PSVT

Question 1

Definition?

Answer 1

Type of arrhythmia originating from a defect in AV conduction resulting in the heart beating faster.

Question 2

RF?

Answer 2

• Substance misuse
• Digoxin toxicity
Cardiac surgery to correct congenital defects

Question 3

ddx?

Answer 3

• Sinus tachycardia-vagal manoeuvres cause it to slow down and prolong PR interval
• AV node re-entry tachycardia retrograde activation of atria, P waves found in second half of tachycardia cycle
Atrial flutter-regular tachycardia with atrial flutter rate

Question 4

Epidemiology?

Answer 4

Age: young
Sex: male 2:1
Ethnicity:

Question 5

Aetiology?

Answer 5

• AVNRT-tachycardia cause by dysfunctional AV node with two electrical pathways
• AVRT-accessory pathway between A and V
• Wolff-parkinson white syndrome-congenital-accessory pathway ‘Bundle of Kent’
• AT-atrial pacemaker outside of SAN
AF

Question 6

CP?

Answer 6

• Palpitations
• Dizziness
• Chest pain
• Dyspnoea
• Syncope
Urinary urgency

Question 7

Pathophysiology?

Answer 7

• AVNRT-
  
  • Electrical impulses renter in av node causing a continuous circuit leading to tachycardia
• AVRT
  
  • Orthodromic is when there is either anterograde or retrograde contraction through an accessory pathway
  • Antidromic is both antero and retro but through the AVN itself

Question 8

Investigations?

Answer 8

• ECG
• Digoxin
• CXR
• Theophylline
• Electrolytes
Toxicology screen

Question 9

Management unstable?

Answer 9

• ABCDE or cardioversion( pharm or electrical)
• First line:
• Carotid sinus massage - to cause bradycardia and hence end arrhythmia- insert pic of baroreceptor reflex
• Valsalva manoeuvre- after deep inspiration the patient is told to have an abdominal press and against a closed glottis
• Diving reflex

Question 10

management -AVNRT and orthodromic AVRT?

Answer 10

• 1st line: Adenosine
• 2nd line: IV verpamil, diltiazem, metoprolol, esmolol
• Long term
  
  • Catheter ablation
  • -verapamil and diltiazem, beta blockers, digoxin

Question 11

management- Antidromic AVRT

Answer 11

• 1st line: procainamide
• Long term-
  
  • Catheter ablation
  • Flecainide propafenone (class 1c antiarrythmic drugs)
  • Sotalol
  • Amiodarone
  • Pill in pocket

Question 12

prognosis?

Answer 12

Complications of medications and surgeries could affect this

Question 13

complications?

Answer 13

Sudden cardiac death

Catheter ablation complications