University:
Michigan State University
Course:
MED 611 | Cardiology Clerkship
Academic year:

2021
Views:

201

Pages:

3
Author:

esfredint7qo

This is a simplified summary of all ECG abnormalities 1. AV Blocks * **1st Degree AV Block:** * Prolonged PR (>200ms; 1 big square) * Due to β-blocker, CCB, athletes * **2nd Degree (Mobitz I)** * Progressive PR prolongation + dropped QRS * Grouped beats, irregular RR * Similar causes to 1st degree * **2nd Degree (Mobitz II)** * Most progressive, dropped QRS * Often seen with BBB * Usually symp: dizziness, syncope * **3rd Degree AV Block** * Regular RR intervals 2. Bundle Branch Block * If one: Normal P, Prolonged QRS * If both: AV block * Can cause: RBBB: RSR' pattern * LBBB: QS in V1, ST elevation & T inversions * LBBB: LBBB EKG Interpretation... EKGs to know: Sinus Rhythm Atrial Fib/Flutter Ischemia (STEMI, NSTEMI) LBBB, RBBB Vent. fib/Torsades AV Blocks ① Are P waves present? If present: they originate in SA node / Upright in II, III, aVF No P wave, irregular rhythm: A-fib/flutter No P wave, regular rhythm: SVT, PAC, A-tachy, AV block P wave present, irregular rhythm: Sinus rhythm + PAC, A-tachy, AV block No P wave, regular rhythm: SVT, Vent. tachy, A-tachy, AV block ② Regular or Irregular? R-R interval ③ Wide or Narrow QRS Wide: > 3 small boxes / 120 ms Mostly BBB / Vent. tachy Narrow: < 3 Small boxes No BBB, HIS Conduction is normal ④ Check Intervals PR: (Normal: < 1 big box) Prolonged in AV block, Vagal tone, drugs Shortens with symp tone QT: (Normal: < ½ RR interval) Prolonged with ↓ K (hypokalemia), heart failure, sepsis Shortens with ↑ Ca (confusion, constipation) Anti-arrhythmics ⑤ ST Segments T wave Inverted: ischemia, early repolarization, ↓ K Peaked: early ischemia, ↑ K ST depression: Subendocardial ischemia (NSTEMI/UR) ST elevation: Transmural ischemia (STEMI)