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Publications (3)6.5 Total impact

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    ABSTRACT: Few researchers have conducted 24-hour total heart beat (THB) studies in patients with bradycardia, and its prevalence and significance in the elderly remain controversial. The aim of this study was to compare of distribution of THB, underlying diseases and effects of medication on THB in inpatients with bradycardia less than 80,000 beats/24 hrs between elderly and young patients. There were 303 Holter monitorings of bradycardia out of 7,687 consecutive monitorings, with only the earliest monitoring registered when duplicating. The age distribution of these 303 patients with bradycardia showed a two-peak pattern: a large peak at age 65-70 and a small peak at age 15-20. Thus we divided them into a young group aged under 65 (194 patients: mean 49.1) and an elderly group aged 65 or more (109 patients: mean 71.0). There was no difference in mean THB or distribution of THB between the two age groups, irrespective of medication which had a side effect of bradycardia. Underlying diseases included three bradyarrhythmias; such as sinus bradycardia, sick sinus syndrome and II or III degree AV block, long QT syndrome, ischemic heart disease, cardiomyopathy, valvular disease and others. There was no difference in mean THB or distribution of THB between the two age groups in each disease group. Moreover, with respect to bradyarrhythmias, there was a small distribution of THB between 75,000 and 70,000 beats/24 hrs in patients without medication while there was a sparse distribution of THB in patients with medication.
    Nippon Ronen Igakkai Zasshi Japanese Journal of Geriatrics 06/2003; 40(3):254-60. DOI:10.3143/geriatrics.40.254
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    ABSTRACT: Few researchers have conducted heart rate (HR) studies in healthy very elderly subjects aged 70 years or older, and there are no longitudinal follow-up studies in this population. The objective of this study was to evaluate long-term changes in HR and heart rate variability (HRV) with aging in healthy elderly persons by means of comparison between two Holter monitor recordings obtained at an interval of 15 years. The study population consisted of 15 healthy elderly persons (10 women and 5 men) aged 64 to 80 years (mean 70 +/- 4.1) at the first recording, and 79 to 95 years old (mean 85 +/- 4.1 years) at the second recording 15 years later. Nighttime (midnight to 5 AM) and daytime (noon to 5 PM) HR and HRV were obtained, and paired t tests were performed to assess the differences in each parameter of nighttime and daytime HR and HRV between the two (15-year interval) Holter monitor recordings. The results of the t-test comparisons were as follows: there was a significant increase in minimal, maximal, and average HRs (nighttime, p < .01; daytime, p < .05, respectively). On the other hand, with regard to HRV, there was a significant nighttime decrease in the SDNN index (mean of standard deviations of normal RR intervals between adjacent QRS complexes resulting from sinus node depolarizations for all 5-minute segments) (p = .0086), and a significant daytime increase in the NN50 (number of adjacent normal RR intervals >50 milliseconds) per hour (p = .0425). Moreover, there was a significant decrease in the low-frequency (LF) component (nighttime, p = .0151; daytime, p = .0032), and a significant decrease in the LF/HF ratio (nighttime, p = .0270; daytime, p = .0371), but there was no significant change in the nighttime or daytime high-frequency (HF) component. HR increased with age over the 15-year period in the healthy elderly persons. As for concurrent changes in HRV, however, the parameters of sympathetic modulation decreased, and the parameters of parasympathetic modulation were unchanged or slightly increased.
    The Journals of Gerontology Series A Biological Sciences and Medical Sciences 12/2000; 55(12):M744-9. DOI:10.1093/gerona/55.12.M744 · 4.98 Impact Factor
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    ABSTRACT: We attempted to test the hypothesis that dual atrioventricular (A-V) nodal pathways with second-degree atrioventricular block (2nd A-V block) present as a different clinical entity from those with A-V nodal reentranttachycardia (AVNRT). By evaluation with Holter monitoring (2.9 +/- 2.5 recordings/patient) and 12-lead electrocardiogram (11.9 +/- 11.6), 177 patients with dual A-V nodal pathways could be divided into three subgroups. Thirty-two patients had 2nd A-V block only (2nd A-V block group), 57 had AVNRT only (AVNRT group), 88 had neither 2nd A-V block nor AVNRT (silent group), and none had 2nd A-V block and AVNRT both. Electrophysiologic studies showed that the atrio-His interval was significantly greater (P < 0.0001) and the maximal 1:1 atrioventricular conduction rate was lower (P < 0.0001) in the 2nd A-V block group than in the other two groups. These differences were nullified after the administration of atropine. These results suggest that patients with dual A-V nodal pathways can be classified into three clinical subgroups based on the presence of either 2nd A-V block or AVNRT. We suggest also that patients of the 2nd A-V block group may have a more augmented vagal tone on the A-V node than the other two groups.
    The American Journal of the Medical Sciences 08/1997; 314(1):11-6. DOI:10.1097/00000441-199707000-00003 · 1.52 Impact Factor