Atrial Fibrillation: The Daily PANCE Blueprint
A 63-year-old male presents to the emergency department with a strange sensation in his chest. He states that it started this morning and has not been improving. He drinks alcohol regularly and smokes a pipe. His temperature is 98.6°F (37.0°C), blood pressure is 85/58 mmHg, the pulse is 140/min, respirations are 18/min, and oxygen saturation is 95% on room air. The ECG shows low-amplitude fibrillatory waves without discrete P waves and an irregularly irregular pattern of QRS complexes. Which of the following is the best initial step in management?
- Adenosine
- Diltiazem
- Metoprolol
- Synchronized cardioversion
- Vagal maneuvers
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)
Smarty PANCE Content Blueprint Review:
Covered under ⇒ PANCE Cardiology Blueprint (13%) - Conduction Disorders (PEARLS) - Atrial Fibrillation