Severe Hypophosphatemia Leading to Acute Worsening of Heart Failure and Myopathy: A Case Report.

This case highlights a rare instance of severe hypophosphatemia precipitating acute exacerbation of heart failure and myopathy in an 88-year-old male patient residing in a long-term care facility. The patient presented with edema and limb weakness, with a background of chronic heart failure, kidney disease, and vitamin D deficiency. Despite initial treatments targeting anemia and heart failure, the patient's condition did not improve until severe hypophosphatemia was identified and treated with phosphate supplementation, leading to rapid clinical improvement. This case highlights the importance of considering hypophosphatemia in the differential diagnosis of worsening heart failure or myopathy, particularly in frail elderly individuals residing in facilities with a high risk of vitamin D deficiency. It suggests that measuring serum phosphate levels should be considered in cases of heart failure or myopathy in such populations to prevent delays in diagnosis and treatment.