Arrhythmia

• Bradycardia


  Heart rate <60 bpm
• Symptoms of bradycardia


  • Syncope/pre-syncope
  • Light headedness
  • Weakness
  • Fatigue
  • Dizziness
• Main causes of bradycardia


  • Drugs
  • Ischemia
  • Electrolytes
• If you don't address the causes of bradycardia, your patient can DIE
• Other causes of bradycardia

  • Physiological (athletes, while sleeping)
  • Autonomic related (cough syncope, micturition syncope, carotid hypersensitivity)
  • Hypo-thyroidism
  • Hypo-thermia
  • Fish Ciguatera poisoning
  • Drugs (β blockers, calcium channel blockers, digoxin, organophosphates)
• Cardiac causes of bradycardia


  • SA node dysfunction (sinus bradycardia, sinus pause/arrest)
  • AV node dysfunction (first degree heart block, second degree heart block (Wenckebach, Mobitz type 2), third degree heart block (complete))
• On an ECG, we pay particular attention to p waves, PR interval and QRS complex
• First degree heart block

  Prolonged PR interval
• Second degree heart block (Wenckebach or Mobitz Type 1)

  Progressive prolongation of PR interval followed by a dropped QRS complex
• Second degree heart block (Mobitz Type II)

  Constant PR interval followed by a dropped QRS complex, QRS complexes appear in clumps, more likely to cause hemodynamic compromise and progress to complete heart block than Mobitz 1, needs pacemaker
• Third degree heart block

  No relationship between P waves and QRS complexes, needs pacemaker
• Management of bradycardia


  1. Assess if patient is stable or unstable

  2. Seek and treat reversible causes

  3. Monitor the patient

  4. Provide O2 for hypoxia

  5. Address ischemia and hypotension

  6. Identify and treat any underlying systemic conditions e.g. electrolyte disturbances
• First line medication for bradycardia

  • Atropine (0.6mg, maximum of 3mg)
• Second line medications for bradycardia

  • Isoprenaline infusion
  • Adrenaline infusion
• Life-threatening causes of bradycardia

  • Hypoxia
  • Heart failure
  • Severe lung diseases
• Approach to treatment of bradycardia

  1. Medical management (medications like pacing agents, vasodilators, inotropes)

  2. Lifestyle changes (adopting healthy lifestyle, reducing stress)

  3. Mechanical assist devices (cardiac pacemakers, defibrillators)
• If the causes of bradycardia are treatable, targeting them is the primary approach used to manage the condition
• Tachycardia


  Rapid heart rate
• Approach to tachycardia

  1. Don't panic

  2. Ask yourself: narrow or wide, regular or irregular, presence/absence of P waves, timing of P waves relative to QRS complex

  3. Assess condition of patient (stable or unstable)
• Amiodarone


  A class-III antiarrhythmic drug that works by blocking sodium channels, reducing depolarization rate and decreasing heart rate. It also acts on calcium channels to further slow depolarization and prolong repolarization.
• Severe lung diseases


  Certain severe lung diseases, such as COPD or pneumonia, can cause a lack of oxygen in the body and lead to bradycardia
• Ventricular tachycardia


  Ectopic cells within the ventricles stimulating the heart to contract
• Causes of ventricular tachycardia


  • Myocardial muscle deterioration
  • Drug stimulation
• Symptoms of Unstable ventricular tachycardia

  Change in mental status or loss of consciousness
• Managing stable ventricular tachycardia


  Antiarrhythmic medications- Amiodarone 300mg IV over 10-20 mins, then 900mg over 24 hrs
• Managing unstable ventricular tachycardia


  Immediate cardioversion
• What to do after converting ventricular tachycardia to a sinus rhythm

  Administer an antiarrhythmic infusion- Amiodarone 300mg IV over 10-20mins, then 900mg over 24 hrs
• Apply the management principles of ventricular tachyarrythmias

  1. Assessment

  2. Stabilization

  3. Medical management

  4. Cardioversion for severe tachycardia
• Assessment


  The first step is to assess the patient's condition and the situation. This includes monitoring vital signs and performing a thorough physical examination.
• Stabilization

  Stabilizing the patient includes providing oxygen, maintaining airway clearance, and controlling bleeding, if any.
• Medical management of VT

  Medical management involves giving medications like anti arrhythmic drugs, vasodilators, sedatives, and electrolytes.
• DC Cardioversion


  In case of severe tachyarrhythmias.