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Biomedical subjects

O Tateishi

Publications and source records attributed to O Tateishi.

14 recordsLinked to original sources
PubMed2002

Changes in circadian rhythm in heart rate and parasympathetic nerve activity after an eastward transmeridian flight.

Distortions of the circadian rhythm structure of the heart rate and parasympathetic nerve activity after an eastward transmeridian flight were studied. We recorded the ambulatory electrocardiograms of 12 healthy young men for 11 days: 3 days in Tokyo before the flight and 8 days in San Francisco following it. Heart rate variability was determined by power spectrum analysis, and high frequency power (0.15-0.4 Hz) was used as the index of parasympathetic tone. The structural characteristics of the circadian rhythm were analyzed by dividing consecutive RR data into four parts: the preflight days, the second and third days, the fourth and fifth days (Days 5-6) and the sixth and seventh days. Eight of the 12 cases were analyzed completely. The circadian period of the heart rate decreased after the flight. The peak time of parasympathetic nerve activity shifted from the small hours to the daytime, the maximum shift being during days 5-6 after the flight. We concluded that a structural disturbance of the circadian rhythm of the heart rate and parasympathetic nerve activity were observed.

Adult↗
PubMed2001

[Clinical significance of the acoustic detection of coronary artery stenosis].

OBJECTIVES: The clinical usefulness was investigated of phonocardiography of coronary artery disease based on stenosis sounds. METHODS: Heart sounds were recorded in 128 patients undergoing coronary angiography and 40 normal young men. Acoustic recordings were made with the patient supine using five sensors affixed to the skin on the left sternal border at the second (L2), third (L3) and fourth (L4) intercostal spaces, and the right sternal border at the second (R2) and third (R3) intercostal spaces. Approximately 400 msec of waveforms immediately following the second heart sound were passed through a band pass filter (400-1,500 Hz) and subjected to frequency analysis using the maximum entropy method. The ratio of heart sound amplitudes within the 400-700 Hz band to those within the 400-1,500 Hz band was designated as the power ratio. RESULTS: The relationship between the degree of stenosis and the stenosis sounds suggested that the power ratio was greater in mild or moderate (50-75%) stenosis. The patients were divided into the stenosis [American Heart Association (AHA) 50-75%], severe stenosis (AHA 90-100%), and normal groups. The power ratio was significantly greater (p < 0.005) in the stenosis group than in the normal and severe stenosis groups for patients with stenosis of the left anterior descending artery or the left main trunk (single-vessel disease). Using a cut-off level of 45%, the sensitivity was 71%, specificity was 65%, and accuracy was 66%. The greatest power ratio difference was recorded at L4, and represented noninvasive detection of mild to moderate stenosis in the left anterior descending artery or left main trunk. No other site showed any statistically significant difference. Detection was impossible in multivessel disease or in cases complicated with valvular disease. CONCLUSIONS: Phonocardiography may allow reliable detection of coronary artery stenosis with mild (AHA 50-75%) stenosis.

Coronary Stenosis↗
PubMed1994

Observation of sleep-related breathing disorders in patients with coronary artery disease by ambulatory electrocardiogram-respiration monitoring system.

Eighty-five coronary artery patients examined using an ambulatory electrocardiogram-respiration monitoring system (AERMS) in which a respiratory sensor was strapped to the right upper abdominal wall. Apnea was defined as a cessation of abdominal wall movement lasting at least 10 sec. Sleep-related breathing disorder (SRBD) was diagnosed if at least 30 apneic episodes were observed during sleep. The cardiac events evaluated during follow-up included occurrence of sudden death, myocardial infarction and ventricular tachycardia. SRBD was detected in 9 of 85 patients (11%). There were more patients with low EF (EF < 50%) in the SRBD group than in the non-SRBD group (p < 0.01). During follow-up for a mean period of 18.4 +/- 7.6 months after ambulatory recording, four of nine (44%) patients in the SRBD group had cardiac events, compared with only four of 79 (6%) patients in the non-SRBD group (p < 0.001). Thus, coronary artery patients who were complicated with SRBD showed poor cardiac function and had a high incidence of cardiac events.

Aged↗
PubMed1988

Shift of atrial reentrant tachycardia with transient entrainment to an uncommon and a common type of atrial flutter.

Atrial reentrant tachycardia (ART) which demonstrated transient entrainment shifted to an uncommon type of atrial flutter (AF) with premature atrial stimulation, and then returned to ART spontaneously. Subsequently, this ART shifted to a common type of AF by rapid atrial pacing, which was further transformed into an uncommon type of AF and finally terminated by rapid atrial pacing. The mechanism of AF in clinical cases is still controversial, but in this case, AF, both uncommon and common types, is considered due to macro-reentry within the atria. To explain the shift of ART to AF and mutual transformation between common and uncommon type of AF, we made a schematic figure of reentry loop within the atria of ART and AF.

Aged↗
PubMed1988

[Coronary artery blood flow velocity non-invasively measured using a vessel-tracking pulsed Doppler system].

A newly-developed noninvasive method was used to measure left coronary blood flow during phantom experiments. Two techniques were used in which: (1) the sample position can always be set in a fluctuating vessel using a wall echo-tracking method with a phase-locked-loop, and (2) the Doppler reference signal was generated separately synchronous with the wall echo signal. These techniques were combined, using a commercially available pulsed Doppler apparatus (SSH-40B: Toshiba). Basic experiments were performed using a blood vessel phantom to verify the validity of these systems. Blood flow velocity in the fluctuating tube could be measured clearly using a vessel-tracking method. The blood flow velocity of the left anterior descending artery was measured in three normal subjects and in seven patients from the third intercostal space along the left sternal border. The velocity pattern was characterized by a crescendo-decrescendo shape in diastole. The peak velocity which appeared in diastole ranged from 19 to 69 cm/sec, with no difference by disease entity. However, in all cases, the blood flow velocity signals were marred by extraneous signals, making it impossible to measure blood flow velocity during systole. Further improvement of the system is mandatory in order to use this flowmeter clinically.

Adult↗
PubMed1986

Effects of four antiarrhythmic drugs on the induction and termination of paroxysmal supraventricular tachycardia.

The electrophysiological effects of antiarrhythmic drugs were tested in 36 patients with recurrent paroxysmal supraventricular tachycardia (PSVT), 25 of whom had accessory pathway reentrant tachycardia (APRT) and 11 A-V nodal reentrant tachycardia (AVNRT; 10 of the slow-fast type one of the fast-slow type). The test drugs were procainamide (used in 19 patients), verapamil (in 27), disopyramide (in 31), and propranolol (in 15). The drugs were tested for their ability to terminate episodes of PSVT as well as to inhibit their induction. Procainamide had an inhibitory effect on APRT in nine of 12 patients (75%) and terminated episodes of APRT in seven of 11 patients (63.6%); in all of them V-A block was responsible for the termination. In four of six patients (66.7%) with slow-fast AVNRT and in one patient with fast-slow AVNRT, inhibition of the induction of tachycardia attacks was noted after procainamide. Termination of AVNRT was seen in the same number of patients. Verapamil inhibited the induction of APRT in 12 of 18 patients (66.7%) and terminated episodes of APRT in 10 of 16 patients (62.5%), all by A-V block. In six of eight patients (75%) with slow-fast AVNRT, inhibition of the induction as well as termination of tachycardia were noted after verapamil. Disopyramide had an inhibitory effect on APRT in seven of 23 patients (30.4%) and terminated APRT in five of 21 patients (23.8%) by V-A block, while AVNRT (all slow-fast type) was terminated in only one of eight patients (12.5%) by disopyramide. Disopyramide was less effective than previously reported. This could be attributed to a relatively low dosage and slow infusion speed. Propranolol inhibited the induction of APRT and terminated episodes of APRT in only one of 10 patients (10%). In two of four patients (50%) with slow-fast AVNRT, an inhibitory effect by propranolol was noted, but termination was seen in only one patients.

Adolescent↗
PubMed1985

Strobofibrescopic colour video recording of vocal fold vibration.

We have designed a system for strobofibrescopic video recordings of vocal fold vibration. The system consists of a flexible laryngofibrescope, an improved model of laryngo-stroboscope, a colour video-camera, a video printer, a video-recorder and a TV monitor set. This system is applicable to most patients, even to children and those patients whose larynx is difficult to visualize.

Aged↗
PubMedDate not supplied

Strobofiberscopic video recording of vocal fold vibration.

We describe our current system for strobofiberscopic video recording of vocal fold vibration and our early clinical experiences. The advantages of the strobofiberscopic video system over the strobotelescopic video systems are 1) the range of subjects is wide, and 2) the patient can phonate while maintaining normal head position during examination.

Adolescent↗