Dysrhythmia

Question 1

Features of acute AF?

Answer 1

Irregularly irregular QRS complexes
Absence of P waves
Often tachycardic
chaotic baseline (Atrial flutter)

Question 2

Investigations for acute AF?

Answer 2

ECG
Bloods - serum electrolytes, cardiac markers, TFTs, toxicology screen

TOE - transoesophageal echocardiogram - to exclude ventricular clots (Often present if AF >48hrs)

Question 3

Management of acute AF - if haemodynamically stable, with thrombus present

Answer 3

1st - rate control - beta blocker/NPD CCB - Bisoprolol OR Diltiazem/verapamil
THEN - anticoagulate for 3-4 weeks - LMWH + Warfarin OR DOAC

THEN - cardiovert - DC or Amiodarone/Flecanide

Question 4

Management of AF, with thrombus and Heart failure

Answer 4

1st - rate control - with Digoxin or Amiodarone
THEN - anticoagulate 3-4 weeks
THEN - cardiovert DC or Amiodarone/flecanide

Question 5

Management of AF - haemodynamically stable, without thrombus in LV

Answer 5

CHADVASC 0-1 - rate control with beta blocker/CCB + cardiovert

CHADVASC 2+ - rate control, cardiovert + heparin + Long term anticoagulation

Question 6

Management of haemodynamically unstable acute AF

Answer 6

Do no delay cardioversion to anticoagulate
Bisoprolol or Digoxin if Heart failure
THEN
Cardiovert
Then investigate thrombus and anticoagulate if necessary

Question 7

What is an SVT?

Answer 7

Supraventricular tachycardia
Typically from formation of accessory pathways (AVNRT - av nodal re-entry tachycardia)
Regular, atrial tachycardia
P waves have unusual morphology

Question 8

ECG features of SVT?

Answer 8

Tachycardia >100bpm
Narrow QRS - but with normal ish morphology
Absent P-wave / or inverted (therefore not sinus Tachycardia)
Regular rate/rhythm - therefore not AF

Question 9

Management of SVT?

Answer 9

Vagal manoeuvres
Adenosine - 6mg/IV - after 1-2 mins 12mg/IV - after 1-2 mins 12mg/IV

Max dose 30mg IV

Long term - catheter ablation of accessory pathways

Question 10

ECG features of ventricular tachycardia (VT)?

Answer 10

Regular - therefore not AF/flutter, not VF
Tachycardia - >100bpm
broad complex tachy - QRS complexes look fucked - no p wave visible - therefore not SVT
Might by polymorphic - Torsades de Pointes (TdP)
AV node dissociation

Question 11

Management of VT?

Answer 11

WITHOUT pulse - cardiac arrest - ALS algorithm

WITH pulse -
Amiodarone 300mg IV/20 mins
THEN - Amiodarone 900mg / 24hrs infusion

TdP - Magnesium sulphate
(often hypomagnesemia in TdP)

Question 12

ECG features of ventricular fibrillation (VF)

Answer 12

Irregularly irregular QRS complexes of variable morphology ( therefore not VT, not SVT not AF)

Essentially just looks totally fucked

Question 13

What are the 4H’s and 4T’s, that cause VF

Answer 13

Hypothermia
Hypoxaemia
Hypovolaemia
Hypo/erkalaemia/calcaemia

Tension pneumothorax
Tamponade
Toxins
Thromboembolism

Question 14

What are the shockable vs non-shockable rhythms?

Answer 14

Shockable:
VF
pulseless VT

Non-shockable:
PEA - pulseless electrical activity
Asystole

Question 15

Management of VF according to ALS algorithm?

Answer 15

CPR - 30:2
Shockable - up to 3x shocks
Then give Adrenaline 1:1000 0.5mL
Give Amiodarone 300mg IV
Continue CPR

Question 16

Features of the different types of heart block?

Answer 16

1st degree - Prolonged PR interval (>5 ss)

2nd degree (Mobitz I) - PR gradually lengthens, and then drops a QRS

2nd degree (Mobitz II) - QRS dropped in pattern e.g. 3:1

3rd degree - complete heart block - dissociation of P waves and QRS complexes

Question 17

Management of heart block

Answer 17

Atropine 500mcg IV

If response insufficient or severe HB:

Further Atropine 500mcg IV - Max dose 3mg

Question 18

Clinical features of heart block

Answer 18

Proximal block - bundle of His takes over - ~50bpm

Distal block - severe bradycardia ~30bpm

bradycardia = <60bpm