Arrythmia Flashcards
If etopic beats are troublesome, how can they be treated?
Beta blockers
If a patient has AF what 2 assessments can be carried out to assess risk?
CHADVASC + HASBLED
At what score on the CHADVASC would you consider treating?
more than or equal to 1
If a patient has a HASBLED of <1 can they be treated?
Yes. 0-1 can be anticoagulated
What score on the HASBLED tool is anticoagulation not suitable?
2
What 2 ways can AF be controlled?
Ventricular rate or attempting to restore sinus rhythm
Presentation of AF patient
Palpitation, fatigue, SOB, syncope, chest discomfort
What are 2 cardiac assessments to diagnose for AF
ECG + ECHO
When must emergency electrical cardioversion be offered?
if patient presents with life threatening haemodynamic instability
If a patient presents acutely without life threatening haemodyamic instability what type of treatment should be offered
if < 48 hours - Rate / rhythm
If > 48 hours - Rate preferred
If a patient is going to undergo cardioversion what drug options can be given IV
Amiodarone or Flecanide
What 2 drugs are used for urgent rate control?
IV beta blocker + verapamil
How long should a patient have been anticoagulated for if they have had AF >48 hours and are going to undergo cardioversion?
3 weeks
How long after cardioversion should a patient be anticoagulated for?
4 weeks
First line rate control drugs
Beta blocker + RL CCB (diltiaziem or verapamil)
In what patients is Digoxin consider for rate control?
Sedentary patients or if they have CHF + AF
Why is Digoxin only considered for sedentary patients or CHF in AF?
It is only effective for controlling ventricular rate at rest
Drug treatment post cardioversion
Beta blocker or oral anti-arrythmic
Examples of oral anti-arrythmics
Flecanide, Propafone, Amiodarone, Dronedarone, Soltalol
How many weeks prior to cardioversion can amiodarone be started?
4 weeks
How many months after cardioversion is amiodarone continued for?
12 months
If there is no ischaemic heart disease what 2 anti-arrhythmics cannot be given?
Flecanide or propafenone
What approach can be utilised in paraoxysmal AF?
Pill in pocket - with flecanide
What should be offered to all patients wiht new onset AF?
Anticoagulation
How is paroxysmal SV tacycardia treated?
Usually terminates spontaneously, if not give IV adenosine
Examples of Class 1 anti-arrthymics
1A: Quinidine
1B: Lidocaine, Mexiltene
1C: Flecanide, Propafenone
Examples of Class II anti-arrthymics
Beta blockers
Examples of Class III anti-arrthymics
Amiodarone, Soltalol, Dronedarone
Examples of Class IV anti-arrthymics
Verapamil, diltiaziem
What blood abnormality can lidocaine cause?
Methylhaemoglobinaemia ( treated wiht methylthionium chloride)
If flecanide is given concurrently with amiodarone what does the BNF recommend?
Reduce dose by half
What may soltatolol prolong?
QT interval
What 2 electrolyte imbalances must soltalol be avoided in?
HypOkalaemia + HypOmagnesemia
Dose regime of Amiodarone
200mg TDS 7 days, 200mg BD 7 days, 200mg OD maintenance
IV amiodarone dose
5mg/kg over 20-120 mins
What hep C drug can cause severe bradycardia wiht amiodarone
Sofosbuvir
Four major side effects of amiodarone
- Corneal microdeposits
- Pulmonarytoxicity
- Thyroidtoxicity
- Hepatoxicity
How is hypothyroidism associated with amiodarone treated?
Levothyroxine
What symptoms suggest amiodarone associated pneumonitis?
SOB, new persistent cough
What should you monitor with amiodarone therapy?
TFT (baseline + 6 months), LFTs ( baseline + 6 months), CXR (baseline), Potassium (baseline)
What should be monitored with IV amiodarone?
ECG
What should patients be advised about in regards to photosensitivity reactions with amiodarone?
Use SPF daily, shield from sunlight during and on several months of discontinuning ( long t1/2)
What route should adenosine be given by?
Large or centeral vein
What should be monitored wiht adenosine?
ECG
MHRA warning with soltalol
QT prolongation - can cause life threatening arrhythmias. Avoid in low K+ and Mg2+
What electrolyte imbalance should you be cautious of with Dronedarone?
Low K+ and low Mg2+
When should you discontinue treatment with Dronedarone in liver injury
If 2 consecutive alanine aminotransferase concentrations exceed 3 x ULN
If a patient hasa dry cough and are on dronedarone why do we need to be cautious?
Risk of pulmonary toxicity
Monitoring with Dronedarone
ECG< monitor for HF, serum creatinine (baseline + 7 days from initiation), LFT (baseline, 1 week and 1 month then monthly for 6 months then every 3 months)
How should adenosine be given?
Large central vein
Example of a caridac glycoside
Digoxin
At what HR limit should Digoxin be held?
<60bpm
If patient is in sinus rhythm with HF do they need digoxin loading?
No a satisfactory digoxin level can be achieved over one week
How often should Digoxin maintenance dosing be given?
OD dosing ( can split to BD if nausea is an issue)
What 2 factors add to the likelihood of unwanted side effects with digoxin?
- Concentration of Digoxin
2. Sensitivity of myocardium
What digoxin range is likely to indicate toxicity?
1.5 - 3 mcg/L
What electrolyte imbalance predisposes patients to digoxin toxicity?
Hypokalaemia (can be managed by adding in K+ sparring diuretics / supplements)
If Digoxin toxicity occurs, what is the antidocte?
Digoxin specific antibodies
How does Digoxin work?
Increases force of myocardial contractility and reduces conduction at the AV node
Dose of digoxin for rapid digitialisation
750 to 1500 mcg over 24 hours in divided doses
Maintenance dose of Digoxin in AF
125 - 250 mcg OD
Maintenance dose of Digoxin in HF
62.5 to 125mcg OD
If a patient is on concurrent amiodarone / dronedarone / quinine what does the BNF suggest to do to the Digoxin dose?
Reduce by half
By how much does the digoxin dose need to be increased by if switching from IV to PO?
20 - 33% in order to maintain same digoxin level
If digoxin monitoring is indicated, when should it be carried out?
6 hours post dose (ideal 8 - 12 hours) after at least 7 days of treatment
Target level of Digoxin (general)
0.8 to 2ng/mL
Target level of Digoxin in HF patients
0.6 - 0.8ng/L
Target level of Digoxin in AF patients
1 - 2 ng/L
Signs of Digoxin toxicity
Blurred yellow vision, nausea, Arrhythmia, Rash, conductive disturbances
How is the digoxin elixir administered?
Using pipette
