Arrhythmia Flashcards
Define Arrhythmia
• abnormal rhythmic of the heart
• issues with generating impulses
What are the types of arrhythmias?
• bradycardia: <60bpm
• tachycardia: 100-150bpm
• flutter: 150-350bpm
• fibrillation: 350bpm
What can disrupt heart rhythm?
• drugs
• inflammation
• trauma
• electrolyte imbalance
• hypoxia/ischaemia
Define Ischaemia?
Reduced flood flow to tissue
• low levels of nutrients and energy
• high levels of waste products (lactic acid)
Define Hypoxia?
Reduced oxygen supply to tissue, regardless of blood flow
Hypoxemia = reduced oxygen supply, leading to hypoxia if severe
What are the 3 mechanism of Arrhythmia?
• inappropriate automaticity
• triggered activity
• re-entry mechanisms
Describe inappropriate automaticity
• usually the cells of the SA have the ability to generate spontaneous AP - (automaticity)
• however, here other cells of the heart, which shouldn’t act as pace makers, generate their own impulses
Describe Triggered activity?
• Early afterdepolarisation - abnormal depolarisation occurs during the repolarisation phase - linked with QT syndrome
• Delayed afterdepolarisation - abnormal depolarisation, which occurs after the repolarisation phase - linked with increases Ca levels
Describe Re-entry mechanism
• electrical impulses travel on a circular pathway
• ectopic depolarisation occurs
ectopic = electrical impulses originating from abnormal location
What is the cause of sinus tachycardia?
• increase sympathetic activity
• decreased parasympathetic activity
• hypotension
• hypothyroidism
What is the treatment of sinus tachycardia?
• CCB’s
• oxygen
• bed rest
What is the cause of sinus bradycardia?
• increased parasympathetic activity
What is the treatment of sinus bradycardia?
Anticholinergics
^ they block the action of acetylcholine (which increases HR)
What is Premature atrial contractions & its treatment?
? = Extra heart beats, originating from atria
Treatment = CCBs or digoxin
What is the mechanism of Atrial flutter
Re-entry
