Arrhythmias Flashcards
What is cardiac monitoring?
A way of observing the electrical activity of the heart to ensure it is working normally. Electrodes are placed on the body and connected to a monitor, allowing 24-hour observation of the heart’s activity.
What is PT on a clotting screen?
The prothrombin time (PT) is a measure of the time taken for blood to clot via the extrinsic pathway.
What is APTT on a clotting screen?
Theactivated partial thromboplastin time(APTT) is a measure of the time taken for blood to clot via theintrinsicpathway.
What is thrombin time on a clotting screen?
This is a test of how fastfibrinogen is converted to fibrinby thrombin. In cases of a prolonged time, the cause is either a synthetic issue or consumption issue.
What treatment can help if ectopic beats are troublesome?
Treatment is rarely required, and reassurance is usually sufficient however beta-blockers are sometimes effective.
How is atrial fibrillation classified?
- Paroxysmal (episodes terminate within 7 days of onset).
- Persistent (lasts longer than 7 days).
- Longstanding persistent (duration at least 12 months).
- Permanent (no further attempts to restore or maintain sinus rhythm).
What are the main treatment strategies for atrial fibrillation?
Rate control
Rhythm control
What should be done for patients with life-threatening haemodynamic instability due to new-onset AF?
Emergency electrical cardioversion to restore sinus rhythm without delay for anticoagulation.
When can rate or rhythm control be offered to a patient with new-onset AF?
Rate or rhythm control can be offered if the onset is less than 48 hours. Rate control is preferred if onset is more than 48 hours or uncertain.
What is the preferred first-line treatment strategy for atrial fibrillation? - Rate control…
Rate control, unless the patient has new-onset AF, atrial flutter, heart failure primarily caused by AF, or a reversible cause.
What medications are used for rate control in AF?
Beta-blockers or rate-limiting calcium channel blockers like diltiazem or verapamil.
What is the approach when monotherapy for rate control fails?
Combination therapy with a beta-blocker, digoxin, or diltiazem. If symptoms persist, consider rhythm control.
What is the first-line treatment for rhythm control after cardioversion?
Standard beta-blocker. If not suitable, consider anti-arrhythmic drugs like amiodarone, flecainide, or propafenone.
What is the CHA2DS2-VASc score used for?
To assess stroke risk in patients with atrial fibrillation and guide anticoagulation decisions.
What is the recommended anticoagulation treatment for stroke prevention in atrial fibrillation?
Direct-acting oral anticoagulants (DOACs) like apixaban, dabigatran, edoxaban, or rivaroxaban. Warfarin is an alternative if DOACs are contraindicated.
What is the risk score used to assess bleeding risk in patients with AF?
ORBIT bleeding risk score.
What is the recommendation for patients with a CHA2DS2-VASc score of 2 or above?
Anticoagulation for stroke prevention should be offered.
What is the “pill-in-the-pocket” approach in rhythm control?
The patient takes an oral anti-arrhythmic drug to self-treat an episode of paroxysmal atrial fibrillation.
What is recommended for patients with a CHA2DS2-VASc score of 0 (men) or 1 (women)?
Anticoagulation is not required but should be reassessed as the patient ages or if other risk factors develop.
What is the main role of digoxin in the treatment of atrial fibrillation?
Digoxin is useful for controlling ventricular response in persistent and permanent atrial fibrillation and atrial flutter.
How is the maintenance dose of digoxin determined in atrial fibrillation?
It is usually determined by the ventricular rate at rest, which should not fall persistently below 60 beats per minute.
What is the main factor that determines the dosage of digoxin?
Renal function is the most important determinant of digoxin dosage.
What is the most common frequency for administering digoxin?
Digoxin has a long half-life and is typically administered once daily, though higher doses may be divided to avoid nausea.
What condition can hypokalaemia cause in patients on digoxin?
Hypokalaemia predisposes patients to digitalis toxicity (digoxin poisoning), which should be managed with a potassium-sparing diuretic or potassium supplementation.
How can life-threatening digoxin toxicity be reversed?
Digoxin-specific antibody fragments can be used to reverse life-threatening digoxin toxicity associated with ventricular arrhythmias or bradyarrhythmias.
What is atrial flutter, and how is it treated?
Atrial flutter is treated by controlling the ventricular rate or attempting to restore sinus rhythm. It responds less well to drug treatment than atrial fibrillation.
What is the usual treatment for controlling ventricular rate in atrial flutter?
Ventricular rate can be controlled with a beta-blocker, diltiazem, verapamil, or digoxin (especially in those with heart failure).
What are the methods to achieve conversion to sinus rhythm in atrial flutter?
Conversion to sinus rhythm can be achieved by electrical cardioversion, pharmacological cardioversion, or catheter ablation.
What is the preferred treatment for atrial flutter in patients who cannot tolerate or respond to other drugs?
Amiodarone hydrochloride can be used when other drug treatments are contraindicated or ineffective.
What often causes paroxysmal supraventricular tachycardia (PSVT) to terminate spontaneously?
PSVT often terminates spontaneously or with reflex vagal stimulation, such as the Valsalva maneuver, immersing the face in ice-cold water, or carotid sinus massage.
What should be done if reflex vagal stimulation is ineffective for PSVT?
If reflex vagal stimulation is ineffective, intravenous adenosine should be given. If adenosine is ineffective or contraindicated, intravenous verapamil is an alternative (but avoid in patients recently treated with beta-blockers).
What should be done for unstable sustained ventricular tachycardia?
Patients with unstable sustained ventricular tachycardia should receive direct current cardioversion to restore sinus rhythm. If this fails, IV amiodarone should be administered, and direct current cardioversion repeated.
What is the treatment for patients at high risk of cardiac arrest following restoration of sinus rhythm?
Patients at high risk will require maintenance therapy, often with an implantable cardioverter defibrillator (ICD). Beta-blockers, sotalol, or amiodarone may be used in combination with the device or alone when an ICD is not appropriate.
What is Torsade de Pointes, and what causes it?
Torsade de Pointes is a form of ventricular tachycardia associated with long QT syndrome. It can be drug-induced or caused by factors such as hypokalaemia, severe bradycardia, or genetic predisposition.
How is Torsade de Pointes treated?
Magnesium sulfate intravenous infusion is usually effective. Beta-blockers (except sotalol) and atrial/ventricular pacing can also be considered. Anti-arrhythmics should be avoided as they can worsen the condition.
How does hypokalaemia affect anti-arrhythmic drugs?
Hypokalaemia enhances the arrhythmogenic (pro-arrhythmic) effect of many anti-arrhythmic drugs.
What drugs are contraindicated in supraventricular arrhythmias associated with accessory conducting pathways like Wolff-Parkinson-White syndrome?
Cardiac glycosides and verapamil are contraindicated in such arrhythmias.
