To determine the response of plasma atrial natriuretic peptide (ANP) to treatment with an angiotensin converting enzyme (ACE) inhibitor in heart failure, seven patients (NYHA Functional Class III-IV) were studied before and after the addition of ramipril to maintenance digoxin and diuretic treatment. 2. Baseline arterial ANP levels were raised, but fell during ramipril treatment in parallel with changes in both haemodynamic recordings (arterial pressure, pulmonary artery diastolic pressure, and right atrial pressure) and hormone levels (angiotensin II and aldosterone). 3. Coronary sinus ANP, measured in three patients, was greater than concomitant arterial levels, and the coronary sinus ANP secretion rate was calculated to be between 15 and 119 pmol/min. 4. These results demonstrate that improvement in haemodynamic function during ACE inhibitor treatment is associated with a decline in elevated ANP levels, and support the concept that atrial stretch or pressure regulates the secretion of atrial peptides in man.
