Shortcomings of Hemodynamic Theory
“Every violation of truth is not only a sort of suicide in the liar, but is a stab at the health of human society.”—Ralph Waldo Emerson
1. Opposing muscular forces of muscular vasoconstriction and cardiac contraction would be inherently inefficient. Muscular contraction rapidly consumes ATP reserves, resulting in muscle exhaustion.
2. Blood pressure is assumed to be the driving force of blood flow, but flow resistance determines cardiac output. Exercise conditioning proliferates muscle capillaries, reduces flow resistance, lowers resting blood pressure, and enhances cardiac output during exercise without causing hypertension. Microvascular damage that reduces cardiac output and tissue perfusion causes essential hypertension.
3. Fluid flow acceleration in pipes induces exponential increases in turbulent flow resistance, but the heart produces ten-fold increases in cardiac output during intense exercise while consuming less energy than a 40-watt light bulb, with negligible increases in muscular size and weight.
4. Direct autonomic innervation is lacking in peripheral muscles and tissues.
5. Mammalian hearts weigh less than 1% of total body weight and are so weak that they cannot pump blood more than a few inches above their height. Mammalian brains are accordingly located inches above the heart. The elevated head of the giraffe requires a disproportionately gigantic heart that leaves little room for lungs and intestines.
6.Were cardiac output to be directly determined by cardiac contractility, then the forces of blood pressure and the palpable pulse would appear simultaneously and equally throughout the arterial tree during systole, when the heart muscle ejects blood, because both water and blood are incompressible, and exercise conditioning should increase cardiac size and weight. Instead, cardiac contractility varies little from beat to beat; exercise conditioning induces insignificant increases in cardiac size and weight; in trained athletes blood pressure remains normal during intense exercise and falls below normal at rest.
7. In the static hydraulic brake system of a car, brake pedal force transmits instantaneously and equally throughout all inner surfaces of the brake system. This implies that the force of blood pressure should appear instantaneously and equally throughout the arterial tree during systole, when the heart contracts. Instead, blood pressure appears only during diastole, when the heart muscle is at rest, in the form of turbulent pulse waves that propagate throughout the arterial tree, generating lateral forces that press against the inner walls of arteries. These lateral forces manifest as the palpable pulse and enable blood pressure measurement as they travel toward the periphery.
8. Blood pressure varies from location to location, and is perturbed by temperature, arterial length, arterial diameter, arterial curvature, arterial bifurcations, arterial strictures, wave reflections, heart rate, and blood viscosity as well as cardiac contractility.
9. Cardiac contractility varies little from beat to beat, and flow resistance is the primary determinant of cardiac output and cardiac efficiency.
10. Pulsatile turbulent lateral forces, blood pressure, and atherosclerosis resistance generally increase in concert as arterial diameter declines toward the periphery.
11. Efforts to derive cardiac output from conventional blood pressure and pulse wave measurements have proved futile.
12. Electric pumps encounter exponential increases in flow resistance and power consumption with increasing pipe flow rates in “Newtonian” fluids such as water, oil, steam, and atmospheric gases. In contrast, non-Newtonian mammalian blood exhibits exponential decreases in flow resistance with increasing acceleration in pipes and arteries. This disparity is ignored in medical literature and research.
13. One might expect large mammals to possess disproportionately large hearts and generate high blood pressure to propel blood to distant parts of their body, but instead blood pressure is remarkably similar among mammals.