A man in his 70s with stage 4 chronic kidney disease (CKD) and atrial fibrillation (AF) presented with 1 month of progressive dyspnea on exertion, orthopnea, and worsening lower extremity edema. He previously underwent ablation for AF with symptomatic recurrence 6 weeks prior to presentation. He had been treated with flecainide, 100 mg twice per day, with a recent change to 100 mg 3 times per day dosing. On initial presentation to the emergency department, the patient was alert and oriented. He had a blood pressure of 119/80 mm Hg, heart rate of 101 beats per minute, and pulse oximetry of 98% on room air. His cardiovascular examination was consistent with congestive heart failure. Initial laboratory workup revealed a creatinine level of 2.1 mg/dL (baseline, 1.3 mg/dL; to convert to µmol/L, multiply by 88.4), blood urea nitrogen levels of 45 mg/dL, serum potassium level of 4.7 mmol/L, serum lactate levels of 4.6 mmol/L, troponin levels of 0.06 ng/mL (to convert to µg/L, multiply by 1.0), and brain-type natriuretic peptide levels of 1032 pg/mL (to convert to ng/L, multiply by 1.0). His electrocardiogram (ECG) on initial presentation is shown in Figure 1 and baseline ECG in Figure 2. Transthoracic echocardiogram (TTE) demonstrated new, severe biventricular systolic dysfunction with left ventricular ejection fraction (LVEF) of 15% to 20%. The LVEF was previously 55% to 60% 6 months prior to this presentation.
Bucklew EA, Reis SE, Kancharla K. Wide QRS Tachycardia in a Man With a Medical History of Atrial Fibrillation. JAMA Intern Med. 2019;179(4):567–569. doi:10.1001/jamainternmed.2018.8603
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