Arrhythmias

Question 1

List some narrow complex tachycardias

Answer 1

This are the supra ventricular rhythms:

• Atrial fibrillation
• Atrial flutter
• Sinus tachycardia
• Junctional tachycardia
• Atrial tachycardia (supraventricular tachycardia)

Question 2

List some features of a presentation of palpitations that may help you to distinguish whether the diagnosis is of sinus tachycardia or a genuine tachy-arrhythmia

Answer 2

Onset: Sinus tachycardia starts/stops gradually, while tachyarrhythmias start/stop instantaneously
Vagal manœuvres helpful for supra ventricular tachyarrhythmias but not sinus tachycardia
Syncope occurs in tachyarrhythmias but not sinus tachycardia
Background of stress/anxiety in sinus tachycardia, while anxiety only occurs during an attack of tachycarrythmia, not before

Question 3

What is a broad complex tachycardia?

Answer 3

Either supra ventricular tachycardia with aberrancy e.g. bundle branch block, or ventricular tachycardia

Question 4

What is the main clinical feature of a patient presenting with a tachy-arrhythmia?

Answer 4

Palpitations

Question 5

What is paroxysmal AF?

Answer 5

Lasting 48hrs - 7 days, but always terminating itself, without intervention

Question 6

What is persistent AF?

Answer 6

Episode of AF lasting more than 7 days, which may be terminated by treatment with medication or cardioversion

Question 7

What is permanent AF?

Answer 7

AF which cannot be terminated by medication or cardioversion, or which has lasted >1 year without cardioversion being attempted

Question 8

Patient with first detected atrial fibrillation who is acutely compromised - what would be the management?

Answer 8

DC shock or medical cardioversion, with LMWH. If success, consider rhythm control medication to maintain sinus rhythm, if failure consider rate control

Question 9

What score is used to anticipate a patient’s risk of thromboembolism in AF? List it’s components and the management based on scoring.

Answer 9

CHA2DS2VASc:

Congestive heart failure = 1 point
Hypertension = 1 point
Age >75 = 2 points
Diabetes = 1 point
Stroke = 2 points
Vascular disease = 1 point
Age 65-74 = 1 point
Sex category (female) = 1 point

Score 0 = Low risk, no anticoagulation required
Score 1 or more = Oral anticoagulation

Question 10

What is the HAS-BLED score and what is it used for?

Answer 10

Used for assessing bleeding risk e.g. in a patient due to start warfarin:

Hypertension
Age >65
Abnormal LFTs, U&Es (1 point for each)
Stroke
Bleeding risk (previous bleed or predisposition)
Labile INRs i.e. 8 drinks per week)
Drugs predisposing to bleeding e.g. NSAIDs, anti-platelets

Score > 3 indicates raised 1-year risk of bleeding so consider alternative or more regular reviews on warfarin

Question 11

What is Wolff-Parkinson-White Syndrome?

Answer 11

Accessory conduction between atria and ventricles

Question 12

What is the characteristic ECG change in WPW syndrome?

Answer 12

Delta wave - a slurred upstroke

Narrow PR interval

Question 13

What is the treatment for Wolff-Parkinson-White Syndrome?

Answer 13

Radiofrequency ablation to the accessory conduction pathway

Question 14

What are the ECG features of first degree heart block?

Answer 14

Prolonged PR interval (more than 0.2 seconds)

Question 15

What are the ECG features of complete heart block?

Answer 15

No association between P waves and QRS complexes

Question 16

What is second degree heart block? What are the different types?

Answer 16

There is intermittent failure of AV node conduction so there are intermittent dropped beats (not every P wave is followed by a QRS complex) Types:
Mobitz 1, Mobitz 2
2:1 heart block

Question 17

What are the features of Mobitz 1 heart block?

Answer 17

Progressively lengthening QRS complex until eventually a beat is dropped. This is Wenckebach phenomenon.

Question 18

What are the features of Mobitz 2 heart block?

Answer 18

Prolonged PR interval of the same prolongation until eventually there is a dropped beat

Question 19

List some drug causes of prolonged QT interval

Answer 19

Amiodarone
Stall
Class 1a antiarrhythmic drugs
Tricyclic antidepressants
SSRIs (especially citalopram)
Methadone
Chloroquine
Terfenadine (non-sedating anti-histamine)
Erythromycin
Haloperidol