bananas's version from 2015-05-17 03:06

Basic ECG

Question Answer
What's the rate?1 big box:300 BPM, 2:150, 3:100, 4:75, 5:60, 6:50
1500 / small squares
What is sinus arrhythmia?Normal phenomenon. Heart rate increases with inspiration due to increased venous return!
Is it sinus?P wave! Upright in I/II and inverted in aVR
What is the P wave?Atrial depolarization
Normal P wave interval?<2.5 small squares (110 ms)
What is the PR interval?AV propagation
Normal PR interval3-5 small squares (120-200 ms)
What is QRS?Ventricular depolarization
Normal QRS<3 small squares (120 ms)
What is QT?Ventricular repolarization
Normal QT interval11 small squares (<440 ms)
What can cause a narrow QRS?(QRS <120 ms) Sinus rhythm, ectopic, SVT, junctional rhythm
What can cause a broad QRS?(QRS >120 ms) Premature ventricular complex (PVC), V-tachycardia, Bundle branch block
Normal axis+I +II [normal people stand upright]
Left axis+I -II [left people don't see eye to eye]
Right axis-I +II [right people always meet]
What can cause a left axis deviation?Inferior wall MI, LBBB, LAFB, LVH
What can cause right axis deviation?Right heart strain (pulmonary embolism), RBBB, LPFB, RVH

Try to decipher these blurry ECG's!

Question Answer
Atrial Fibrillation. Irregularly irregular, No P waves, 100-180 BPM.
3rd degree heart block (complete)
2nd degree heart block (Mobitz II) Dropped beats that is not preceded by a longer PR interval.
Atrial flutter. Sawtooth pattern. 300+ BPM.
1st degree heart block. Long PR interval >200 ms
2nd degree heart block (Mobitz I). PR gets Longer, longer, longer, DROP -- that's a case of Wenckebach!
Ventricular fibrillation. Complete chaos.
Wolff Parkinson White. Delta wave!
Premature Ventricular contraction (PVC). Early, wide QRS (>160).
Supraventricular tachycardia. Narrow QRS, Buried P wave, 140-280 BPM
Monomorphic ventricular tachycardia. >3 ventricular complexes with wide QRS. REgular rate and rhythm.
Torsades de Pointes. Wide QRS with changing amplitude.


Question Answer
Most common arrhythmia?Atrial fibrillation
Atrial fibrillationIrregularly irregular. No P-waves. 100-180 BPM.
Causes of atrial fibrillationHTN, CAD, ARF, HF.
How do you treat acute atrial fibrillation?<48 hours: synchronized cardioversion (low risk of embolism)
How do you treat chronic atrial fibrillation? >48 hoursAnticoagulate (Warfarin+Heparin), Rate control (Beta blocker, CCB, Digoxin), Rhythm control (Antiarrhythmics 1C or III)
Atrial flutterSawtooth flutter. ~300 BPM. Regular rhythm.
How do you treat atrial flutter?catheter ablation
Ventricular fibrillationComplete chaos. Broad complex. Electrical activity of a dying ventricle.
How do you treat ventricular fibrillation?Defibrillate! (no cardioversion)
Supraventricular tachycardia (SVT)200+ BPM, Narrow QRS. Buried P wave. [Rapid rhythm above the AV node due to re-entry or automaticity)
How do you treat supraventricular tachycardia?Adenosine: blocks AV re-entry.
Premature ventricular contractions (PVC)Caused by microinjury to purkinje.
Bigeminy1 PVC per 1 beat.
Trigeminy1 PVC per 2 beats.
Ventricular escapefailure of SA/AV node signal so the ventricle conducts itself. No P wave, <30 BPM, Wide QRS.
Junctional escapeIndependent AV node. Narrow RS <.02
Monomorphic ventricular tachycardiaWide QRS, Regular rhythm, independent P wave.
What is can cause 1st degree heart block?Borrelia Burgdorferi (lyme disease)
2nd degree heart block, Mobitz type IPR gets longer longer longer DROP, that's a case of wenckebach! Typically asymptomatic.
2nd degree heart block, Mobitz type IIDropped beats without PR changes. Can progress to 3rd degree.
How do you treat Mobitz type IIPacemaker
3rd degree heart blockAtria and ventricles are completely independent due to absence of AV conduction.
What can cause 3rd degree heart block?Lyme disease.
How do you treat 3rd degree heart block?Pacemaker.
Wolff-Parkinson White syndromeCongenital accessory pathway. Delta waves! Short PR interval *kisses* QRS.
What accessory pathway is often present in WPW?Bundle of Kent
How do you treat WPWProcainamide or Amiodarone.
Torsades de pointesPolymorphic ventricular tachycardia. Twisting ribbon. Due to decreased Mg+ or K+
Which drugs induce Torsades de Pointes?Prolong QT: anti-Arrhythmics (Ia, III), anti-Biotics (Macrolides, chloroquine), Anti-Cychotics (haloperidol and Risperidone), anti-Depressants (TCA's), -Navirs, Methadone [ABCD HIV and Meth]
How do you treat Torsades de pointes?Magnesium sulfide.
Paroxysmal Supraventricular Tachycardia (PSVT)re-entry impulse via AV node
What's a treatment option for PSVT?Carotid sinus massage: stimulate baroreflex to increase parasympathetic tone to slow AV node firing
Which congenital defects predispose to Torsades de Pointes?Increased QT: Jervell and Lange-Nielson

Localize an MI

Question Answer
lead Ilateral (LCX)
lead IIinferior (RCA)
lead IIIinferior (RCA)
aVLlateral (LCX)
aVFinferior (RCA)
V1septal (LAD)
V2septal (LAD)
V3anterior (LAD)
V4anterior (LAD)
V5lateral (LCX)
V6lateral (LCX)
inferior wallII, III, aVF (RCA)
septal wallV1, V2 (LAD)
anteroseptalV1, V2, V3, V4 (LAD)
lateral wallI, aVL, V5, V6 (LCX)
RVR leads V4R, V5R, V6R
posterior wall V7, V8, V9
what does an ST depression indicate?Ischemia! subendocardial occlusion (mural, not complete!)
what does an ST elevation indicate?full occlusion. MI. Acute injury happening right now!
what does a Q wave indicate?Infarct. Dead tissue. Time INDETERMINANT.
how can you tell that an MI has moved on from the hyperacute phase?ST elevation diminishes, and the T wave INVERSION!