Calcium-regulating peptide hormones and blood electrolytic balance in chronic heart failure.

Calcium-regulating system is important for the functional activity of myocardium. However, little is known about the role of this system in the pathogenesis of cardiovascular diseases. Blood samples from the patients with chronic heart failure (CHF) caused by ischaemic disease (coronary artery disease) (NYHA class I-IV) were used to analyze the levels of calcium, inorganic phosphate, sodium, potassium, parathyroid hormone (PTH) and parathyroid hormone-related protein (PTHrP). The heart beat rate and arterial blood pressure were chosen as additional tests for the functional status of cardiovascular system. The alteration of electrolytes homeostasis was found dependent on the severity of the pathology being maximally expressed in the NYHA class IV patients. Similar tendency was demonstrated for circulating PTH and PTHrP with the highest blood concentrations observed in patients of the NYHA class III and IV. The extent of these changes was found more pronounced in the female patients. It is suggested that the calcium-regulating hormonal system is involved in the pathogenesis of the ischaemic heart disease; however the sharp increase of PTH and PTHrP at the severe stages of pathology may play a compensatory role in maintaining the heart function.