Biomedical subjects

Shingo Hori

Publications and source records attributed to Shingo Hori.

13 recordsLinked to original sources

PubMed2006

Orthostatic decrease in cardiac chaos during the head-up tilt test in patients with vasovagal syncope.

BACKGROUND: Autonomic dysfunction contributes to orthostatic intolerance in vasovagal syncope (VVS), but as it has not been identified by spectral analysis of heart rate variability (HRV) in previous studies, the present hypothesis was that nonlinear analysis of HRV would identify the orthostatic intolerance in VVS. METHODS AND RESULTS: Twenty-six patients with VVS and 14 matched controls were subjected to 80-degree head-up tilt test (positive: 13 patients; negative: 13 patients and 14 controls). There were no differences in the orthostatic changes in the indices of spectral analyses of HRV among the 3 groups. The Lyapunov exponent (LE) was calculated from 200 consecutive RR-intervals to investigate chaotic behavior, and cardiac chaos was defined as the incidence of the presence of a positive finite LE. Orthostatic decreases in cardiac chaos were observed in the VVS patients (both the positive and negative groups), although there was no orthostatic decrease in the control group (ANOVA: p = 0.008). The receiver-operator characteristic curve indicated that cardiac chaos during the tilt identified VVS regardless of the results of the tilt (p < 0.001, sensitivity: 85.7%, specificity: 96.2%). CONCLUSIONS: The decrease in cardiac chaos during the tilt test was specific to patients with VVS, even if their response to the test was negative.

Adult↗

PubMed2005

Emergency medical services in Japan: an opportunity for the rational development of pre-hospital care and research.

Japan is at a crossroads in the development of its Emergency Medical Services (EMS). At present, Japan has an essentially pure scoop-and-run, defibrillation system. However, there is a strong movement toward expanding the scope of paramedic practice to include more complex, Advanced Life Support (ALS) and trauma protocols to its nationally standardized pre-hospital protocols. The implications of introducing complex pre-hospital protocols guided by the use of existing scientific evidence to support such action is discussed in the context of Japan's unique opportunity to test many fundamental questions in pre-hospital medical care and the public's understanding and acceptance of these practices. Japan, a technologically advanced country that is not encumbered by entrenched "standards of care," has the opportunity to develop an efficient and rational EMS system.

Ambulances↗

PubMed2005

Flow-independent myocardial ischemia induced by endothelin-1: an NADH fluorescence analysis.

The endothelin-1 (ET-1) is known to cause myocardial ischemia; however, whether this effect is entirely dependent on vasoconstriction is uncertain. The aim of this study was to characterize the myocardial ischemia after the intracoronary administration of endothelin-1, and compare it with that induced by coronary stenosis. In the left anterior descending coronary artery of 15 dogs, a mild inflow reduction (30%) was produced for 10 minutes using intracoronary endothelin-1 (46 +/- 33 pmol/min) or coronary stenosis. The hearts were rapidly cross-sectioned at short axial plane and freeze-clamped within 120 milliseconds using a specially developed device to visualize and quantify the area of ischemia (%IA) with NADH fluorescence photography. The %IA was larger in the endothelin-1 group than in the stenosis group (66 +/- 23 versus 18 +/- 18, P = 0.0005); furthermore, the ischemia was transmural in the ET-1 group, but limited to subendocardium in the stenosis group. ET-1 increased the coronary arterial resistance especially in subepicardial region and produced smaller ischemic foci in microcirculation. The mechanism of larger ischemia produced by ET-1 might depend on pro-ischemic effects on myocytes and vasoconstriction of the coronary microcirculation, predominantly in the subepicardium in vivo.

Animals↗

PubMed2005

Heat stroke with multiple organ failure treated with cold hemodialysis and cold continuous hemodiafiltration: a case report.

A 23-year-old comatose man was presented in the emergency room. He had been working inside a building under construction on a hot summer's day. His core body temperature was 42.1 degrees C and he was diagnosed with heat stroke. Urgent cooling procedures, including applying cold vapor to the patient's skin, a gastric lavage with cold water and an intravenous cold saline infusion, were not completely successful and his body temperature remained above 40 degrees C. Because his high temperature was refractory to conventional cooling procedures and we suspected that acute renal failure (ARF) by rhabdomyolysis would develop, we applied hemodialysis (HD) using cold dialysate (initially 30 degrees C and later 35 degrees C), followed by continuous hemodiafiltration (CHDF) with cold dialysate (35 degrees C) at a high flow rate of 18,000 mL per hour. The patient's body temperature fell below 38.0 degrees C within 3 h and was kept below 38.0 degrees C. Continuous hemodiafiltration was continued for one week. During the first week, the patient suffered from multiple organ failure (MOF) involving renal failure, as well as the failure of heart, liver, lung, and central nervous systems. Disseminated intravascular coagulation also developed. However, by virtue of cold CHDF, he almost recovered 3 weeks after the onset, except for remaining mild liver and renal dysfunction. In severe heat stroke, cold HD and high flow, cold CHDF should be a therapeutic choice for cooling and treatment of MOF. Considering mild liver and renal dysfunction still remained, this case suggested these procedures should be initiated at the very beginning of the treatment of severe heat stroke.

Adult↗

PubMed2005

A case of severe heat stroke with abnormal cardiac findings.

We document serial changes in the electrocardiogram (ECG) and myocardial markers in a case of severe heat stroke treated with cooling procedures. A 23-year-old comatose male with heat stroke was presented in the emergency room. The condition of the patient was complicated by hepatic failure, rhabdomyolysis, acute renal failure, and cardiac abnormalities. ECG revealed diffuse ST-T elevation; serum levels of myocardial markers were remarkably high and diffuse hypokinesis was observed on the echocardiogram. Cooling procedures, including applying cold vapor to the patient's skin, a gastric lavage with cold water, and an intravenous cold fluid infusion were not successful. Since multiple organ damage (heart, liver, central nervous system, and kidney) was evident, we utilized continuous hemodialysis and hemofiltration, using cold dialysate for efficient cooling. The patient recovered from the multiple organ damage and was removed from the intensive care unit 14 days after the onset. The cardiac abnormalities had normalized within several days without any damage to the myocardium. Q waves were not detected in any lead in the ECG. When interpreting ST-T elevation in the ECG of a heat stroke patient, caution should be used so as to not misdiagnose it as an acute myocardial infarction.

Adult↗

PubMed2005

Prognostic value of a qualitative test for heart-type fatty acid-binding protein in patients with acute coronary syndrome.

Heart-type fatty acid-binding protein (h-FABP) is a novel diagnostic marker for myocardial infarction, but its prognostic value has not been established in patients with acute coronary syndrome (ACS). We sought to determine the value of qualitative analysis of h-FABP for predicting 30-day adverse events in patients with ACS. A retrospective observational study was conducted on patients at a community hospital, and 130 patients admitted through the emergency room (ER) for ACS were identified among 12,077 patients who presented to the ER between January and June 2003. Of these 130 patients, 90 (mean age, 66.8 years, 67 males) who had ACS were eligible for this study. Qualitative tests for serum h-FABP and troponin T (cTnT) were performed on presentation. Follow-up information on adverse events within 30 days after admission, defined as cardiac death or recurrent ACS, was obtained from the medical records. The qualitative tests for h-FABP and troponin T were positive in 62.2% and 36.7%, respectively. The cumulative adverse event rate at 30 days was 14.8% in the h-FABP-positive group and 3.2% in the negative group. The adjusted relative risk of a positive h-FABP test for adverse events was 44.98 (95% CI: 1.48 to 1,364.88). A positive h-FABP test was an independent predictor of adverse events within 30 days in these patients.

Aged↗

PubMed2004

Long-term survival of Japanese patients transported to an emergency department because of syncope.

STUDY OBJECTIVE: Cardiovascular disease mortality is affected by ethnic differences and is lower in Japan than in Western countries. Although patients with cardiac syncope have significantly higher mortality than patients with noncardiac syncope in Western countries, no such phenomenon has been described in Japan. The aim of this study is to clarify the long-term mortality of patients with syncope who are brought to an emergency department (ED) in Japan. METHODS: This retrospective observational study was conducted on patients treated in the ED of Keio University Hospital in Tokyo. Nine hundred twelve consecutive patients who presented with syncope were identified. The patients were classified into 2 groups according to the cause of syncope: cardiac syncope and noncardiac syncope. Follow-up information about mortality was obtained from mailed questionnaires and medical records. Mortality data were analyzed using the actuarial life-table method and a Cox proportional hazards model. RESULTS: Follow-up information was obtained for 715 patients. The median follow-up period was 38 months, during which 63 patients died. At 5 years, the 23.1% (95% confidence interval [CI] 12.7% to 33.4%) mortality of the patients with cardiac syncope was significantly higher than the 8.2% (95% CI 5.5% to 10.9%) mortality of the patients with noncardiac syncope (P<.0001). The incidence of cardiac death among the patients with cardiac syncope was 17.2% (95% CI 7.8% to 26.5%) compared with 0.9% (95% CI 0% to 1.8%) in the noncardiac syncope group (P<.0001). Cardiac syncope was an independent predictor of overall mortality and cardiac mortality (relative risk 2.81 [95% CI 1.53 to 5.16], 18.74 [95% CI 5.90 to 59.52]). CONCLUSION: Cardiac syncope is associated with higher mortality than noncardiac syncope in this Japanese patient population.

Adolescent↗

PubMed2004

IgD myeloma with systemic amyloidosis with chest discomfort as an initial symptom.

A 53-year-old man was admitted to Keio University Hospital because of serious dyspnea and edema of the lower extremities. Eighteen months previously, the patient had complained of chest discomfort, and was then admitted for the first time to our hospital for evaluation of chest pain. Electrocardiography showed poor R wave progression in leads Vl through V4, and diffuse nonspecific ST-segment and T wave abnormalities with low voltage. However, no definitive diagnosis could be made at this initial admission and a calcium-channel blocker was prescribed. Despite this treatment, the patient was readmitted with worsening dyspnea and lower extremity edema. The diagnosis of heart failure and nephritic syndrome was made at the second admission. In addition, immunoelectrophoresis showed a monoclonal IgD (lambda) M protein and increased plasma cells in the bone marrow, suggesting a diagnosis of multiple myeloma. The patient was thus given dexamethasone (20 mg per day for 4 days) intravenously, but his symptoms did not improve. Two weeks later, the patient deteriorated further with congestive heart failure and renal failure, and subsequently died of cardiac arrest with ventricular fibrillation. On autopsy, IgD (lambda)-positive plasma cell proliferation was found in the bone marrow, confirming the diagnosis of multiple myeloma. In addition, amyloid deposition was detected in various organs including the heart, kidneys, esophagus, duodenum, ileum, colon, tongue, and lungs. In particular, the weight of the heart was 650 g demonstrating a hypertrophic septum and amyloid deposition in the myocardium and even coronary arteries. In summary, the final diagnosis was IgD (lambda) multiple myeloma associated with systemic amyloidosis.

Amyloidosis↗

PubMed2003

Role of vagal control in vasovagal syncope.

The vasovagal reaction is thought to be caused by sympathetic withdrawal and vagal augmentation. While measurements of muscle sympathetic nerve activity support sympathetic withdrawal in tilt induced syncope, the results of previous attempts to quantify vagal control using spectral analyses of heart rate variability (HRV) remain controversial. The sampling period used in the HRV studies is related to the discordant results. In the present study, HRV was computed every second using wavelet transformation to clarify the role of vagal control in tilt induced syncope during the 80-degree head-up tilt test (positive: 10 patients with vasovagal syncope; negative: 10 patients with vasovagal syncope, and 10 control subjects). Autonomic modulations were assessed using the absolute power of the low frequency (LF) (0.04-0.15 Hz) and high frequency (HF) (0.15-2.00 Hz) oscillatory components of R-R variability. Although the LF did not change during the tilt procedure, a decrease in the systolic arterial pressure (SAP) and increases in the R-R interval and HF were observed for the last 30 seconds before the tilt induced syncope in the tilt-positive group. Analyzing the hemodynamic measurements and spectral indices for the last 5 minutes preceding the tilt induced syncope, the study found that the SAP, R-R interval, and HF changed simultaneously during the 30-second period immediately before the tilt induced syncope. Further, the HF was positively correlated with the R-R interval and negatively correlated with the SAP. In conclusion, continuous spectral analysis of the R-R interval demonstrated increased vagal influence on the heart in tilt induced syncope.

Adult↗

PubMed2002

Acute subdural hematoma caused by ruptured cerebral aneurysms: diagnostic and therapeutic pitfalls.

On rare occasions, rupture of a cerebral aneurysm causes acute subdural hematoma (SDH) in addition to subarachnoid hemorrhage (SAH). The frequency of SDH resulting from aneurysmal rupture is summarized, and its clinical and radiological characteristics, as well as potential pitfalls in the diagnosis and the management of this life-threatening condition are described. Among 641 patients with nontraumatic SAH treated between 1992 and 2000, 12 patients (1.9%) presented with SDH due to aneurysmal rupture. The SAH grade on admission was grade II in one patient, grade IV in three patients, and grade V in eight patients. Four underwent both hematoma evacuation and clipping of the aneurysm, four underwent hematoma evacuation alone, and the other four patients were treated conservatively. The outcome was good recovery in two patients, severe disability in one patient, and death in nine patients. Patients with a good outcome had a better SAH grade on admission, smaller midline shift, and smaller SDH volume on the initial CT scan, and they had been treated by both SDH evacuation and clipping of the aneurysm. Emergency one-stage operations may be beneficial for aneurysmal SDH patients who are in good SAH grade, or those who are in poor SAH grade but show some neurological recovery after resuscitation. It should also be mentioned that there are cases of aneurysmal SDH without recognizable SAH on the CT scans, and that a case of aneurysmal SDH may present as a case of 'head trauma' after an accident, because of the disturbance of consciousness resulting from aneurysmal rupture.

Adult↗

PubMed2002

Cardiopulmonary arrest induced by anaphylactoid reaction with contrast media.

Anaphylactoid reactions to iodinated contrast media can cause life-threatening events and even death. A 44-year-old woman presented with cardiopulmonary arrest (CPA) immediately following the administration of nonionic iodinated contrast media for an intravenous pyelography. Her cardiac rhythm during CPA was asystole. She was successfully resuscitated by the radiologists supported by paged emergency physicians using the prompt intravenous administration of 1 mg of epinephrine. Neither laryngeal edema nor bronchial spasm was observed during the course of treatment, and she was discharged on the 4th day without any complications. The patient did not have a history of allergy, but had experienced a myocardial infarction and aortitis. She had undergone 11 angiographies and had been taking a beta-adrenergic receptor antagonist. Planned emergency medical backup is advisable to ensure resuscitation in the event of an anaphylactoid reaction to the use of contrast media in-hospital settings.

Adrenergic Agonists↗

PubMed2002

Thrombolysis candidates for the treatment of stroke at an emergency department in Japan.

OBJECTIVES: To study the proportion and characteristics of potential candidates for the intravenous administration of tissue plasminogen activator (IV-tPA) among patients with cerebral infarction in a Japanese emergency department (ED). METHODS: A retrospective observational study was performed using patients who had been transported by ambulance between August 1988 and April 2000 to an urban ED of a university hospital located in the Tokyo metropolitan area. Potential candidates for IV-tPA were identified using the criteria of the National Institute of Neurological Disorders and Stroke (NINDS) study. RESULTS: Of all 30,064 patients transported by ambulance, 526 were diagnosed as having cerebral infarction. Among them, 190 patients arrived at the ED within two hours of symptom onset (early ED arrivers). In comparison of their demographics with late ED arrivers (n = 319), atrial fibrillation, male gender, and consciousness disturbance were related with early ED arrivers, while aging and diabetes were related with late ED arrivers. As to the stroke subtype, patients with an embolic infarction accounted for 76.8% among early ED arrivers. Application of exclusion criteria identified 114 patients, who were suitable for the thrombolysis treatment, indicating that the proportion of potential IV-tPA candidates was 21.7% among all cerebral infarction patients and 0.38% among all ED patients. CONCLUSIONS: The number of potential IV-tPA candidates among patients transported to the ED by ambulance in Japan was substantial, where the proportion of embolic infarction cases was extremely high.

Aged↗

PubMed2002

Characteristics of elderly patients presenting to the emergency department with injury.

BACKGROUND: In Japan, emergency departments (ED) receive a large proportion of elderly patients each year. As such, injuries in the elderly are a common reason for presentation to the ED. Knowledge about the characteristics of injuries presenting to the ED would be invaluable in devising strategies to prevent injury in the elderly. OBJECTIVE: To analyze the characteristics of injuries in the elderly presenting to the ED and compare them with those of the younger population. SETTING: The ED at Keio University Hospital, a large inner city teaching hospital located in Tokyo. METHOD: A retrospective analysis of data extracted from the ED database of the Keio University Hospital. Information regarding patients aged 65 years or above presenting with injury was analyzed and compared with those aged less than 65 years. Prehospital triage by emergency personnel was adopted as the severity of patients, namely "life-threatening" or "non life-threatening". RESULTS: 20% of all ED presentations of elderly patients were injury related compared to 39% of non-elderly. Compared to the non-elderly, elderly patients presenting to the ED with injury were more likely to be female, sustained injury from trauma unrelated to motor vehicle accidents (MVA) and requiring hospital admission as a result of "non life-threatening" injuries. They were less likely to have injuries from MVA or burns. The number of "life-threatening" injury cases and mortality in both groups were similar. There was evidence that the number of ED presentations relating to injury is increasing in the elderly population. CONCLUSION: Elderly injury patients are a distinct group with distinctive demographics, mechanism of injury and outcomes. This information would be useful in the planning of injury prevention programs, with particular emphasis on elderly females and MVA-unrelated trauma.

Adult↗