1. Resident Survival Skills
Arrhythmias

2. Bradyarrhythmias

3. Sick Sinus Syndrome Bradycardia/Tachycardia syndrome; Brady first
Sxs: Syncope, palpitations, dizziness
Diagnose with ECG or Holter. If inconclusive, need electrophysiologic testing
If asymptomatic, leave alone. If symptomatic, needs pacemaker

4. First Degree AV Block
Delay at the AV node results in prolonged PR interval
PR interval>0.2 sec
Discontinue PR prolonging drugs
EP consult if symptomatic

5. Second Degree AV Block Type I (Wenckebach)
Increasing delay at AV node until a p wave is not conducted
Often comes s/p inferior MI with AV node ischemia
Gradual prolongation of the PR interval before a skipped QRS.
AV Node gets “fatigued” and fails to conduct impulse
No tx if asymptomatic

6. Second Degree AV Block Type II (Mobitz)
PR interval constant
Sudden loss of a QRS wave because p wave was not transmitted beyond AV node.
May be precursor to complete heart block and needs pacing
PACE everyone

7. Third Degree AV Block
Complete heart block where atria and ventricles beat independently AND atria beat faster than ventricles
Must treat with pacemaker.
Urgent EP consult

8. Pacemaker Indications
2nd degree AV block associated with signs
ie. bradycardia, heart failure, and asystole greater than or equal to 3 seconds
2nd degree AV block with neuromuscular diseases
ie. myotonic muscular dystrophy, Erb dystrophy, and peroneal muscular atrophy, even in asymptomatic patients (progression of the block is unpredictable in these patients)
Mobitz II 2nd degree AV block with wide QRS complexes
Asymptomatic Mobitz I 2nd degree AV block with the block at intra- or infra-His level found on EP testing (level II recommendation)

9. Tachyarrhythmias

10. AVNRT
Most common cause of SVT, most common cause of palpitations in structurally normal hearts
Paroxysmal, spontaneous or induced
Regular rhythm, classic appearance = no P waves
Responds to vagal maneuvers, adenosine

11. Atrial Flutter Flutter waves = “sawtooth pattern”
Seen best II, III, aVF
Conduction 2:1, 3:1, 4:1, variable (rarely 1:1)
Regular rhythm, doesn’t cardiovert with vagal maneuvers/adenosine
Variable conduction may mimic A fib

12. Atrial Fibrillation Most common sustained arrhythmia
Irregularly irregular rhythm
No P waves, fibrillatory waves may be present

13. Multifocal Atrial Tachycardia
Rapid, irregular atrial rhythm from multiple ectopic foci within atria
At least 3 different P wave morphologies (not PACs)
Most commonly with severe COPD or CHF, poor prognostic sign
Resolves with treatment of underlying disorder