Angiotensin converting enzyme inhibitors and angiotensin II receptor antagonists in the treatment of chronic heart failure

Renin-angiotensin system: This system plays a major role in regulation of blood pressure. Angiotensin converting enzyme inhibitors (CEI) modify the balance between the vasocilator and diuretic properties of bradykinin and the vasoconstrictor and antidiuretic properties of angiotensin II, favoring vasodilatation and natriuresis. Angiotensin II receptor antagonists (ARAII) block AT1 receptors and stimulate AT2 receptors with favorable vasodilator and natriuretic affects. CEI: Converting enzyme inhibitors play an indispensable role in the treatment of heart failure and should be prescribed at high dosage. They have a long-term beneficial effect. ARAII: These compound could play a role in the future, but studies conducted to date comparing ARAII and CEI have been unable to demonstrate superior or equivalent effects with ARAII, and do not warrant their prescription for hypertension.