Transcutaneous pacing AND DC cardioversion

Question 1

What is DC cardioversion

Answer 1

Direct current (DC) cardioversion is a medical procedure to restore sinus rhythm in certain arrhythmias. It involves delivering a synchronised electric current using a defibrillator.

A synchronised shock involves delivering a shock that coincides with the R-wave of the QRS complex. This is essential because an unsynchronised shock may coincide with a T-wave, leading to ventricular fibrillation.

Question 2

what is transcutaneous pacing

Answer 2

Transcutaneous pacing (TCP) is a temporary, non-invasive cardiac pacing technique used to manage bradyarrhythmia. It involves the delivery of electrical impulses through external pacing pads placed on the chest.

Question 3

Indications for transcutaneous pacing

Answer 3

Bradyarrhythmia with life threatening features (shock, syncope, myocardial ischemia, heart failure)
Bradyarrhythmia with high risk of asystole (recent asysotle, mobitz 2 block, complete heart block with broad QRS, ventricular pause >3 seconds)

Question 4

Indications for using DC cardioversion

Answer 4

Unstable tachyarrhythmias: characterised by the presence of life-threatening features (shock, syncope, myocardial ischemia, severe heart failure)
Stable tachyarrhythmias: unresponsive to simple interventions and pharmacological management, i.e. vagal manoeuvres, adenosine, flecainide
Atrial fibrillation (AF): elective cardioversion where rhythm control is appropriate

Question 5

Contraindications to DC cardioversion

Answer 5

Patient refusal (absolute contraindication)
Severe electrolyte disturbances: should be corrected before attempting cardioversion unless an emergency
Inadequate anticoagulation for elective cardioversion in AF: if AF is present for >48 hours, elective cardioversion should be delayed to allow therapeutic anticoagulation for at least 3 weeks to prevent thromboembolic events
Left atrial thrombus: cardioversion should be delayed until clot resolution, with therapeutic anticoagulation