AFib with Rapid Ventricular Response (RVR)

• Irregularly irregular tachyarrhythmia falling under the umbrella of supraventricular tachycardias

• EKG findings include lack of P-waves (look at lead II) & lack of isoelectric baseline

• If patient has a bundle branch block (underlying vs. rate-related), the QRS complex will be “wide,” & this is referred to as “AFib with aberrancy”

Management > Diagnosis 🛑

• As with all tachyarrhythmias, the management — & thus your time to “sit & think” — flows from the stability of the patient. For this reason, the assessment of AFib w/ RVR starts with a “Common & Can’t Miss” approach at the bedside, after which a more “Systematic” diagnostic approach can be deployed

• The DDx for atrial fibrillation (“disordered tachycardia”) & sinus tachycardia (“ordered tachycardia”) have great overlap owing to the fact both are generally triggered by something. In other words, more often than not, AFib w/ RVR & sinus tachycardia do not represent endpoint diagnoses. Always start with assessment for acute triggers, which can then be followed by an assessment for subacute-chronic triggers that may synergistically accumulate (e.g. CHF, OSA/OHS, Pulmonary HTN, Atrial Enlargement)

• Paroxysmal AFib of > 48 hr duration is unlikely to convert, so anticoagulation needs to be considered (i.e. CHA₂DS₂-VASc Score)

Work-Up ⚡

• ECG: confirm rhythm & assess for ischemia → Troponin if concern

• CMP: electrolytes, acidosis, renal function

• CXR: pulmonary infiltrate(s) → CT PE if high suspicion (i.e. hypoxemia) but CXR ⊖

• TSH, FT4, FT3: thyrotoxicosis

• Infectious Work-up: targeted vs. broad

• Echocardiogram / POCUS: LV ejection fraction, regional wall motion abnormality, atrial enlargement, valvulopathy, IVC diameter/collapsibility, RV systolic pressure, B-lines, pericardial effusion

• History: ingestions, alcohol intake, medications

• mikearcieri.bsky.social’s clinical expertise ✨

• https://litfl.com/atrial-fibrillation-ecg-library/