Blood pressure : technique simplified / W.H. Cowing.

  • Cowing, W. H. (William Henry), 1872-1916.
Date:
1913
Catalogue details

Licence: In copyright

Credit: Blood pressure : technique simplified / W.H. Cowing. Source: Wellcome Collection.

    22/132 (page 20)
    BLOOD PRESSURE and column or indicator oscillation for diastolic pressure, because of greater accuracy. (2) The readings were slightly higher by the auscultatory than by the palpatory method. (3) The pulse pressure measured the energy of the heart in systole in excess of the diastolic pressure. For clinical purposes it represented the load of the heart. Under normal conditions it was approximately 50 per cent of the diastolic pressure. The myocardial load might, there- fore, be expressed pulse pressure P. P. by the fraction — : or — diastolic pressure D. P. (4) Since the diastolic pressure measured the peripheral resistance it was a better index of hypertension than the systolic pressure. A sustained diastolic pressure of 100 to 110 signified hypertension. The diastolic was less influenced by physiological factors than the sys- tolic pressure. (5) The comparison between systolic, dia- stolic, and pulse pressures was of clinical value in the interpretation of circulatory changes and of more importance than the estimation of sys- tolic pressure alone. (6) In arterial hypertension and myocar- dial decomposition in the broad sense, the pulse pressure and heart load was increased, as a rule, the overload factor varying greatly from 50 per cent to 175 per cent in this series. The greater the overload factor the greater was the danger of myocardial exhaustion.