Completed

You have now completed the history and physical examination of a 45-year-old male with findings consistent with dilated cardiomyopathy. Further evaluation includes selected laboratory studies. The following laboratory tests were normal complete blood count, electrolytes, blood urea nitrogen, creatinine, blood glucose and liver function tests. Lipid profile, thyroid function, iron studies and HIV were assayed because they may also give clues to the underlying pathogenesis of the patient's cardiomyopathy.

The B-type natriuretic peptide (BNP) level was also obtained. This is a neurohormone secreted mainly by ventricular myocytes in response to volume expansion and pressure overload. A BNP level correlates with severity and prognosis of congestive heart failure. It can also help differentiate between pulmonary and cardiac causes of dyspnea.