Subthreshold electrical stimuli to the heart from the anterior chest wall with an. external pacemaker was used to suppress temporalily the implanted ventricular inhibited demand pacemaker. The value of this method in the management of patients under digitalis intoxication is illustrated.

View full abstract

1. In an 8-year follow-up of an adult population of 14, 900 persons, age 20 and over who undergo periodic medical examination biennially, atrial fibrillation (AF) was found in 80 cases. The prevalence, with both sexes combined, was 0.5%, and approximately 3.4 times higher in males than in females. The peak prevalence in males was 2.6% in the 60-69 age group, while in females it was 1.7% in the 70+ age group. 2. Onset of AF was seen during the period of observation in 45 cases. Incidence was the highest in males of the 60-69 age group, being 55 cases per 10, 000 population per year. 3. Main associated disease was hypertensive heart disease (HHD) in 42.4%, ischemic heart disease (IHD) in 23.8%, mitral valvular disease (MVD) in 23.8%, thyrotoxic in 3.8%, and unknown in 6.2%. 4. Age of onset was 48.7 years among cases with MVD, 65.2 years among cases with HHD, and 66.8 years for cases with IHD. 5. Prediction of occurrence of AF was attempted using as controls non-AF cases matched by sex, age, and disease with the 43 cases that had developed AF during the period of observation. It was found that the overall estimate of the severity of disturbance of cardiac function is an important factor and that premature atrial contraction has the highest predictive value among

View full abstract

The results of the follow up study on 907 cases of congenital heart disease were reported. 1. Death rate was highest in Group A, the cases of which visited our hospital under one month of age. The death rate over all Groups was 12%. 2. Natural closure of VSD was 21% in Groups A, B, C, the cases of which visited our hospital under 12 months of age. 3. There were 13 cases of VSD in which obstructive changes developed in the right ventricular outflow tract . 4. Six cases of VSD with aortic insufficiency were reported. 5. There were 12 cases in which clinically pulmonary vascular obstruction was suspected. VSD with such severe pulmonary hypertension should be operated on early, probablly under 2 years of age.

View full abstract

Statistical and patho-histological analysis of 73 autopsied cases of C.H.D., which have received no surgical treatment ante-mortem, have been performed. Fitting of survivorship curve to Weibull function have been attempted and marked tendency of "early failure" in the period of infancy and childhood and of "random failure" in the adolescence have been proven. Several patho-histological features which characterize the visceral changes of each malformation group have been presented. Special remarks have been laid upon the meaning of cardiomegaly of C.H.D. as the space occupying process and its biological significance has been briefly discussed.

View full abstract

Natural history of the idiopathic cardiomyopathy was studied. In part I idiopathic cardiomyopathy, excluding hypertrophic obstructive cardiomyopathy, familial cardiomyopathy, endocardial fibroelastosis seen in infant and secondary cardiomyopathy, was sub-jected. Subjects reported in Part I were classified into type I with 3 subdivisions and type II by histological findings of the heart and incidence and natural history of each type were discussed with comparing each other. Natural history is variable and different in each type such as fluminating and chronic. Calculated survival rate at 5th year was 75%. In part II familial cardiomyopathy was sub-jected. In this group onset of initial symptoms was most frequent at 2nd decade that was earlier than the other non-familial group reported in part I. Age of death was variable in each case. In part III endocardial fibroelastosis seen in infant obtained from the Annual of the Pathological Autopsy Cases in Japan was subjected. Majority of this group died within one year. 76% of the cases died within 6 months were accompanied by another heart anomalies but in the survived cases over 6 months or more complication of another heart anomaly was rather rare. Major causes of death through each type of cardiomyopathy reported in part I and II were sudden death and intractable chronic congestive heart failure. In familial cardiomyopathy sudden death had occured at the rate of 75% that was much more frequent than the rate of 40% observed in the non-familial idiopathic cardiomyopathy reported in part I.

View full abstract

It has been clarified, in our department, by use of coronary catheterization, that coronary insuf-ficiency is essentially concerned with myocardial metabolism, and that various coronary vasodilators can not increase coronary blood flow in sclerotic coronary heart diseases so well as in healthy persons. Moreover in cases of myocardial infarction the coronary blood flow is reduced and myocardial oxygen consumption was decreased. In this paper, peculiarities of carbohydrate nary metabolism in ischemic heart diseases and the influence of coronary vasodilators upon it were investigated, to find the clinicopathopharmacological principle of therapy for coronary insufficiency by coronary vasodilators. Methods:The blood from femoral artery and from coronary sinus taken with coronary sinus cathet-erization were analyzed as follows. Blood glucose was determined by the method of Somogyi or glucose oxydase, lactate by hydroxydiphenyl method after Barker and Summerson and pyruvate by dinitrophenylhydrazine method after Friedemann and Haugen. Coronary blood flow was measured by the nitrous oxide method and myocardial oxygen consumption by the Van Slyke Neill method. Resting myocardial carbohydrate metabolism were measured in 89 cases, namely, 16 controls (5 normal, 6 slight pulmonary tuberculosis and 5 with no evidence of sickness in the main organs), 20 noncoronary heart diseases (chiefly various valvular diseases), 10 hypertension (with or without coronary insufficiency), 26 coronary diseases (old myocardial infarct and coronary insufficiency without hypertension) and 17 hepatic myocardosis (chiefly liver cirrhosis). In 45 of these cases, the myocardial carbohydrate metabolism after administration of various coronary vasodilators were measured also. Coronary vasodilators examined were Dipyridamole, Carbochromene, PF-26, Iproveratril, Xanthine derivatives, Benziodarone and Isosorbide dinitrate. Results: A) Myocardial carbohydrate metabolism in the resting state (Table I) 1) Glucose The myocardial extraction, the extraction ratio and the usage of glucose in noncoronary heart diseases were higher significantly than in other groups. Those in hypertension showed a low tendency. 2) Lactate The myocardial extraction, extraction ratio and usage of lactate in hypertension showed a lower tendency compared with other groups. 3) Pyruvate The same tendency seen in lactate was observed also in pyruvate of hypertension group.

View full abstract

Recent many investigations have been demonstrated the changes of coronary circulation, general hemodynamics and myocardial metabolism during exercise and the relation between ECG changes. This report is one of these studies, but in which the bicycle loading is so intensive that the ischemic ECG changes appear in the patients with coronary diseases, and the balance of myocardial oxygen utilization to cardiac performance is studied at the same time. Methods and Subjects The systemic hemodynamic parameters were determined by right heart catheterization with direct Fick's method and coronary circulation was measured by coronary sinus catheterization with N₂0 desaturation technique and blood gas analyzing were made with Van Slyke-Neill method before and during exercise. Exercise was performed in the supine position with a bicycle ergometer for 15 minutes at a level of 50 watts. Thirty-three patients with circulatory diseases were subjected, consisting of 5 with neurocirculatory asthenia (NCA), 8 with hypertension (HT), 6 with hypertensive coronary failure (HTC), 7 with coronary heart disease (CHD) and 6 with than heart disease (HD). All subjects were divided also into 3 groups according to the electrocardiographic changes before and after the exercise test, namely, 16 cases of group 1 whose ECG has never shown ischemic finding before and after the Master's double two step test or ergometer, 14 cases of group 2 whose ECG has shown ischemic changes after the exercise tests or before exercise also and 3 cases of group 3 whose ECG has normalized partly in ischemic changes after exercise. Results Continuous measurement of oxygen and carbon dioxide in expired air of 17 patients with Metabolar made in Fukuda and Co. demonstrated that the bicycle ergometry at a rate of 50 watts demanded 4.4 Cal./min. and it takes about 66 calories for for 15 minutes, which is about 2.5 times of calories demanded for Master's double two step test. In spite of the observation, in 31 cases out of 33 patients, the electrocardiographic changes after bicycle ergometer evaluated by Master's criteria were quite same with the result of Master's double two step test which was done as the pretest. Characteristic findings of various circulatory diseases Heart rate increased in all groups equally during exercise. The cardiac index and stroke index were the lowest in CHD at rest, however the rate of increase during exercise was the highest. Systemic vascular resistance was the highest in CHD at rest. During exercise systemic vascular resistance decreased in all groups and the rate of decrease in CHD was significantly greater than that of NCA. Mean blood pressure increased slightly in HT and HTC during exercise. Left ventricular work was the highest in HT at rest and increased in all groups. Myocardial tension was the highest in HT and the lowest in CHD at rest and increased significantly in all groups during exercise. Coronary blood flow showed no significant difference among the diseases at rest.

View full abstract

The purposes of this investigation were as follows: (1) How much of a thermal gradient is there, depending on the site measured, in the heart and the great vessels? (2) What kind of the qualitative or quantitative thermal change is seen in each sites? (3) How much heat production is there in the heart, brain and liver? Materials and Methods: The temperature measurements for this investigation were carried out with a thermistor catheter which had a thermistor mounted at the top. The study was done on eleven adults who had either congenital or acquired heart disease. By connecting the thermistor catheter to one arm of a bridge circuit and balancing it with a variable resistor on the other arm, the signal that came over this circuit was amplified and continuously recorded. On this record Δ10Ω was set to be 0.06°C and the amplitude to be about Δ1.0cm. The temperature was counted out back-ward with the value of the resistance of the calibration curve which was made by the variable resistor. This calibration curve was made by comparing the value of the resistance of a thermistor with the respective water temperature. The water temperature then was changes gradually. The temperature measurements were made in the following nine sites: l) the pulmonary artery wedge position 2) the pulmonary artery 3) the outflow tract in the right ventricle 4) the right atrium 5) the inferior vena cava 6) the right hepatic vein 7) the superior vena cava 8) the left jugular vein 9) the left subclavian vein The thermistor was attached in the nostril in order to see the respiratory cycle. The cases were examined during the normal respiration, the deep breath period and during no respiration. The time constant of the catheter and the recorder were within 0.15 seconds. In this study the mean circuit of one second was used. Furthermore, the calculation was made by the planimetry according to the calibration.

View full abstract