Lecture Notes on Arrhythmias

Introduction

• Presented by Tom from zerofinals.com
• Focus on arrhythmias, with resources available at zerofinals.com/arrhythmias
• Based on Resuscitation Council UK guidelines 2021
• Importance of attending courses, following guidelines, and involving seniors in patient treatment

Cardiac Arrest Rhythms

• Types: Shockable and Non-shockable
  • Shockable: Ventricular tachycardia and ventricular fibrillation
  • Non-shockable: Asystole and Pulseless Electrical Activity (PEA)

Narrow Complex Tachycardia

• Definition: Fast heart rate with QRS complex < 0.12 seconds
• Differentials:
  • Sinus tachycardia (treat underlying cause)
  • Supraventricular tachycardia (vagal maneuvers, adenosine)
  • Atrial fibrillation (rate or rhythm control)
  • Atrial flutter (similar treatment as atrial fibrillation)
• Life-threatening features: Treated with synchronized DC cardioversion under sedation or general anesthetic; IV amiodarone if shocks are unsuccessful

Broad Complex Tachycardia

• Definition: QRS complex > 0.12 seconds
• Groups:
  • Ventricular tachycardia or unknown cause (IV amiodarone)
  • Polymorphic ventricular tachycardia (IV magnesium)
  • Atrial fibrillation with bundle branch block (treated as atrial fibrillation)
  • Supraventricular tachycardia with bundle branch block (treated as supraventricular tachycardia)

Atrial Flutter

• Cause: Reentrant rhythm in atrium
• ECG Feature: Sawtooth pattern
• Treatment: Similar to atrial fibrillation, including anticoagulation and radiofrequency ablation

Prolonged QT Interval

• Definition: QT interval > 440 ms in men, > 460 ms in women
• Causes: Long QT syndrome, medications, electrolyte imbalances
• Management: Avoid prolonging meds, correct electrolytes, use beta-blockers, pacemakers
• Acute management of Torsades de Pointes: Correct underlying issues, magnesium infusion

Ventricular Ectopics

• Features: Premature ventricular beats, common in all ages
• Management: Reassurance for healthy individuals, beta-blockers for symptoms

Heart Block

• First Degree: Delayed conduction, every P wave followed by QRS
• Second Degree:
  • Mobitz Type 1 (Wenckebach): Progressive PR interval lengthening
  • Mobitz Type 2: Intermittent absence of QRS
• Third Degree (Complete): No relation between P waves and QRS, risk of asystole

Bradycardia

• Definition: Heart rate < 60 bpm
• Causes: Medications, heart block, sick sinus syndrome
• Management: Atropine, pacing, permanent pacemaker

Conclusion

• Emphasized the importance of testing knowledge for long-term retention (testing effect)
• Zero to Finals offers resources for studying and testing knowledge
• Encouragement to utilize flashcards and practice questions available on the member site