Aspects on "traditional" vasodilators in the treatment of chronic heart failure

Vasodilator therapy of heart failure has through the last 5-10 years become a well established treatment. Traditionally these drugs have been classified after their primary site of action on the vascular beds. Thus drugs primarily acting on the arteriolar bed are called afterload-reducing agents and are exemplified by hydralazine. Drugs primarily acting on the venous bed have been called preload-reducing reducing agents and the typical example is nitroglycerin. Other drugs, like prazosin, act on both the arteriolar and venous vascular beds. The classification is, however, not as sharp as originally believed since preload- and afterload-reducing activities mix with each other. Treatment with vasodilators for chronic heart failure has mainly been advocated in patients with valvular regurgitation, ischemic heart disease and various types of dilated cardiomyopathies. It seems appropriate today to put some questions concerning vasodilator therapy for heart failure. Among such questions are: When in the natural history of congestive heart failure should vasodilator therapy be commenced? How effective is long-term administration of vasodilating drugs? May vasodilator therapy decrease mortality in congestive heart failure? What about the efficacy of new vasodilating drugs compared to more traditional ones? In the review of vasodilating drugs besides ACE inhibitors, these questions will be addressed.