Atrioventricular nodal dysfunction secondary to hyperparathyroidism.

The relationship of hyperparathyroid-associated hypercalcemia with clinical significant bradyarrythmias still remains controversial. We present a 66-year-old patient with dizziness, headache and paroxysmal 2:1 atrioventricular block. A 24-hour Holter report revealed symptomatic intermittent 2(nd) degree (2:1) atrioventricular block with a mean heart rate of 46 bpm.