Multiple tragic biophysical errors in relation to hypertension in surgery and medicine, constitute conceptual atrocities: 1) Many physicians believe that perfusion decays with the fourth power of the radius, which is the result of a doxastic misunderstanding of the Poiseuille equation. These phenomena are even more transcendent in the case of surgical situations when the homeostatic metastability is more critical and with less margin to be compensated. 2) Furthermore, when seen the occlusion of an artery, frequently, instead of measuring the radius, they measure the apparent cross-sectional area. 3) By reducing the driving pressure with antihypertensive drugs, we are decreasing axial pressure in the flow and consequently the perfusion. 4) The sphygmomanometer measures transmural pressure and not driving pressure which is what produces perfusion. 5) The main hemodynamic cause of damage is not transmural hypertension but Laplacian tension. 6) The damage to the arteries does not depend on transmural pressure but on the energy density per time, in units of Joules per cubic meter per second, or Watts per cubic meter. 7) Hypertension, ceteris parivus, increases perfusion. 8) The baroreceptors do not respond to transmural pressure but to Laplacian arterial tension. 9) The brain and the heart have self-regulation of their perfusion, but vasodilators increase perfusion in other tissues, reducing cerebral and coronary perfusion due to the stolen effect. 10). Strictly, all gradients constitute potential energy, as happens in the instances of the concentration gradients, temperature gradients, pressure gradients, and electrical gradients. 11) The derivative of pressure with respect to time, that is the change in pressure due to change in time, is the derivative of the work per volume per time (change in work density due to time), that is, power density. 12) What determines the perfusion is the axial gradient, not of pressure but energy. 13) Hyperbolically if we consider taking the pressure of a pachyderm, we would obtain readings significantly higher. 14) Pressure is, in reality, energy density, which means, energy per infinitesimal unit of volume. 15) The venous return consists of the blood flow returning to the right heart. Because the input of the right side must equal its output, then in the steady-state situation, the cardiac outputs of the right and left sides are essentially equal. Consequently, the systemic venous return matches the systemic cardiac output. The venous return should be equal to or less than the cardiac output. The heart, as a pump, cannot expel a volume that has not been received; notwithstanding, in the case of valve regurgitation, the heart can expel a fraction of the venous return twice. The clinical physician should ask himself or herself: Is the preload volume in the EDV or the pressure at the time of the EDV which has been diminished before starting the isovolumic contraction?
Measurement of Right Atrial Volume and Diameters in Healthy Nepalese with Normal Echocardiogram
