And number of vasodilators have been shown to reverse the peripheral vasoconstriction that occurs in congestive heart failure. The most important group of vasodilator agents is the angiotensin-converting enzyme(ACE) inhibitors .
These agents help improve heart failure symp toms, in part, by blocking production of angiotensin II and reducing afterload. In addition, ACE inhibitors have been shown to reduce mortality in patients with both symptomatic and asymptomatic left ventricular dysfunction . The major side effects of ACE inhibitors include occur in approximately 10% of patients and is related to tor use Hydralazine in combination with oral nitrates has also been shown to reduce mortality in patients with symptomatic congestive heart failure, although not to the de gree of ACE inhibitors.
This combination provides an alternative to the patient who is ACE-inhibitor intolerant or may require additional therapy for blood pressure control antagonists, prevent the binding of angiotensin II to its receptor. This has the theoretic advantage of blocking the effects of angiotensin II produced in the blood stream, as well as at the tissue level. In addition, the angiotensin II receptor blockers do not interfere with metabolism and, therefore, are not associated bradykinin with cough. Several small studies comparing ACE inhibitors to angiotensin II lockers suggest that these two classes of agents may be equally effective in reducing morbidity and mortality heart failure patients. How until long-term studies are completed, angiotensin II receptor blockers should be reserved for those patients intolerant of ACE inhibitors or hydralazine and nitrates.
The negative inotropic effects of the calcium channel blockers and their activation of the sympathetic nervous system make these agents less attractive in the treat ment of patients with congestive heart failure. In particular, several studies have shown worsening of heart failure symptoms in patients treated with nifedipine. Other calcium channel blockers, such as diltiazem, have been shown to improve symptoms.