ELM 15 - Dysrhythmias treatment

Question 1

How can the surgical treatment of ablation treat dysrhythmias?

Answer 1

• Can locate and destroy defective abnormality
• Ablation used to correct supraventricular tachycardias and Wolff-Parkinson-White syndrome

Question 2

What is the electrical treatment of cardioversion?

Answer 2

• Jolts heart out of abnormal rhythm and back into its pattern
• If there’s a pulse synchronised electrical cardioversion can be done, shock is synchronised with cardiac cycle to be given during the R wave
• This minimises shock triggering worse dysrhythmia

Question 3

What is electrical treatment of defibrillation?

Answer 3

• Non synchronised pulse of electricity given when patient has pulseless tachycardia or ventricular fibrillation
• Aims to depolarise a large block of cardiac muscle

Question 4

What is an implantable cardioverter defibrillator?

Answer 4

• Constantly checks cardiac electrical activity and electrodes deliver a shock if dysrhythmia detected
• Implanted using catheter above femoral or pectoral artery
• Main circuitry in chest below collar bone

Question 5

What is the hERG?

Answer 5

Gene that codes for alpha subunit of potassium ion channel

Question 6

What happens when hERG is mutated?

Answer 6

Long QT syndrome where the time between Q and T is lengthened
Causes delay in repolarisation and can lead to TDP

Question 7

What is drug induced long QT syndrome?

Answer 7

Some drugs bind to hERG channel and inhibit its function
Pharmaceutical companies now have to test drugs to see if they interact with hERG
EG antihistamine terfenadine was removed from market