Echocardiogram shows some global reduction in left ventricular function. no echo features to suggest inflammation/pericarditis. what could cause this?

Decreased EF: Reduced LV function at your age is unusual, and may be due to issue with the heat muscle, infections can do this, certain viral infections are known. You should see a heart doctor to discuss the finding of the 2DE and ascertain as to why there is decreased function. A follow up 2DE should be considered at a certain interval. Best of luck.