Cardiovascular system

Question 1

Why is special care needed when using 2 or more anti-arrhythmic drugs?

Answer 1

The -ve inotropic effects tend to be additive. Care especially needed if myocardial function is impaired

Question 2

What is the main method of treatment for life threatening new-onset AF?

Answer 2

Emergency electrical cardioversion

Question 3

What can be used if the AF is non life threatening?

Answer 3

Electrical cardioversion or pharmacological

Question 4

How can ventricular rate be controlled?

Answer 4

Standard beta blocker, rate limiting CCB (diltiazem or verapamil) as monotherapy

Question 5

Which beta blocker should not be used for ventricular rate control?

Answer 5

Sotalol

Question 6

What can be used for rate control after monotherapy fails?

Answer 6

Combo of two drugs: beta-blocker, digoxin or diltiazem

Question 7

How can sinus rhythm be maintained post-cardioversion?

Answer 7

Standard beta blocker

Or sotalol, flecainide, propafenone or amiodarone

Question 8

When should verapamil be avoided?

Answer 8

In patients taking beta-blockers: increased risk of severe hypotension and asystole

Question 9

What is cardioversion?

Answer 9

Procedure where tachycardia or other arrhythmias are converted to a normal rhythm using electricity or drugs

Question 10

What is used if AF present for more than 48 hours?

Answer 10

Electrical cardioversion

Question 11

What should be completed ideally before electrical cardioversion?

Answer 11

Anticoagulation at least 3 weeks before and 4 weeks after

Question 12

What are the two assessments used to assess stroke risk.

Answer 12

CHADVASC (stroke risk)

ORBIT (bleeding risk- newly recommended by NICE in 2021)

Question 13

How does amiodarone work? (high risk med)

Answer 13

Alters sinus rhythm to restore normal heart beat (has a long 1/2 life and may need loading doses)

Question 14

How long can side effects occur after stopping amiodarone?

Answer 14

Up to a year due to long 1/2 life

Question 15

What are the warning signs for amiodarone? (7)

Answer 15

> Corneal microdeposits (reversible on withdrawal, v.common, rare interfere w/vision)
Impaired vision (optic neuritis or neuropathy, STOP to avoid blindness)
Thyroid function (contains iodine so can cause hypo or hyperthyroid. May need to stop treatment to start carbimazole and treat thyrotoxicosis)
Hepatotoxicity (stop if jaundice)
Pulmonary toxicity
Neurological effects (tremor, peripheral neurop)
Phototoxic skin reactions (burning sensation, erythema, persistent slate grey skin colour, use suncream)

Question 16

What monitoring is required with amiodarone?

Answer 16

> TFT (before treat+ every 6 months)
> LFT (before treat+ every 6 months 
> Serum K+ (before treat)
> Chest x-ray (before treat)
> ECG w/IV (resus must be available)

Question 17

Can amiodarone be used in pregnancy?

Answer 17

Has a risk of neonatal goitre- use only if no alt

Question 18

Can amiodarone be used in breastfeeding?

Answer 18

Avoid- present in milk signif amounts (may cause neonatal hypothyroidism)

Question 19

What medication can cause severe bradycardia and heart block when given with amiodarone?

Answer 19

Sofosbuvir with daclatasvir or ledipasvir or simeprevir

Question 20

Which drugs does amiodarone increase the plasma conc of?

Answer 20

• Coumarins
• Dabigatran
• Digoxin
• Flecainide
• Phenindione
• Phenytoin

Question 21

What medications can cause increased risk of ventricular arrhythmias when given with amiodarone?

Answer 21

• Amisulpride
• Atomoxetine
• Chloroquine
• Citalopram
• Disopyramide
• Escitalopram
• Haloperidol
• Hydroxychloroquine
• Levofloxacin
• Lithium
• Mizolastine
• Mefloquine
• Moxifloxacin
• Phenothiazines
• Pimozide
• Quinine
• Sulpride
• Telithromycin
• Tolterodine
• Tricyclics

Question 22

Which meds can increase risk of bradycardia, AV block and myocardial depression when given with amiodarone?

Answer 22

> Beta-blockers
Diltiazem
Verapamil

Question 23

What can occur when simvastatin and amiodarone are given together?

Answer 23

Increased risk of myopathy

Question 24

What is the important safety feature associated with sotalol?

Answer 24

It can prolong QT interval- leading to life threatening ventricular arrhythmias

Question 25

What monitoring is required with sotalol?

Answer 25

• ECG and measurement of corrected QT interval

- Serum electrolytes (should be corrected before starting treatment)

Question 26

How does digoxin work?

Answer 26

Slows down heart rate while increasing force of heart rate contraction

Question 27

Key facts about PK and PD of digoxin

Answer 27

• Long half life
• May need loading dose
• Therapeutic range 1-2 mcg/L
• Forms have different bioavailabilities: IV (100%), tablet (50-90%), Elixir (75%)

Question 28

Warning signs of digoxin

Answer 28

• Cardiac (arrhythmias, heart block)
• Neuro (weakness, lethargy, dizziness, headache, confusion, psychosis)
• GI (anorexia, N/V, Diarrhoea, abd pain)
• Visual (blurred/yellow vision)
• Overdose (stop immediately- range= 1.5 to 3mcg/L)

Question 29

What monitoring is required with digoxin?

Answer 29

• Serum electrolytes (can lead to toxicity if disturbance present)
• Renal function (reduced function= accum of metabolite
• Plasma digoxin (mainly in renal impair, bloods 6hrs after dose)
• Heart rate (should be above 60bpm

Question 30

Drug interactions with digoxin

Answer 30

• Increased plasma conc with: ciclosporin, diltiazem, itraconazole, lercanidipine, macrolides, nifedipine, quinine, mirabegron, spironolactone and verapamil
• Reduced plasma conc w/ St John’s wort
• Renal function impairing drugs affect digoxin plasma conc
• Concom use with acetazolamide, amphotericin, loop diuretics or thiazide can cause hypokalaemia= increase risk cardiac and digox toxicity

Question 31

What patients are considered high risk for VTE?

Answer 31

• Substantial reduction in mobility
• Obesity
• Malignant