Theoretical and Evidence-Based Benefit of Afterload Reduction in the Postoperative Pediatric Heart

Rational use of vasodilators to induce afterload reduction is predicated on a thorough knowledge of the constituents of afterload and of the role ventriculoarterial coupling plays in determining their effects. Afterload reduction therapy should be goal directed with the intent to improve stroke volume and tissue oxygen delivery rather than to decrease blood pressure per se. This review will summarize the components comprising circulatory system afterload and will use ventriculoarterial coupling concepts to demonstrate the variable but predictable effects of vasodilator therapy on hemodynamics and tissue oxygen delivery. This article addresses the third of eight topics comprising the special issue entitled “Pharmacologic strategies with afterload reduction in low cardiac output syndrome after pediatric cardiac surgery”. Keywords: Ventriculoarterial coupling, afterload reduction, vasodilation, ventricular performance, ventricular compliance, ventricular elastance, arterial elastance, oxygen delivery, preload recruitable stroke work.