The development study of a new noninvasive circulatory monitor enables to make predictions about a cardiovascular accident during elderly dental treatment

• Project/Area Number: 07672157
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Surgical dentistry
• Research Institution: Tokyo Medical and Dental University
• Principal Investigator: OHWATARI Tsuneto Tokyo Medical and Dental University, Geriatric Dentistry, Assistant, 歯学部, 助手 (80194322)
• Project Period (FY): 1995 – 1996
• Project Status: Completed (Fiscal Year 1996)
• Budget Amount: ¥2,600,000 (Direct Cost: ¥2,600,000); Fiscal Year 1996: ¥1,400,000 (Direct Cost: ¥1,400,000); Fiscal Year 1995: ¥1,200,000 (Direct Cost: ¥1,200,000)
• Keywords: Elderly / Chaos / Heart rate variability / Heart rate varibility / 高齢者(Elderly) / 心電図(Electro cardiogram) / 心拍変動(Heart rate variability) / カオス(Chaos) / アトラクター(Attractor)

Research Abstract

The ultimate purpose of this study was to develop a new circulatory monitor, which enables to make predictions about a cardiovascular accident during dental treatment, with chaotic analysis of RR interal variability for the achievement of saftety elderly dental treatment. We initially carried out a basic study for chaotic analysis, then investigated the influence of aging on RR interval variability (result 1), and then analyzed the RR interval variability of arrhythmia during dental treatment (result 2).
Result 1
The effect of aging on circulatory regulation was investigated by means of chaotic analysis of RR interval variability.
The four items as follows were compared with groups of healthy young and aged subjects ; (1) mean value of RR interval and CVRR, (2) power spectrum, (3) attractor, and (4) correlation dimension.
As a results, attractor of aged tended to smaller than that of younger subjects. And there was a tendency for CVRR to be low in the older subjects than younger people. Th e absolute power of low frequency component of the younger subjects was higher than that of aged with statistical significance. There was no difference in correlation dimension between two age groups.
It was shown that the effect of aging on the complexity of circulatory regulation seems to be little, but the dynamics of circulatory regulation tend to decrease with aging.
Result 2
With the purpose to make prediction of arrhythmia during dental treatment of the aged, we carried out the chaotic analysis of RR interval variability of arrhythmia.
As a result, in the normal ECG the shape of attractor was long oval figure and correlation dimension was relatively high. On the other hand, the shape of attractors of atrial fibrillation, strong respiratory arrhythmis, multifocal ventricular premature beats, and the sinus bradycardia with long periodicity were specific. The correlation dimensions of those arrhythmias were different.
It was shown that the differences of attractors may relatte to those of genesis of arrhythmias. Therefore, there is a possibility that the chaotic analysis of RR interval variability may be a prediction mean for arrhythmia in the elderly dental treatment.