B.25 Cardioversion Flashcards
B.25 Cardioversion
define
The restoration of normal heart rhythm in patients with tachycardia or arrhythmia using electric current (electric cardioversion) or drugs (chemical cardioversion).
B.25 Cardioversion
define Synchronized electrical cardioversion
Synchronized electrical cardioversion is a procedure designed to stop an unusually rapid heart rate or cardiac arrhythmia by administering a controlled electrical current to the heart at a precise moment during the cardiac cycle.
B.25 Cardioversion
define pharmacological cardioversion
Pharmacologic cardioversion employs medication rather than an electrical shock to restore normal cardiac rhythm.
A therapy used to restore sinus rhythm in patients with arrhythmias such as atrial fibrillation, atrial flutter, atrial tachycardia and ventricular tachycardia. Common antiarrhythmic drugs that are used include flecainide, propafenone, ibutilide, and dofetilide. Less effective than electrical cardioversion (external direct current).
B.25 Cardioversion
Indications
✅ Symptomatic patients (especially new-onset)
✅ Hemodynamically unstable AF (emergency!)
✅ First episode of AF or paroxysmal AF
✅ To improve symptoms or cardiac function in patients where rhythm control is preferred over rate control
✅ Tachycardia-induced cardiomyopathy
B.25 Cardioversion
what do you do when there is AF < 48 hours
Can cardiovert without anticoagulation in stable patients (but safer if anticoagulated)
B.25 Cardioversion
what do you do when there is AF > 48 hours or unknown duration
Must anticoagulate for ≥3 weeks before and ≥4 weeks after OR perform TEE to exclude clot first
B.25 Cardioversion
describe electrical cardioversion
Most effective (success rate ~90%)
Synchronized shock delivered during R wave (to avoid inducing VF)
Done under sedation
Used in hemodynamic instability, or when drug failure occurs
B.25 Cardioversion
electrical cardioversion indication
Defibrillation is only indicated if either of the following is the case:
- An irregular wide-complex cardiac rhythm is identified. - VT, torsades de pointes, and SVT with pre-excitation are some of the more common causes of WCT. Ventricular fibrillation also causes irregular wide-complex cardiac rhythm, but the patients will be pulseless.
- The device fails to synchronize with the patient’s cardiac rhythm - The three rhythms that the device may fail to synchronize with are polymorphic ventricular tachycardia, multifocal atrial tachycardia, and junctional tachycardia. These rhythms should be treated with defibrillation if the patient is unstable.
B.25 Cardioversion
What is Synchronized electrical cardioversion
A form of electrical cardioversion in which a low-energy shock is delivered at or just after the peak of the R-wave of the QRS complex.
B.25 Cardioversion
Indications of Synchronized electrical cardioversion
Unstable narrow-complex tachycardia with pulse (e.g., supraventricular tachycardia, including Afib with RVR and atrial flutter)
Unstable regular wide-complex tachycardia with pulse (e.g., monomorphic ventricular tachycardia - In pulseless ventricular tachycardia, defibrillation is the method of choice.
B.25 Cardioversion
Procedure of Synchronized electrical cardioversion
- Preparation and procedural sedation for cardioversion
- Place paddles or electrode pads firmly on the thorax of the patient (anteroapical or anteroposterior position).
- Choose the synchronized (SYNC) mode of shock on the defibrillator device.
- Select the recommended dose of electrical energy according to the patient’s cardiac rhythm.
- Regular narrow-complex tachycardia: 50–100 J biphasic waveform
- Irregular narrow-complex tachycardia: 120–200 J biphasic waveform (preferred) OR 200 J monophasic [9]
- Regular wide-complex tachycardia: 100 J biphasic waveform - “Clear” the patient.
- Deliver shock.
- Reassess the rhythm and check the pulse.
B.25 Cardioversion
describe Pharmacological Cardioversion and what drugs are used
pharmacotherapy for the conversion of Afib to sinus rhythm
- Most likely to be effective for arrhythmias of < 7 days’ duration
- More effective for atrial flutter than Afib, but there is a risk of conversion to 1:1 conduction with propafenone and flecainide - This risk can be mitigated by giving either a beta blocker or ndHP CCB ≥ 30 minutes before administering either medication.
B.25 Cardioversion
Pharmacological Cardioversion Indications
- Hemodynamically stable patients, in whom procedural sedation may be harmful
- Patient preference
B.25 Cardioversion
What medication is used in the hospital with normal LV Function
IV amiodarone (off-label)
alternatively, procainamide (off-label)
B.25 Cardioversion
What is the Pill-in-pocket strategy
a single, self-administered dose of an antiarrhythmic used outside of the hospital to terminate Afib
Indication: infrequent, recent-onset Afib after a first successful dose in a hospital setting
Agents: flecainide (off-label) or propafenone (off-label)
Typically given in conjunction with a beta blocker or ndHP CCB
B.25 Cardioversion
Post-Cardioversion Strategy
Continue anticoagulation ≥4 weeks (if duration >48 hrs)
Consider antiarrhythmic drugs to maintain sinus rhythm (e.g. amiodarone, sotalol)
Address underlying cause: HTN, OSA, alcohol, valvular disease
Educate on symptom monitoring and stroke prevention
