CHAPTER 2: CVS: Arrythmias Flashcards
Which complication can AF lead to?
Stroke
What must all all patients with AF be assessed for? (2)
- Risk of stroke
2. Risk of thromboembolism
Which 2 things can AF treatment aim to manage?
- Rate
2. Rhythm
In patients with AF, how often should anticoagulation, stroke and bleeding risk be reviewed?
Yearly
What must all patients presenting with life-threatening haemodynamic instability caused by new-onset AF undergo?
Emergency electrical cardioversion
If a patient presents with acute AF less than 48 hours since onset, which is preferred: rate or rhythm control?
Either
If a patient presents with acute AF more than than 48 hours since onset, which is preferred: rate or rhythm control?
Rate control - but cardioversion is preferred
Which is first line drug treatment? Rate or rhythm control?
Rate
What are the exceptions to using rate control first line in AF? (5)
- New-onset AF
- Heart failure secondary to AF
- AF suitable for ablation
- AF with a reversible cause
- Rhythm control is more suitable
Which 2 drug classes are first line for rate control of AF?
- Beta-blocker
2. Rate-limiting calcium channel blocker
Give 2 examples of rate limiting calcium channel blockers
- Verapamil
2. Diltiazem
If a single drug fails to control the rate in AF, a combination of 2 drugs can be used from which selection?
- Beta-blocker
- Digoxin
- Diltiazem
If symptoms are not controlled with 2 rate limiting drugs in AF, what should be considered?
Rhythm control strategy
If ventricular function is diminished, a combination of which 2 drugs is preferred?
Beta-blocker (licensed in heart failure) + Digoxin
When AF is accompanied by congestive heart failure which drug is used?
Digoxin
If drug treatment is required to maintain sinus rhythm after cardioaversion, which drug is used?
A beta blocker
Which drug can be started 4 weeks before and continued for up to 12 months post-cardioversion?
Amiodarone
Which drug cannot be given if there is known ischaemic or structural disease?
Flecainide
In selected patients with paroxysmal AF, how can sinus rhythm be restored?
“Pill in pocket” approach where a patient takes oral flecainide to self-treat an episode of AF when it occurs
Which assessment tool does NICE recommend for the assessment of clotting risk?
CHAADSVASC
What does CHADSVASC stand for?
C - Congestive heart disease H - Hypertension A - Age >70 (2) A - Age >65 D - Diabetes S - Stroke/TIA (2) V - Vascular disease S - Sex = female
Which 2 parameters on CHADSVASC give a score of 2?
- Age >70
2. Stroke
Which gender on CHADSVASC gives a score of 1?
Female
What does HASBLED stand for?
H - Hypertension A - Abnormal liver function A - Abnormal renal function B - Bleeding L - Labile INRs E - Elderly D - Drugs and Alcohol
In males, what does the CHADSVASC score have to be for them not to receive any thromboprophylaxis for stroke prevention?
0
In females, what does the CHADSVASC score have to be for them not to receive any thromboprophylaxis prevention?
1
If patients present with new-onset AF, what should be provided until an assessment it made and they are started on oral anticoagulation?
Parenteral anticoagulation
Can anticoagulation therapy be held solely based on the risk of falls?
No
What are the options for oral anticoagulation in AF?
- Warfarin
- Rivaroxaban
- Apixaban
- Dabigatran
Is aspirin an option for the prevention of stroke in AF?
NO
Which drug is used to treat bradycardia after MI?
Atropine
If atropine fails to treat bradycardia after MI, what should be administered?
Adrenaline IV infusion
What is Torsade de Pointes?
A form of ventricular tachycardia associated with a long QT interval
What can cause Torsade de Pointes? (4)
- Drugs
- Hypokalaemia
- Bradycardia
- Genetics
Which electrolyte state can enhance the arrythmogenic effect of drugs?
Hypokalaemia
What is the drug of choice for supraventricular arrythmias?
Adenosine
Which drug prolongs the half life of adenosine? (8-10sec usually)
Dipyridamole
Give an example of a cardiac glycoside
Digoxin
Which other drug can be of use in supraventricular arrythmias?
Verapamil
Which drug should verapamil never be given with?
Beta-blockers
Can the GP initiate amiodarone?
No, specialist initiation only or in a hospital
Compared with oral amiodarone, how fast does IV amiodarone act?
Very rapidly
Amiodarone has a very long half life, how long can this extend?
Several weeks
How long can it be required for amiodarone to reach steady state?
Many weeks or months
What is the loading dose regimen for amiodarone?
week 1: 200mg TDS
week 2: 200mg BD
week 3 and thereafter: 200mg OD
What are the 5 toxicities of amiodarone?
- Corneal microdeposits
- Thyroid
- Pulmonary toxicity
- Liver toxicity
- Peripheral neuropathy
What counselling must be delivered to patients taking amiodarone due to the risk of corneal microdeposits?
Drivers may be dazzled by lights
Regarding its risk of corneal microdeposits, when should treatment with amiodarone be stopped?
If it interfers with vision - risk of blindness
Which substance does amiodarone contain which causes it to have a risk of thyroid toxicity?
Iodine
How can amiodarone affect the thyroid?
Both hyperthyroidism and hypothyroidism can occur
What should happen with a patient taking amiodarone gets thyrotoxicosis?
Withdraw amiodarone (at least temporarily) to help achieve control.
Which treatment of thyrotoxicosis may be required if a patient experiences it while taking amiodarone?
Carbimazole
What should happen with a patient taking amiodarone gets hypothyroidism?
Treatment should be continued and the patient should receive replacement therapy
What should happen with a patient taking amiodarone shows signs of extreme liver disease?
Discontinue treatment
Which side effect of amiodarone should be suspected if a patient presents with shortness of breath or cough?
Pneumonitis
Which monitoring is required for patients on amiodarone? (4)
- Thyroid function before treatment then every 6 months
- LFTs before starting then every 6 months
- Chest X-ray before starting
- Serum potassium before starting
Which thyroid function markers should all be measured?
TSH, T4 and T3
What does a have T4 and T3 but a low TSH indicated?
Thyrotoxicosis
Which diluent should amiodarone be administered with?
Glucose 5%
What should patients be counselled on regarding the risk of phototoxicity with amiodarone?
Shield skin from light during treatment and for several months after discontinuing
Which beta-blocker may prolong QT and cause potentially life-threatning arrhythmias?
Sotalol
What is the antidote for digoxin?
Digoxin-specific antibody, Digifab
In AF, what is the maintenance dose of digoxin usually determined by?
The ventricular rate at rest
What must the ventricular rate at rest not fall below at rest?
60 BPM
Is a digoxin loading dose required for patients who have heart failure and are in sinus rhythm?
No
What is the most important determinant of digoxin dosage?
Renal function
At which digoxin range does the likelihood of toxicity increase progressively?
1.5 to 3mcg/L
In which population should digoxin be used with special care due to the risk of digitalis?
Elderly
Is regular monitoring of digoxin necessary?
No, only if problems are suspected
Which electrolyte disturbance predisposes the patient to digoxin toxicity?
Hypokalaemia
How is hypokaleamia managed if a patient is on digoxin? (2)
- Potassium-sparing diuretic
2. Potassium supplements
When digoxin is given concomitantly with amiodarone, dronedarone and quinine, what should be done to the dose?
Half
How much should the dose of digoxin be increased by when switching from IV to oral route?
20-33%
What should be monitored when treating with digoxin? (2)
- Renal function
2. Electrolytes
Which calcium channel blocker is used in subarachnoid haemorrage to reduce the amount of blood reaching the area?
Nimodipine
