Flashcards in Arryhthmia Deck (48):
Where do heart impulses arise?
What happens after the impulse arises- describe course of impulse?
It spreads across the atria and goes down through the AV node through bundle of His and across the ventricles
Where can arrhythmias arise?
Different places- atria, AV node or ventricles
What does the P wave show?
Atrial depolarisation in response to SA node triggering
What does the PR interval show?
Delay of AV node to allow filling of ventricles
What does the QRS complex show?
Depolarisation of ventricles, triggers main pumping contractions.
What does the ST segment show?
Beginning of ventricle repolarisation, should be flat
What does the T wave show?
What do you look at when looking at ECGs?
How broad QRS complexes are:
Narrow < 120ms
What is the first thing you need to do if you have a tachycardic patient?
Determine whether they are stable or unstable
What do you do if the patient is unstable with tachycardia?
What are the signs of instability?
Reduced conscious level
Systolic BP <90mmHg
What do you give if a patient has regular narrow complex tachycardia?
What does adenosine do?
Blocks AV node
Where do regular narrow complex tachycardia come from?
Top of heart (supraventricular tachycardia) and if you block the conduction through AV node, you terminate the tachycardia
What usually causes irregular narrow complex tachycardia?
What does it mean if it is broad complex tachycardia?
It is coming from the ventricles
How do you treat broad complex tachycardia?
Amiodarone or shock them
What causes irregularly broad complex tachycardia?
Torsades de pointes
What are delta waves?
Slurred upstroke to QRS complex- caused by accessory pathway- extra pathway that the electrical activity can travel down other than AV node and bundle of His
What type of tachycardia involves accessory pathway?
AV re-entry tachycardia
What are the two most likely causes of regular narrow complex tachycardia?
AV nodal re-entry tachycardia
AV re-entry tachycardia (due to accessory pathway)
What are the short term and long term treatment for both types of regular narrow complex tachycardia?
AV nodal blocking agents (AVNRT)
Class I anti-arrhythmics (AVRT)
What is the main cause of irregular narrow complex tachycardia?
How does atrial fibrillation work?
Electricity arises in very disorganised fashion from atria
A lot of these little fibrillations in atria get conducted down through AV node into the ventricles so you tend to get tachycardia
What is the treatment of AF dependent on?
What do you do if someone with AF is haemodynamically unstable?
What do you do if someone with AF is haemodynamically stable?
What do you give if there is an underlying structural heart disease?
What do you give if there is no underlying structural heart disease?
What else do you do after bringing an AF patient back to sinus rhythm?
Anti-coagulate them as AF is a leading cause of stroke
What is the CHA2DS2-VASc Score?
A score used to estimate risk of having a stroke of someone in atrial fibrillation
C- Congestive heart failure
S- Systemic emboli or previous stroke
Vasc- Vascular disease
At what CHA2DS2-VASc score, should they be anti-coagulated?
What is atrial flutter?
Organised rhythm caused by a small circuit that is usually set up in the right atrium. Can conduct down through AV node into ventricles
What is the key feature of atrial flutter on ECG?
How do you treat atrial flutter?
Same way as atrial fibrillation- need to be anti-coagulated and generally tend to use the same drugs
What are the criteria for cardioverting patients?
Anticoagulated for >3 weeks
Or they present <48 hours from onset of symptoms
Anyone that is haemodynamically stable and has been in AF for >48 hours has to be anticoagulated before they are cardioverted
What forms of rate control drugs are there?
Rate limiting CCBs
For rhythm control, what would you give to young, healthy patients without any underlying structural heart disease?
Flecainide (sodium channel blocker) or propafenone or sotalol
What if sodium channel blockers don't work to control rhythm?
What is the main treatment for rhythm for patients with underlying structural heart disease?
What drugs are most commonly used for rate control?
What drugs are most commonly used for rhythm control?
How do you treat bradycardia due to 3rd degree heart block?
Firstly give atropine
Then external transcutaneous pacing
Definitive treatment- pacemaker
What does it mean if there ST elevation in V1 and V5?
Anterior STEMI (blocked left anterior descending coronary artery)
How do you treat STEMI?
What would you give to someone before they go to the cathlab?
Aspirin and clopidogrel