Original communication
Hydraulic formula for calculation of the area of the stenotic mitral valve, other cardiac valves, and central circulatory shunts. I

https://doi.org/10.1016/0002-8703(51)90002-6Get rights and content

Abstract

  • 1.

    1. Standard hydrokinetic orifice formulas have been applied to stenotic mitral, pulmonic, tricuspid, and aortic valves, patent ductus arteriosus, and atrial and ventricular septal defects. These formulas were considered applicatble because of the high kinetic energy losses through small orifices or in the presence of high volume flow.

  • 2.

    2. In its general form, the formula is as follows: A = FC2gh where A = cross-sectional area in cm.2 of the orifice F = flow rate in c.c. per second C = empirical constant g = gravity acceleration h = pressure gradient across the orifice in mm. Hg.

  • 3.

    3. Cross-sectional valve areas have been calculated in twenty-one patients with mitral stenosis. Calculated and measured areas have checked within 0.2 cm.2 in six post-mortem examinations and in five patients at the time of operation. Repeated calculations from different sets of data in the same patient have checked well in all instances. Valve area showed a good correlation with severity of pulmonary symptoms. Changes in valve area following finger fracture valvuloplasty were observed in two patients. The exponential relation of pressure to flow and valve area is briefly discussed.

  • 4.

    4. The stenotic cross-sectional area has been calculated in ten patients with pulmonic stenosis with one post-mortem observation and in two patients with patent ductus arteriosus with operative correlations.

  • 5.

    5. Calculations have likewise been made but without post-mortem confirmation in tricuspid stenosis, atrial septal defect, and ventricular septal defect. Formulas are presented for calculation of the size of the aortic orifice in aortic stenosis. In these groups, the empirical constant, C, has not as yet been determined and must await the collection of post-mortem data.

  • 6.

    6. In each case an attempt has been made to assess the sources of error as well as the degree of accuracy involved in the particular formula.

  • 7.

    7. The chief value of these formulas is that they present an objective evaluation of surgical procedures designed to widen stenotic orifices or to abolish abnormal shunts. Furthermore, a theoretical prediction of the benefit to be derived from surgical widening of stenotic valves may be made.

References (38)

  • R. Gorlin et al.

    Studies of the Circulatory Dynamics in Mitral Stenosis; Altered Dynamics at Rest

    Am. Heart J.

    (1951)
  • R. Gorlin et al.

    Physiologic Method for Calculation of Cross-sectional Area of the Mitral Valve

    J. Clin. Investigation

    (1950)
  • R.L. Daugherty

    Hydraulics

    (1937)
  • N.A. Coulter et al.

    Development of Turbulence in Flowing Blood

    Am. J. Physiol.

    (1949)
  • R.D. Seely et al.

    Comparison of Cardiac Output Determined by the Fick Procedure and a Direct Rotameter Method

  • Y. Henderson

    A Neglected Feature of the Mechanics of Mitral Stenosis

    J. A. M. A.

    (1922)
  • H.K. Hellems et al.

    Pulmonary “Capillary” Pressure in Man

    J. Applied Physiol.

    (1949)
  • Dexter, L., Whittenberger, J. L., Haynes, F. W., Goodale, W. T., Gorlin, R., and Sawyer, C. G.: Effect of Exercise on...
  • J.P. Peters et al.
  • W.F. Hamilton et al.

    Pressure Pulse Contours in the Intact Animal: I. Analytical Description of a High-frequency Hypodermic Manometer With Illustrative Curves of Simultaneous Arterial and Intracardiac Pressures

    Am. J. Physiol.

    (1934)
  • M. Rappaport et al.

    An Electronic Multi-range Multi-channel Direct-Writing Pressure Recorder

  • C.J. Wiggers

    Modern Aspects of the Circulation in Health and Disease

    (1923)
  • W.P. Lombard et al.

    Effect of Pulse Rate on the Length of the Systoles and Diastoles of the Normal Human Heart in the Standing Position

    Am. J. Physiol.

    (1919)
  • W.P. Lombard et al.

    Effect of Posture on the Length of the Systole of the Human Heart

    Am. J. Physiol.

    (1919)
  • C.J. Wiggers et al.

    Physiologic Investigation Into the Dynamic Action of the Heart in Functional Cardiac Disorders

    J. Lab. & Clin. Med.

    (1919)
  • J. Burstein

    The Diastolic Phases of the Cardiac Cycle in Man

    Am. J. Physiol.

    (1923)
  • J.W. Dow et al.

    Pulmonary “Capillary” Pressure as an Index of Left Atrial Mean Pressure in Dogs

  • Zimmerman, H.: Personal communication to L....
  • Unpublished...
  • Cited by (0)

    This work was supported in part by grants from the National Heart Institute, United States Public Health Service, and the Life Insurance Medical Research Fund.

    United states Public Health Service Research Fellow of the National Heart Institute.

    View full text