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Signature ✍️
- 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”
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DDx 🏳️🌈
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- Vitals: hypoxia, fever?
- ECG: ischemia?
- Volume status: dry, wet?
- BMP: electrolytes?
- Context: e.g. recent surgery?
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- IVC
- Hypovolemia
- Atria
- ↑ stretch: decompensated CHF, pHTN, HTN emergency
- Local irritation: misplaced CVC
- Obstruction: myxoma
- Ventricles
- Acute cardiomyopathy: ischemia, myocarditis, Takotsubo
- Chronic cardiomyopathy: separate DDx
- Valves
- Numerous valvulopathies
- Pericardial
- Pericarditis
- Tamponade
- Conduction System
- Electrolytes derangements
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- Pulmonary
- Airway/Alveolus: AE-COPD, pneumonia, non-cardiogenic pulmonary edema
- Interstitium: ILD
- Pleural: pneumothorax
- Vascular: PE, pHTN
- Metabolic/Toxic
- Thyrotoxicosis
- EtOH intoxication (”Holiday Heart Syndrome”)
- Uremia
- Anemia
- Acidemia
- Adrenergic
- Sepsis
- Fever
- Severe systemic inflammation (e.g. metastatic malignancy)
- β-agonists
- Vasopressors (e.g. dopamine, epinephrine)
- Sympathomimetics (e.g. cocaine, methamphetamine)
- Extreme exercise
- EtOH & Benzo. withdrawal
- Rare
- Infiltrative thoracic masses
- Compressive thoracic masses
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Principles❗
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
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References 📚
- mikearcieri.bsky.social’s clinical expertise ✨