[New pathogenetic mechanisms of idiopathic dilated cardiomyopathy: changes in coronary microcirculation].

There is growing evidence of the presence and relevance of coronary microvascular abnormalities in many cardiac diseases. In particular, it has been recently shown that dilated cardiomyopathy is characterized by coronary microvascular dysfunction since its early onset. Abnormal coronary microcirculatory function is not an effect of myocardial damage but in turn seems to be able to cause progressive contractile dysfunction, ventricular dilatation and heart failure. The mechanisms are largely unknown but both myocardial hypoperfusion and myocardial ischaemia are most probably involved. It has been demonstrated that in patients with dilated cardiomyopathy the presence of severe coronary microcirculatory dysfunction is an independent and relevant prognostic factor. From these studies it is more and more evident that coronary microvascular dysfunction is a new pathogenetic mechanism in dilated cardiomyopathy and that the coronary microcirculation should be considered a new target of treatment in cardiac diseases at risk to evolve towards heart failure.