Design of coronary circulation: A minimum energy hypothesis

The coronary circulation consists of a complex system of blood vessels that nourishes the heart muscle. In order to understand the coronary circulation, it is essential to understand the design rules or scaling laws of the system under homeostatic conditions. Our hypothesis is that the cost of operation of fluid conduction and fluid metabolism are minimized, i.e., the minimum energy hypothesis. This hypothesis along with conservation of energy under steady-state flow leads to scaling relationships between vascular length and volume of coronary arterial tree, diameter and length of coronary vessel branches and lumen diameter and blood flow rate in each vessel branch. These relationships are validated based on a complete set of anatomical data of the entire coronary arterial tree down to the capillaries and a steady-state flow analysis. Our results show very good agreement between the theoretical predictions and the experimental data. These results provide insight into the design of the coronary arterial tree in health and may be used as a reference state for the study of coronary artery disease.