Cardiovascular Flashcards
(185 cards)
What are the 4 classes of anti-arrhythmic drugs?
Class 1 - Membrane stabilising drugs (Na+ blockers) - Rhythm Control
Class 2 - Beta-blockers - Rate Control
Class 3 - K+ channel blockers - Rhythm Control
Class 4 - calcium-channel blockers (rate-limiting) - Rate Control
Give examples of Class 1 anti-arrhythmic drugs.
Rhythm Control
- Disopyramide
- Lidocaine
- Flecainide / Propafenone (CI in asthma / severe COPD, avoid in structural / ischaemic heart disease)
Give examples of Class 2 anti-arrhythmic drugs.
Rate Control
- Bisoprolol
- Propranolol
- Esmolol
Give examples of Class 3 anti-arrhythmic drugs.
Rhythm Control
- Amiodarone - 4 weeks before and 12 months after electrical cardioversion to increase success.
- Sotalol
- Dronedarone
Give examples of Class 4 anti-arrhythmic drugs.
Rate-Control
- Verapamil
- Diltiazem
Give examples of other anti-arrhythmic drugs.
- Adenosine
- Digoxin - effective in sedentary patients with non-paroxysmal AF and in patients with associative CHF.
What is AF?
Abnormal, disorganised electrical signals fired causing the atria to fibrilate (quiver) resulting in a rapid and irregular heartbeat.
What are the symptoms of AF?
- Heart palpitations
- Dizziness
- SOB
- Tiredness
What are the complications of AF?
- Stroke
- HF
What are the types of AF?
- Paroxysmal - episodes stop within 48 hours without treatment.
- Persistent - episodes last >7 days.
- Permanent - present all the time.
What is cardioversion?
Cardioversion is procedure which restores sinus rhythm. It uses a defibrillator device.
How is acute, new onset AF managed?
If the patient has life-threatening haemodynamic instability:
- Use electrical cardioversion.
If the patient does NOT have life-threatening haemodynamic stability:
- <48 hours of symptoms - rate or rhythm control (cardioversion OR amiodarone / flecainide).
- > 48 hours of symptoms - rate control (verapamil / beta-blocker).
Outline the pharmacological management of AF.
- 1st-Line: Beta-blockers (not sotalol) / rate-limiting CCB / digoxin for rate control.1
Use monotherapy, then dual therapy, then consider rhythm control.
- 2nd-Line: Rhythm control using Class 1/3 anti-arrhythmic.
What needs to be assessed in patients who have AF?
Risk of thromboembolic stroke and the risk of bleeding.
How is risk of thromboembolic stroke assessed for patients with AF?
CHA2DS2VASc Score
C = CHF / LVSD (Yes = 1) H = HTN (Yes = 1) A2 = Age 75+ (2) D = Diabetes Mellitus (Yes = 1) S2 = Stroke / TIA / VTE Hx (Yes = 2) V = Vascular Disease (Yes = 1) A = Age 65-74 (1) Sc = Sex category (female = 1, male = 0)
Anticoagulation is indicated if score = 2+.
How is bleeding risk assessed for patients with AF?
HAS-BLED Score
H = HTN, >160mmHg systolic (1) A = Abnormal liver / renal function (1) S = Stroke Hx (1) B = Bleeding Hx / predisposition (1) L = Labile INR (1) E = Elderly >65 (1) D = Drugs, antiplatelet or NSAID use (1)
When should anticoagulation be given in patients with AF?
If the risk of thromboembolic stroke > risk of bleeding.
AND
CHA2DS2VASc score = 2+.
What is the choice of anticoagulant for AF?
New-onset AF = parenteral anticoagulant
Diagnosed AF = Warfarin / DOAC
What is ventricular tachycardia (VT)?
Quick, abnormal HR.
How is ventricular tachycardia managed?
- Pulseless = immediate defibrilation and CPR
- Unstable sustained VT = direct current cardioversion. If failed, IV amiodarone and repeat cardioversion.
- Stable sustained VT = IV anti-arrhythmic (preferably amiodarone)
- Non-sustained VT = beta-blocker
How is Torsades de pointes managed?
Magnesium sulfate.
What causes Torsades de pointes?
- Drugs that cause QT interval prolongation..
- HypOkalaemia.
- Bradycardia.
What is paroxysmal supraventricular tachycardia?
A type of supraventricular tachycardia, named for its intermittent episodes of abrupt onset and termination. Often people have no symptoms but may include palpitations, feeling lightheaded, sweating, shortness of breath, and chest pain.
How is paroxysmal supraventricular tachycardia managed?
- Reflex vagal nerve stimulation.
- IV adenosine (CI in COPD / asthma).
- IV verapamil.
If the patient is haemodynamically unstable, cardioversion is required.
If there are recurrent episodes, catheter ablation or other anti-arrhythmics may be used.