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 98.6ยฐF (37.0ยฐC), 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.ย Atrial fibrillation classically presents with a strange sensation in one’s chest of an odd or rapid heart rate. Common risk factors include older age, hypertension, heart failure, valvular and coronary disease, obesity, sleep apnea, alcohol use, and hyperthyroidism. 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
- Risk factors: older age, hypertension, heart failure, valve and coronary disease, obesity, sleep apnea, excess alcohol, and hyperthyroidism
- 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 can be done early, with anticoagulation started before or at the time of cardioversion
- Duration โฅ 48 hours or unknown: 3 weeks of therapeutic anticoagulation or a transesophageal echo (TEE) showing no left atrial thrombus before cardioversion, then anticoagulation for at least 4 weeks afterward
- Unstable Patient with rapid ventricular rate =ย synchronizedย cardioversion
Treatment
- Anticoagulationย is determined by CHA2DS2-VASc scoring to assess theย risk of stroke
- Direct oral anticoagulantsย orย DOACย (eg, dabigatran, rivaroxaban, apixaban, or edoxaban) rather than warfarinย for most patientsย in whom oral anticoagulant therapy is chosen
- Warfarin (not a DOAC) is required with a mechanical heart valve or moderateโsevere rheumatic mitral stenosis; anticoagulate if CHA2DS2-VASc is 2 or more in men or 3 or more in women, and aspirin is not adequate stroke prevention
- Adjusted-doseย warfarinย target INR isย 2.5 (range 2โ3)
- Rate controlย strategy of managing atrial fibrillation aims to keep the heart rateย below 110 beats per minute – Calcium channel blocker (diltiazem, verapamil) orย beta-blocker (metoprolol)
Smarty PANCE Content Blueprint Review:
Covered under โ PANCE Cardiology Blueprint (11%) -ย Conduction Disorders (PEARLS) - Atrial Fibrillation