栃木県Ｉ町の循環器集団検診における心エコー法の有用性

The purpose of this investigation was at first to clarify the clinico-epidemological characteristics of hypertension in Tochigi Prefecture, especially in Ishibashi Town, second to examine the usefulness of echocardiography in a community survey on cardiovascular diseases. The results were as follows: 1. The trends of mortality of hypertensive heart disease in Tochigi Prefecture. 1) The mortality of hypertensive heart disease in Tochigi Prefecture showed a tendency to decrease for these ten years. It was higher in Tochigi Prefecture than in all over the country. 2) The survey of National Health Insurance records in Ishibashi Town revealed that 56.6% of the patients with cardiovascular disease accompanied with hypertension. 2. The epidemiological findings on cardiovascular diseases in Tochigi Prefecture as compared with those all over the country. 1) The averages of systolic and diastolic blood pressure were lower. 2) The incidence of left ventricular highvoltage and ST-T change in electrocardiography was higher. 3) The incidence of myocardial infarction and angina pectoris was lower. 4) The incidence of silent myocardial ischemia was higher. 5) There was no difference of hypertensive heart disease between in Tochigi Prefecture and all over the country. 3. The multivariate analysis of findings of the community survey on cardiovascular disease (mainly ischemic heart disease and hypertensive heart disease) in Ishibshi Town. 1) Severity of hypertension, anamnesis of hypertension and subjective symptom of heart in relation with ischemic heart disease. 2) Anamnesis of hypertension and abnormality of electrocardiography in relation with hypertensive heart disease. These factors above mentioned were suggested to have strong relation with ischemic heart disease and hypertensive heart disease, by application of the quantification method of Hayashi's second type to data of a community survey on cardiovascualr diseases in Ishibashi Town. 4. The relation between echocardiography and blood perssure level. 1) There was a significantly clear relation between thicknes of intervascular septum and blood perssure level (p<0.01), and also between thickness of postrior wall and blood pressure level. 2) Diastolic descent rate of mitral valve made a clear decrease adversely to the level of blood pressure. 3) Partial correlation coefficient of examination items in the community survey with the level of blood pressure was the highest (0.42) in thickness of intervascular septum of echocardiography, secondly higher (0.33) in anamnesis of hypertension and thirdly higher (0.14) in age factor. 4) Examination of pertial correlation coefficient of those factors by age revealed that in age group from 30 to 59, thickness of intervascular septum of echocardiography had the highest correlation (0.46) with blood pressure level and in age group more than 60 anamnesis of hypertension had the highest correlation (0.60). Findings above mentioned are likely to suggest the usefulnes of echocardiography in community survey on cardiovascular diseases, as well electrocardiography and other methods of examinaiton.