The common denominator of these effects of sildenafil is the expression of PDE5 in both the human left and right ventricle, specifically in smooth muscle and endothelial cells, and in the cardiomyocytes themselves, which is considerably increased in end-stage ischemic cardiomyopathy, and the assumption that this may contribute to at least right ventricular heart failure [20]. Here, PDE5A is linked to ischemic cardiomyopathy.