Anti Arrythmics

Question 1

What anti arrhythmic drugs are there?

Answer 1

• Adenosine

Question 2

Indications

Answer 2

• Immediate termination of supraventricular tachycardia

- Diagnosis of SVT/VT

Question 3

Contraindications?

Answer 3

• Heart block
• Long QT syndrome
• COPD
• Severe hypotension

Question 4

Cautions?

Answer 4

• Heart transplant

Question 5

What receptors does adenosine work on?

Answer 5

• A1 adenosine receptors

Question 6

What do A1 adenosine receptors open?

Answer 6

• ACh sensitive potassium channels

Question 7

What does the opening of ACh sensitive potassium channels lead to?

Answer 7

• Hyperpolarisation

- Inhibition of calcium channels

Question 8

What does the hyperpolarisation and inhibition of calcium channels cause?

Answer 8

• A brief period of heart block sufficient to terminate the SVT

Question 9

How is adenosine administered?

Answer 9

• Intravenous bolus with increasing dosages until arrhythmia is terminated

Question 10

Besides termination of the arrhythmia, what are the other outcomes of IV bolus adenosine?

Answer 10

• Alternate diagnosis

- Max dose reached

Question 11

Why are adverse reactions from adenosine short lived?

Answer 11

• Very short half life

Question 12

What are the adverse reactions for adenosine?

Answer 12

• Bronchospasm
• Chest pain
• Flushing
• Nausea
• Bradyarrhythmia is possible

Question 13

What drug interacts with adenosine and causes a prolonged anti arrhythmic affect?

Answer 13

• Dipyridamole

- Also if patient is already on anti arrhythmics

Question 14

What should patients be warned about before administering adenosine?

Answer 14

• Effects unpleasant

- Feels like being thumped in the chest