Blood-pressure primer : the sphygmomanometer and its practical application / by Francis Ashley Faught.

  • Faught, Francis Ashley, 1881-1963.
Date:
1914
Catalogue details

Licence: Public Domain Mark

Credit: Blood-pressure primer : the sphygmomanometer and its practical application / by Francis Ashley Faught. Source: Wellcome Collection.

Provider: This material has been provided by the Augustus C. Long Health Sciences Library at Columbia University and Columbia University Libraries/Information Services, through the Medical Heritage Library. The original may be consulted at the the Augustus C. Long Health Sciences Library at Columbia University and Columbia University.

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    uncertain and unreliable that no dependence could be placed on them. The studies of Warficld and others have shown the accuracy of this method, which can be relied upon to give an accurate reading under practically all circumstances, irrespective of the age of the patient, the size of the vessel, or the size of the arm to which the cuff is attached. In' order to analyze the results of a complete blood- pressure observation, it is essential to review the fac- tors controlling blood-pressure. From the clinical standpoint at least, we may consider the blood-pressure depending mainly upon the contractile powers of the heart, which pumps the blood forward, on the one hand, and the calibre of the blood-vessel walls, which offer peripheral resistance to its flow, on the other. And also that peripheral resistance itself depends largely on the tonicity of the walls of the blood-vessels which comprise the general capillary system. Patho- logically, we must recognize that changes in blood- pressure are largely due to departures from the normal force of the heart and to alterations in the elasticity and tonicity of the general arterial tree. It will thus be seen that the systolic pressure will approximate closely the actual pressure developed by the heart within the heart itself at the moment of systole, while the mini- mal or diastolic pressure wall be the measurement of the peripheral resistance, w^hich is able to maintain to a varying degree the arterial pressure, while the heart is dilating, plus the factor of elasticity, wdiich also aids in maintaining the continued pressure in the vessel during diastole. In the pulse pressure, then, we must have the