ECG RoundsECG Rounds

July 22, 2004July 22, 2004

Adam Oster R4Adam Oster R4

14M with Palpitations:14M with Palpitations:

14M with Palpitations14M with Palpitations

14M in sinus14M in sinus

Accessory Pathway Accessory Pathway SyndromesSyndromes WPW one of many accessory pathway WPW one of many accessory pathway

diseasesdiseases Bundle of KentBundle of Kent Classically 3 features…Classically 3 features… Accessory pathway has longer Accessory pathway has longer

refractory period during long cycle refractory period during long cycle lengths (sinus rhythm) lengths (sinus rhythm)

Can conduct faster than the AVNCan conduct faster than the AVN MC Tachycardia is MC Tachycardia is

– orthodromic AVRT (70-80%)orthodromic AVRT (70-80%)

Orthodromic AVRTOrthodromic AVRT

Usually initiated by PACUsually initiated by PAC– Accessory pathway refractoryAccessory pathway refractory– PAC PAC Anterograde conduction Anterograde conduction

down AVN and retrograde up down AVN and retrograde up accessory pathwayaccessory pathway

– Narrow QRSNarrow QRS

AVRT vs AVNRT: AVRT vs AVNRT: Rosen 2002Rosen 2002

AVNRT vs AVRT:AVNRT vs AVRT:Journal of the American College of Cardiology. May, Journal of the American College of Cardiology. May, 2003.2003.

AVNRT vs AVRTAVNRT vs AVRT

N=148 with ECGs both in narrow-N=148 with ECGs both in narrow-complex SVT and in SRcomplex SVT and in SR

Gold standard was Gold standard was electrophysiologic studies electrophysiologic studies followed by catheter ablation if followed by catheter ablation if necessarynecessary

3 blinded EPs reviewing for3 blinded EPs reviewing for apriori apriori ECG findingsECG findings

AVNRT vs AVRTAVNRT vs AVRT

AVNRTAVNRT

AVNRTAVNRT

AVNRT vs AVRTAVNRT vs AVRT

Accuracy = 91%

AVNRTAVNRT

Usefulness of the ST-Usefulness of the ST-Segment in aVRSegment in aVR

American Journal of Cardiology. December, 2003.American Journal of Cardiology. December, 2003. N=338 in PSVTN=338 in PSVT All had EP studiesAll had EP studies

The ST-segment in aVRThe ST-segment in aVR

AVRTAVRT

AVRTAVRT

Usefulness of the ST-Usefulness of the ST-Segment in aVRSegment in aVR ST seg elevation in AVRST seg elevation in AVR

– For AVRTFor AVRT Sens 71%Sens 71% Spec 70%Spec 70% Accuracy 70%Accuracy 70%

AVRTAVRT

AVNRT vs AVRT:AVNRT vs AVRT:Putting it All TogetherPutting it All Together V1V1

– Psudo r’ Psudo r’ think AVNRT think AVNRT Inferior leadsInferior leads

– Psuedo S Psuedo S think AVNRT think AVNRT ST up in AVRST up in AVR

– Think AVRT (but not only)Think AVRT (but not only)

Management Management PrinciplesPrinciples StabilityStability Narrow vs wideNarrow vs wide Regular vs irregularRegular vs irregular

AF/antidromic/WCT

WPW:WPW:Localising the PathwayLocalising the Pathway LOCATION V1 V2 QRS axis left LOCATION V1 V2 QRS axis left

posteroseptal (type A) +ve +ve posteroseptal (type A) +ve +ve left right lateral (type B) -ve -ve left right lateral (type B) -ve -ve left left lateral (type C) +ve +ve left left lateral (type C) +ve +ve inferior (90 degrees) right inferior (90 degrees) right posteroseptal -ve -ve left posteroseptal -ve -ve left anteroseptal -ve -ve normal anteroseptal -ve -ve normal

Anteroseptal pthwy

AxisAxis

Lt lateral pathway