Relias Dysrhythmia Basic A |35 ECG Rhythm Questions with Verified Answers+Diagrams| A+ScoredPack

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1 Relias Dysrhythmia Basic A 2025-2026 | 35 ECG

Rhythm Questions with Verified Answers + Diagrams |

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QUESTIONA1




Rationale:

TheArhythmAstripApresentedAdisplaysAanAoverallAregularAsinusArhythmAwithAoneAearly,Awide,AandAbizarreAQ
RSAcomplexAthatAinterruptsAtheAnormalApattern.AThisAaberrantAcomplexAisAnotAprecededAbyAaAPAwave,AandAitA
hasAaAdurationAsignificantlyAlongerAthanAtheAsurroundingAQRSAcomplexesA—
AaAhallmarkAfeatureAofAaAprematureAventricularAcontractionA(PVC).




InAnormalAsinusArhythm,AeachAQRSAcomplexAfollowsAaAPAwaveAatAregularAintervals,AandAtheAmorphologyAisA
uniform.AHowever,AinAthisAstrip,AoneAQRSAcomplexAappearsAprematurelyAandAdoesAnotAfollowAtheAsameAshap
eAorAdurationAasAtheAothers,AindicatingAthatAitAoriginatesAfromAtheAventriclesAratherAthanAtheAatria.

, ThisAdistinguishesAtheArhythmAfrom:

 SinusArhythmAwithAPACA(D):APACsAhaveAprematureAPAwavesAfollowedAbyAnormal-
lookingAQRSAcomplexes.AHere,AtheAaberrantAbeatAlacksAaAprecedingAPAwaveAandAisAwide.
 NormalAsinusArhythmA(C):ANormalArhythmAwouldAnotAincludeAprematureAorAectopicAbeats.
 SinusAtachycardiaA(A):AAlthoughAtheAoverallArhythmAisAnotAslow,AtheArateAisAnotAfastAenoughAtoAbeAco
PageA|A nsideredAtachycardiaA(>100Abpm),AandAtheAirregularAbeatAdoesAnotAalignAwithAaAtachycardicApattern.
2
PVCsAareAcommonAandAmayAbeAbenignAorArelatedAtoAunderlyingAcardiacAissues,AespeciallyAifAtheyAoccurAfrequ
ently.ARecognitionAisAkeyAinAtelemetry,Amed-surg,AandAcardiacAstep-
downAsettings.APatientsAmayAexperienceApalpitations,AbutAoftenAnoAsymptomsAareApresent.AIfAsymptomaticAorAf
requent,AfurtherAevaluationAmayAincludeAelectrolyteAmonitoring,AcardiacAenzymes,AandAECG.




RATIONAILE

ThisAECGArhythmAstripAclearlyAdemonstratesAtheAcharacteristicsAofAaAsecond-
degreeAAVAblock,ATypeAI,AalsoAknownAasAMobitzAIAorAWenckebachAphenomenon.AInAthisAtypeAofAblock,Ath
eAPRAintervalAprogressivelyAlengthensAwithAeachAsuccessiveAbeatAuntilAaAPAwaveAisAnotAfollowedAbyAaAQR
SAcomplexA—AthisAisAtheAkeyAdiagnosticAhallmark.

IfAyouAcloselyAobserveAthisAstrip:

 TheAPAwavesAareApresentAandAconsistent.
 TheAPRAintervalsAgetAlongerAandAlonger,AbeatAbyAbeat.
 Eventually,AaAQRSAcomplexAisAdroppedA(you’llAseeAaAPAwaveAthatAisn’tAfollowedAbyAaAQRS),AandAthe
nAtheAcycleArepeats.

ThisAprogressiveAconductionAdelayAoccursAatAtheAlevelAofAtheAAVAnode,AwhichAtemporarilyAfailsAtoAconductAth
eAimpulseAtoAtheAventricles.AAfterAtheAdroppedAbeat,AtheAcycleAresets.

, Here’sAhowAthisArhythmAdiffersAfromAotherAchoices:

 A.A3rdAdegreeAheartAblock:AThisAshowsAcompleteAdissociationAbetweenAatrialAandAventricularAactivity
.AThere’sAnoArelationshipAbetweenAPAwavesAandAQRSA—AwhichAisAnotAtheAcaseAhere.
 C.ASinusAbradycardia:AAAslowAbutAregularArhythmAwithAconsistentAPRAintervalsAandAoneAPAforAeachA
QRSA—Athere’sAnoAdroppedAbeatAorAPRAvariation.
PageA|A  D.ASinusArhythmAwithA1stAdegreeAAVAblock:AThisAwouldAshowAaAconsistentlyAprolongedAPRAinterv
3 alA(>0.20Aseconds),AbutAnoAdroppedAQRSAcomplexes.

MobitzAIAisAoftenAbenignAandAtransient,AespeciallyAinAathletesAorAduringAsleep,AandAmayAnotArequireAtreatmen
tAunlessAsymptomaticA(e.g.,Asyncope,Adizziness).AMonitoringAisAkey,AandAatropineAmayAbeAconsideredAifAsympt
omaticAbradycardiaAisApresent.