Differential Diagnoses Of SVT: Common EP Lab Techniques Hongsheng M. Guo, MD Park Nicollet Heart & Vascular Center Minnesota, USA

SVT Ablations at Park Nicollet (2006-2010)

Systematic Approaches Baseline findings Tachycardia Maneuvers during tachycardia History

Baseline Findings Ventricular Preexcitation 15 10 86 3 % AVNRT ORT AT Ventricular Preexcitation 15 10 86 3 Dual AVN Pathways 55 6 8 Decremental VA conduction AP response to para-His pace 18 17 83 <1 AP response to diff RV pace VA Block > 600 ms 11 42 5 VA block with adenosine

HV = -15 ms PPV for ORT=86%

AH Jump PPV for AVNRT=86%

Decremental VA Conduction >99% Nodal Respnse

RV Pacing at 700 ms PPV for ORT, 5%

Adenosine

ParaHisian Pacing

AP Response

ParaHisian Pacing

ParaHisian Pacing Adjust current output (mA) Adjust catheter position Watch morphology subtle change closely

ParaHisian Pacing Schematic representation of response to para-Hisian pacing between conduction over the AV node alone (A), conduction over an accessory pathway alone (B), and conduction over the AV node and accessory pathway combined (C). Source: Heart Rhythm 2005; 2:667-672 (DOI:10.1016/j.hrthm.2005.01.026 )

ParaHisian Pacing: Nodal Response

ParaHisian: AP Response PPV for ORT, 83%

Differential RV Pacing VA Index= VA (basal) – VA (apical) Martinez-Alday, et al Circulation 1994;89:1060

Differential RV Pacing: Nodal Response

Posteroseptal AP Martinez-Alday, et al Circulation 1994;89:1060

Systematic Approaches Baseline findings Tachycardia Maneuvers during tachycardia History

Tachycardia Characteristics % AVNRT ORT AT Septal VA <70 ms 47 >99 <1 Eccentric A activation 31 76 24 SVT terminates with AV block 10 66 34 ↑VA >20 ms w/ BBB 7 100 Development of LBBB 12 4 92 Induction with critical AH 55 91 8 1 SVT CL >500 ms 3 83 17 AV block during SVT 60 40

Septal VA <70 ms Not ORT

Eccentric Atrial Activation Not AVNRT

SVT: What’s the machanism? ORT AVNRT Not sure.

What is this?

Quick Maneuver

SVT: What’s the mechanism? ORT AVNRT Not sure.

Systematic Approaches Baseline findings Tachycardia Maneuvers during tachycardia History

RA Pacing During SVT

LA (CS) Pacing During SVT

RV Pacing During SVT

What is this patient trying to tell you?

SVT Induction

Which Statement is true? VA activation is eccentric. This is likely ORT. AV accessory pathway is ruled out. AV accessory pathway is not ruled out.

His Refractory PVC

His Refractory PVC

RV Pacing During SVT

True or not: Atrial tachycardia is ruled out? A. True. B. False.

RV Pacing

RV Pacing: AT?

Is This AT?

Fusion During Right ORT Fusion with ventricular overdrive pacing during orthodromic reentrant tachycardia in a patient with a right free-wall accessory pathway. Before ventricular overdrive pacing, the ventricles are fully depolarized by the tachycardia wavefront via the AV node. A: Ventricular overdrive pacing results in fusion between the pacing wavefront (black) and the tachycardia wavefront (white with black stippling). With continued pacing there is progressive fusion with increasing amounts of ventricular myocardium depolarized by the pacing wavefront. B: Retrograde limb of the tachycardia eventually is driven by the paced wavefront, and a stable collision point results. This stable point of collision is located below the His bundle and results in constant QRS fusion. Source: Heart Rhythm 2011; 8:2-7 (DOI:10.1016/j.hrthm.2010.09.089 )

Fusion During Left Lateral ORT and AVNRT First beat of stable morphology during ventricular overdrive pacing in a patient with (A) orthodromic reentrant tachycardia and a left lateral accessory pathway (B) atrioventricular nodal reentrant tachycardia (AVNRT). The stable collision point with a left lateral accessory pathway is above the His bundle and results in a fully paced QRS morphology because the pathway is far from the pacing site. Because the ventricles are part of the tachycardia circuit in orthodromic reentrant tachycardia, the tachycardia must be reset coincident with or before the first beat with a stable QRS morphology. In AVNRT, the first beat of stable morphology (= the end of the transition zone) is fully paced but does not reset the tachycardia circuit. The pacing wavefront must first penetrate the His bundle and lower common pathway before it resets the tachycardia circuit. Source: Heart Rhythm 2011; 8:2-7 (DOI:10.1016/j.hrthm.2010.09.089 )

Fusion During ORT A: Orthodromic reentrant tachycardia in a patient with a decrementally conducting septal accessory pathway. Atrial timing is delayed with the first beat of right ventricular pacing diagnostic of orthodromic reentrant tachycardia. The stimulation-to-atrial interval (SA) becomes fixed during the transition zone (TZ), two beats before SM1. B: Atypical atrioventricular nodal reentrant tachycardia. Atrial timing is not altered, and the SA does not become fixed until SM3 and SM4, respectively, well after the end of the TZ. F = fusion between pacing wavefront and tachycardia circuit; SM = beat of stable morphology. Source: Heart Rhythm 2011; 8:2-7 (DOI:10.1016/j.hrthm.2010.09.089 )

Fusion During AVNRT A: Orthodromic reentrant tachycardia in a patient with a decrementally conducting septal accessory pathway. Atrial timing is delayed with the first beat of right ventricular pacing diagnostic of orthodromic reentrant tachycardia. The stimulation-to-atrial interval (SA) becomes fixed during the transition zone (TZ), two beats before SM1. B: Atypical atrioventricular nodal reentrant tachycardia. Atrial timing is not altered, and the SA does not become fixed until SM3 and SM4, respectively, well after the end of the TZ. F = fusion between pacing wavefront and tachycardia circuit; SM = beat of stable morphology. Source: Heart Rhythm 2011; 8:2-7 (DOI:10.1016/j.hrthm.2010.09.089 )

Michaud, G. F. et al. J Am Coll Cardiol 2001;38:1163-1167 Long RP SVT Michaud, G. F. et al. J Am Coll Cardiol 2001;38:1163-1167 Scatterplot showing the mean value {+/-} SD of the stimulus-atrial-ventriculo-atrial (S-A-VA) interval (ms) for patients with either ORT using a septal accessory pathway or atypical AVNRT

Michaud, G. F. et al. J Am Coll Cardiol 2001;38:1163-1167 Long RP SVT Michaud, G. F. et al. J Am Coll Cardiol 2001;38:1163-1167 Scatterplot showing the mean value {+/-} SD of PPI-TCL (ms) for patients with either ORT using a septal accessory pathway or atypical AVNRT

Michaud, G. F. et al. J Am Coll Cardiol 2001;38:1163-1167 RV Is In The SVT Circuit Michaud, G. F. et al. J Am Coll Cardiol 2001;38:1163-1167 Entrainment of orthodromic reciprocating tachycardia (ORT) using a right posteroseptal bypass tract from the right ventricular apex (RVA) at a cycle length of 440 ms

RV Is Not In The SVT Circuit Michaud, G. F. et al. J Am Coll Cardiol 2001;38:1163-1167 Entrainment of atrioventricular node re-entrant tachycardia (AVNRT) from the right ventricular septum (RVS) at a cycle length of 510 ms

A>B>E B A Entrainment Mapping m m TCL=24 hours PPI=24 + 2xm hours A

What is the right diagnosis? Typical AVNRT Atypical AVNRT ORT Atrial tachycardia Not sure

What is the right diagnosis? A. VT B. Atrial tachycardia C. AVNRT D. ORT (right AP) E. ORT (left AP) F. Not Sure

What’s the mechanism? 09705818 A. VT B. Atrial tachycardia C. AVNRT D. ORT (right AP) E. ORT (left AP) F. Not Sure

Irregular AA During SVT

What’s the mechanism? 09705818 AT ORT AVNRT Not Sure

What’s the mechanism? 09705818 AT ORT AVNRT Not Sure

Single diagnostic pacing maneuver for supraventricular tachycardia George D. Veenhuyzen, MD, FHRS, Kelly Coverett, MD, F. Russell Quinn, MRCP, PhD, John L. Sapp, MD, Anne M. Gillis, MD, Robert Sheldon, MD, PhD, Derek V. Exner, MD and L. Brent Mitchell, MD Source: Heart Rhythm 2008; 5:1152-1158 (DOI:10.1016/j.hrthm.2008.04.010 )

Rule-OUT AVNRT ORT AT Septal VA <70 ms X Eccentric A activation X* SVT terminates with AV block SVT terminates by V pcae with no A SVT CL >500 ms AV block during SVT Induction with critical AH SVT persists when V isolated * Typical AVNRT

Rule-IN AVNRT ORT AT Septal VA <70 ms X ± VA increase by >20 ms w/ BBB SVT terminates by V pace during His ERP with no A SVT CL >500 ms True VAAV response

Step-by-step Systemic Approach History Vagal effect Adenosine Baseline Delta waves, or other evidence of AP Dual AVN pathway VA conduction Tachycardia VA: time, sequence BBB Induction AV block Maneuvers His premature RV pacing: VAV or VAAV, PPI-TCL

The Famous Quotation: SVT的消融应精确，优雅，有品味，精美的艺术品。 “SVT ablation should be precise, elegant, and classy, an art work. One should take every opportunity to fully appreciate all aspects before the dragon is killed. Burning while learning certainly does not belong here!” SVT的消融应精确，优雅，有品味，精美的艺术品。 每个人都应该利用一切机会充分欣赏各方面之前，龙被杀害。 燃烧的同时学习当然不属于这里！

Dragon ≠ 中国龙 LOST IN TRANSLANTION!