Arrhythmias Flashcards
(35 cards)
What are the 4 types of SVT
AF
AVNRT
AVRT
Flutter
Tachycardia what are the adverse features you should exclude?
shock, syncope, MI, heart failure
Describe features AF & causes
Absent p wave, ireffulary irregular
CV causes - IHD, valvular disease
Non CV causes - electrolytes, thyroid, caffeine
Mgmt AF
Rate control - BB, N-D CCB, digoxin (sedentary or HF)
Rhythm control - young, acute onset failed rate control
Elective DCCV + sedation - rule out something at 48 hours.
Flecaininde if severe paroxysmal symptoms - not for structural heart disease
Whether to anticoagulant - what 2 scores
CHADSVASC
HASBLED - falls, alcohol
Irregular pulse + abdo pain
Ischaemic mastery
Irregular pulse + focal neurology
TIA
Irregular pulse + SOB
decompensated HF (not usually PE)
Irregular pulse + painful limb
thrombotic event + ischaemia
Who should you not give BB to?
Asthmatics
What does digoxin toxicity present like?
N + V, blurred/yellow vision, diarrhoea, confusion, hyperkalaemia.
What electrolyte abnormality can digoxin cause?
Hypercalcaemia (risk of digitalis toxicity); hypokalaemia (risk of digitalis toxicity); hypomagnesaemia (risk of digitalis toxicity)
What does digoxin toxicity present like on ECG
Reverse tick (ST section)
Palpitations, normally resolve, clicking sensation, anxiety Hx, narrow complex tachycardia, “pseudo r waves”
AVNRT
What is the mechanism of AVNRT
Ectopic beat reaches AV node as the fast pathway its refractory period - electrical current → retrograde conduction to atria and anterograde into ventricle- p wave after QRS most clear in V1 or V2.
Mgmt of SVT
Vagal manoever - stimulate vagus nerve ↑ parasympathetic drive.
Adenosine - blocks AV node - asystole
Contraindications to adenosine, what to give instead
CI in asthma - give verapamil
Contraindication to carotid sinus massage
Previous stroke
Carotid plague
Wolf parkinson white
Slurred upstroke, shortened PR
Patho of WPW
Accessory pathway, can get retrograde conduction as well as anterograde - can present similar to AVNRT
Atrial flutter - describe
300bpm - saw tooth pathway - reentry circuit in atrium, block in AV node which can be 2:1, 3:1, 4:1, VR rate will either be 150, 100, 75
Mgmt of atrial flutter
Same as AF
How does complete heart block appear on ECG, which type of MI can cause this.
P waves not associated to QRS, common in inferior MI
Causes of AV conduction
IHD, valve disease, medications, aging, fibrosis
