Atrioventricular conduction defect associated with severe hyponatremia.

Hyponatremia is the most common electrolyte disorder among hospitalized patients and in the clinical setting. Patients with hyponatremia may develop a variety of symptoms, primarily neurological and gastrointestinal. Hyponatremia is more frequently encountered in patients with an underlying heart disease, particularly in the elderly. We hereby present a case of complete atrioventricular block in an elderly patient who had undergone aortic valve replacement and had been using thiazide. Complete atrioventricular block improved after sodium replacement therapy and no other cause of electrolyte disorder was documented.