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Biomedical subjects

Teruo Takano

Publications and source records attributed to Teruo Takano.

At least 73 records · Page 4Linked to original sources

Parasympathetic blockade promotes recovery from atrial electrical remodeling induced by short-term rapid atrial pacing.

The purpose of the present study was to assess the influence of autonomic blockade on shortening of effective refractory period (ERP) induced by short-term rapid atrial pacing (RAP) and its recovery process. Fifteen patients (8 men, 7 women, age 52 +/- 16 years) without structural heart disease and without a history of atrial fibrillation were included in this study. All patients underwent RAP at a cycle length of 300 ms for 5 minutes, after which the ERP was measured in all patients at 1, 3, 5, 7.5, and 10 minutes following cessation of RAP. In ten patients, these RAP and measurements of ERPs were repeated after administration of propranolol (P) and subsequent administration of atropine (P + A), respectively. In the remaining five patients atropine (A) was given first and then the administration of propranolol followed (P + A). Relative to the baseline value, the ERP immediately after RAP did not differ significantly from the Control(C), P, A, or P + A (C, 79%+/- 8%; P, 82%+/- 9%; A, 80%+/- 6%; P + A, 82%+/- 13%). However, the ERP 3 minutes after cessation of RAP was significantly (P < 0.05) longer in A (93%+/- 4%) and P + A (97%+/- 5%) than that in C (86%+/- 5%) and P (86%+/- 5%). The recovery time for ERP to return to pre-RAP value was significantly shorter during A and P + A than during either C or P (C, 536 +/- 161 s; P, 503 +/- 172 s; A, 282 +/- 111 s; P + A, 291 +/- 147 s; P < 0.05). Parasympathetic blockade may promote recovery from ERP shortening induced by short-term RAP.

Atropine↗

Successful radiofrequency catheter ablation of an anteroseptal (superoparaseptal) atrioventricular accessory pathway from the left ventricular outflow tract.

This case report describes a patient with Wolff-Parkinson-White syndrome in whom the ECG exhibited a typical pattern of an anteroseptal (superoparaseptal) accessory pathway. Successful radiofrequency catheter ablation was achieved from the septal side of the left ventricular outflow tract. It might be worthwhile to map the left side of the anterior septum if an accessory pathway potential is not appreciable along the tricuspid annulus to avoid the potential complication of AV block in patients with a typical anteroseptal accessory pathway ECG pattern.

Atrioventricular Node↗

Office cardiologists cooperative study on whole blood rapid panel tests in patients with suspicious acute myocardial infarction: comparison between heart-type fatty acid-binding protein and troponin T tests.

BACKGROUND: The whole blood rapid troponin T test, used to determine the early diagnosis of acute myocardial infarction (AMI), is effective only for 3-4 h after onset. METHODS AND RESULTS: The present office cardiologists cooperative study compared the diagnostic efficacy of a newly developed whole blood rapid panel test for heart-type fatty acid-binding protein (H-FABP) with that of the rapid troponin T test in 129 consecutive patients with suspicious AMI according to certain time-frames from onset to presentation. Thirty-one patients (24.0%) had a final diagnosis of AMI. The respective sensitivities of the rapid H-FABP and troponin T tests were 100% vs 50% (p<0.05) for patients presenting within 3 h of onset; 75% vs 0% for those between 3 and 6 h; 100% vs 60% for those between 6 and 12 h; and 100% vs 100% for those presenting later than 12 h. The respective specificities were 63% vs 96.3% (p<0.05); 93.8% vs 93.8%; 72.7% vs 100%; and 75.0% vs 87.5%. Negative predictive value was 100% vs 86.7%; 93.8% vs 78.9%; 100% vs 84.6%; and 100% vs 100%, respectively. Patients with non-AMI myocardial damage associated with unstable angina or severe heart failure showed positive H-FABP test results and blunted the specificity. CONCLUSIONS: When using the novel rapid H-FABP test, cardiac emergency triage to exclude non-AMI patients should be effectively organized within 3 h of onset.

Adult↗

Effects of green tea intake on the development of coronary artery disease.

BACKGROUND: Green tea, a popular beverage in Japan, contains many polyphenolic antioxidants, which might prevent atherosclerosis. This study was designed to determine whether the consumption of green tea is proportionately associated with a decreased incidence of coronary artery disease (CAD) and the cardiovascular and cerebrovascular prognosis. METHODS AND RESULTS: The study group comprised 203 patients who underwent coronary angiography (109 patients with significant coronary stenosis and 94 patients without). Predictors for CAD were analyzed and the patients' cardiovascular and cerebrovascular events were followed. Green tea consumption was significantly higher in patients without CAD than in those with CAD (5.9+/-0.5 vs 3.5+/-0.3 cups/day; p<0.001). An inverse relationship between the intake of green tea and the incidence of CAD was observed (p<0.001). The green tea intake per day was an independent predictor for CAD based on a multivariate logistic regression analysis (odds ratio: 0.84 and 95% confidence interval: 0.76-0.91). In contrast, the green tea intake was not a predictor of cardiovascular and cerebrovascular events based on the Cox proportional hazard model. CONCLUSIONS: Green tea consumption was associated with a lower incidence of CAD in the present study population in Japan. Therefore, the more green tea patients consume, the less likely they are to have CAD.

Beverages↗

Ongoing myocardial damage in chronic heart failure is related to activated tumor necrosis factor and Fas/Fas ligand system.

BACKGROUND: Elevated concentrations of cardiac troponin T and heart-type fatty acid-binding protein (H-FABP) identify patients with chronic heart failure (CHF) and ongoing myocardial damage (OMD) who are at increased risk for future cardiac events. Cardiomyocyte necrosis and/or apoptosis via activated tumor necrosis factor (TNF) and the Fas/Fas ligand (FasL) system may be related to the development of OMD. METHODS AND RESULTS: The serum concentrations of H-FABP, a sensitive marker of membrane damage of cardiomyocytes, soluble Fas (sFas) and TNF-alpha were measured in 38 patients with CHF. The concentrations of H-FABP, TNF-alpha and s-Fas in patients with New York Heart Association (NYHA) III + IV were all significantly higher than in those patients in NYHA II (H-FABP; III + IV 9.3+/-5.9 vs II 5.1+/-1.8 ng/ml, p=0.003, TNF-alpha; III + IV 10.5+/-3.8 vs II 8.0+/-2.7 pg/ml, p=0.02, sFas; III + IV 3.36+/-1.37 vs II 2.58 +/-0.84 ng/ml, p=0.03). Increased concentrations of H-FABP significantly correlated with the concentrations of TNF- alpha (r=0.57, p=0.0001) and sFas (r=0.69, p<0.0001), independent of renal function. CONCLUSION: OMD detected by H-FABP, a marker of membrane damage, is related to activated TNF and the Fas/FasL system, which suggests a pathophysiological role of cardiomyocyte necrosis and/or apoptosis in patients with worsening heart failure.

Aged↗

Differences in the clinical course of acute massive and submassive pulmonary embolism.

BACKGROUND: Acute massive or submassive pulmonary embolism (PE) has high mortality, but the clinical course according to the location of onset (ie, in-hospital or out-of-hospital) is unknown. METHODS AND RESULTS: In the present study 56 consecutive patients with acute massive or submassive PE were studied retrospectively and a comparison made of the clinical characteristics, and outcomes between in-hospital onset (Group A) and out-of-hospital onset (Group B). Patients in Group A (n=28) had more frequent comorbidities with hemodynamic instability (54% vs 4%, p<0.0001) and temporary risk factors (93% vs 11%, p<0.0001), whereas patients in Group B (n=28) had a longer duration of symptoms (median: 5.5 days vs 0.5 day; p<0.0001), and had higher systolic pulmonary artery pressure (63+/-17 mmHg vs 46+/-12 mmHg, p=0.0006). Although in-hospital mortality did not differ between the 2 groups, the recurrence rate was higher in Group B (23% vs 0%, p=0.03). CONCLUSIONS: Patients who had in-hospital onset of PE had mostly temporary risk factors, unstable hemodynamics and a lower recurrence rate compared with the cases of out-of-hospital onset. In cases of in-hospital onset, prompt diagnosis and suitable treatment is needed to prevent fatalities and cases of out-of-hospital onset should be followed carefully for recurrence.

Acute Disease↗

Measurement of end-tidal carbon dioxide in patients with cardiogenic shock treated using a percutaneous cardiopulmonary assist system.

We have reported that percutaneous cardiopulmonary assist systems (PCPS) are effective in treating life-threatening cardiogenic shock that is intractable to treatment with intraaortic balloon pumping (IABP). However, there are few clinical indices that can be used to evaluate the effectiveness of PCPS. End-tidal carbon dioxide (ET-CO(2)) content reflects pulmonary blood flow. We monitored ET-CO(2) continuously and determined whether we could use it as a new index to evaluate the effectiveness of PCPS. Seventeen patients with cardiogenic shock were intubated and evaluated by ET-CO(2) monitoring during PCPS. The etiology of shock included acute myocardial infarction (n=10), acute myocarditis (n=2), recent coronary artery bypass graft (n=1), cardiac rupture (n=1), hypertrophic obstructive cardiomyopathy complicated by ventricular fibrillation (n=1), left atrial myxoma (n=1) and artificial valve malfunction (n=1). PCPS was extremely effective in 10 of 17 patients (58.8%), and they recovered from the cardiogenic shock. The remaining 7 patients did not recover from shock, and died during PCPS. Six of ten patients who recovered from shock were successfully weaned from PCPS and 4 patients had good long-term survival. In the cases where PCPS was effective, the ET-CO(2) measured soon after the beginning of PCPS was significantly higher than in the cases in which PCPS was ineffective. Furthermore, the ET-CO(2) content increased gradually with the improvement in hemodynamics. In contrast, ET-CO(2) content remained low if PCPS was not effective. The ET-CO(2) represents a useful predictor of survival or death and is also a good index for weaning in patients treated with PCPS.

Adult↗

A case of hepatocellular carcinoma with situs inversus totalis.

We report a case of hepatocellular carcinoma with situs inversus totalis treated by hepatectomy. A 70-year-old asymptomatic female with hepatocellular carcinomas in segments 5, 6 and 8 underwent transarterial embolization in the department of medicine. However, hepatocellular carcinoma in segment 8 relapsed, and she was referred to the department of surgery. Laboratory tests revealed elevation of serum PIVKA2 level (4,690 ng/mL). Angiography revealed tumor stain in segment 8, 3 cm in diameter. No aberrant vessels were detected on angiography. The operator stood on the patient's left, and partial hepatectomy could be performed safety after careful examination of the anatomy. Although aberrant vessels are detected in many patients with situs inversus totalis, operations can be performed safely on them with sufficient understanding of the anatomy.

Aged↗

A case of massive left atrial lipoma occupying pericardial space.

We report a rare case of massive left atrial lipoma occupying pericardial space. A 52-year-old male was admitted because of cardiomegaly of unknown etiology. Computed tomography showed a large epicardial mass located along the anterior surface of the heart, from the diaphragm level through the aortic arch level. The mass showed an attenuation value identical with that of subcutaneous adipose tissue and contained some areas with high density. The mass was not enhanced by contrast media. Histologic examination of the specimen obtained by percutaneous biopsy demonstrated mature adipose tissue. An encapsulated adipose mass weighing 620 g, which originated from the left atrium without any invasion to the pericardium, was completely excised. Microscopic examination revealed mature adipose tissue with partial necrosis, confirming the diagnosis of lipoma.

Cardiac Surgical Procedures↗

Relationship between brain natriuretic peptide, myocardial wall stress, and ventricular arrhythmia severity.

We previously demonstrated that the severity of arrhythmias is reflected by circulating brain natriuretic peptide (BNP) concentrations in patients without signs of congestive heart failure. In the present study, we evaluated the relationships between the severity of the arrhythmia, BNP concentration, and echocardiographic findings. The subjects consisted of 52 patients with ventricular premature contractions (VPC) but no manifestations of heart failure and no digoxin or beta-blocker therapy. Patients underwent Holter monitoring, plasma sampling for BNP measurement, and transthoracic echocardiography (TTE). We scored the motion of 16 left ventricular segments, deriving a wall-motion score index (WMSI) by totaling the scores and dividing by the number of segments scored. Twenty-three patients with Lown grade I to II arrhythmias constituted group A while group B consisted of 29 Lown III to IV patients. Group B had BNP concentrations triple those in group A (57.2 versus 18.1 pg/mL, P < 0.01). Left ventricular ejection fraction (LVEF) was similar in groups A and B (65.2% versus 62.1%, NS). Although left ventricular end-diastolic dimension (LVEDD) was normal in both groups, group B exhibited a larger LVEDD than group A (50 versus 46 mm, P < 0.005). The correlation (r) between BNP and interventricular septum thickness (IVST) was 0.27 (P = 0.013) in group A and 0.37 (P < 0.0001) in group B. Between BNP and posterior wall thickness (PWT), the correlation was 0.23 (P = 0.014) in group A versus 0.33 (P < 0.0001) in group B. The WMSI in group B was higher than in group A (1.34 versus 1.11, P < 0.05). We believe that besides the changes in echocardiographic parameters, the BNP elevation in group B could be a response to abnormal wall stress from the severe ventricular arrhythmias.

Aged↗

Angiotensin-converting enzyme inhibitors are not effective at inhibiting further fibrous changes in the atria in patients with chronic atrial fibrillation: speculation from analysis of the time course of fibrillary wave amplitudes.

To examine whether angiotensin-converting enzyme (ACE) inhibitors are effective at inhibiting further fibrous changes in atria in patients with chronic atrial fibrillation, we retrospectively evaluated the time course of fibrillatory wave amplitudes and the effects of an ACE inhibitor on the changes. We reviewed medical records and electrocardiographic files. The patients were eligible for inclusion if they had chronic atrial fibrillation for more than 10 years. The fibrillatory wave with the greatest amplitude was measured in lead V1 of standard electrocardiograms. A total of 31 patients were enrolled and were divided into two groups according to treatment. Twelve patients were classified as the ACE inhibitor group and 19 as the non-ACE inhibitor group. There was no significant difference in the mean value of the fibrillatory wave amplitude at baseline between the 2 groups (ACE inhibitor group, 0.23 +/- 0.02 mV; non-ACE inhibitor group, 0.18 +/- 0.02 mV). The fibrillatory wave amplitude decreased significantly after 10 years in both groups (ACE inhibitor group, 0.10 +/- 0.02 mV; non-ACE inhibitor group, 0.11 +/- 0.01 mV) and the changes in the fibrillatory wave amplitude were similar between the 2 groups. These results suggest that ACE inhibitors are not effective at inhibiting further fibrous changes in atria in patients with chronic atrial fibrillation.

Angiotensin-Converting Enzyme Inhibitors↗

Hybrid treatment of acute massive pulmonary thromboembolism: mechanical fragmentation with a modified rotating pigtail catheter, local fibrinolytic therapy, and clot aspiration followed by systemic fibrinolytic therapy.

OBJECTIVE: We sought to evaluate the efficacy and safety of a hybrid treatment for acute massive pulmonary thromboembolism in patients with hemodynamic impairment by combining mechanical fragmentation, local thrombolysis, and clot aspiration. SUBJECTS AND METHODS: Within a period of 35 months, 25 patients with hemodynamic impairment (eight men and 17 women; age range, 35-77 years) were treated with mechanical thrombus fragmentation using a modified rotating pigtail catheter. After embolus fragmentation, all patients received an intrapulmonary injection of recombinant human-tissue plasminogen activator and then underwent manual clot aspiration with a large-lumen percutaneous transluminal coronary angioplasty guide catheter. RESULTS: All the patients survived, and their clinical status improved. Posttreatment angiography showed an improvement in pulmonary perfusion in all patients (mean Miller score before treatment, 22.2; after treatment, 13.6; p < 0.01). Mean pulmonary artery pressure decreased from 32.6 to 23.4 mm Hg (p < 0.01). Mean treatment time was 124.6 min. CONCLUSION: Hybrid treatment with mechanical fragmentation using a rotating pigtail catheter combined with local fibrinolysis and manual clot aspiration resulted in a rapid and safe improvement in the hemodynamic condition of patients with acute massive pulmonary thromboembolism. This hybrid treatment appears to be especially useful in patients at high risk for right ventricular failure and is a minimally invasive alternative to surgical embolectomy.

Acute Disease↗

Therapeutic angiogenesis by autologous bone marrow cell implantation for refractory chronic peripheral arterial disease using assessment of neovascularization by 99mTc-tetrofosmin (TF) perfusion scintigraphy.

We investigated efficacy and safety of implantation of autologous bone marrow mononuclear cells plus platelets, including endothelial progenitor cells (EPCs), for recovering refractory chronic peripheral arterial disease (PAD) using visual and quantitative analyses by 99mTc-tetrofosmin (TF) perfusion scintigraphy, and also investigated various quantitative assessments objectively. We performed 12 consecutive cases and 19 limbs and hands with severe chronic PAD that were almost Fontaine class IV (11/12 cases, about 92%) in this trial. This treatment was very effective in relieving severe pain of PAD, especially for Buerger's disease. We used a visual analog scale (VAS) for measurement of pain level. The maximum pain level before implantation was 66.5+/-5.0 mm, and it decreased to 12.1+/-2.2 mm after implantation (p < 0.001). Rest pain in legs and fingers was resolved in 11 cases (11/12 cases, 92%). All patients could measure pain-free walking time on a treadmill, which improved remarkably (140+/-53 s before implantation vs. 451+/-74 s after implantation, p = 0.034). Resting ankle brachial pressure index (ABI) in legs implanted with bone marrow mononuclear cells was also improved (0.65+/-0.08 before implantation vs. 0.73+/-0.07 after implantation, p = 0.055). According to 99mTc-TF perfusion scintigraphy, the proximal area (region from knee to ankle) was 1.32+/-0.10 before implantation versus 1.56+/-0.11 after implantation (p = 0.007). 99Tc-TF perfusion scintigraphy in the distal area (region from ankle to end of toes, or from wrist to end of fingers) was 0.79+/-0.06 before implantation versus 0.83+/-0.06 after implantation (p = 0.29). Ischemic legs and hands that were injected showed increased perfusion blood flow. 99mTc-TF perfusion scintigraphy was effective to estimate visual and quantitative analysis of collateral vessels in neovascularization. We were successful with this new treatment for the most severe, chronic PAD that was not curable by any of the current treatments. Thus, this therapeutic angiogenesis could be a new strategy for saving severe ischemic limbs and hands.

Aged↗

[Detection of myocardial ischemia by analysis of the shape of exercise-induced ST elevation in infarct-related leads].

OBJECTIVES: Possible mechanisms of exercise-induced ST elevation in infarct-related leads include ventricular dyskinesis, and myocardial ischemia in the infarct region. Detection of ischemia in viable myocardium in the infarct region is important to determine the therapeutic strategy. This study evaluated whether the analysis of the shape of exercise-induced ST elevation(convex or concave type) is useful to detect myocardial ischemia in the infarct region. METHODS: Ninety-eight patients (78 males, 20 females, mean age 59 +/- 10 years) with prior Q wave myocardial infarction underwent the treadmill exercise test. Patients were divided into three groups according to the exercise-induced ST changes: No ST-E group, 27 patients without ST changes; Concave ST-E group, 52 patients with concave type ST elevation; Convex ST-E group, 19 patients with convex type ST elevation. Coronary arteriography was evaluated in all patients. Dobutamine stress echocardiography was performed in 38 patients, including 28 patients in the Concave ST-E group and 10 patients in the Convex ST-E group. Biphasic or worsening response on dobutamine stress echocardiography was defined as ischemic response. RESULTS: Coronary arteriography revealed significant stenosis of the infarct-related artery in 30% of the No ST-E group, 47% in the Convex ST-E and 86% in the Concave ST-E groups (p < 0.05). Dobutamine stress echocardiography revealed myocardial ischemia in the infarct region in 30% in the Convex ST-E group and 75% in the Concave ST-E group(p < 0.05). CONCLUSIONS: The Concave ST-E group had a higher incidence of stenosis of the infarct-related artery and myocardial ischemia in the infarct region. Analysis of the shape of exercise-induced ST elevation in infarct-related leads is useful for the detection of ischemia of viable myocardium.

Aged↗

Improved stratification of perioperative cardiac risk in patients undergoing noncardiac surgery using new indices of dobutamine stress echocardiography.

OBJECTIVES: Prediction of perioperative cardiac events associated with noncardiac surgery remains difficult in patients whose functional capacity cannot be evaluated by exercise testing. Dobutamine stress echocardiography (DSE) has been used in these patients to improve risk stratification, but the results of standard DSE provide only a binary index of risk (positive or negative). Two new semiquantitative indices of DSE (semi-DSE) were retrospectively examined to determine the prediction of perioperative cardiac events compared to standard DSE. METHODS AND RESULTS: Clinical assessment of cardiac risk factors and standard DSE were performed safely in 122 consecutive patients (73 men, 49 women) undergoing noncardiac surgery. Preoperative revascularization was performed in 12 patients. The perioperative cardiac events consisted of 2 deaths, 4 cases of heart failure, and 2 cases of angina pectoris. For the semi-DSE indices, the extent of ischemia was indexed as the number of wall segments (SEG) displaying biphasic or worsening segmental wall-motion score, and the severity of ischemia (SI) was indexed as the sum of the differences in wall-motion scores between peak stress and rest divided by the number of affected segments. The optimal cut-off values of these indices for predicting cardiac events were 4.0 for SEG and 1.0 for SI. The risk stratification was further refined by these indices (high-, moderate-, and low-risk groups). The diagnostic accuracy of the semi-DSE indices, evaluated by the area under the receiver operating characteristic curves, was better than that of standard DSE (p < 0.001). CONCLUSIONS: Semi-DSE may improve cardiac-event risk stratification compared to standard DSE in patients undergoing noncardiac surgery whose functional capacity cannot be evaluated by exercise stress testing.

Aged↗

Use of a whole blood rapid panel test for heart-type fatty acid-binding protein in patients with acute chest pain: comparison with rapid troponin T and myoglobin tests.

PURPOSE: We sought to determine the clinical utility of a newly developed qualitative test to measure heart-type fatty acid-binding protein levels in blood for the early identification of myocardial infarction. METHODS: We measured heart-type fatty acid-binding protein levels in 371 consecutive patients with acute chest pain and suspected myocardial infarction, and compared the performance of this test with those of troponin T and myoglobin tests. Levels of heart-type fatty acid-binding protein >or=6.2 ng/mL were considered as positive results. RESULTS: A final diagnosis of acute myocardial infarction was made in 181 patients (49%). Of the 68 patients who presented within 2 hours of the onset of symptoms, 37 (54%) had a final diagnosis of myocardial infarction. The sensitivity of the rapid heart-type fatty acid-binding protein test was 89% (33/37), significantly higher than for troponin T (22% [8/37]; P<0.001) and myoglobin (38% [14/37]; P<0.001). However, the specificity of troponin T (94% [29/31]) was significantly better than for heart-type fatty acid-binding protein (52% [16/31]; P= 0.002) within 2 hours. The area under the receiver operating characteristic curve for heart-type fatty acid-binding protein levels was greater than that for myoglobin (0.72 vs. 0.61, P = 0.01) among patients who presented within 2 hours. CONCLUSION: A novel whole blood rapid heart-type fatty acid-binding protein test can be useful in the early evaluation of patients who present with acute chest pain.

Acute Disease↗

Induction of hepatic injury by hepatitis C virus-specific CD8+ murine cytotoxic T lymphocytes in transgenic mice expressing the viral structural genes.

In the present study, we generated killer cells specific for hepatitis C virus (HCV) structural protein by re-stimulation of immune spleen cells from H-2(d) haplotype transgenic (Tg) mice, expressing the core, E1, E2, and NS2 genes of HCV regulated by the Cre/loxP switching system. The generated killer cells were conventional CD8(+)L(d) class-I MHC molecule-restricted cytotoxic T lymphocytes (CTLs) and specific for the HCV E1 structural protein. Because the CTLs could also kill hepatocytes from the Tg mice expressing HCV structural proteins in vitro, we attempted to transfer those CTLs intravenously into interferon regulatory factor-1 (IRF-1) negative, CD8-deficient Tg mice representing the HCV structural genes on hepatocytes to examine whether the inoculated CD8(+) CTLs can eliminate hepatocytes expressing the HCV genes in vivo. We observed an elevation of serum ALT level as well as damage of the liver tissue histologically. To our knowledge, this is the first demonstration to show that HCV-specific CD8(+) CTLs specifically attack hepatocytes expressing the HCV structural proteins both in vitro and in vivo.

Adenoviridae↗