Arrhythmia - Lecture Pharmacology and Extra Notes

Question 1

How do the beta blockers work?

Answer 1

Depress the sympathetic NS and stop relase of NA and adrenaline
Slow down HR

Question 2

How does amiodarone work?

Answer 2

Increases AP duration and prolongs repolarisation phase 3

Question 3

How does digoxin work?

Answer 3

Positive intrope - makes sure enough Ca is available and blocks the Na-K ATPase pump

Question 4

What is digoxins main problem? How is it managed?

Answer 4

Toxicity

K levels are monitored as tox is worse when K is low

Drug levels in body are monitered so we know if its still safe

Drug should be stopped if it is toxic
If levels still high give Digibind

Question 5

How does digibind work?

Answer 5

Digoxin immune antibody - binds with it and is excreted in urine

Question 6

What is digoxin toxicity symptoms?

Answer 6

Patient has visual disturbances - glowing/halo type
Xanthopsia
Nausea and vomiting
Brady/tachy cardia

Question 7

What is xanthopsia?

Answer 7

Colour vision deficiency where yellow is shown in vision a lot

Question 8

What are the Class 1 drugs that have not been mentioned in the previous decks as they were not in the ox. handbook?

Answer 8

Sodium channel blockers - 3 sub classes and each block Na but act differently

1a - Disopyramide
1b - Phenytoin, Lidocaine
1c - Flecainide

Question 9

Describe the effects these class 1 drugs have on AP duration and repolarisation

Answer 9

1a - Increased AP duration and delayed repolarisation

1b - Decreased AP duration and accelerated repolarisation

1c - Little effect

Question 10

What will digoxin toxicity look like on an ECG

Answer 10

Reverse tick of ST segment/Odd ST segment