[Mechanisms and consequences of changes of the vasomotor activity in cardiac insufficiency]

Changes in vasomotor tone in cardiac failure are related to the severity of the cardiac failure. The causative factors include dysfunction of the baroreceptor reflex, abnormal stimulation of the normal physiological regulators of cardio-circulatory function such as the sympathetic nervous and the renin-angiotensin-aldosterone system, and certain local factors characteristic of cardiac failure such as salt and water retention at vascular wall and interstitial level or changes in the metabolism of certain tissues. These changes are variable according to the region perfused and their interaction results in preferential redistribution of blood flow to the coronary and cerebral circulations at the expense of other regions such as the splanchnic and cutaneous vessels. In addition, they play a key role in the adaptive peripheral mechanisms to left ventricular failure and to the modulation of the vascular effects of drug therapy. An improvement in our understanding of these mechanisms and their consequences is important from the physiopathological, prognostic and therapeutic points of view.