Tag: metoprolol

AF & tachycardia

AF & tachycardia

Cardiology expert Adele Pope returns with an approach differentiating tachycardia and managing atrial fibrillation. We also discuss ventricular ectopics, bigeminy and peri-operative anticoagulant and anti-platelet adjustment.

Differential

  • Life threatening
    • VT
    • SVT
      • AFib
      • Flutter
  • Common triggers of AFib
    • Post operative state
    • Myocardial infarction
    • Sepsis
    • Anaemia
    • Hypo- or hypervolaemia
    • Pulmonary embolus
    • Electrolyte disturbance
  • Cardiac dysrhythmia
  • Non-cardiac
    • Anemia
    • Anxiety
    • Dehydration
    • Electrolyte imbalance (especially hypokalemia and hypomagnesemia)
    • Fever/ sepsis
    • Hyperthyroidism
    • Hypoglycemia
    • Ischemia
    • Metabolic disorders
    • Pain
    • Poisoning and toxic exposure
    • Pulmonary embolism
    • Respiratory disease (e.g. pneumonia, pneumothroax)
    • Shock
    • Trauma
    • Withdrawal syndromes

Approach

  • ECG and new set of vitals before you arrive
  • Eyeball the patient/ABCs
  • History
    • Old or new tachyarrhythmia?
    • Chest pain
    • SOB
    • Palpitations
    • Exact time of onset of symptoms
    • Cardiac history
      • Prev AF
      • Ischaemic heart disease
      • Valvular disease
      • Hypertension
      • Heart failure
    • ROS
  • Vitals + Examination
    • General inspection + peripheries for perfusion
    • JVP
    • Auscultation
      • Confirm rhythm
      • Valvular dysfunction
    • Wound
    • Calves/leg oedema
  • ECG
    • Narrow complex or wide complex?
      • QRS > 3 squares could be a wide complex tachycardia (call a code)
      • Concordance (V1 – V6 often point in one direction in VT)
      • AV dissociation indicated VT
    • If narrow complex, is it regular or irregular?
      • Irregular is probably AFib
  • Consider investigations
    • FBC, U&E (including Mg), TFT
    • Consider septic workup
    • Consider troponin
  • Management
    • Consider observation
    • 500 mL fluid bolus
    • Metoprolol tartrate 50 mg (not if overloaded or in steroid-dependent asthma)
    • Diltiazem short acting 30 mg as an alternative
  • Documentation
    • Review past notes
    • Current medications – has a dose been missed?
    • Basics (date/time/name/reason for review)
    • Positives and pertinent negatives
    • Impression and differential with justification.
    • Have you eliminated life threatening conditions?
      • Why has this arrhythmia developed?
      • Is there a risk of deterioration?
    • Type of AFib (first episode, paroxysmal, persistent, or permanent)
    • Clear and specific plan
    • Immediate investigations
    • Fluids
    • Electrolytes correction
    • Beta blocker?
    • Anti-arythmic?
    • Anti-coagulation?
    • Consider echo, TOE, CXR, ETT
    • Consider discussion with senior and escalation, especially if called back to patient again.

Concluding remarks

  • Get help early for:
    • Wide complex tachycardia
    • Poor perfusion/hypotension
    • Pulmonary oedema
  • Main triggers are post operative state, myocardial infarction, sepsis and anaemia.
  • AF may be the first sign of a significant problem, so a good review of systems is needed.
  • AF may precipitate cardiac and perfusion problems (ischemia, heart failure, atrial thrombus), so identify patients at risk.
  • Timing:
    • Assume onset of AF to be greater than 48 hours ago unless there is a clear history of onset
    • AF >48 hours needs anticoagulation prior to cardioversion
    • All patients should be anticoagulated for 2 weeks following cardioversion
  • Bigeminy and ectopics
    • Ventricular ectopics are normal. If >50% of ventricle beats are ectopic, consider structural heart disease.
    • Bigeminy is also often normal (two ectopic beats in a row).
    • Obtain a rhythm strip to determine the frequency of ectopics beats.
    • Discuss with cardiology if >50% or recurring trigeminy.

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