142 



CONDITIONS AFFECTING THE PULSE-RATE. 



3. Conditions affecting the Pulse-Rate. 



Frequency in Health- In man the normal pulse-rate = 71 to 72 beats per 

 minute, in the female about 80. In some individuals the pulse-rate may be higher 

 (90 to 100), in others lower (50), and such a fact must be borne in mind. The 

 following conditions influence it 



(a.) Age. 



Newly Born, 



1 Year, 



2 Years, 



3 



4 



5 

 10 



Beats per 

 Minute. 



130 to 140 



120 to 130 



105 



100 

 97 



94 to 90 

 about 90 



10 to 15 Years, 



15 to 20 ,, 



20 to 25 ,, 



25 to 50 



60 



SO 



80 to 90 



Beats per 

 Minute. 



. 78 



. 70 



. 70 



. 70 



. 74 



. 79 



over 80 



(b.) The length Of the body has a certain relation to the frequency of the 

 pulse. The following results have been obtained by Czarnecki from the formula? 

 of Volkmann and Kameaux 



Length of Body 

 in 10 Ctm. 



80 to 90 . 



90 to 100 . 



100 to 110 . 



110 to 120 . 



120 to 130 . 

 130 to 140 



Pulse. 

 Calculated. Observed. 



69 

 67 

 65 

 63 

 60 



74 

 68 

 65 

 64 

 60 



(c.) The pulse-rate is increased by muscular activity, by every increase of the arterial 

 blood-pressure, by taking of food, increased temperature, painful sensations, and by 

 psychical disturbances. [Increased heat or fever (Pyrexia) increases the frequency, 

 and as a rule the increase varies with the height of the temperature. Dr. Aitken 

 states that an increase of the temperature of 1 F. above 98 F. corresponds with an 

 increase of ten pulse-beats per minute ; thus, 



Temp. F. 

 no 



'O ..... 



99 



100 . . . 



101 



102 



This is merely an approximate estimate.] It is more frequent when a person is 

 standing than when he lies down. Music accelerates the pulse and increases the 

 blood-pressure in dogs and men (Dogiel). Exposure to increased barometric 

 pressure diminishes the frequency. 



The variation of the. pulse-rate during the day 3 to 6 a.m. =61 beats ; 8 to 11 

 a.m. =74. It then falls towards 2 p.m. ; towards 3 (at dinner-time) another 

 increase takes place and goes on until 6 to 8 p.m., =70; and it falls until mid- 

 night =54. It then rises again towards 2 a.m., when it soon falls again, and 

 afterwards rises as before towards 3 to 6 a.m. 



4. Variations in the Pulse-Rhythm. 



On applying the fingers to the normal pulse we feel beat after beat occurring 

 at apparently equal intervals. Sometimes in a normal series a beat is omitted 

 = pulsus intermittens, or intermittent pulse; at other times the beats become 



