Complex SVT with differentiationAdvanced Cardiac Arrhythmia Training Course ( 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 15, 2012 於台北國賓飯店
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%
12-lead ECG fordifferential diagnosis of SVTs (important!)
Retrograde P wave in SVT (Tai CT et al. JACC 1997)
Short RP SVT1. Slow-Fast AVNRT: No apparent retrograde P wave: 50% Pseudo R’ in V1 or pseudo-S in inferior leads: 50% (RP<70 ms)• Orthodromic AVRT: 70 ms<RP<PR The presence of delta wave in NSR.6. AT with PR prolongation: the presence of AV block favors AT.
SVT with Electrical Alternans• Electrical (QRS) alternans during narrow QRS tachycardias is a rate-related phenomenon.• It depends on an abrupt increase to a critical rate.• It is independent of the tachycardia mechanism. (Morady F et al. JACC 1987)
Long RP SVT1. Fast-Slow AVNRT: Positive p wave in V1 and negative p wave in inferior leads.• Are the P waves of SF and FS AVNRT different?4. Orthodromic AVRT using decremental (slow) APs.3. AT with normal PR interval.
PJRT• The arrhythmia was permanent or incessant in 23/49 cases (47%) and paroxysmal in 26/49 (53%).• Eight patients (16%) presented with tachycardia- induced cardiomyopathy (TIC).• The accessory pathway (AP) was located in the right posteroseptal region in 37 cases (76%) and in atypical sites in 12 cases (24%).• Regression of TIC was observed in all cases (8/8) after catheter ablation. (Meiltz A et al. Europace 2006)
Favors AVNRT1. 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)
AVNRT• Antegrade SAVN: AH jump > 50 ms• Continuous curve AVNRT• V induced SF AVNRT• AVNRT with retrograde eccentric activation• Clinically documented, non-inducible AVNRT (Lee SH, et al. AJC 1997)• During 23+/-13 months of follow-up, none of the 16 patients with slow-pathway ablation had recurrence of PSVT.• However, 7 of the 11 patients without ablation had PSVT recurrence at 13+/-14 months of follow-up. (Lin JL et al. JACC 1998)
Definitions• Retrograde FAVN: short VA, HIS earliest-A and no decremental conduction.• Retrograde SAVN: long VA, CSO earliest-A and decremental conduction.• V pacing: long VA interval with jump (>50 ms); A sequence changes from HIS to CSO earliest2. SVT: AH<HA, CSO earliest-A• Retrograde intermediate AVN: Intermediate VA interval, HIS and CSO-A simultaneously, minimal decremental conduction• S-I (AH>HA) or F-I (AH<HA) (Tai CT et al. AJC 1996)
Continuous curve SF AVNRT Induction of AVNRT Induction of AVNRT 18 (Tai CT et al. Circulation 1997)
V Pacing Induced SF AVNRT Retrograde fast Antegrade slow 19 Lee PC et al. J Interv Card Electrophysiol. 2005
SF AVNRT with eccentric A activation 20 (Ong M. et al. IJC 2007)
Favors AVRT1. No decremental conduction during pacing (except slow AP).2. The eccentric atrial activation with short VA interval (>70 ms)4. VA interval increases >30 ms with functional BBB.
His refractory VPC• 35-55 ms before the His deflection.• Advance the following A: AVRT• VPC terminate the SVT without conducting to the atrium: rule out AT, favors AVRT.• VPC from the sites other than RVA: LV: for left side APs RVOT: for septal APs
VPC reset SVT (FS AVNRT) No advance A VA= 140 ms VA= 250 ms Lower common pathway Same retrograde A sequence
VPC reset SVT (AVRT) Advance A 342 342 323 378 His refractory VPC
VPC terminates SVT (AVRT) Without conduction to atrium, R/O AT His refractory VPC, R/O AVNRT
Ventricular Overdrive Pacing (VOP) (10-40 msshorter than tachycardia) during SVT
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.
VOP during SVT (FS AVNRT) A V V V A V AV AV A Same retrograde A sequence Lower common pathway
VOP during SVT (AT) A A V V 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)
Ablation Strategy of AVNRT• Make a correct diagnosis!!!• Ablation of antegrade or retrograde slow AVN• Anatomic approach: PMA• Electrogram approach: 小 A, 大 V (slow potential)• Junctional tachycardia during RF• Mapping during V pacing but ablation during SR (for retrograde SAVN only): ABL-earliest A• How to avoid AV block?• Ablation during A pacing• Avoid ablation during SVT or V pacing.• Quick hand! Quick leg! Quick brain! (You have
Ablation Strategy of AVRT• Make a correct diagnosis!!!• Localization of the APs: 12-lead ECG algorithm and intracardiac recordings.• A-V or V-A fusion or earliest• Antegrade approach: for RT AP• Retrograde approach: for LT AP6. V site (subvalvular): small A, large V, stable ablation catheter7. A site (ante- or retro-grade): larger A, unstable ablation catheter
Test 2 A 57 Y/O male patient had an arrhythmic attack during hospitalization. PSVT with (RBBB) cycle length alternans and a fixed short RP interval Cycle length alternans due to one longer and another shorter PR interval Diagnosis: Orthodromic AVRT with dual AVN physiologyInitiation?
Test 2:RAS1S2 500/380 ms One P with three Q 1. FAVN 2. SAVN 3. AVRT echo
Test 2: Spontaneous Initiation of SVT One P with Two Q Orthodromic AVRT with antegrade FAVN and retrograde LL AP