Several aspects of renal dysfunction was analysed biomathematically and the following results were obtained : (1) A mathematical analysis of diuretic response was developed to show a new diagnostic method for differentiating the causative factors involving in edema formation. The diuretic response test may be beneficial in dertermining the indication of antialdosterone agents in the treatment of the patients with edema. (2) A quantitative index of potassium excreting potency of the diuretic was introduced. (3) The mechanism of the delayed excretion of cations in the aged after administration of sodium thiosulfate was discussed. (4) Mathematical studies of the PSP excretion test revealed that the mode of excretion of PSP followed an exponential function. (5) The ideal excretion curves of PSP with urinary dead space is given and cases showing an abnormal curve were illustrated. (6) The mechanism of the discrepancy of PSP test and PAH clearance in the patients with heart failure was discussed. (7) Mathematical analysis of the mechanism of urea excretion in patients with renal failure revealed that there may be certain kinds of metabolic regulation and a decrease of the rate of urea production (the rate of protein metabolism) when renal function decreases.

View full abstract

Although routine scalar electrocardiogram is an important tool for recognition of right ventricular hypertrophy, minimal or moderate degree of right ventricular hypertrophy are not infrequently overlooked by this method. On the other hand, recent studies have indicated the superior sensitivity of the vectorcardiogram in this purpose. In order to find out a characteristic pattern of vectorcardiogram in right ventricular hypertrophy, a quantitative analysis was made on QRS and T loop of 33 catheterized cases with pure mitral stenosis, and the results were compared with the hemodynamic date. Diagnostic significance of rightward displacement of half-area and terminal QRS vector has been pointed out.

View full abstract

The prognosis of atrial infarction is much worse than ventricular infarction because of atrial arrhythmias and rupture of the atrial wall. Hence it would be important clinically to make an accurate diagnosis of atrial infarction. In view of the discrepancy as to the interpretation of electrocardiographic findings in an atrial infarction among workers, an attempt was made to find out possible relations between lesions and electrocardiographic responses to an experimental injury of the atria. The results are reported with discussion in the present paper.

View full abstract

Quantitative observations on the pulmonary arterial pressure pattern were made by approaching mathematically using the method of FOURIER analysis and the first derivatives. Concept that the pulmonary arterial system was a transfer element of the control system made it possible to make analysis of its stability by utilizing the results of FOURIER analysis. Right heart catheterization was performed of thirty-two patients with mitral stenosis, atrial septal defect and chronic pulmonary emphysema. The Bode diagram revealed that the high energy distribution in the higher frequency was seen in cases with chronic pulmonary emphysema than in mitral stenosis or atrial septal defect. Gain margin and phase margin were smaller in chronic pulmonary emphysema than in the other two groups. Pulmonary vascular compliance was nearly inversely proportional to gain margin and phase margin. Positive relationships were found between PA dp/dt and gain margin and phase margin. Positive relationship were also found between PA dp/dt and RV dp/dt. The stability of the pulmonary arterial system was chiefly determined by the distensibility of the pulmonary artery. And this distensibility effects the systolic ejection and possibly the contractility of the heart muscle.

View full abstract

The relationship between heart sounds S₃ and S₄ in PCG on one hand and vibrations in lateral BCG on the other were studied referring to the clinical data. According to the author the protodiastolic lateral wave in BCG is clinically useful, while the presystolic lateral wave is not. The conclusions on protodiastolic waves are as follows. 1) S₃ decreased its amplitude with aging in normal cases. 2 ) Vibrations always originated in the heart, and decrease in amplitude of S₃ showed only the decrease in the capabillity of transmission. 3) Almost all cases with accentuated S₃ were accompanited by accentuated protodiastolic lateral wave and their clinical conditions were very severe. 4) The cases with accentuated protodiastolic lateral wave, without accentuated S₃, were considered to be the pre-stage of protodiastolic gallop rhythm and they had clinical significance. 5) Accentuated S₃ without accentuated protodiastolic lateral wave was not clinically significant. 6) Protodiastolic lateral wave originated from right ventricle was accompanied by accentuated S₃, only when its amplitude became very large.

View full abstract

Various types of assisted circulation have been experimentally and clinically proved by many investigators to be effective in intractable heart failures. Among these various types of assisted circulation, veno-arterial pumping has advantages of its simple equipment, easy procedure, minimum injury to the blood elements, etc. However, owing to the characteristics of veno-arterial pumping, the unsaturated blood perfuses the lower half of the body, when an arterial cannule is inserted into the femoral artery. The author has experimentally investigated the effects of prolonged veno-arterial pumping on an organism and has examined histological changes in some organs, chiefly the kidney, the adrenal gland, the lungs, the myocardium, etc., after long-term veno-arterial pumping. In Group I, healthy mongrel dogs were anesthetized with ether by endotracheal intubation. The equipment for veno-arterial pumping consisted of an arterial cannule inserted into a femoral artery, a venous cannule into a jugular vein, and a Sigmamotor Model TM-2 or a specially designed "Circulatory Assistor H-1", a kind of roller type pump. Veno-arterial pumping were performed in 9 dogs for 5-26 hrs. at the perfusion rate of 40-50cc per kg of the body weight per minute. Four dogs of them died in the course of the perfusion : 2 died of shock following blood transfusion, 1 of fibrine embolism in the renal arteries, and 1 of over-heating. Biopsy or necropsy was carried out in all the dogs. The histologic examination of the kidney revealed the findings ranged from Glomerulo-nephrosis in dogs perfused for 5 hrs. to Tubular necrosis in dogs perfused approximately for 24 hrs. The findings of congestion and atelectasis were microscopically observed in the lungs, and the increase of lipoids was recognized in all layers of the adrenal cortex.

View full abstract