower common pathway

47. Mapping retrograde pathway and terminate
SVT (after ablation of antegrade SAVN)

48. RAO LAO
• Ablation of
Antegrade
SAVN
• Ablation of
retrograde
intermediate
AVN

49. Case 2
A 28 Y/O male fireman had recurrent attacks of tachycardia during exercise
RVOT-VT, PSVT with LBBB or Preexcited tachycardia?

50. NSR (Intermittent Preexcitation)
AP location?

51. RVS1S1 350 ms
350

52. RVS1S1 340 ms
Favors AP
Sudden VA block
340

53. RVS1S2 500/310 ms
F-S echo

54. RAS1S2 Induced Tachycardia
Wide QRS complex tachycardia:
VT?, or Preexcitated tachycardia? PSVT with LBBB

55. Wide QRS Tachycardia
TCL= 256 ms

56. Question?
• What’s the mechanism of Wide QRS
complex tachycardia?
VT? Preexcitated tachycardia? PSVT with
LBBB? PSVT with LBBB
• What’s the next step to D.D?

57. VPC terminate tachycardia
Without conduction to A
VPC
Can rule out AT

58. VOP terminate tachycardia
Sudden VA block
The same A sequence
No lower common pathway
AVNRT is not likely

59. Initiation of NQRS tachycardia

60. NQRS Tachycardia
TCL= 244 ms shorter than SVT with LBBB (256 ms)
Favor left side AP?

61. VPC reset SVT
248 233
His refractory VPC

62. Ablation site: RPS

63. Success within 5 seconds
RF on
VA block

64. Immediate recurrence within 5”
RF off

65. Ablation site 1: RPS

66. Success within 3 seconds
VA block

67. Immediate recurrence within 3”

68. Ablation site 2: RPS

69. Ablation site: LMS

70. Success within 5 seconds
VA block

71. Ablation site 3: LMS

72. Transient CAVB

74. PS APs
(Chiang CE et al. Circulation 1996)

75. MS APs
(Chang SL et al. JCE 2005)

76. Small & narrow P wave RA & LA depolarization simultaneously
Test A P wave in the midpoint between the two QRS beats
Diagnosis: SF AVNRT with 2:1 AV block

77. Test
AT with 2:1 AV block?
What’s the next step?

78. Test: VOP 2:1 to 1:1 conduction

79. 謝謝聆聽
敬請指教