Figure 2.

Schematic of the integrative physiology of HFpEF showing various extracardiac mechanisms and how they are involved. From top left, counterclockwise: lung involvement including primary lung disease leading to PAH, secondary PVH, impaired lung muscle mechanics, and eventual increase pulsatile RV load; abdominal compartment mechanisms including splanchnic circulation (preload), bowel congestion leading to endotoxin translocation and systemic inflammation; skeletal muscle mechanisms including impaired metabolism and peripheral vasodilation; renal mechanisms including passive congestion leading to renal impairment, changes in neurohormonal axis activation, hypertension, abnormal fluid homeostasis, eventual oliguria/renal insufficiency; ventricular-vascular mechanisms including ventricular stiffening leading to systolic and diastolic impairment, diminished systolic reserve, increased cardiac energetic demands and fluid-pressure shift sensitivity. (Illustration credit: Ben Smith)