wide complex tachycardia
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DESCRIPTIONJay Green Emergency Medicine Resident, PGY-3 July 24, 2008. Wide Complex Tachycardia. Objectives. Improve our ability to distinguish various WCT. Regular WCT VT (monomorphic) SVT + accessory pathway SVT + BBB SVT with a Na channel blocker. Irregular WCT Polymorphic VT - PowerPoint PPT Presentation
Jay GreenEmergency Medicine Resident, PGY-3July 24, 2008
VT (monomorphic)SVT + accessory pathwaySVT + BBBSVT with a Na channel blocker
Polymorphic VT Torsades de PointesA fib + accessory pathwayA fib + BBBA flutter + variable block + BBBMAT + BBBV Fib
ObjectivesImprove our ability to distinguish various WCT
An Approach to WCT(Is the patient stable or unstable?)
What is the rate?
Is the rhythm regular or irregular?
Are there p waves?Are they related to the QRS?Are they flutter waves?Are the p waves of the same morphology?
Is the QRS morphology consistent?
35M palpitations, lightheadedIrregular WCT, marked variation in QRS morphology, no P waves = AF + WPW
Wolff-Parkinson-White SyndromeMost common ventricular pre-excitation syndrome (bundle of Kent)Triad:Short PR (0.10 sec)Slurred QRS upstroke (delta wave)If WCTRates can approach 300bpmSignificant QRS morphology variation
57M weakness, palpitationsIrregular WCT, consistent QRS morphology, no P waves = AF + RBBB
44M chronic alcoholic, unresponsiveIrregular WCT, varying QRS morphology (undulating) = Torsades de Pointes
47M palpitationsIrregular WCT, consistent QRS morphology, P waves, consistent R-R in groups = A flutter + variable block + RBBB
60M dyspnea, palpitations, hx COPDIrregular WCT, consistent QRS morphology, irregular P waves, inconsistent R-R = MAT + RBBB
Summary Irregular WCT The BadAF + WPWQRS morphology variationRates can approach 300bpmAF + BBBConsistent QRS morphologyRate limited by AV node (usually < 200bpm)Polymorphic VTQRS morphology variation (more chaotic than WPW)Rates consistently rapid (often > 300bpm)Unstable
Summary Irregular WCT The GoodAtrial flutter with variable block + BBBP waves present, some not conductedConsistent QRS morphologyConsistent R-R interval in groupsMAT + BBBIrregular P waves of different morphologyConsistent QRS morphologyInconsistent R-R interval
41M weaknessIrregular wide complex rhythm, peaked T, no P = hyperkalemia
ECG Findings in HyperkalemiaPeaked T-waves (>5mm)QT shorteningST elevationIncreased PR/loss of P waveWidening/Slurring QRSSine wave appearancePotentially mistaken for VT2nd/3rd degree block, VF, asystole
72F SOB, PMH: recent MIRegular WCT, AV dissociation & fusion beat (rhythm strip), capture beat (V1) = VT
61M fever, cough, dyspneaRegular WCT, P waves in V1 = atrial tachycardia + LBBB
VT vs. SVT With AbberancyAngina, MI, CABG, valvular dz, or CHF PPV 95% for VTHemodynamic stability not usefulECG findingsA-V dissociation (discernable in 20%)PPV 100%AV association not helpful (present in 50% VT)Fusion beats, capture beats (discernable in 5-10%)PPV 100%
VT vs. SVT With AbberancyWellens criteriaMany criteriaWellens HJJ, Bar FWHM, Lie KI. The value of the electrocardiogram in the differential diagnosis of a tachycardia with a widened QRS complex. Am J Med 1978;64:27-33.Brugada criteria4-step approach using WellensSN 98.7%, SP 96.5% for VT (original study)Brugada P: A new approach to the differential diagnosis of a regular tachycardia with a wide QRS complex, Circulation 83:1649, 1991.EPs: SN 79-83%, SP 43-70%, K = 0.54-058Isenhour et al. Wide Complex tachycardia: continued evaluation of diagnostic criteria. Academic Emergency Medicine. Jul 2000;7(7): 769-773.Herbert et al. Failure to agree on the electrocardiographic diagnosis of ventricular tachycardia. Ann Emerg Med. 1996;27(1):35-8.
Summary Regular WCTVTFusion beats, capture beats, AV dissociationPMH: cardiac diseaseSVT + BBBAbsence of fusion/capture beats and AV dissociationPre-existing BBBSVT + accessory pathwayAbsence of fusion/capture beats and AV dissociationPre-existing accessory pathwaySVT + Na channel blocker
64F SOB, hypotension, PMH: a fibRegular WCT, bidirectional = Digoxin toxicity
60 M with CP and hypotensionIrregular WCT, rate > 250, inconsistent QRS morphology = AF + WPW
62F palpitationsIrregular WCT, consistent QRS morphology = AF + RBBB
63F syncope, PMH: DM & arthritisHyperkalemia
43M severe palpitationsRegular WCT, no P waves = presumed VT What if old ECG with pre-existing RBBB? = SVT
62F lightheaded, PMH: MI x 2Regular WCT, no P waves = VT
61M palpitations, lightheadedRegular WCT, AV dissociation in V1 & II = VT
74M CP, palpitationsRegular WCT, no P waves, fusion beat = VT Fusion beatRhythm strip
*Irregular WCT, marked variation in QRS morphology = AF + WPW**Irregular WCT, consistent QRS morphology, no P waves = AF + RBBBPVCs, LAD from old MI*Irregular WCT, varying QRS morphology (undulating) = Torsades de Pointes
*Irregular WCT, consistent QRS morphology, P waves, consistent R-R in groups = A flutter + RBBB
*Irregular WCT, consistent QRS morphology, irregular P waves, inconsistent R-R = MAT + RBBB *More likely to deteriorate into unstable rhythms*Less likely to deteriorate into unstable rhythms*PMH: CRFHK (K=8.7)*Dowling*Regular WCT, AV dissociation & fusion beat (rhythm strip), capture beat (V1) = VT
*Regular WCT, P waves in V1 = atrial tachycardia + LBBB (need upright P in II, III, aVF, V1 to say sinus tachy)
*Bottom line, these criteria may help, but remember fusion beats, capture beats, AV dissociation**Irregular WCT, rate > 250, inconsistent QRS morphology = AF + WPWIrregular WCT, consistent QRS morphology = AF + RBBBalso LAD (bifascicular block)*HK (K=8.3)*Regular WCT, no P waves = presumed VT*Regular WCT, AV dissociation in V1 & II = VT *Regular WCT, no P waves = presumed VT; fusion beat on rhythm strip*