1. Since 1949, a remarkable increase of cases with myocardial infarction, cardiac diseases and anginal pains among the hospital patients has been noted in Japan.There is a slight decrease in the incidences of these diseases during the war time from 1942 to 1945.The survey does not show a significant increase of myocardial infarction among out-patients, but it seems likely that it is also gradually increasing.The recent increase of myocardial infarction among the hospital cases in Japan seems to be partly due to the advancement of diagnostic methods, especially of precordial leads of E. C. G. However, similar increases in cardiac diseases and in patients with anginal pains probably indicate that the progress of diagnostic methods is not the only cause of the increase of myocardial infarction but there is an actua increase of myocardial infarction. Several causes such as participation of coronary atherosclerosis, hypertension etc. have been pointed out, but the arguments have not reached agreement.2. The differences seen in the geographical distributions of myocardial infarction and the patients with anginal pains are partly due to the character of the clinic participated in the study. For example, in Maekawa's Clinic (Kyoto) the incidence of myocardial infraction is very much higher than in any other clinics. As the number of patients with cardiac diseases is especially large in this clinic, the high incidence in this clinic cannot be taken as showing high incidence in Kyoto area. From this survey it is difficult to make a conclusive comment on the geographical difference in the incidence of myocardial infarction.

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1. Coronary sclerosis first appears in the second decade (Kyushu University) or in the third decade (Tokyo University) and then increases in frequency and intensity with age.2. Coronary sclerosis appears in younger age group than those in whom aortic sclerosis appears (Kyushu University) or both of them appear in about the same age groups (Tokyo University).There is no significant difference in their frequencies. (Tokyo University).3. Incidences of basilar and renal sclerosis are less frequent than that of coronary and aortic sclerosis and the first appearance of the former is always far behind the latter.4. All types of sclerosis, coronary, aortic, basilar and renal, seem to be more frequent and much severe in males than in females.5. Severe coronary sclerosis usually accompanies extensive arteriosclerosis of other arteries such as aorta, basilar artery and renal artery.One of the important factors which cause coronary sclerosis seems to be the same factor which causes the arteriosclerosis in many other organs in the whole body.6. It seems that the factors from the cardiac wall (cardiac muscle) also influence the incidence of coronary sclerosis. These factors are the compression to coronary arteries, the increase of the peripheral resistance in coronary circulation, etc.7. Although there are a few discrepancies between the report from Tokyo University and that from Kyushu University because of different standard of judging for the grade of arteriosclerosis, they are so small that there are no different conclusions.8. The frequency of myocardial infarction in Kyoto area was much less than that in Tokyo area ; and the frequency of coronary sclerosis in Kyoto was also less than that in Tokyo area and Kyushu area.

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