Biomedical subjects

Teruo Takano

Publications and source records attributed to Teruo Takano.

At least 37 records · Page 2Linked to original sources

PubMed2006

Initial experiences of removal of intra-aortic balloon pumps with the Angio-Seal.

Angio-Seal, a vascular hemostasis device, has been shown to be safe and effective in rapidly achieving hemostasis after cardiac catheterization or coronary intervention. We propose that similar results can be obtained with Angio-Seal when removing an intra-aortic balloon pump (IABP). We studied 16 patients in whom Angio-Seal was utilized in IABP removals. The primary safety endpoint was a composite of major complications such as retroperitoneal bleeding, vessel occlusion, loss of distal pulses, vascular surgery or death, and minor complications such as hematoma (> 10 cm), AV fistula or pseudoaneurysm by 7 days after removal. The time-to-hemostasis was 2-5 minutes (mean 3.3 minutes). There were no instances of major or minor complications by the seventh day in any patients.

Adult↗

PubMed2006

[Progress in the diagnosis and treatment of acute coronary syndromes].

As the pathogenesis of acute coronary syndromes (ACS) has been well increasingly defined, there has been enormous progress in the diagnosis and treatment of ACS during the past 50 years. The previous terminology referring to the heterogeneity of the disease has shifted toward a unifying concept encompassing the wide spectrum of manifestations of ACS, subdivided for the purpose of therapeutic considerations into ST elevation myocardial infarction (MI), and non ST elevation ACS with or without cell necrosis (utilizing troponins), namely non ST elevation MI or unstable angina. The advent of coronary care units and the results of randomized clinical trials on reperfusion therapy, thrombolysis or percutaneous coronary intervention, and medical treatment with various pharmacological agents have substantially changed the therapeutic approach, and decreased in-hospital mortality.

Angina, Unstable↗

PubMed2006

Type I CD36 deficiency associated with metabolic syndrome and vasospastic angina: a case report.

A 54-year-old man was admitted to our hospital for evaluation of chest pain occurring at rest in the morning. ST segment depression was observed during a treadmill exercise test. Coronary angiography identified spontaneous spasm of the proximal right coronary artery, and right coronary obstruction was improved from 90% to about 50% stenosis after intracoronary administration of nitroglycerin. Myocardial iodine-123 beta-methyl-p-iodophenyl-pentadecanoic acid uptake was absent, but thallium-201 uptake during single photon emission computed tomography was normal, and neither platelet nor monocyte expression of the CD36 molecule was observed, indicating type I CD36 deficiency. High blood pressure, elevated plasma triglyceride and fasting plasma glucose levels, and low high-density lipoprotein values suggested metabolic syndrome. The final diagnosis was type I CD 36 deficiency associated with metabolic syndrome and vasospastic angina.

Angina Pectoris, Variant↗

PubMed2005

Improvement of sympathetic response to exercise by oral administration of ascorbic acid in patients after myocardial infarction.

BACKGROUND: Recent studies indicated that excessive oxidative stress in an animal heart failure model injures both the sympathetic nerve endings and receptors, resulting in disturbance of norepinephrine release and sensitivity to norepinephrine. However, it has not been clarified whether this phenomenon is expressed clinically in patients with heart disease. Therefore, we examined the efficacy of ascorbic acid administration as an antioxidant vitamin in relation to the heart rate and norepinephrine response to exercise in patients after myocardial infarction. METHODS: In this randomized crossover trial, 21 male patients who had had myocardial infarction underwent symptom-limited ergometer cardiopulmonary exercise testing twice, that is, without and with ascorbic acid (2 g) administration. Plasma norepinephrine concentrations were assessed at rest and at peak exercise, and heart rate responsiveness to the norepinephrine increment from rest to peak exercise (DeltaHR/logDeltaNE) was calculated. RESULTS: In the exercise test after ascorbic acid administration, peak oxygen consumption (VO(2)) improved over baseline. Ascorbic acid administration significantly increased the change in heart rate and norepinephrine from rest to peak exercise and DeltaHR/logDeltaNE. The increment in heart rate was significantly correlated with peak VO(2) in each test. CONCLUSION: Ascorbic acid intake before exercise improved exercise capacity through enhancement of the heart rate and norepinephrine response to exercise in patients after myocardial infarction. These findings suggest that ascorbic acid intake improves sympathetic dysfunction resulting from injury by excessive oxidative stress after myocardial infarction.

Aged↗

PubMed2005

Dual-isotope myocardial SPECT in patients with redefined myocardial infarction.

BACKGROUND: According to the redefinition of myocardial infarction (MI) by the ESC/ACC Committee, patients with unstable angina (UA) without significant elevation of creatine kinase (CK) but with elevation of troponin T should be diagnosed as MI. METHODS: One hundred and forty-six consecutive patients formerly diagnosed as UA, with peak CK levels 0.10 ng/ml). Dual SPECT findings were analyzed qualitatively and quantitatively in blinded manner. RESULTS: Forty-seven patients (32%) were redefined as MI and 99 patients (68%) were redefined as UA. On admission, there were small but statistically significant elevations in laboratory parameters such as white blood cell count, C-reactive protein, CK and CK-MB in the redefined MI group compared with the redefined UA group. The proportion of patients with perfusion and metabolic abnormalities was significantly higher in the redefined MI group (Tl defect 36% vs. 4%, odds ratio: 13.5, p<0.001; BMIPP defect 64% vs. 23%, odds ratio: 5.8, p<0.001). Semi-quantitative evaluation revealed that the total Tl and BMIPP scores were significantly higher in the redefined MI patients (p<0.001). CONCLUSIONS: In the redefined MI patients, perfusion and metabolic abnormalities occurred frequently and more extensively. However, Tl/BMIPP dual SPECT had limited ability to detect minor myocardial infarcts classified as redefined MI. A more sensitive stratification combined with troponin T directed assignment should be established to incorporate the ongoing minor infarcts which could not be assessed by serial dual-scintigraphic evaluations.

Aged↗

PubMed2005

B-type natriuretic peptide as an integrated risk marker in non-ST elevation acute coronary syndromes.

BACKGROUND: Elevated B-type natriuretic peptide (BNP) levels show prognostic significance in patients with non-ST elevation acute coronary syndromes, but the underlying pathophysiology remains unclear. METHODS: Two hundred and eighteen consecutive patients with non-ST elevation acute coronary syndromes were studied retrospectively. We compared clinical characteristics between groups with plasma BNP levels above or below the median value, and performed multiple logistic regression analysis to identify independent predictors of supramedian BNP levels. RESULTS: Patients with supramedian BNP (>or=134 pg/ml) were more likely to be elderly (>or=75 years) with diabetes, prior myocardial infarction, and a history of coronary artery bypass grafting. They also had higher cardiac marker levels, a higher Killip class, a lower left ventricular ejection fraction, renal insufficiency (creatinine>or=1.5 mg/dl), and more 3-vessel disease. In multivariate analysis, the strongest independent predictor of supramedian BNP levels was 3-vessel disease (chi(2)=12.1), followed by old age (chi(2)=10.3), renal insufficiency (chi(2)=5.0), higher Killip class (chi(2)=4.2), and lower left ventricular ejection fraction (chi(2)=4.1). All 11 patients dying in hospital had supramedian BNP levels. Its elevation reflected the risk of 3-vessel disease and coronary artery bypass grafting regardless of troponin status. CONCLUSION: In unselected patients with non-ST elevation acute coronary syndromes, an increase of BNP is correlated with the extent of myocardial ischemia, age, renal insufficiency, and ventricular dysfunction. It may be a useful biomarker integrating conventional risk factors for risk stratification in this population.

Aged↗

PubMed2005

Successful treatment of primary cardiac lymphoma and pulmonary tumor embolism with chemotherapy.

A 72-year-old man with a large mass in the right atrium and the pulmonary embolism by chest computed tomography was diagnosed as the primary cardiac B-cell lymphoma (PCL) with pulmonary tumor embolism and pericardial effusion. Upon completion of initial chemotherapy, the mass was markedly reduced, and the pulmonary embolism disappeared on magnetic resonance imaging. This rarely diagnosed entity is treatable with chemotherapy for both PCL and pulmonary embolism.

Aged↗

PubMed2005

Detection of cardiac sarcoidosis using cardiac markers and myocardial integrated backscatter.

BACKGROUND: It is not known whether cardiac markers and cyclic variations of integrated backscatter can be used to detect cardiac sarcoidosis. METHODS: We studied 62 patients with sarcoidosis affecting the lung, eyes, skin, or heart (27 patients with cardiac involvement and 35 patients without). The cyclic variation of integrated backscatter and wall thickening was evaluated in the left ventricular anterior septum and posterior wall. Plasma A-type natriuretic peptide (ANP) and B-type natriuretic peptide (BNP) concentrations and serum cardiac troponin T were also determined. RESULTS: Plasma natriuretic peptide concentrations were higher in the cardiac involvement group (ANP: 15.5 [interquartile range (IQR) 2.5-34.0] vs. 12.0 [10.0-16.5] pg/ml, P=0.25; BNP: 28.6 [5.9-141] vs. 10.1 [4.8-15.4] pg/ml, P=0.049). However, cardiac troponin T concentration was <0.01 ng/ml in all patients. Receiver-operator characteristic (ROC) analysis showed that both ANP and BNP could identify patients with high-degree atrioventricular block, ventricular tachyarrhythmias, or symptomatic heart failure (the areas under the ROC curve were 0.94 and 0.97, respectively). The cardiac involvement group could be distinguished from the noninvolvement group by combining cutoff values for the magnitude of integrated backscatter cyclic variation (5.5 dB) and wall thickening (30%), albeit only for the posterior wall. CONCLUSION: Both ANP and BNP are useful markers for identifying patients with sarcoidosis and cardiac complication(s). Moreover, evaluation of integrated backscatter cyclic variation combined with wall thickening may be of help in detecting cardiac involvement in the posterior wall.

Atrial Natriuretic Factor↗

PubMed2005

Hemodynamic features and impaired arterial oxygenation in patients with portopulmonary hypertension.

Portopulmonary hypertension (P-PHT) is sporadically found in cirrhosis patients who have portal hypertension. We retrospectively investigated the clinical features of six patients with P-PHT and compared their hemodynamics and arterial oxygenation with data from 60 cirrhosis patients without pulmonary hypertension (non-PHT cirrhosis) admitted to our department. The mean pulmonary artery pressure and pulmonary vascular resistance index of P-PHT patients ranged from 25 to 57mmHg and from 399 to 1405dynesscm(-5)m(-2), respectively, and their arterial oxygenation was impaired. The systemic vascular resistance and cardiac index of P-PHT patients were similar level to those of patients with non-PHT cirrhosis. We found 10 patients with non-PHT cirrhosis in whom pulmonary vascular resistance exceeded the critical level for pre-capillary pulmonary hypertension (120dynesscm(-5)). These patients showed a distinctive hemodynamic profile, including a decrease of cardiac output due to contraction of the plasma volume and resultant elevation of systemic vascular resistance. However, the decrease of cardiac output contributed little to the elevation of pulmonary vascular resistance. Our findings suggested that certain factor(s) were acting to raise pulmonary vascular tone in these patients, which might cause chronic damage to the pulmonary vascular bed, leading to the onset of pulmonary hypertension.

Journal Article↗

PubMed2005

A case presenting concurrence of Marfan syndrome, Basedow's disease and Arg353Gln polymorphism-related factor VII deficiency.

We report the case of a 48-year-old Japanese man who suffered from Marfan syndrome with severe aortic regurgitation, mitral regurgitation and rapid atrial fibrillation, which were aggravated by hyperdynamic circulatory conditions associated with coexistent Basedow's disease. Furthermore, concurrence of Arg353Gln polymorphism-related factor VII deficiency was discovered at the preoperative assessments. Both of his two brothers suffered from Marfan syndrome; however they had no findings of Arg353Glu polymorphism-related factor VII deficiency or Basedow's disease. After normalization of thyroid function, he had successfully the operations of Bentall procedure: a composite prosthetic graft: replacement of both the ascending aorta and aortic valve, and mitral valve annuloplasty. No specific therapy such as fresh frozen plasma or factor VII replacement therapy was required. He completely returned to his business work 6 weeks after the operation. Concurrence of Marfan syndrome and factor VII deficiency induced by two-hit genomic abnormalities and furthermore Basedow's disease, which significantly compromised the pathophysiological condition of Marfan syndrome, is extremely rare.

Base Sequence↗

PubMed2005

Assessment of contractile response to dobutamine stress by means of ECG-gated myocardial SPECT: comparison with myocardial perfusion and fatty acid metabolism.

UNLABELLED: The present study assessed left ventricular performance during dobutamine stress measured using gated SPECT, and compared the results to myocardial perfusion and fatty acid metabolism. METHODS: Thirty-six patients with myocardial infarction given (99m)Tc-sestamibi or (99m)Tc-tetrofosmin were examined by gated SPECT at rest and during dobutamine stress (4-20 microg x kg(-1) x min(-1)). After acquiring data at the highest dose, 201TlCl was injected and dual-isotope SPECT was performed to assess myocardial ischemia. Thirty of 36 patients also underwent myocardial SPECT with 123I-BMIPP. Regional wall motion changes during dobutamine infusion were determined from the gated SPECT data and classified as: (1) Improvement, (2) Worsening, (3) No change, and (4) Biphasic response. For myocardial segments of each infarct area, stress 201Tl, rest (99m)Tc and (123)I-BMIPP uptakes were graded on a five-point scoring system of defects from 0 (normal) to 4 (grossly defective). RESULTS: Rest 99mTc defect score index (DSI) in No change area was significantly higher than that in Biphasic area. The ADSI (stress 201Tl - rest (99m)Tc) in Biphasic area was significantly higher than those in Improvement and No change areas. The deltaDSI (BMIPP - (99m)Tc) in Worsening area tended to be higher than that in No Change area. CONCLUSIONS: Regional contractile response to dobutamine stress analyzed by gated SPECT showed that the response in-myocardial infarct areas could be classified by rest and stress myocardial perfusion and BMIPP accumulation.

Coronary Vessels↗

PubMed2005

Pulmonary blood transit time and impaired arterial oxygenation in patients with chronic liver disease.

BACKGROUND: Contrast-enhanced echocardiography (CEE) using agitated saline can detect intrapulmonary vasodilatation (IPVD) in patients with hepatopulmonary syndrome (HPS). We estimated the pulmonary transit time of erythrocytes (PTT) by CEE, using microbubbles, and studied its relationship to arterial oxygenation in chronic liver disease. METHODS: Sixteen patients with chronic liver disease and seven healthy subjects were studied. PTT was defined as the time between opacification of the right atrium and left atrium on CEE, using human serum albumin-air microbubble complexes with a mean diameter of 4 microm (Albunex). IPVD was detected by CEE with agitated saline. Arterial blood gases were analyzed with patients in the supine position, and while they were seated. Cardiac output (CO) was determined by Doppler echocardiography. RESULTS: The mean PTT value for all of the patients was 4.0 +/- 1.4 s. One of the 3 patients who showed IPVD was normoxemic. Mild orthodeoxia was observed in the patients with abnormal alveolar-arterial oxygen difference (A-aDO2) values (>15 mmHg), but not in those with normal A-aDO2 values, or in the healthy subjects. PTT was correlated with PaO2 (r = 0.52; P < 0.05; n = 16) and A-aDO2 (r = -0.54; P < 0.05; n = 16) in the seated position. CO was significantly correlated with PTT (r = -0.62; P < 0.05; n = 15), but not with PaO2 and A-aDO2, in both positions. CONCLUSIONS: PTT may be a useful parameter for evaluating arterial oxygenation in patients with chronic liver disease with early HPS.

Adult↗

PubMed2005

Arterial hypoxemia and intrapulmonary vasodilatation in rat models of portal hypertension.

BACKGROUND: Rats with chronic bile duct ligation (CBDL) and portal vein ligation (PVL) are used as models of portal hypertension. CBDL rats show hypoxemia with intrapulmonary vasodilatation (IPVD), and are recognized as a model of hepatopulmonary syndrome (HPS), while PVL rats are normoxemic. We investigated the differences in arterial oxygenation between these models, and the key factors leading to HPS. METHODS: Forty-eight Sprague-Dawley rats were prepared as CBDL or PVL models, or as Sham rats. Arterial oxygenation, hemodynamics (reference sample method), and IPVD were simultaneously evaluated in conscious and unrestrained animals, using (141)Ce- or (113)Sn-labeled microspheres (15 microm in diameter), respectively. Endothelin-1 (ET-1) and nitrate/nitrite (end products of nitric oxide; NOx) production by the lung tissue (increment across the lungs) was also determined. RESULTS: The extent of IPVD was similar in both models, but hypoxemia was only observed in CBDL rats. The ET-1 level and the increment in NOx were significantly increased in CBDL rats, and the increment was directly correlated with impairment of oxygenation. Blood flow through the bronchial arteries (anatomical shunting) was increased in CBDL rats, reaching more than three times the level in PVL rats or Sham rats. CONCLUSIONS: These results support the hypothesis that NO derived from the lung tissues contributes to hypoxemia, and IPVD appears to be a prerequisite for impaired oxygenation. The considerable increase of anatomical shunting may potentially contribute to impaired oxygenation in CBDL rats.

Animals↗

PubMed2005

Adenosine-sensitive atrial tachycardia originating from the proximal coronary sinus.

BACKGROUND: Atrial tachycardia (AT) can originate from the proximal coronary sinus (CS). However, detailed electrophysiologic characteristics of the tachycardia are not available. OBJECTIVES: We describe the electrophysiologic characteristics, response to adenosine 5'-triphosphate, and results of radiofrequency ablation of AT with the earliest activation in the proximal CS. METHODS: In 7 of 54 patients (age 57 +/- 18 years) with nonmacroreentrant "focal" AT undergoing electrophysiologic study and radiofrequency ablation, the earliest atrial activation site was located in the proximal CS. RESULTS: The earliest activation site was inside the CS 13 +/- 3 mm from the ostium. The AT could be induced and terminated by atrial extrastimuli or burst pacing. In all patients, the AT was also terminated by a very small dose of adenosine 5'-triphosphate (4.2 +/- 1.1 mg). Rapid ventricular pacing during the tachycardia produced ventriculoatrial dissociation. Radiofrequency ablation directed at the earliest atrial activation site was effective in only three patients (group A). In the remaining four patients (group B), after the radiofrequency energy deliveries, the earliest activation site shifted to an adjacent site with a small increase in the cycle length. Three group B patients underwent successful ablation in the slow pathway region. No recurrence was observed over a follow-up period of 22 +/- 5 months. CONCLUSION: AT with earliest activation in the proximal CS is sensitive to a small dose of adenosine 5'-triphosphate. In some patients, radiofrequency applications in the slow pathway region are effective even if the local activation is not early.

Adenosine↗

PubMed2005

Inhibition of the reverse mode of the Na+/Ca2+ exchange by KB-R7943 augments arrhythmogenicity in the canine heart during rapid heart rates.

To test the hypothesis that the reverse mode of the Na+/Ca2+ exchange augmented by a rapid heart rate has an antiarrhythmic effect by shortening the action potential duration, we examined the effects of KB-R7943 (2-[2-[4-(4-nitrobenzyloxy)phenyl]ethyl] isothiourea methanesulfonate), a selective inhibitor of the reverse mode of the Na+/Ca2+ exchange, to attenuate this effect. We recorded the electrocardiogram, monophasic action potential (MAP), and left ventricular pressure in canine beating hearts. In comparison to the control, KB-R7943 significantly increased the QTc value and MAP duration. MAP alternans and left ventricular pressure alternans were observed after changing the cycle length to 300 milliseconds in the control studies. KB-R7943 magnified both types of alternans and produced spatially discordant alternans between right and left ventricles. Early after-depolarizations and nonsustained ventricular tachycardia occurred in the presence of KB-R7943. Our data suggest that the reverse mode of the Na+/Ca2+ exchange may contribute to suppression of arrhythmias by abbreviating action potential duration under pathophysiological conditions. This conclusion is based on further confirmation by future studies of the specificity of KB-R7943 for block of the reverse mode of the Na+/Ca2+ exchange.

Action Potentials↗

PubMed2005

Enhancing electrical cardioversion and preventing immediate reinitiation of hemodynamically deleterious atrial fibrillation with class III drug pretreatment.

UNLABELLED: Nifekalant for shock-resistant atrial fibrillation. INTRODUCTION: In severely ill patients, the development of atrial fibrillation (AF) may provoke lethal hemodynamic instability requiring immediate electrical defibrillation, which often is unsuccessful. Using the novel potassium channel blocking agent nifekalant, we prospectively assessed the hypothesis that class III antiarrhythmic drugs facilitate electrical cardioversion and suppress the immediate recurrence of hemodynamically deleterious AF. METHODS AND RESULTS: Among 1896 adults admitted to the intensive care unit for cardiovascular diseases, hemodynamically destabilizing new-onset AF (systolic blood pressure<90 mm Hg) resistant to conventional electrical cardioversion occurred in 27 patients, and of these, 24 patients (70+/-12 years) were enrolled. Twenty-one patients had congestive heart failure and 11 patients had been mechanically ventilated. After three failed transthoracic cardioversions due to failure of conversion to SR (11 patients) or immediate reinitiation (13 patients), nifekalant (0.25+/-0.04 mg/kg) was administered intravenously, and electrical defibrillation was reattempted. In 18 patients (75%), sinus rhythm was restored and maintained after nifekalant infusion (6 patients) or subsequent transthoracic cardioversion (12 patients). Nifekalant administration significantly decreased the heart rate and increased systolic blood pressure during AF (P<0.001), and successful cardioversion rapidly further ameliorated these parameters (P<0.001). Logistic regression analysis showed that atrial defibrillation failure (relative risk [RR] 19.34, P=0.05) and age of >75 years (RR 15.25, P=0.03) were independent predictors of in-hospital death. CONCLUSION: Nifekalant renders electrical defibrillation and the prevention of the early recurrence of hemodynamically unstable AF more successful without deteriorating hemodynamics, and successful defibrillation is associated with a more favorable patient outcome. Pretreatment with other class III drugs, e.g., ibutilide or dofetilide, would also be efficacious in patients with failed urgent electrical cardioversion.

Aged↗

PubMed2005

Anatomic and electrophysiologic evaluation of a right lateral atrioventricular Mahaim fiber.

We report a patient who underwent an electrophysiologic study and radiofrequency catheter ablation for a right lateral Mahaim fiber. During sinus rhythm with overt preexcitation, propagation mapping was performed in the right ventricle using a three-dimensional electro-anatomical mapping system (CARTO). Small discrete potentials, which reflected the excitation of the Mahaim fiber, could be recorded along the line from the vicinity of the parental tricuspid annulus to approximately one-third of distal site from the base to the apex. The relationship of the timing of its potential to the anatomical location could be disclosed on recordings of the local electrogram and anatomical map.

Adolescent↗

PubMed2005

Radiofrequency catheter ablation of a coronary sinus-ventricular accessory connection in dextrocardia with complete situs inversus and an anomalous inferior vena cava.

An anomalous inferior vena cava (IVC) is often associated with patients with dextrocardia. However, radiofrequency catheter ablation in such a case with that combination has not been reported. We encountered a case of Wolff-Parkinson-White syndrome with dextrocardia associated with complete situs inversus and an azygos continuation of the IVC. A steep angulation at the junction of the azygos vein and superior vena cava precluded the precise mapping of the anatomical right cavity with a femoral vein approach. Successful catheter ablation of an accessory connection between the coronary sinus and left ventricle could be achieved with a right cubital vein approach.

Catheter Ablation↗