Cardiology Flashcards
Causes of bradycardia?
Sick sinus syndrome
Hypothyroidism
Cushing reflex
Medications
BBB
Anterior/ inferior MI
What is sick sinus syndrome?
Degenerative sclerosis of conductive system needing pacemaker
What are the adverse signs of bradycardia?
Shock
Syncope
Heart Failure
Myocardial Ischaemia
Management of bradycardia with adverse features?
Atropine 500mcg IV every 3-5 mins up to 3mg
How does atropine work?
Inputs vagal input
Next steps is atropine 3mg doesnt work in bradycardia with adverse features?
Transcutaneous pacing
Adrenaline 2-10 mcg IV
Isoprenaline 5mcg IV
Transvenous pacing
How does transcutaneous pacing work?
Defib and sedation with electrical capture (QRS) and mechanical capture (pulse)
Bradycardias with risk of asystole?
Mobitz Type 2
Complete heart block
Previous asystole
Ventricular pause >3s
Treatment of bradycardia with risk of asystole?
Atropine 500mcg IV every 3-5 mins til 3mg
Reversal agent in BB/CCB overdose?
Glucagon
Causes of heart block (AV block)?
Idiopathic sclerosis
High vagal tone athletes
Inferior MI
Hyperkalaemia
SLE
Drugs
First degree heart block?
PR prolongation but no dropping of QRS. PR >5ss / 200ms
What is Mobitz Type 1 heart block/ Wenckebach?
Prolonging PR interval til one drops
What is Mobtiz type 2 heart block?
Dropping of QRS every 3:1/4:1 often symptomatic and requires pacemaker
What is third degree heart block?
Complete heart block with no association with atria and ventricles. Urgent pacemaker due to risk of asystole and VT.
Clinical signs of complete heart block?
Cannon waves JVP
Variable intensity S1
Wide pulse pressure
Indications for permanent transvenous pacing?
Complete heart block
Mobitz Type 2
Symptomatic Mobitz 1
Symptomatic Sick Sinus Syndrome
Symptomatic asystole pause >3s
Asymptomatic asystolic pause >6s
Permanent brady following MI anterior most common
Cardiac resynchronisation therapy
What is cardiac resynchronisation therapy?
In severe HF (EF <35%) and symptomatic despite 3 months optimal medical management needs biventricular pacemaker.
If pacemaker used as secondary prevention how long should they not drive for?
6 months
SVT vs sinus tachy?
SVT has no P waves and starts suddenly and will continue at this rate without variation til stops
Regular narrow complex tachycardias include?
Sinus tachycardia
Atrial flutter
AVRT
AVNRT
Junctional tachycardia
AVRT caused by?
Accessory pathway e.g., WPW
What is Multifocal atrial tachycardia?
Autonomous atrial cells acting as SAN most commonly in severe COPD
Management of Tachycardia with adverse features (shock, syncope, HF, myocardial ischaemia)?
Synchronised DC cardioversion up to X3