1 Introduction

The cardiac natriuretic system, composed of atrial and brain natriuretic peptides (ANP and BNP), plays a major role in blood pressure and fluid homeostasis, protecting the organism from volume and pressure overloads. Accordingly, the cardiac hormones have been shown to delay the occurrence of overt heart failure through their diuretic, natriuretric and vasodilatory properties [1–3]. Adrenomedullin, mainly produced by vascular smooth muscle cells and by vascular endothelial cells, is also secreted by the failing human heart. This potent vasorelaxing and natriuretic peptide can thus be considered as a third cardiac hormone, involved in circulation control [4,5].

Short term survival is no longer the pivotal issue for most heart-transplant recipients (Htx) because of enhancement in organ preservation, surgical and medical therapies. Consequently, improving quality of life after heart transplantation arises as an important goal, which might be reached through exercise and training programs [6–8]. Since cardiac natriuretic peptides greatly participate in cardiovascular adaptations, it appeared interesting to focus this review on ANP, BNP and adrenomedullin (ADM) responses to exercise and training after heart transplantation.

Relative rather than absolute work load will be used to compare groups since it is generally considered to be a better indicator of the magnitude of fluid-regulating hormone changes, both in normal subjects and in Htx [9]. After discussing why circulating ANP, BNP and ADM are elevated in Htx, we will investigate the stimuli of their secretion during exercise and present the few data available concerning their response to exercise training after heart transplantation.

2 Increased circulating cardiac natriuretic peptides after heart transplantation

After successful cardiac transplantation, normalization of filling pressures, as well as normalization of the renin–angiotensin–aldosterone and the sympathetic systems, generally occur, explaining why persistent elevation of circulating ANP and BNP was unexpected [10–13]. In fact, replacing the failing heart by a so-called …