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Antidiuretic hormone and atrial natriuretic peptide in congestive heart failure
Insights
Captopril treatment normalized high plasma antidiuretic hormone (ADH) levels in congestive heart failure (CHF) patients. This suggests captopril may improve water balance by reducing ADH and angiotensin II in CHF.
Area of Science:
- Cardiology
- Endocrinology
- Pharmacology
Background:
- Congestive heart failure (CHF) is often associated with neurohormonal imbalances.
- Elevated levels of antidiuretic hormone (ADH) and atrial natriuretic peptide (ANP) are observed in CHF patients.
- The role of these hormones in CHF pathogenesis and treatment requires further investigation.
Purpose of the Study:
- To investigate the effect of captopril on plasma ADH and angiotensin II levels in CHF patients.
- To examine the relationship between CHF severity and plasma ANP concentrations.
- To explore the potential benefits of captopril in managing fluid balance in CHF.
Main Methods:
- Plasma ADH and angiotensin II were measured in 8 NYHA class III-IV CHF patients before and during captopril treatment.
- Plasma ANP was measured in 17 CHF patients across different severity classes and in 18 healthy controls.
- Radioimmunoassay was used for hormone level determination.
Main Results:
- Captopril treatment normalized elevated plasma ADH levels in CHF patients, sustained for at least 6 months.
- Plasma angiotensin II levels were also reduced to normal ranges with captopril therapy.
- Plasma ANP levels correlated with CHF severity, being highest in the most severe cases and elevated in paroxysmal supraventricular tachycardia with polyuria.
Conclusions:
- Captopril effectively reduces elevated ADH and angiotensin II in CHF patients, potentially improving water balance.
- ANP is a circulating hormone released in response to increased preload and atrial stretch in conditions like CHF and tachycardia.
- These findings highlight the neurohormonal dysregulation in CHF and the therapeutic potential of ACE inhibitors.
Abstract:
Plasma concentrations of antidiuretic hormone (ADH) were measured in 8 patients with congestive heart failure (CHF) of NYHA functional class III-IV, before and during treatment with captopril, 6.25-25.0 mg t.i.d., added to their drug regimen. Before captopril treatment, plasma ADH was high, 2.5 times the upper limit of normal reference values. During treatment with captopril, plasma ADH levels were normalized, and remained so throughout the study, for at least 6 months. Plasma levels of angiotensin II were also reduced to a normal level. Reduction of plasma ADH during captopril treatment in CHF may partly depend on reduced angiotensin II formation, and may be beneficial by improving water balance. Atrial natriuretic peptide (ANP), was measured by radioimmunoassay in 17 patients with CHF. The highest levels were measured in the most severe CHF cases, and intermediate high values on NYHA functional class I-II patients. Plasma ANP concentrations in control patients (n = 18) without cardiac diseases ranged between 0 and 30 pg/ml. In two patients with paroxysmal supraventricular tachycardia, associated with transient polyuria, high plasma ANP concentrations were noticed during tachycardic episodes. Thus, ANP appears to be a circulating hormone in humans, and is released into the blood in clinical conditions associated with raised preload and atrial wall stretch.