New Positive Inotropic Agents in the Treatment of Congestive Heart Failure

Newer Phosphodiesterase InhibitorsAmong the most promising recent developments in positive inotropic agents has been the description of a class of drugs that have both potent positive inotropic and vasodilatory effects (Table 1). Initial reports have documented that these drugs do not inhibit sodium–potassium ATPase, nor are their inotropic effects diminished by reserpine-induced depletion of endogenous catecholamine stores, pretreatment with beta-adrenergic or alpha-adrenergic blockers, H2 antagonists, agents that block prostaglandin synthesis, or drugs that selectively block the fast inward sodium channels. Hence, they are often referred to as "non-glycoside, non-sympathomimetic" positive inotropic agents. Although structurally dissimilar from one another . . .