fig6

Figure 6. Endothelial to Myocardial Signaling in Cardiovascular Aging: Mitochondrial ROS, NO Deficiency, and Myocardial Stiffness Driving HFpEF (Created in BioRender. Shila TA (2026) https://BioRender.com/zlp092e). HFpEF: Heart failure with preserved ejection fraction; ROS: reactive oxygen species; eNOS: endothelial nitric oxide synthase; sGC: soluble guanylate cyclase; cGMP: cyclic guanosine monophosphate; PKG: protein kinase G; mtROS: mitochondrial reactive oxygen species; NO: nitric oxide; ECM: extracellular matrix.