Resistant hyponatraemia in a patient with follicular lymphoma and heart failure with reduced ejection fraction: a case report.

ABSTRACT

BACKGROUND: Hyponatraemia is a common problem in patients with heart failure. It can be difficult to treat, especially in the presence of the patient's needs for diuresis and manipulation of the renin-angiotensin-aldosterone system (RAAS). CASE SUMMARY: This concerns a 74-year-old woman with follicular lymphoma and severe global left ventricular systolic dysfunction secondary to treatment with R-CHOP chemotherapy. She presented a difficult challenge in the management of her decompensated heart failure alongside hyponatraemia as low as 113 mmol/L. This was resistant to standard treatment. The resistance to usual measures necessitated treatment with Tolvaptan, a selective arginine vasopressin V2 inhibitor used to treat hyponatraemia in syndrome of inappropriate anti-diuretic hormone. This, along with a strict fluid restriction of 500 mL/day, resolved the patient's hyponatraemia and enabled her discharge home on tolerated heart failure treatment. She has now remained stable for almost 12 months. DISCUSSION: The potential causes of hyponatraemia are discussed along with the role of Tolvaptan in its management.