Atrial Fibrillation: The Daily PANCE Blueprint

Answer: D. Synchronized cardioversion

This patient is presenting with unstable vitals and an ECG suggestive of atrial fibrillation. The best initial step in management is synchronized cardioversion. Atrial fibrillation classically presents with a strange sensation in one’s chest of an odd or rapid heart rate. It typically occurs in patients with a history of ischemic heart disease, valvular abnormalities, or connective tissue disorders. The diagnosis is confirmed with an ECG, and unstable patients (hypotension and tachycardia) should be immediately cardioverted. The ECG demonstrates an irregular rhythm with no discernible P-waves.

• Answer 1: Adenosine is the next step in management after vagal maneuvers in a stable patient with supraventricular tachycardia (SVT)
• Answer 2: Diltiazem is a calcium channel blocker and is an initial treatment of choice for atrial fibrillation in stable patients
• Answer 3: Metoprolol is a beta-blocker and is an initial treatment of choice for atrial fibrillation in stable patients
• Answer 5: Vagal maneuvers are the best initial step in management in a stable patient with SVT

Atrial Fibrillation Pearls

• EKG: erratic baseline and no discrete P waves, in between irregularly spaced QRS complexes
• Elderly, excessive alcohol use
• Symptoms range from syncope, dyspnea, palpitations to no symptoms
• Irregularly irregular pulse

low-amplitude fibrillatory waves without discrete P waves and an irregularly irregular pattern of QRS complexes

When to Cardiovert

• Duration of Afib < 48 hours – cardioversion, amiodarone (obtain transesophageal echo (TEE) to determine if a clot is present prior to cardioversion)
• Duration > 48 hours – anticoagulate for 21 days (3 weeks) prior to cardioversion
• Unstable Patient with rapid ventricular rate = synchronized cardioversion

Treatment

• Anticoagulation is determined by CHA2DS2-VASc or CHADS2 scoring to assess the risk of stroke
• Direct oral anticoagulants or DOAC (eg, dabigatran, rivaroxaban, apixaban, or edoxaban) rather than warfarin for most patients in whom oral anticoagulant therapy is chosen
• Warfarin is preferable to DOACs in patients with mechanical heart valves, mitral stenosis, unacceptable increase in cost, EGFR < 30 ml/min, on certain medications (ex. phenytoin or certain antiretroviral therapy)
• Adjusted-dose warfarin target INR is 2.5 (range 2–3)
• Rate control strategy of managing atrial fibrillation aims to keep the heart rate below 110 beats per minute – Calcium channel blocker (diltiazem, verapamil) or beta-blocker (metoprolol)