LAUSR

A 67-year-old woman with end-stage renal disease on peritoneal dialysis, insulin-dependent diabetes mellitus, hypertension, and peripheral artery disease presented to the emergency department with a week-long history of progressive confusion, nonproductive cough, and discoloration of the digits on her right foot. In the emergency department, she was found to have lactic acidosis (pH 7.09, serum lactate 6.7 mmol/L rising to >20), leukocytosis, and transaminitis. Computed tomography scans showed a subacute occipital lobe infarct and occlusion of the peroneal artery at the ankle. An ECG was obtained (Figure 1). What is the underlying conduction abnormality? Please turn the page to read the diagnosis. Blake G. Smith, MD Jonathan Kalehoff, MD G. Neal Kay, MD