A new method for the quantitative analysis of the exercise electrocardiogram was developed for the diagnosis of coronary heart disease. In this method, a second order function, f(t)=at²+bt +c, which represents the configuration of the initial portion of the ST-T segment was obtained by the function fitting method and its coefficients a (a parameter which represents the ST-T pattern) and c (a parameter which reflects the ST junction's depression) were used for the evaluation of the exercise electrocardiogram. Serial changes in the ST-T pattern throughout exercise tests were also investigated using this method in two distinct groups; a group of 35 healthy adults (group H) and a group of 28 patients with effort angina pectris (group EA). Although the smaller coefficients a and c which were obtained during an after exercise tests in group EA may reflect the ischemic changes, substantially large overlaps in each of these parameters was observed between group H and group EA. However, the discrimination between these two groups was improved if the combination of coefficients a and c were applied. These results strongly suggest that the configuration of the ST-T pattern is indispensable for the evaluation of the exercise electrocardiogram and that the new quantitative method used in this study is useful in the objective analysis of the fine changes in the ST-T pattern.

View full abstract

Mechanisms for cyclical reduction in peripheral blood pressure and flow of partially constricted coronary artery of anesthetized dogs has been examined. In 64 of 97 preparations, cyclical reduction in coronary blood pressure and flow developed 3 to 32 min after the beginning of constriction. Period duration of the cyclical reduction range from 1 to 32 min. The cyclical reduction was frequently associated with elevation of the ST segment of surface electrocardiogram, systolic bulge of the left ventricle and excitation of afferent cardiac sympathetic nerve fibers. in the preparations in which cyclical reduction was not produced by constriction, a brief stretching of the constricted portion provoked the cyclical reduction. Segmental or diffuse narrowing of the constricted coronary artery which occurred during the reduction in pressure and flow was demonstrated by selective arteriography. Also, segmental spasm in the constricted coronary artery was demonstrated by photography. No obvious difference in the constricted portion of the artery was observed histologically between the preparations in which cyclical reduction developed and those in which cyclical reduction was not produced. The results indicate participation of vasospasm in the cyclical reduction of blood pressure and flow in partially constricted coronary artery.

View full abstract

1. A total of 112 subjects, including 37 controls, 43 hypertensives, 27 IHD and 5 HCM, were tested by routine RCG and ECG gated RCG. 2. The atrial contribution to ventricualar filling (c/b ratio) was measured by ECG-gated RCG and a characteristic increase was found in IHD (37.5±7.7, mean±s.d.) and Hypertensives (26.5±8.0) compared to controls (16.1±5.0). 3. The increase in c/b ratio and the decrease in PDdV/dt in IHD seemed to be caused by primary abnormalities in the relaxation of the ventricle. 4. ECG-gated RCG, being a non-invasive method, serves useful informations in estimating ischemic heart disease especially by a quantitative analysis of the diastolic filling.

View full abstract

1. In comparison with adult rats, the myocardial cells of young post-natal rats contain more ribosomes, glycogen particles and roughsurfaced endoplasmic reticulums, but fewer mitochondria and myofibrils. The mean volume percentages of mitochondria both atria and both ventricles, those of myofibrils are 44 to 48%, and those of glycogen particles are 14 to 18%. 2. In comparison with young post-natal rats, the myocardial cells of 7-day-old rats contain better-developed mitochondria and myofibrils, but fewer ribosomes, glycogen particles and rough-surfaced endoplasmic reticulums. 3. The volume percentages of mitochondria, myofibrils or glycogen particles in 3-month-old rats are almost the same as those of adult rats. Namely, the mean total areas occupied in the sarcoplasm by mitochondria in the four chambers are 32 to 36%, those by myofibrils are 53 to 58%, and those by glycogen particles are 4 to 8%. 4. Thus, for the three main intracellular components; mitochondria myofibrils, and glycogen particles; there are no significant differnces among the mean contents in the four chambers at any age. 5. In spite of abrupt circulatory changes at birth, both damages of myofibrils and intracellular organs and intracellular edema are seldom seen in the myocardium of young post-natal rats. Such shows that the young post-natal rat cardiac muscle has sufficient tolerance to these natural loads. 6. Mitosis was found in the cardiac muscle cells of an 8-day-old rat and cell proliferation after birth was confirmed. 7. Throughout the developmental periods, the minimum diameters of the nuclei in both atria and both ventricles did not greatly alter to become significantly different. 8. The cell diameter of the left atrium of 0-day-old rats was significantly smaller than that of the right atrium, right ventricle or left ventricle. The cell diameters of the right atrium and right ventricle were not significantly altered until the 7th day after birth, but that of the left atrium increased markedly for the same period, and then, became equal to that of the right atrium or right ventricle. Further, the cell diameter of the left ventricle increased markedly. After that period, the cell diameters of both atria and both ventricles increased prominently with increasing age. The increase was more prominent in the ventricular than in the atrial myocardiums. 9. Mitochondrial destruction and intracellular edema were found in the myocardium of young post-natal rats after volume load by blood equalling the whole blood volume. In the myocardium of adult rats during the same volume load, however, the above damages were only slight, and numerous enlarged mitochondria with increased number of cristae occupied a larger intracellular space. These results show that the tolerance of young post-natal cardiac muscle is poorer than that of adult cardiac muscle.

View full abstract

Cardiovascular, aerobic, and ventilatory responses to a multistage treadmill test of near-maximal exercise were determined in 208 middle-aged Chinese men to provide standards in health, and to identify differences in relation to hypertension, coronary heart disease, chronic pulmonary disease and stroke. Except in patients with hypertension, exercise duration was shortened and symptom-limited oxygen uptake was reduced in all disease groups. Unexpectedly, stroke patients exhibited lower heart rate responses to exercise than did patients with coronary heart disease.

View full abstract

A rare and instructive case of myocardial infarction in a 29-year-old woman was presented. In this case it was clinically suspected that myocardial infarction was due to metastatic choriocarcinoma of the heart. This was confirmed by autopsy. It was emphasized that metastatic choriocarcinoma of the heart could be a cause of myocardial infarction in young women.

View full abstract