Disturbances of the Heart / Discussion of the Treatment of the Heart in Its Various Disorders, With a Chapter on Blood Pressure

by Oliver T. Osborne

ALTITUDE

It has long been known that altitude increases the heart rate and tends to lower the systolic and diastolic blood pressures; that these conditions, though actively present at first, gradually return to normal, and that after a prolonged stay at the altitude may become nearly normal for the individual. Burker [Footnote: Burker, K.; Jooss, E.; Moll, E., and Neumann, E.: Ztschr. f. Biol., 1913, lxi, 379. The Influence of Altitude on the Blood, editorial, THE JOURNAL A. M. A., Nov. 1, 1913, p. 1634.] showed that altitude increases the red blood cells from 4 to 11.5 percent, and the hemoglobin from 7 to 10 percent The greatest increase in these readings is in the first few days. It has also been shown that with every 100 mm. of fall of atmospheric pressure there is an increased hemoglobin percentage of 10 percent over that at the sea level. [Footnote: Blood and Respiration at Moderate Altitudes, editorial, THE JOURNAL A. M. A., Feb. 20, 1915, p. 670.]

Schneider and Havens [Footnote: Schneider and Havens: Am. Jour. Physiol., March, 1915.] find that in low altitudes abdominal massage increases the red corpuscles, and the percentage of hemoglobin in the peripheral vessels. While there is thus apparently a reserve of red corpuscles while the individual is in a low altitude, in a high altitude they find such reserve to be absent; in other words, abdominal massage did not cause this increase in red corpuscles in the peripheral vessels. This absence of reserve is easily accounted for by the fact that after one reaches the high altitude there is an increase in red corpuscles and hemoblogin in the peripheral blood.

Schneider and Hedblom [Footnote: Schneider and Hedblom: Am. Jour., Physiol., November, 1908.] showed that the fall in systolic pressure at altitudes is greater and more certain than the fall in diastolic, some individuals even having a rise in diastolic pressure. This rise in diastolic pressure is probably caused by dyspnea.

Schrumpf, [Footnote: Schrumpf: Deutsch. Arch. f. klin. Med., 1914, cxiii, 466] on the other hand, finds that normal blood pressure is not much affected by an ascent of about 6,500 feet, while patients with arteriosclerosis and hypertension, without kidney disease, have a fall in pressure. A patient with coronary disease should certainly not go to any great altitude, while patients with compensated valvular lesions, he found, were not injured by ordinary heights. He found that altitude seemed to decrease high systolic and diastolic pressures, while it even elevated those which were below normal, and caused these patients to feel better.

Any person who has a circulatory disturbance, and who must or does go to a higher altitude, should rest for a series of days, until his blood pressure and blood have reached an equilibrium.

Smith [Footnote: Smith, F. C.: The Effect of Altitude on Blood Pressure, THE JOURNAL A. M. A., May 29, 1915, p. 1812.] made a series of observations on blood pressures at Fort Stanton which has an altitude of 6,230 feet. He took the blood pressure readings in fifty-four young adults, seventeen of whom were women, and found that the average systolic reading in the men was 129 mm., and in the women 121, while the average diastolic in the men was 84, and in the women 82. Therefore he agrees with Schrumpf that the effect of altitude on normal blood pressure has been overestimated. In tuberculosis he found that the effect of altitude was not great. He does not believe that this amount of altitude, namely, a little more than 6,000 feet, makes much difference in an ordinary tuberculous patient. He did not find that artificial pneumothorax made any important change in the blood pressure. His findings do not quite agree with Peters and Bullock, [Footnote: Peters, L. S.r and Bullock, E. S.: Blood Pressure Studies in Tuberculosis at a High Altitude, Arch. Int. Med., October, 1913, p. 456.] who studied 600 cases of tuberculosis at an altitude of 6,000 feet, and found the blood pressure was increased, both in normal and in consumptive individuals. They also found that the increase in blood pressure, which kept gradually rising up to a certain limit, was indicative that the tuberculous patient was not much toxic; therefore the increase in blood pressure was of good prognosis.