A 57-year-old man is referred for assessment of his low serum sodium of 125 mEq/L. On examination, he has pitting edema and elevated neck veins. His urine sodium is 10 mEq/L and urine osmolality 350 mOsm/kg.For the above patient with hyponatremia, select the most likely diagnosis.
congestive heart failure (CHF) extrarenal sodium and fluid losses SIADH polydipsia