Arrhythmias Flashcards
What are the main types of arrhythmias? (5)
- AFib
- Atrial flutter
- Paroxysmal SVT
- Arrhythmias after MI (paroxysmal tachycardia, rapid irregularity, bradycardia)
- VTach (pulseless v-tach or VF)
What treatment is required for ectopic beats?
If spontaneous and the patient has a normal heart, treatment is rarely required and reassurance will suffice
If they are particularly troublesome, beta-blockers are sometimes effective and may be safer than other suppressant drugs
What are the treatment goals in the management of AFib? (3)
Rate control
Rhythm control
Stroke prevention
What is the management of life-threatening hemodynamically unstable new-onset AFib?
Emergency electrical cardioversion WITHOUT delaying to achieve anticoagulation
What is the management of non-life-threatening hemodynamically STABLE new-onset AFib (<48 hours)?
Rate OR rhythm control
What treatment is preferred for management of non-life-threatening hemodynamically STABLE new onset AFib presenting after 48 hours or if duration is uncertain?
Rate control (and anticoagulation)
What is the cutoff for cardioversion in patients with acute AFib?
48 hours
- if less than 48 hours, rate or rhythm control
- if more than 48 hours, rate control only (no cardioversion before anticoagulation)
What are the options for chemical cardioversion in the treatment of AFib? (2)
- Amiodarone (preferred if there is structural heart disease)
- Flecainide
What are the options for urgent rate control in AFib? (2)
- IV beta-blocker
2. IV verapamil
When is electrical cardioversion preferred to chemical?
If AFib has been present for more than 48 hours, electrical cardioversion is preferred and should not be attempted until the patient is fully anticoagulated for AT LEAST 3 weeks
- if this is not possible, parenteral anticoagulation should be commenced, and a left atrial thrombus ruled out immediately before cardioversion
** prior to cardioversion, offer rate control as appropriate
What may be offered to patients with AFib in the interim before cardioversion is performed?
Rate control
Is it necessary to continue oral anticoagulation after cardioversion?
Yes, for at least 4 weeks
For patients receiving cardioversion for AFib with onset >48 hrs, how long should they be anticoagulated first?
At least 3 weeks
Rate control the preferred first-line drug treatment strategy for AFib EXCEPT in patients with… (4)
- New-onset AFib
- Atrial flutter suitable for an ablation strategy
- AFib with a reversible cause
- If rhythm control is more suitable based on clinical judgement
What are the main options for controlling ventricular rate? (2)
- Beta-blocker (not sotalol)
- Non-dihydropyridine CCB (diltiazem or verapamil)
- Digoxin is usually only effective for controlling the ventricular rate at rest, and should therefore only be used as monotherapy in predominantly sedentary patients with non-paroxysmal atrial fibrillation.
When a single drug fails to adequately control the ventricular rate, what drug combinations can be offered?
A combination of two drugs including a beta-blocker, digoxin, or diltiazem
If ventricular function is diminished, what drug combination is preferred for controlling ventricular rate?
Beta-blocker + digoxin
What drug is preferred for managing AFib in patients with heart failure?
Digoxin
What drug may be used to maintain sinus rhythm in patients with AFib post-cardioversion?
A beta-blocker
- If a standard beta-blocker is not appropriate or is ineffective, consider an oral anti-arrhythmic drug such as sotalol hydrochloride, flecainide acetate, propafenone hydrochloride, or amiodarone hydrochloride
What drug may be used before and after electrical cardioversion for AFib to increase success of the procedure and maintain sinus rhythm?
Amiodarone 4 weeks before and continuing for up to 12 months after
What ‘rhythm control’ drugs should be avoided in patients with known ischemic or structural heart disease? (2)
- Flecainide
- Propane one
- Consider amiodarone hydrochloride in patients with left ventricular impairment or heart failure.
Which ‘rhythm control’ drug is preferred in patients with LV impairment or HF?
Amiodarone
How is paroxysmal AFib defined?
Episodes of AFib that self-terminate within 7 days, usually within 48 hours, without any treatment
What is the ‘Pill-in-pocket’ strategy for PAFib?
The person self-manages paroxysmal AFib by taking anti arrhythmic drugs only when an episode of atrial fibrillation starts
To which patients is the ‘Pill-in-pocket’ strategy for AFib offered? (4)
Patients who:
- Have no history of LV dysfunction, or valvular or ischemic heart disease AND
- Have a history of infrequent symptomatic episodes of PAFib AND
- Have a SBP > 100 and a resting HR >70 bpm AND
- Are able to understand how to, and when to, take the medication
In which patients should the risk of stroke be calculated using the CHADS-VASc stroke risk score? (3)
- Symptomatic or asymptomatic paroxysmal, persistent, or permanent AFib
- Atrial flutter
- Continuing risk of arrhythmia recurrence after cardioversion back to sinus rhythm or catheter ablation
What is the CHADS-VASc score?
Estimator for stroke risk in patients with cardiac arrhythmias
C- CHF H- HTN A- age >75 (2 points) D- DM S- stroke/TIA/thromboembolism (2 points)
V- vascular disease (prior MI, PAD, aortic plaque)
A- age 65-74
Sc- sex female
When should bleeding risk be assessed with the ORBIT bleeding risk score?
- When considering starting anticoagulation in people with AFib AND
- When reviewing people already taking anticoagulation
What is the ORBIT score?
An estimator of bleeding risk for people taking anticoagulation for atrial fibrillation, similar to HAS-BLED score
O- older age (age 74 or more) R- reduced hemoglobin/anemia B- bleeding history I- insufficient kidney function T- treatment with antiplatelet
1 point for each risk factor
0-2 is low risk
3 is intermediate risk
4-5 is high risk
How do you interpret the score of the CHADS-VASc scoring system for patients with AFib?
0: no antithrombotic therapy
1: consider anticoagulation with a DOAC, taking into account bleeding risk
2+: offer anticoagulation with a DOAC, taking into account bleeding risk
A 30 year old woman with atrial fibrillation is being considered for stroke risk prevention. She has a CHADS-VASc score of 1. Should she be offered a DOAC for anticoagulation?
No; her 1 point is due to being female, therefore her stroke risk is very low and anticoagulation is not justified
Which drugs may be offered to patients with Paroxysmal AFib whose symptoms persist after standard beta-blocker therapy OR for whom beta-blocker therapy is inappropriate? (5)
Oral anti-arrhythmics:
- Dronedarone
- Sotalol
- Flecainide
- Propafenone
- Amiodarone
*vs in select patients with INFREQUENT episodes of symptomatic PAF, who may be offered the ‘pill-in-pocket’ approach with flecainide or propafenone
What is the HAS-BLED score?
A tool for assessing bleeding risk prior to and during anticoagulation
H- HTN (SBP >160)
A- abnormal renal or liver function (1 point each)
S- stroke
B- bleeding tendency
L- labile INR (time in therapeutic range <60%)
E- elderly (>65)
D- drugs (eg concomitant aspirin, NAIDs) or alcohol (1 point each)
Score:
0-2 indicates low risk
3+ indicates high risk
Can anticoagulation treatment be withheld solely because of the risk of falls?
No
What is the preferred form of anticoagulation for stroke prevention in patients with AFib?
DOACs: apixaban, dabigatran, edoxaban, rivaroxaban
*except in patients with valvular heart disease in whom warfarin is preferred
Can aspirin be offered as monotherapy for stroke prevention in AFib?
No
What can be offered for stroke prevention in patients with AFib in whom anticoagulation is contraindicated or not tolerated?
Left atrial appendage occlusion may be considered
What should be offered to patients with new-onset AFib who are receiving sub therapeutic or no anticoagulation therapy pending assessment and initiation of appropriate anticoagulation?
Parenteral anticoagulation eg LMWH
To which patients with AFib should oral anticoagulation be offered? (3)
Anticoagulation should be offered to patients with confirmed diagnosis of AFib in whom
- Sinus rhythm has not been successfully restored within 48 hours of onset
- There is a high risk of recurrence including history of recurrence, structural heart disease, history of prolonged AFib (more than 12 months), history of failed attempts at cardioversion
- The risk of stroke outweighs the risk of bleeding
What are the treatment goals for management of Atrial flutter? (2)
- Controlling ventricular rate OR
- Attempting to restore and maintain sinus rhythm
*AFlutter generally responds less well to drug treatment than atrial fibrillation
What are the options for achieving sinus rhythm in patients with Atrial flutter? (3)
- Electrical cardioversion (by cardiac pacing or direct current)
- Pharmacological cardioversion
- Catheter ablation
Is anticoagulation required in patients with a history of Atrial flutter lasting more than 48 hours?
Yes, if the duration of Atrial flutter is unknown or has lasted >48 hours, cardioversion should not be attempted until the patient has been fully anticoagulated for at least 3 weeks
- oral anticoagulation should be given after cardioversion and continued for at least 4 weeks
If anticoagulation is not possible for 3 weeks prior to cardioversion in the treatment of Atrial flutter, what should be done instead?
Parenteral anticoagulation should be commenced and a left atrial thrombus ruled out with echo immediately before cardioversion
What is the treatment of choice in cases of Atrial flutter where rapid conversion to sinus rhythm is necessary eg hemodynamic compromise?
Direct current cardioversion
What is the treatment of choice for recurrent atrial flutter?
Catheter ablation
What is the role of anti-arrhythmic drugs in the management of atrial flutter?
Limited to none; anti-arrhythmic drugs are not always successful
Flecainide or propafenone can slow atrial flutter, resulting in 1:1 conduction to the ventricles, and should therefore be prescribed in conjunction with a ventricular rate controlling drug such as a beta-blocker, diltiazem hydrochloride [unlicensed indication], or verapamil hydrochloride. Amiodarone hydrochloride can be used when other drug treatments are contra-indicated or ineffective