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Satoshi Nakatani

Publications and source records attributed to Satoshi Nakatani.

At least 37 records · Page 2Linked to original sources
PubMed2005

Infective tricuspid valve endocarditis with pulmonary emboli caused by Campylobacter fetus after tooth extraction.

We describe a case of infective endocarditis caused by Campylobacter fetus accompanied by pulmonary emboli. A 52-year-old man was referred to our hospital due to febrile temperatures with a history of dental treatment followed by eating raw meat. Computed tomography revealed multiple infiltrations and a nodule with low attenuation area and feeding vessels. A mobile mass, possible vegetation, attached to the tricuspid valve was detected by transthoracic echocardiography. Two blood cultures disclosed Campylobacter fetus. Long-term antibiotic therapy was given, curing the infection with valvuloplasty. We presented the possibility that infective Campylobacter fetus endocarditis after dental treatment was caused by eating raw meat.

Campylobacter Infections↗
PubMed2004

Regional heterogeneity of left ventricular myocardial work quantified using anatomical M-mode echocardiography.

BACKGROUND: Although assessment of left ventricular (LV) regional work per unit of myocardium (RWM) from the wall stress-area relationship has been proposed using M-mode echocardiography, the applicable region was limited. Anatomical M-mode is a new technique which permits the M-mode cursor to be angled in any direction on digital two-dimensional images. Our objective was to characterize regional heterogeneity of LV myocardial work using anatomical M-mode. METHODS: Sixteen patients were studied: 5 with idiopathic dilated cardiomyopathy (DCM), 4 hypertrophic cardiomyopathy (HCM), and 7 controls. Digital 2-dimensional echocardiographic cineloops were acquired from the mid LV short-axis view simultaneously with high-fidelity LV pressure. Using anatomical M-mode, LV internal diameters and wall thickness (H) were determined to calculate mean wall stress (sigma) at 6 equiangular directions. The volume of region, which was given by area times H, was assumed to be constant throughout one cardiac cycle from the incompressibility of myocardium. Thus, 1/H is proportional to the regional area, and then RWM was determined as an area within the sigma-ln (1/H) loop at each direction (positive values indicated a counterclockwise loop rotation). RESULTS: RWM from controls were heterogeneous with the highest in the lateral segments. The 6-segment average RWM was lower in both patients with DCM and HCM than controls (3.9 +/- 1.7 and 2.1 +/- 0.3 vs. 5.5 +/- 1.4 mJ/cm(3), both p < 0.05). RWM was particularly deteriorated at septal and inferior segments in patients with DCM (2.3 +/- 0.9 and 3.0 +/- 1.5 mJ/cm(3), both p < 0.05 vs. control) and at hypertrophied anterior and anteroseptal segments in patients with HCM (0.4 +/- 0.1 and 0.8 +/- 0.6 mJ/cm(3), both p < 0.01 vs. control). CONCLUSIONS: Anatomical M-mode enabled RWM assessment at all segments including the inferoseptum and lateral regions that had been impossible for analysis, revealing regional heterogeneity. The present method has the potential to provide additional information on myocardial mechanical condition.

Cardiomyopathy, Dilated↗
PubMed2004

A novel data mining approach to the identification of effective drugs or combinations for targeted endpoints--application to chronic heart failure as a new form of evidence-based medicine.

BACKGROUND: Data mining is a technique for discovering useful information hidden in a database, which has recently been used by the chemical, financial, pharmaceutical, and insurance industries. It may enable us to detect the interesting and hidden data on useful drugs especially in the field of cardiovascular disease. METHODS AND RESULTS: We evaluated the current treatments for chronic heart failure (CHF) in our institute using a decision tree method of data mining and compared the results with those of large-scale clinical trials. We enrolled 1,100 patients with CHF (NYHA classes II-IV and EF < 40%) who were hospitalized at the National Cardiovascular Center during the past 31 months. Drugs prescribed at discharge were extracted from the clinical database. Both echocardiograms and plasma BNP level at 6-12 months after discharge were determined prospectively. It was found that beta-blockers, angiotensin converting enzyme inhibitors, and angiotensin II receptor antagonists independently improve both the plasma BNP level and %fractional shortening (FS), while oral inotropic agents increased the plasma BNP level and decreased %FS. These findings agree with evidence accumulated from several large-scale trials. Interestingly, statins, histamine receptor blockers, and alpha-glucosidase inhibitors also attenuated the severity of CHF, suggesting the possibility of new treatment of CHF. CONCLUSION: Clinical data mining using Japanese CHF patients yielded almost identical data to the results of large-scale trials, and also suggested novel and unexpected candidates for CHF therapy. Further validation of the data mining approved in the cardiovascular field is warranted.

Chronic Disease↗
PubMed2004

Plasma asymmetric dimethylarginine and coronary and peripheral endothelial dysfunction in hypertensive patients.

BACKGROUND: The attenuation of coronary flow reserve (CFR) and endothelium-mediated vasodilation of the brachial artery (EMV-BA) have been frequently reported in hypertensive patients. The present study investigated the link between CFR and EMV-BA in hypertensive patients. We hypothesized that changes in serum asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthase, and concomitant insulin resistance may be underlying factors connecting the two pathologic alterations. METHODS: A total of 75 patients (30 men and 45 women, 61.5 +/- 10.1 years of age) with essential hypertension and without coronary artery disease and diabetes mellitus were included in the study. Measurements of CFR were made using adenosine-triphosphate stress transthoracic Doppler echocardiography, and forearm EMV-BA was measured by venous occlusion strain gauge plethysmography. A plasma ADMA assay and a 75-g oral glucose tolerance test were also performed. RESULTS: Average CFR and EMV-BA values were 2.54 +/- 0.63 and 86.0 +/- 54.7%, respectively. A significant correlation was found between CFR and EMV-BA (r = 0.493, P <.001). Both CFR and EMV-BA were also significantly correlated with age and plasma ADMA concentration, but were not correlated with insulin resistance, plasma insulin, or left ventricular mass. Multiple regression analysis revealed that ADMA was the only statistically independent parameter associated with CFR and EMV-BA. CONCLUSIONS: The similar deterioration in endothelial function in coronary and peripheral vascular territories may be mainly due to increased plasma ADMA concentration. Plasma ADMA appears to play a major role in endothelial dysfunction in hypertensive patients, independent of insulin resistance or left ventricular hypertrophy.

Aged↗
PubMed2004

Consequence of atrial fibrillation and the risk of embolism after percutaneous mitral commissurotomy: the necessity of the maze procedure.

BACKGROUND: We sought to investigate the incidence and risk of embolism after percutaneous balloon mitral commissurotomy (PMC) and delineated the necessity of the maze procedure in patients with atrial fibrillation (AF). METHODS: Clinical records of 326 patients, who underwent PMC between April 1988 and March 2003, and 162 patients, who underwent mitral valve surgery (MVS) combined with the maze procedure (MVS/maze) in the same period, were reviewed. We examined the consequence of cardiac rhythm and the incidence and risk of embolism after PMC. Next our current criteria for indication of the maze procedure, which included duration of AF less than 10 years, voltage of f wave on electrocardiography greater than 0.1 mV, cardiothoracic ratio less than 70%, and left atrial dimension less than 70 mm, were applied to all patients. These criteria were satisfied by 190 patients of PMC (PMC group) and 114 patients of MVS/maze (MVS/maze group) and the early and late results of the two groups were compared. RESULTS: Thirty-eight patients suffered from embolic complications after PMC. Of these 33 patients experienced AF before intervention. The actuarial embolism-free rate at 10 years was 81.9% in patients with AF before PMC and 92.9% in patients with sinus rhythm before PMC (p = 0.01). Univariate predictors of embolism after PMC included previous embolic history (p = 0.01), AF (p = 0.01), pressure gradient (p = 0.01), age (p = 0.03), and mitral valve area (p = 0.04). Multivariate analysis identified AF as the independent predictor of embolism in the late follow-up period (p = 0.03). In a comparative study of the selected patients the actuarial AF-free rates after MVS/maze were 89.9% at 1 year and 85.7% at 5 years and were significantly higher than those of 17.3% at 1 year and 4.2% at 5 years after PMC (p < 0.0001). The actuarial embolism-free rate in the MVS/maze group was 98.0% at 5 years and was significantly higher than that of 84.8% at 5 years and 82.4% at 10 years in the PMC group (p = 0.01). CONCLUSIONS: PMC alone is not sufficient with regard to sinus rhythm recovery and prevention of embolism. Surgical treatment concomitant with the maze procedure may be beneficial for patients with AF.

Atrial Fibrillation↗
PubMed2004

[Usefulness of conscious sedation with midazoram during transesophageal echocardiographic examination].

OBJECTIVES: Although transesophageal echocardiography is useful to identify various cardiovascular diseases, the semi-invasive nature of the examination hampers its routine application. We investigated whether conscious sedation using a low dose of intravenous midazoram was safe and useful during the examination. METHODS: We asked 55 consecutive patients undergoing transesophageal echocardiography (44 with midazoram, mean age 59 +/- 16 years, and 11 without midazoram, mean age 62 +/- 8 years) and the examiners about the effects of midazoram using a questionnaire. RESULTS: The mean dose of midazoram was 2.2 mg (range 1-3.5 mg). All examinations were done without any adverse events. Eighty-two percent of the patients with midazoram considered the examination under conscious sedation tolerable, whereas 91% without midazoram felt it untolerable. Most examiners felt manipulation of the echo probe was easier in patients with midazoram than in those without (69% vs 27%). CONCLUSIONS: Conscious sedation with a low dose of intravenous midazoram facilitated and increased patient tolerance during transesophageal echocardiographic examination.

Aged↗
PubMed2003

Failure to prevent progressive dilation of ascending aorta by aortic valve replacement in patients with bicuspid aortic valve: comparison with tricuspid aortic valve.

BACKGROUND: Patients with bicuspid aortic valve (BAV) have been frequently complicated with ascending aortic dilation possibly because of hemodynamic burdens by aortic stenosis (AS) or regurgitation (AR) or congenital fragility of the aortic wall. METHODS AND RESULTS: To clarify if the aortic dilation could be prevented by aortic valve replacement (AVR) in BAV patients, we studied 13 BAV (8 AR dominant, 5 AS dominant) and 14 tricuspid aortic valve (TAV) patients (7 AR, 7 AS) by echocardiography before and after AVR (9.7+/-4.8 years). We also studied 18 BAV (11 AR, 7 AS) without AVR. Diameters of the sinuses of Valsalva, sinotubular junction and the proximal aorta were measured. The annual dilation rate was calculated by dividing changes of diameters during the follow-up period by the body surface area and the observation interval. We found that aortic dilation in BAV patients tended to be faster than that in TAV patients, although a significant difference was found only at the proximal aorta (0.18+/-0.08 versus -0.08+/-0.08 mm/(m2/year), P=0.03). BAV patients with and without AVR showed similar progressive dilation. AR dominant group showed tendency of more progressive dilation than AS dominant group in BAV, although it did not reach statistical significance. TAV patients did not show further aortic dilation after AVR. CONCLUSIONS: AVR could not prevent progressive aortic dilation in BAV. Since the aorta did not dilate in TAV, progressive aortic dilation in BAV seems mainly due to the fragility of the aortic wall rather than hemodynamic factors.

Adult↗
PubMed2003

Löffler's endocarditis associated with unusual ECG change mimicking posterior myocardial infarction.

A73-year-old man with a history of bronchial asthma and atrial fibrillation was admitted to our hospital because of dyspnea and back pain. Blood analysis revealed a marked increase in total blood cell and eosinophil counts. The creatine kinase and creatine kinase-MB increased slightly. The ECG demonstrated significant ST-segment depression that mimicked acute posterior myocardial infarction. Emergent coronary angiography showed no stenotic lesions. The histological findings in endomyocardial biopsy showed thickened endocardium associated with significant eosinophilic infiltration, which was compatible with Löffler's endocarditis. After the administration of prednisolone, the patient's general condition, eosinophilia, ECG abnormalities, and histological findings were improved dramatically. The endomyocardial biopsy in the acute phase was helpful for diagnosis and therapeutic decision-making.

Aged↗
PubMed2003

A new screening method to diagnose coronary artery disease using multichannel magnetocardiogram and simple exercise.

BACKGROUND: Magnetocardiography (MCG) is a non-contact mapping technique to record cardiac action currents. The Master's two-step electrocardiogram (ECG) test is a simple exercise method for screening coronary artery disease (CAD), but it is inadequate concerning the sensitivity. Our aim was to develop a new screening method using multichannel MCG instead of ECG. METHODS: Thirty subjects (aged 54 +/- 16 years, 27 males), 17 of whom had CAD confirmed by coronary angiography, underwent the Master's exercise ECG test. After the exercise, MCG signals were acquired every minute during recovery with a 64-channel MCG system (MC-6400, Hitachi Ltd). We integrated tangential components of the MCG signals within QRS (during 20, 40, 80, and 120 ms centering on R-wave peak) immediately after exercise (Iex) and 5 minutes after exercise (Irec). The exercise-induced change of currents [(Iex-Irec)/Irec] was determined and normalized for each channel, and the maximal change among 64 channels, maximal QRS integral change, was used as a diagnostic index for myocardial ischemia. RESULTS: The maximal QRS integral change during 40 ms was significantly higher in the CAD group than in the control group (0.81 +/- 0.51 vs. 0.36 +/- 0.19, p < 0.01). A sensitivity and specificity for predicting CAD by the change > 0.44 were 82 % and 85 %, respectively, yielding a diagnostic accuracy of 83 %. The conventional Master's ECG test identified the CAD patients with a diagnostic accuracy of 63 % (sensitivity 47 %, specificity 85 %). CONCLUSION: The Master's two-step exercise test with a 64-channel MCG system showed the high diagnostic accuracy, despite of non-contact recording and simple exercise. The magnetic field in the depolarization process has the potential to detect the subtle myocardial ischemia induced by exercise.

Adult↗
PubMed2003

Early and late stroke after mitral valve replacement with a mechanical prosthesis: risk factor analysis of a 24-year experience.

OBJECTIVE: We evaluated risk factors for mortality and stroke after mechanical mitral valve replacement between May 1977 and December 2001. METHODS: Early and late mortality and stroke were assessed. Potential predictors of mortality and stroke were entered into a Cox proportional hazards model. Actuarial survival and freedom from stroke were determined by a log-rank test. RESULTS: Mitral valve replacement was performed in 812 patients. Concomitant procedures included left atrial appendage closure in 493 (61%) patients, tricuspid annuloplasty-replacement in 348 (43%) patients, maze procedure in 185 (23%) patients, plication of the left atrium in 148 (18%) patients, and other procedures in 151 (19%) patients. Five-year actuarial survival was 91.1% +/- 2.3%. Freedom from stroke at 8 years was significantly better in patients with sinus rhythm versus atrial fibrillation (P <.001). Ninety-nine percent of patients with mitral valve replacement combined with a maze procedure were free from stroke, whereas only 89% of patients with mitral valve replacement alone were free from stroke at 8 years after surgical intervention. Seventy-two patients had late stroke; sixty-five patients (90%) were in atrial fibrillation, and 47 (65%) patients had the left atrial appendage closed. Multivariate analysis showed that late atrial fibrillation (odds ratio, 3.39; 95% confidence interval, 1.72-6.67; P =.0001) and omission of the maze procedure (odds ratio, 3.40; 95% confidence interval, 1.14-10.14; P =.003) were the significant risk factors for late stroke. CONCLUSIONS: Persistent atrial fibrillation was the most significant risk factor for late stroke after mechanical mitral valve replacement. Restoration of sinus rhythm with a maze procedure nearly eliminated the risk of late stroke, whereas neither closure of the left atrial appendage nor therapeutic anticoagulation prevented this complication.

Adolescent↗
PubMed2003

Quantitative assessment of short axis wall motion using myocardial strain rate imaging.

Although left ventricular wall motion has been usually assessed with four-point scale (1 = normal; 2 = hypokinesis; 3 = akinesis; 4 = dyskinesis) based on the visual assessment, this method is only qualitative and subjective. Recently, a new echocardiographic system that enables calculation of myocardial strain rate based on tissue Doppler information has been developed. We investigated whether myocardial strain rate could quantify regional myocardial contraction in 17 patients with and without wall motion abnormalities including 6 patients undergoing dobutamine stress echocardiography. Left ventricular short-axis wall motion was assessed with standard two-dimensional echocardiography at basal, mid-ventricular, and apical levels. The same levels were imaged with tissue Doppler method to determine regional myocardial strain rate. Sixty-four segments were judged normokinesis, 53 segments hypokinesis, and 18 segments akinesis at rest; 16 segments were judged normokinesis and 6 segments hypokinesis at stress. No segments characterized dyskinesis. Strain rates of normokinetic, hypokinetic, and akinetic wall segments at rest were significantly different each other (-2.0 +/- 0.6 for normokinesis,-0.6 +/- 0.5 for hypokinesis,P < 0.0001 vs. normokinesis, and-0.008 +/- 0.3 for akinesis, P < 0.0001 vs. normokinesis and hypokinesis). Further, strain rates well reflected the change in wall motion induced by dobutamine challenge: strain rates in the 15 segments revealing augmented wall motion changed from -2.0 +/- 0.7 to -4.7 +/- 1.7 (1/sec) (P < 0.0001) and those in the 7 segments revealing deteriorated or unchanged wall motion changed from -2.1 +/- 1.0 to -1.7 +/- 0.8 (1/sec) (P < 0.05). In conclusion, strain rate agreed well with assessed wall motion. Strain rate imaging may be a new powerful tool to quantify regional wall contraction.

Adult↗
PubMed2003

Rapid evaluation of right and left ventricular function and mass using real-time true-FISP cine MR imaging without breath-hold: comparison with segmented true-FISP cine MR imaging with breath-hold.

PURPOSE: To evaluate the accuracy of cardiac function measured with real-time true fast imaging with steady-state precession (True-FISP) cine without breath-hold compared with those measured from segmented True-FISP cine with breath-hold. METHODS: Eighteen consecutive patients and six healthy volunteers were enrolled in the study group. Both real-time multislice True-FISP cine imaging without breath-hold and single-slice segmented True-FISP cine imaging with multiple breath-holds were performed in short-axis imaging sections to encompass the entire ventricles. Vertical long-axis cine imaging using real-time True-FISP cine sequence without breath-hold was performed to evaluate heart motion during respiration in 13 subjects. Ventricular volume and mass were evaluated by four observers independently with manual tracing. RESULTS: Real-time True-FISP cine quality was sufficient for contour detection in all 24 subjects. Cardiodynamic measurements based on real-time True-FISP cine correlated well with those based on segmented True-FISP cine [left ventricular (LV) end-diastolic volume: r = 0.98; LV end-systolic volume: r = 0.98; LV ejection fraction: r = 0.91; LV mass: r = 0.96; right ventricular (RV) end-diastolic volume: r = 0.89; RV end-systolic volume: r = 0.94; RV ejection fraction: r = 0.79]. Intra- and interobserver variability were sufficiently small in real-time True-FISP cine without breath-hold. Heart motion during respiration along the long axis of the left ventricle (2.2 mm to 3.7 mm) was much less than the slice interval (10 mm), confirming that misregistration of slice position during respiration was low. CONCLUSION: Real-time True-FISP cine without breath-hold has high reproducibility and is applicable to patients with severe cardiac dysfunction and/or arrhythmias.

Adolescent↗
PubMed2003

Current characteristics of infective endocarditis in Japan: an analysis of 848 cases in 2000 and 2001.

The Japanese Circulation Society appointed a committee to develop guidelines for the prevention, diagnosis and management of infective endocarditis in Japan. In making such guidelines, the committee required information on the current clinical characteristics of infective endocarditis and therefore performed a nationwide questionnaire survey of cases from 2000 and 2001. In total, data were received for 848 cases from 277 of the 817 hospitals surveyed. Mean age was 55+/-18 years and most patients were aged in their 50 s or 60 s; 53.9% of the patients had infective endocarditis of unknown origin (without any prior predisposing conditions or procedures) and the second most common etiology was post dental procedures. The most common microorganism was Gram-positive cocci (345 streptococci and 221 staphylococci) and methicillin resistant Staphylococcus aureus (MRSA) was found in 7.3%. Although more than 90% of cases with Streptococcus viridans were sensitive to penicillin G, 6.6% were resistant. All MRSAs were sensitive to vancomycin. The information obtained from the survey assisted in the making of the guidelines, which should become an indispensable tool for all clinicians.

Adult↗
PubMed2003

Restrictive cardiomyopathy with right-sided dominant heart failure after sinus conversion from atrial fibrillation: case report.

A 44-year-old woman with restrictive cardiomyopathy showed right-sided dominant heart failure after conversion to sinus rhythm from paroxysmal atrial fibrillation (AF). During cardiac catheterization, the hemodynamics were compared before and after cardioversion; that is, with AF and with sinus rhythm. The hemodynamic parameters worsened after conversion to sinus rhythm, with a significant decrease in heart rate, but improved with atrial pacing. Pacemaker implantation was performed to avoid bradycardia while keeping the sinus rhythm with amiodarone. As a result, the patient has been free from symptoms of heart failure for almost 1 year and her serum brain natriuretic peptide level also improved remarkably.

Adult↗
PubMed2003

Carotid intima-media thickness is correlated with impairment of coronary flow reserve in hypertensive patients without coronary artery disease.

Hypertensive individuals occasionally experience angina-like chest pain despite having angiographically normal coronary arteries, and the etiology of this phenomenon has been suggested to be associated with depressed coronary flow reserve (CFR). Carotid intima-media thickness (IMT) assessed by ultrasound is correlated with not only cerebrovascular disease but also coronary artery disease and left ventricular hypertrophy (LVH). The aim of our study was to investigate the association between CFR and carotid IMT in patients with essential hypertension. We performed transthoracic Doppler recording of diastolic coronary flow velocity in the left anterior descending coronary artery at baseline and after maximal vasodilation by adenosine triphosphate infusion in 24 normotensive subjects and 125 hypertensive patients. CFR was defined as the ratio of hyperemic to basal averaged peak coronary flow velocity. Common cardiovascular risk factors, left ventricular mass index (LVMI), relative wall thickness (RWT), and carotid IMT were evaluated. The CFR of hypertensive patients (2.55 +/- 0.52) was significantly decreased compared with that of normotensive subjects (3.15 +/- 0.45). CFR showed a significant correlation with age, systolic blood pressure, RWT, and carotid IMT. Stepwise regression analysis revealed that, among carotid IMT, LVMI and RWT, only carotid IMT was a strong and independent parameter for predicting CFR in hypertensive patients. In conclusion, B-mode ultrasound scanning of the carotid artery seemed to be of clinical value in the screening of patients with LVH and impaired microcoronary circulation. These associations may explain the links between cardiac and cerebrovascular involvements in patients with hypertension.

Aged↗
PubMed2003

[Diagnosis by new echocardiographic techniques].

Echocardiography has been very powerful for not only evaluating hemodynamics and cardiac function but also finding causes of heart failure. Moreover, recent advancements in echocardiography enable us to assess patients with heart failure more conveniently and precisely. The quality of 2-dimensional echocardiographic images is dramatically improved by introduction of harmonic imaging method and intravenous contrast agents which opacify the left ventricular cavity. Tissue Doppler echocardiography can provide information on regional myocardial velocity thereby enabling assessment of regional as well as global left ventricular function. Strain and strain rate of the regional myocardium can be also determined by the newest technology based on tissue Doppler echocardiography.

Blood Flow Velocity↗
PubMed2003

[Cauliflower-like giant left atrial thrombus successfully treated by anticoagulants without systemic complication: a case report].

A 64-year-old woman with hypertension presented with a left atrial giant mass during the treatment of congestive heart failure. She was admitted to our hospital for intensive treatment. Transesophageal echocardiography demonstrated a cauliflower-like, large (3 x 2 cm), mobile echogenic mass attached to the left atrial wall. There were no signs of systemic embolism. Anticoagulant therapy was started. Repeated echocardiography showed the mass was reduced gradually and had diminished on the 10th day. She remained asymptomatic during the anticoagulant therapy. The diagnosis was thrombus based on the response to treatment. Surgical removal should be considered for such a large thrombus, but the present case of giant thrombus was successfully treated by anticoagulants without systemic complication.

Anticoagulants↗