Animal studies have allowed important insights into the role of the nitric oxide synthase (NOS) enzymes in atherosclerosis and hypertension, as well as in stroke.
High LV endomyocardial NOS gene expression is observed in athlete's heart and in dilated cardiomyopathy with low diastolic LV stiffness and preserved LV stroke work.
Because of lower endomyocardial NOS gene expression in patients with higher functional class and lower LV stroke work, increased endomyocardial NOS gene expression seems to be beneficial rather than detrimental for the failing heart.
In patients with elevated LV end-diastolic pressure (>16 mm Hg), a closer correlation was observed between endomyocardial expression of NOS2 and LV stroke volume (P=0.001; r=0.74), LV ejection fraction (P=0.0007; r=0.77), and LV stroke work (r=0.82; P=0.0002).