Week 4 - Arrhythmia Flashcards
What is atrial fibrillation?
SA node unable to control depolarisation so atria cells contract uncontrolably. av node bombarded by electrical signals all the time.
What is the most common rhythmic disturbance?
atrial fibrillation
What is the presentation of atrial fibrillation and on ecg?
on ecg:
p waves contract all the time - fibrillary activity. QRS are irregular. heart rate may increase or slow down.
What are symptoms of atrial fibrillation?
may be asymptomatic, may have palptations, fatigue, chest pain, dyspnoea
How do you control atrial fibrillation?
either control rate or rhythm.
- rate controlled with b blockers and CCB’s.
- rhythm controlled with flecainide or cardioversion.
What is a large risk with atrial fibrillation?
chance of stroke due to blood pooling in atria - could embolise to carotid arteries
What surgical methods can be used to control atrial fibrillation?
pacemaker, AV node catheter ablation
What is atrial flutter?
circulating electrical impulse around atrium. atrial rate is 250-300bpm - ventricle gets every other impulse due to refractory period, so 150bpm. cause palptations
What are the treatment methods for atrial flutter?
treat underlying cause.
ablate area where flutter circuit goes.
if doesnt want/cant have catheter ablation, control rate with b blockers and CCB’s, with anticoagulants
cardioversion if needed
What are the 3 kinds of supraventricular tachycardia?
- AV node re-entry tachycardia
- atrioventricular re-entry tachycardia through another point
- atrial tachycardia - signal comes from somewhere other than SA node
What is supraventricular tachycardia?
electrical signals re-entering the atrium after going into ventricles, then entering ventricles again,
causes very fast HR - 100bpm and narrow QRS
What is AV node re-entry tachycardia? symptoms too
sudden fast HR of 200+, dyspnoea, dizziness, fainting, pulsations in neck.
there are 2 pathways re-entering atria through AV. signal goes up abnormal pathway and causes contraction.
How do you treat AV node re-entry tachycardia?
- adenosine slows AV conduction.
- Alt. is CCB - verapamil.
- cardioversion if else fails
What is wolf-parkinson-white syndrome?
atrioventricular re-entry tachycardia through ‘bundle of kent’.
How is wolf-parkinson-white syndrome diagnosed?
ECG shows smaller PR interval below 0.2 and longer QRS complex above 0.12.
How is wolf-parkinson-white syndrome treated?
treat with radiofrequency catheter ablasion of second pathway.
What is ventricular fibrillation?
deadly. contracts independent of atrium
What are symptoms of ventricular fibrillation?
palptations, chest pain, breathlessness, dizziness and syncope
How do you investigate ventricular fibrillation?
- bloods for thyroid hormones and electrolytes,
- echocardiogram for detection of structural issues.
- angiography to check for coronary heart disease
- ECG shows broad QRS complexes frequently and rapidly
Why do we investigate ventricular fibrillation with angiography?
MI, ischaemia and myocardial scarring from infarct may cause ventricular fibrillation. checking for cause.
How do you treat and manage ventricular fibrillation?
treat with cardiac arrest protocol, cardioversion or drugs. revascularise patient and reset sinus rhythm
prevent by treating underlying cause, anti-arrhythmic drugs, ICD
Which arrhythmia causes an irregular pulse?
atrial fibrillation
