EKG Final Exam Guide 2025: Basic Dysrhythmias Interpretation & Study Tips

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Basic Dysrhythmias & EKG Interpretation FINAL EXAM

PREP 2025/2026 ACCURATE QUESTIONS WITH

CORRECT DETAILED ANSWERS || 100%

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Normal Sinus Rhythm .......Answer.........NSR


Rate: 60-100 bpm


Regularity: Regular


P Waves: Normal


PR Interval: 0.12-0.20 s


QRS Duration: 0.04-0.12 s


QT Duration: 0.36-0.44 s


Sinus Node .......Answer.........Sinus Node Problems:

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The SA node can:


--Fire too slow (Sinus Bradycardia [SB])


--Fire too fast (Sinus Tachycardia [ST])


Sinus Bradycardia (SB) .......Answer.........Rate <60 bpm


Etiology--SA node is depolarizing slower than normal, impulse is

conducted normally


--Normal PR interval and QRS interval


--Once SA node fires, everything else happens normal


Can be normal for super athletes


Sinus Tachycardia (ST) .......Answer.........May be appropriate

response to stress


Rate >100 bpm

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Etiology--SA node is depolarizing faster than normal, impulse is

conducted normally


Remember: it is a response to physical or psychological stress,

not primary arrhythmia


Atrial cells .......Answer.........Atrial Arrhythmias


Atrial cells can:


--Fire occasionally from a focus (Premature Atrial Contractions

[PACS])


--Fire continuously due to a looping re-entrant circuit (Atrial

Flutter)


--Fire continuously from multiple foci OR fire continously due to

multiple micro re-entrant "wavelets" (Atrial Fibrillation)