itself. Korke1 reports a large series of observations made (under carefully controlled surroundings) of the respiration, pulse rate, sphygmographic tracings, besides complete blood-pressure readings, from which he concludes that in chronic valvular lesions of the heart due to the usual causes, the blood-pressure is normal or slightly above, whereas in aortic incompetence, complicated with anginal attacks, the blood-pressure, contrary to the usual belief, is often subnormal during the periods between the attacks of angina.

In valvular lesions complicated with chronic nephritis and arteriosclerosis the significance of the high pressure is explained by the accompanying phenomena.

AORTIC INSUFFICIENCY

In well-compensated aortic insufficiency the systolic blood-pressure is usually found to be somewhat elevated (see Fig. 66) ranging between 130 and 160 mm. (Korke's observations do not agree with this.) Following the onset of this lesion the circulatory efficiency of the heart is probably maintained by reflex vascular stimulation and later by changes in the myocardium, as shown by a great left ventricular hypertrophy, so that as long as compensation is maintained the systolic pressure remains above the average level. With the advent of cardiac muscle failure it tends to fall, rising again if the therapeutic measures employed prove effectual.

In discussing the persistent arterial heart sound in aortic regurgitation, which until recently has been a stumbling block in the determination of the diastolic

1Loc. cit.

pressure, Taussig and Cook1 state that, in spite of the prevailing opinion, the persistent arterial sound is not pathogno monic of aortic regurgitation, often being absent in this disease and occasionally present in others.

Prognosis. In heart affections, particularly valvular, a rapid and persistent reduction in systolic pressure is always an unfavorable sign, showing that the heart is beginning to fail. The same may be said of a diminishing pulse pressure, while a slightly elevated systolic pressure may be looked upon with favor.

Special Methods of Determining Aortic Insufficiency.— Leonard Hill has shown that the blood-pressure in the arm as compared with that in the leg in normal individuals, at muscular rest, differs only by the hydrostatic pressure of the column of blood which extends from the leg to the arm. In the horizontal posture they are approximately equal. Exercise in the upright posture produces a much wider variation in the leg than in the arm, a fact which is attributed to the mechanism which regulates the pressure to the heart itself and to the vital centers. In patients with aortic insufficiency he has found a constant greater difference between the arm and the leg readings even during muscular quiet in the recumbent posture, so that he considers a marked and constant excess in the systolic bloodpressure of the lower extremities as compared with the upper as pathognomonic of aortic insufficiency. According to H. A. Hare this variation is not present in other valvular lesions. In normal individuals at rest it rarely exceeds 15 mm., while with aortic insufficiency it may amount to 100.

1 A. E. Taussig and J. E. Cook, Arch. Int. Med., May, 1913, xi, 5.

E. Pesci1 derives valuable information from a study of the difference in systolic blood-pressure in the brachial

FIG. 67.-Girl. Aged twelve. Mitral valvulitis. Acute endocarditis following follicular tonsillitis. Classical signs of endocarditis with a blowing systolic murmur, slight cyanosis, air hunger and a greatly enlarged and tender liver. The rise in pulse pressure following the institution of treatment, was probably the result of return of more blood to the left side of the heart incident to the relief of pulmonary and hepatic congestion following hot packs. The gradual fall in systolic pressure to termination of the case shows a gradual wearing out of the heart caused by the sudden development of a demand for extra work. The rise in pulse rate is characteristic. The last observation was made shortly before death.

and digital arteries in heart disease. In aortic defects the

1 Riforma Medica, June 7, 1909, xxv, 23.

FIG. 68.-Female. Aged fifty-two. Mitral regurgitation. First observation (4) made in period of decompensation in the presence of anasarca, orthopnea, cyanosis and delirium cordis. The case only began to recover muscular tone at (B) and then rapidly progressed to a state of improvement which permitted moderate activity without untoward effect. An attack of right-sided dilatation developed at (C), at which time there was present little edema except in the lungs, which were moderately filled with fluid producing orthopnea, and a continuous cough with frothy expectoration. A similar attack occurred at (D), while at (E) there was some improvement, although the patient was still confined to bed.

pressure in both arteries is much higher than in normals, whereas in associated myocarditis the brachial pressure may be high but the peripheral pressure is low. He considers these observations especially instructive when the brachial and digital pressures are determined before and after exercise. If the heart is functionally capable, a normal proportion of pressures between the two readings is maintained. The lower the peripheral reading as compared with the proximal, the weaker the myocardium.

MITRAL DEFECTS

In mitral defects (Fig. 67) and all other compensated valvular lesions, except possibly a mitral stenosis, the blood-pressure is above normal. Starling1 believes that no matter how ill the patient or how ineffective the work of the heart, the systolic pressure is never below normal. Pesci2 states that in mitral defects during the period of compensation the pressure in both the brachial and digital arteries is low, whereas it is above normal when compensation fails (see Fig. 68).

Mitral Stenosis.-The question as to the usual level of systolic pressure in mitral stenosis has not yet been settled. In those cases showing a subnormal pressure it is explained on the ground that the volume of blood actually passing through the heart is sufficiently reduced to cause this low pressure. On the other hand, the belief that the blood-pressure is high in mitral stenosis is based upon the fact that venous pressure is high and the physics of the circulation demand a certain difference between the arterial

1 Lancet, Sept. 29, 1907.

2 Loc. cit.