A 27-year-old patient with stage 4 CKD from FSGS had a BP of 190/110 mm Hg. The doctor elects to add atenolol 50 mg/d to the treatment program of an ACEI and a dihydropyridine calcium channel blocker, each at maximal dosage. Within one week, the patient develops two episodes of bradycardia to 48 bpm.
When examined in the emergency department for light-headedness, an electrocardiogram showed first-degree heart block with sinus bradycardia. Serum electrolytes, calcium, and magnesium were in the normal range.
