8/12/16 Interactive Cases in General Medicine 6

Question 1

What is the difference between sinus tachycardia and supraventricular tachycardia?

Answer 1

SVT is regular, has no p-waves and is a narrow complex tachycardia

Question 2

What are the 2 types of SVT and what are the differences between them? What is the underlying cause?

Answer 2

AVNRT (nodal)
AVRT (accessory bundle)

Underlying cause is a re-entry pathway either in the node AVNRT or in an accessory pathway AVRT

Question 3

What is the condition in which AVRT occurs due to an accessory pathway? What is shown on the ECG at rest and then in SVT?

Answer 3

Wolff-Parkinson-White syndrome. At rest, there is a short PR-interval, slurred upstroke delta wave. When in SVT, no p waves and narrow complex tachycardia

Question 4

What drug is given to differentiate SVT causes (AVRT/AVNRT)?

Answer 4

Adenosine

Question 5

P waves, regular tachy

Answer 5

Sinus tachycardia

Question 6

No P waves, narrow complex

Answer 6

SVT

Question 7

No P waves, irregular

Answer 7

AF

Question 8

Classify the causes of AF

Answer 8

1. Metabolic: thyrotoxicosis, alcohol
2. Heart: muscle (IHD, HTN, cardiomyopathy), valve (MS/MR), pericardium (pericarditis)
3. Lung: PE, pneumonia, cancer

Question 9

What is VT?

Answer 9

Ventricular tachycardia, broad complex, regular tachycardia. Can be caused by ischaemia, electrolyte imbalance, long QT

Question 10

How is SVT managed?

Answer 10

Rhythm control: if haemodynamically unstable DC cardioversion. If haemodynamically stable, vagal manoeuvres, give adenosine IV with a cardiac monitor (asthma is a relative contraindication).

Question 11

How is VT managed?

Answer 11

If haemodynamically compromised, pulseless VT, defibrillate

If haemodynamically stable, give IV amiodarone, treat cause, consider ICD

Question 12

How if VF managed?

Answer 12

Defibrillation

Question 13

How is AF managed?

Answer 13

If >48h since onset of AF, anticoagulant for 3-4 weeks before cardioversion as this can dislodge the clot and cause a stroke
Rhythm control: DC cardioversion/flecainide
Rate control: beta blocker/digoxin
Complication control: warfarin/rivaroxaban

Question 14

How is LVH diagnosed by ECG?

Answer 14

Deep S V1/2
Tall R in V5/6
Sum S+R >7 large squares
AS or HTN

Question 15

How is acute heart failure treated?

Answer 15

ABC approach:
Sit up and 60-100% O2
GTN or frusemide ventilation
Morphine
Treat underlying cause
Decompensation with pulmonary oedema
Chronic HF: ACEI, BB, spironolactone due to improved cardiac remodelling

Question 16

What does a 3rd heart sound represent?

Answer 16

Rapid ventricular filling in HF, heard better with the bell

Question 17

What does ASD sound like?

Answer 17

Fixed wide splitting in S2, heard better with diaphragm

Question 18

What does a 4th heart sound represent?

Answer 18

Atria contracting against stiff ventricles, LVH

Question 19

What is the ALS algorithm for VF/pulseless VT?

Answer 19

Shock, CPR 2 minutes, assess rhythm, adrenaline every 3-5minutes, correct reversible causes. Amiodarone may also be used

Question 20

What is the algorithm for asystole/PEA?

Answer 20

CPR, treat underlying cause

Question 21

What are the reversible causes of pulseless arrest?

Answer 21

4H 4T
Hypo/hyperkalaemia
Hypothermia
Hypovolaemia
Hypoxia

Toxin
Tamponade
Tension pneumothorax
Thrombus

Question 22

If a patient is hypothermic, how should they be treated?

Answer 22

Warm them before giving any drugs (adrenaline) as metabolism of drugs is slowed