Contributions of risk factors (sex, age, hyperlipidemia, hypertension, diabetes mellitus, obesity and hyperuricemia) to stroke and ischemic heart disease were studied among 1585 teachers aged 31 to 61 years old (M=1043, F=542) in Okinawa where the mortality from stroke was lowest while the propotion due to brain hemorrhage was higher than in the rest of Japan.
Subjects were registered between May 1979 to Mar 1988 and followed until Jan 1992. During the mean follow up period of 7.9 years (11989 person-years) twenty four cases of stroke (2.0/1000 person-years) and sixteen cases of ischemic heart disease (1.3/1000 person-years) occurred. None of the risk factors except for age and being male were significantly related to ischemic heart disease, whereas hypertension adjusted for sex and age contributed significantly to development of stroke, especially brain hemorrhage.

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Two groups of peak incidence of sudden cardiac death (SCD) are apparent in the general population : one type due to myocarditis and cardiomyopathy found mainly in patients in their teens and twenties and the other stemming from ischemic heart diseases seen in patients in their fifites and sixties.
Ninety percent of SCD results from tachyarrhythmias such as ventricular tachycardia and fibrillaton, the mechanism being ventricular ectopic beats induced by ischemia, autonomic nervous disorders, physical exercise, mental stress, mineral imbalances and unexpected drug effects, based upon substrate abnormalities of myocardium.
In experimental models using rabbits, ventricular tachycardia and fibrillation (VT, VF) are observed immediately after marked bradyarrhythmias, such as sinus arrest and AV-block induced by brain injury and marked physical and / or mental aggression.
Ventricular tachyarrhythmias, ventricular tachycardia, and fibrillation could not be seen in rabbits decorticated at the site of the hypothalamic region, suggesting that the hypothalamus has an important role in producing ventricular tachycardia and fibrillation, and is influenced by brain injury and marked aggression. Severe stresses are most likely to be associated with sudden cardiac death.
Behavior patterns in humans may also be associated with SCD. Odds ratios for competitive behavior typical of type A behavior pattern (TABP) are 6.4 in ischemic heart disease (IHD) and 1.6 SCD, the former being much higher than the latter. The frequency of TABP is high among Okinawan centenarians who have not experienced IHD, and for this reason, there are some doubts whether TABP is truly a risk factor for IHD and SCD. There are two types of TABP : “self-assertive type” which include competitiveness and impatience ; and “persistent personality” characterized by “workaholic” tendencies. The role of TABP as a risk factor for SCD and IHD can be better clarified by analyzing the different components of TABP. We have tried to develop a primary screening system for SCD by combination of ECG, radiography, physical examinations, and personal history and have successfully identified in most cases at risk for SCD based on these criteria. There were a few cases that were negative but subsequently experienced SCD causes of which could not be determined by autopsy. The sensitivity of this system may be increased by detection of local gradients by VCG and / or late potential (LP) using signal averaged ECG (SAE).

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[in Japanese]

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This study focuses on cases of recurrent myocardial infarction, and the time between a previous occurrence and recurrence to develop measures to elucidate factors related to the length of this interval prevent recurrence. Subjects were 78 male patients hospitalized at Showa University Hospital, who met the criteria of having records of the time from a previous myocardial infarction until a recurrence. The average interval from a prior myocardial infarction until a recurrence was 67.0 months. Items surveyed included : sex, date of birth, date of previous myocardial infarction, date of recurrence, employed/ unemployed, total serum cholesterol level, serum neutral lipid level, obesity level, presence or absence of hypertension, presence or absence of diabetes, smoker/nonsmoker, presence of absence of hyperuricemia. and family history if any. CATDAP-02 was used to analyze possible relations between the occurrence-recurrence interval and the items surveyed. The results indicated statistical significance of the relation of total serum cholesterol and obesity levels with the time from the occurrence of a myocardial infarction to recurrence. A + 10% to + 15% obesity level had a significant relationship especially for +13% which had a maximum level of significance, whereas + 20% (the usual conventional standard) was only weakly related to the time betweem occurrence and recurrence. A total serum cholesterol level of 180mg/dl to 200mg/dl was related, and this relation was stronger at 180mg/dl, in partcular. No relation was evident at 220mg/dl, which has been conventionally used as a criterion. These findings suggest a need to maintain lower than usually indicated levels of obesity and total serum cholesterol after a myocardial infarction experience.

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[in Japanese]

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