Arrhythmias

Question 1

narrow complex tachycardia definition

Answer 1

rate >100bpm, QRS complex duration <120ms

Question 2

DDx narrow c tachy

Answer 2

sinus tachy, SVT, AF, atrial flutter, atrial tachy

Question 3

management narrow c tachy

Answer 3

DC cardioversion; vagal manoeuvres (valsalva, carotid sinus massage)- increase AV block; adenosine (transient AV block)

Question 4

Wolff Parkinson White pathophysiology

Answer 4

congenital accessory conduction pathway between atria and ventricles. ventricles contract prematurely

Question 5

WPW ecg

Answer 5

short PR interval, wide QRS- slurred upstroke/ delta wave, ST-T changes

Question 6

WPW presentation and treatment

Answer 6

SVT which may be due to AVRT (atrioventricular re-entrant tachycardia); pre excited AF; pre excited atrial flutter. electrophysiology and ablation

Question 7

broad complex tachycardia definition

Answer 7

rate >100 bpm, QRS >120ms (3 small squares)

Question 8

DDx broad c tachy

Answer 8

VT, SVT with aberrant conduction

Question 9

diagnosis broad c tachy

Answer 9

lack of response to adenosine; +ve concordance QRS in chest leads; left axis deviation; 2:1 or 3:1 AV block; fusion or capture beats

Question 10

what is concordance

Answer 10

QRS complexes all positive or all negative

Question 11

what are fusion beats

Answer 11

normal beat fuses with VT complex

Question 12

what are capture beats

Answer 12

normal QRS between abnormal beats

Question 13

management VF or pulseless VT

Answer 13

DC shock

Question 14

management stable VT

Answer 14

O2, IV access for tests, ECG, ABG, amiodarone, magnesium sulphate, DC shock, implant ICD (defibrillators), ablation

Question 15

what is the commonest post MI arrhythmia

Answer 15

ventricular ectopics (also seen in health). suggest electrical instability. consider amiodarone or observe

Question 16

what are Torsades de Pointes

Answer 16

looks like VF but is VT with varying axis. increased QT interval (a side effect of antiarrhythmics). treat- MgS

Question 17

what criteria can be used to distinguish SVT from VT

Answer 17

brugada criteria

Question 18

rate of AF

Answer 18

300-600 bpm

Question 19

how much does cardiac output drop by in AF and why

Answer 19

10-20% as ventricles aren’t primed reliably by the atria, due to the AV node responding intermittently and so an irregular ventricular rate

Question 20

causes of AF

Answer 20

heart failure/ischaemia, hypertension, MI, PE, MV disease, pneumonia, hyperthyroidism, caffeine, alcohol, post op, decr K+, decr Mg2+. rare- cardiomyopathy, constrictive pericarditis, endocarditis

Question 21

symptoms AF

Answer 21

asymptomatic, chest pain, palps, dyspnoea, faintness

Question 22

signs AF

Answer 22

irregularly irreg pulse, apical pulse rate greater than radial, 1st heart sound variable intensity, signs LVF

Question 23

tests AF

Answer 23

ecg- absent p waves, irregular QRS. blood- u&e, cardiac enzymes, thyroid function. echo- left atrial enlargement, poor LV function

Question 24

acute AF treat

Answer 24

O2, U&E, emergency cardioversion; amiodarone. control ventricular rate- verapamil, bisoprolol, 2nd line digoxin, amiodarone. LMWH

Question 25

chronic AF treat

Answer 25

rate control, rhythm control, anticoagulation

Question 26

rate control AF

Answer 26

B blocker or rate limiting Ca blocker 1st line. then digoxin then amiodarone.

Question 27

don't give B blockers with what drugs and why

Answer 27

diltiazem or verapamil- can cause bradycardia

Question 28

rhythm control AF

Answer 28

sotalol, amiodarone. fleicanide- pharm cardioversion if no structural heart disease, amiodarone is there is. AV node ablation, pacing etc.

Question 29

paroxysmal AF

Answer 29

pill in the pocket- sotalol and flecainide.

Question 30

atrial flutter- ecg

Answer 30

cont atrial depol around 300/min. sawtooth baseline +/- 2:1 AV block.

Question 31

atrial flutter can be revealed by

Answer 31

carotid sinus massage, IV adenosine- transiently block AV node may unmask flutter waves.

Question 32

treatment atrial flutter

Answer 32

cardioversion- anticoag before; amiodarone, control rate. b blocker preferred.

Question 33

anticoag and acute AF

Answer 33

heparin until full risk emboli. warfarin if risk emboli high. no anticoag if stable sinus rhythm

Question 34

anticoag and chronic AF

Answer 34

warfarin aim for INR 2-3. aspirin if CI to warfarin. dabigatran- direct thrombin inhibitor.

Question 35

what is sick sinus syndrome

Answer 35

sinus node dysfunction causing brady +- arrest; SA block or SVT alternating with brady/asystole. AF and thromboembolism may occur

Question 36

bradycardia- if rate is below what, give which drug

Answer 36

<40 bpm, give atropine. if necessary- temp pacing wire, isoprenaline infusion or external cardiac pacing.