Determine the rhythm of the following ECGs. Assume every patient is presenting with generalized weakness, dizziness and chest pain.
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ECG 1 (📷)
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- Yes (see lead II, III, avF)
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- Yes
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- Yes appears so
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- Yes.
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- Yes
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- This is likely a sinus rhythm, specifically sinus tachycardia
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- This is sinus tachycardia with a rate close to 120
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ECG 2 (📷 )
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- Yes
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- Yes
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- No
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- No
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- No. There appear more P waves than qrs complexes.
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- Yes
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- This is not a sinus rhythm
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- There appears to be no relationship between the p waves and qrs complexes which confirms av dissociation or 3rd degree av block.
- Some key findings:
- Regular P waves at their own intrinsic rate (~70 bpm).
- Regular wide QRS complexes at a slower intrinsic ventricular escape rhythm (~30–40 bpm). Wide QRS complexes indicate a ventricular origin of pacing (outside the normal his purkinje conduction pathways).
- Lack of any PR interval consistency.
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ECG 3 (📷)
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- Yes in V3
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- in V3 Yes, but can’t tell anywhere else
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- Unable to determine
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- Yes in V3 but unable to determine in other leads
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- Unsure
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- Sinus rhythm cannot be determined here
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- The rhythm is a bizarre looking, regular and very wide complex rhythm with a rate 60-70, consistent with idioventricular rhythm
- Bizarrre appearance + idioventricular rhythm is hyperkalemia until proven otherwise.
- This is also called sine wave. In hyperkalemia, atrial conduction is suppressed and T waves / QRS complexes fuse together creating wide and bizarre complexes.
- Since there are p waves in V3, this could be also be sinus rhythm with very wide QRS
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ECG 4 (📷)
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- No, distinct P waves are not visible in the provided ECG, indicating an absence of organized atrial activity.
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- Does not apply
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- Does not apply
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- Does not apply
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- Does not apply
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- No, this is not sinus rhythm
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- Ventricular escape rhythm at < 20 bpm vs. ventricular escape beats as indicated ny
- Wide QRS complexes consistent with ventricular origin
- No atrial activity
- Slow rate
- The differential diagnosis can be hyperkalemia, complete heart block, drug toxicity. In this case the patient had a K ≥ 7.5 meQ/L. Note the peaked T waves in V1-V3
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ECG 5 (📷)
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- No distinct P waves
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- Does not apply
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- Does not apply
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- Does not apply
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- Does not apply
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- This is not sinus rhythm
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- Ventricularly-paced rhythm
- Pacer spikes preceding each wide QRS complex
- No atrial beats
- This may be a biventricularly paced as some leads have 2 pacer spikes before each QR complex
- W/ superimposed runs of multifocal PVCS vs. polymorphic VT
- See wide qrs complexes with different morphologies that are not triggered by pacemaker
- This is BAD
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ECG 6 (📷)
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- No
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- Does not apply
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- Does not apply
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- Does not apply
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- Does not apply
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- This is not sinus
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- Polymorphic VT specifically Torsades de Pointes with a rate close 150-200
- This is a irregular wide complex tachycardia with QRS complexes that vary in morphology, a hallmark of polymorphic VT.
- The QRS complexes appear to "twist" around the baseline, with amplitudes that progressively increase and decrease in a cyclical pattern (see V1 and V2 rhythm leads) This is characteristic of Torsades de Pointes.
- The rhythm terminated shortly after starting a Mag transfusion and the patient’s K was found to be 2.7 meQ/L. A repeat ECG is below. What’s the QTc?
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This post is for education and not medical advice.