Biomedical subjects

Satoshi Nakatani

Publications and source records attributed to Satoshi Nakatani.

48 records · Page 3Linked to original sources

PubMed2003

[Impaired left ventricular systolic function in mitral stenosis].

OBJECTIVES: Left ventricular dysfunction is known in patients with mitral stenosis, but the incidence and cause remain unclear. The incidence and the factors related to left ventricular dysfunction were investigated in strictly selected patients with isolated mitral stenosis. METHODS: This study investigated 33 patients (5 males, 28 females) with isolated mitral stenosis aged 56 +/- 9 years. Left atrial dimension, left ventricular diastolic and systolic dimensions, mitral valve area, and mean transmitral pressure gradient were measured by echocardiography. Left ventricular ejection fraction was measured by Simpson's method. Patients were divided into two groups according to the ejection fraction (< 50%, > or = 50%). RESULTS: Seven patients (21%) had decreased left ventricular contraction and 26(79%) had normal contraction. The incidence of patients with atrial fibrillation in the low ejection fraction group was significantly higher than in the normal ejection fraction group(86% vs 31%, p < 0.01). There were no significant differences in the severity of mitral stenosis or other echocardiographic indices between the two groups. CONCLUSIONS: Low ejection fraction was present in 21% of patients with mitral stenosis. Since atrial fibrillation was more common in patients with low ejection fraction than those with normal ejection fraction, the rhythm disturbance may be related to the decreased left ventricular contraction.

Echocardiography, Doppler↗

PubMed2002

Effect of disease eccentricity on compensatory remodeling of coronary arteries: evidence from intravascular ultrasound before interventions.

BACKGROUND: Compensatory remodeling occurs to maintain lumen area in human coronary vessels. However, few data exist regarding the relationship between vessel remodeling and plaque distribution. Therefore, we studied coronary sites with or without remodeling by intravascular ultrasound and correlated with disease distribution. METHODS AND RESULTS: A total of 90 coronary sites with significant stenosis (>50%) from 80 patients were examined before interventions. For identifying the vessel remodeling, external elastic membrane (EEM) area was measured at the stenotic sites and the adjacent proximal and distal sites. The reference EEM area was calculated by averaging proximal and distal EEM areas, and percent enlargement of the EEM area was calculated by the formula: [(stenosis EEM area-reference EEM area)/reference EEM area]x100. Plaque area was determined by reducing the lumen from EEM areas. The maximal (max) and minimal (min) distances from the center of the lumen to the EEM were also measured, and the disease eccentricity index was calculated by the formula: [(max-min)/max]. The lesion was defined as eccentric if the index was >0.5 and as concentric if <or=0.5. There were 39 eccentric and 51 concentric lesions. The enlargement remodeling was observed at 32 lesions with the enlargement of EEM area of 28.0+/-16.0% (5.5 to 71.3%). Enlargement was more frequently observed in the eccentric than in concentric lesions (P<0.05). However, within 32 stenoses, which showed enlargement, there was no difference in enlargement between eccentric (n=19, 25.6+/-21.0%) and concentric lesions (n=13, 21.5+/-12.0%). Also, there was no statistical correlation between the increase in plaque area and % enlargement of EEM area irrespective of plaque morphology. CONCLUSIONS: These data demonstrate that in advanced coronary disease compensatory enlargement occurs more frequently at the eccentric than concentric coronary lesions. However, the EEM area was limited to expand regardless of the disease morphology.

Aged↗

PubMed2002

Right ventricular dP/dt/P(max), not dP/dt(max), noninvasively derived from tricuspid regurgitation velocity is a useful index of right ventricular contractility.

BACKGROUND: Although right ventricular (RV) contractility is important in determining functional capacity, few quantification methods are clinically available. RV dP/dt(max) can be assessed by Doppler echocardiography by using tricuspid regurgitation (TR) but is not routinely used because of its dependency on a Doppler incident angle and preload. Doppler-derived dP/dt/P(max) is relatively insensitive to preload and theoretically independent of the incident angle. We investigated the clinical feasibility of this index as an RV contractility index. METHODS: We computed RV dP/dt(max) and dP/dt/P(max) from the TR-derived RV pressure in 68 patients with dominant RV failure (13 in New York Heart Association [NYHA] class I, 33 in class II, 17 in class III, and 5 in class IV). Peak oxygen consumption (peak VO(2)) was measured in 20 patients during a maximal bicycle ergometer test. RESULTS: dP/dt(max) did not significantly correlate with NYHA class. In contrast, dP/dt/P(max) decreased monotonically with the functional class (r = -0.49, P <.0001), and correlated with peak VO(2) (r = 0.66, P <.002). CONCLUSION: TR-derived dP/dt/P(max), not dP/dt(max), is a clinically useful index of RV contractility, allowing researchers to account for the functional capacity.

Adolescent↗

PubMed2002

Enhanced method for predicting left ventricular reverse remodeling after surgical repair of aortic regurgitation: application of ultrasonic tissue characterization.

To predict left ventricular (LV) reverse remodeling after surgical repair of aortic regurgitation, we examined 30 patients with aortic regurgitation accompanying LV dilatation by myocardial tissue characterization with integrated backscatter method. Before and after operation, the magnitude of cyclic variation of integrated backscatter (CVIB) was obtained from anterior septum and posterior wall, and averaged value was calculated in each patient. Before operation, LV end-diastolic dimension, fractional shortening, and LV end-diastolic pressure were not significantly different between the patients with (group GR) and without (group PR) decreased LV end-diastolic dimension after operation. Under these conditions, CVIB, which was 9.6 +/- 1.0 dB from healthy volunteers, was significantly greater in group GR, 5.7 +/- 1.4 dB, than that in group PR, 3.8 +/- 0.8 dB (P =.0003). The patients with CVIB >/= 4 before operation were expected to have reverse remodeling after operation with a sensitivity of 79%, a specificity of 82%. These data indicate that preoperative CVIB from the left ventricle provides pivotal information for predicting reverse remodeling after operation for aortic regurgitation in addition to the conventional echocardiographic parameters.

Adult↗

PubMed2002

Bicuspid aortic valve stenosis complicated by descending aortic dissection mimicking coarctation of the aorta.

We report a rare case of bicuspid aortic stenosis complicated by an ascending aortic aneurysm and aortic dissection of DeBakey type IIIb. A 35-year-old woman was admitted to our hospital to examine her systolic murmur identified at birth. Severe aortic stenosis, dilatation of the ascending aorta, and the narrow color flow signal in the descending aorta were detected by transthoracic echocardiography. Initially, coarctation of the descending aorta was suspected, but aortic dissection, DeBakey type IIIb, was revealed by transesophageal echocardiography. Transesophageal echocardiography is indicated when only insufficient information is available on valve and aortic morphology in patients with bicuspid aortic valve.

Adult↗

PubMed2002

Impact of Cox maze procedure on outcome in patients with atrial fibrillation and mitral valve disease.

OBJECTIVE: We sought to determine whether the Cox maze procedure provides additional benefit to patients with atrial fibrillation undergoing mitral valve operations. METHODS: Between May 1992 and August 2000, we performed 258 Cox maze procedures with mitral valve replacement (n = 147) or mitral valve repair (n = 111). We compared the outcomes of these patients with those of 61 control patients with preoperative atrial fibrillation who underwent mitral valve replacement alone during the same interval. The three cohorts were similar in age, sex, and proportion of patients in preoperative New York Heart Association functional class 3 or 4. RESULTS: Although 5-year survivals were similar among the groups (94% for mitral valve replacement alone, 95% for mitral valve replacement plus maze, and 97% for mitral valve repair plus maze), freedoms from atrial fibrillation at 5 years were significantly higher in the mitral valve replacement plus maze group (78%) and the mitral valve repair plus maze group (81%) than in the mitral valve replacement group (6%, P <.0001). Freedoms from stroke at 5 years were 97% for the mitral valve replacement plus maze group, 97% for the mitral valve repair plus maze group, and only 79% for mitral valve replacement group (P <.0001). Multivariable analysis with Cox hazard model revealed that the most significant risk factor for late stroke was the omission of the Cox maze procedure (P =.003). CONCLUSIONS: The addition of the Cox maze procedure to mitral valve repair and replacement was safe and effective for selected patients. Elimination of atrial fibrillation significantly decreased the incidence of late stroke.

Aged↗

PubMed2002

Detection of spatial repolarization abnormalities in patients with LQT1 and LQT2 forms of congenital long-QT syndrome.

The aim of this study is to detect the spatial current dispersion that appears in the T-wave of patients with congenital long-QT syndrome (LQTS). To observe this dispersion, magnetocardiograms (MCGs)--which have a high spatial resolution--of LQT1 patients (n = 7), LQT2 patients (n = 9) and a control group (n = 33) were recorded. The dispersion was evaluated by plotting current-arrow maps (CAMs) calculated from the MCG signals. In the case of LQT1, abnormal current arrows in the CAMs appeared above the inferior part of the heart in two LQT1 patients with a long corrected QT interval (QTc) (>0.6), and the current direction was from the left (origin side) to the right ventricular muscle (110 degrees). In six out of nine LQT2 patients, abnormal current arrows with angles below 20 degrees were observed above the right inferior part or lower septum; the current direction was from the right (origin side) to the left ventricular muscle. However, in the case of the LQT2 patients, the QTc values did not correlate with the abnormal current. These findings suggest that the origin of abnormal repolarization in LQT1 is the left ventricular muscle and the origin of that in LQT2 is the right ventricular muscle or lower septum. The estimation of the origin in LQTS patients can provide important information such as the risk factor of sudden death.

Adolescent↗

PubMed2002

Trends in the clinical and morphological characteristics of cardiac myxoma: 20-year experience of a single tertiary referral center in Japan.

The purpose of this study was to clarify whether or not a change in the clinical characteristics of cardiac myxoma has occurred during the past 2 decades. The clinical records of 57 patients (22 men, 35 women; age, 52+/-14 years) with myxoma that had been surgically treated between May 1978 and July 1997 at the National Cardiovascular Center in Japan were reviewed. All myxomas were discovered by transthoracic echocardiography. They were divided into an early group (n=30) treated in the first decade (1978-1987) and a late group (n=27) treated in the second decade (1988-1997). The incidence of myxoma, patient characteristics, preoperative symptoms and echocardiographic features did not differ between the 2 groups. In contrast, the maximal dimensions of myxoma in the early group were significantly larger than those in the late group (6.3 +/-2.7 cm vs 4.3+/-1.3 cm, p=0.012). The weight of myxoma in the early group tended to be heavier than that in the late group (76+/-80 g vs 25+/-18 g, p=0.054). The incidence of patients with asymptomatic myxoma also tended to increase in the late group (7% vs 26%, p=0.07). Although there was no difference in the incidence of myxoma, smaller and asymptomatic myxomas were more frequent during the last decade, probably as a result of the development of cardiac imaging, particularly echocardiography.

Adult↗

PubMed2002

Clinical significance of iodine-123-15-(p-iodophenyl)-3-R, S-methylpentadecanoic acid myocardial scintigraphy in patients with aortic valve disease.

The present study sought to determine whether myocardial fatty acid metabolism as assessed with iodine-123-labeled 15-(p-iodophenyl)-3-R,S-methylpentadecanoic acid (BMIPP) scintigraphy is impaired in patients with aortic valve disease (AVD) and whether the degree of the metabolic abnormality reflects the severity of AVD. BMIPP scintigraphy was performed in 12 patients with aortic stenosis (AS), 14 patients with aortic regurgitation (AR), and 9 healthy volunteers, and from that the heart-mediastinum uptake ratio (H/M ratio) corrected by the left ventricular (LV) mass (U/Mass ratio) and the myocardial washout rate (WR) were obtained. The H/M ratio tended to be higher in patients than in healthy volunteers (3.3 +/- 0.7 for AS, 3.5 +/- 0.5 for AR, 3.0 +/- 0.3 for healthy volunteers), and the WR was significantly higher in patients than in healthy volunteers (42.8 +/- 9.1% for AS, 35.7 +/- 6.5% for AR, 19.6 +/- 9.1% for healthy volunteers, p<0.01). In the AS patients, the U/Mass ratio showed significant negative correlations (r=-0.79 to -0.90, all p<0.01) and the WR showed significant positive correlations (r=0.61 to 0.82, all p<0.01) with transaortic pressure gradient, LV wall thickness, and LV mass. Similarly, in AR patients these BMIPP parameters showed proportional changes to the LV volumes and LV mass (r=-0.79 to -0.83, all p<0.01 for U/Mass ratio, r=0.55 to 0.70, p<0.05 to <0.01 for WR). In the 9 patients who underwent aortic valve replacement, the BMIPP parameters tended to normalize with increasing U/Mass ratio (0.90 +/- 0.41 x 10(-2)/g to 1.34 +/- 0.59 x 10(-2)/g, p<0.05) and decreasing WR (41.9 +/- 8.8% to 35.4 +/- 9.2%, p<0.01) after surgery. Myocardial fatty acid metabolism as assessed with BMIPP scintigraphy was impaired in patients with aortic valve disease and the U/Mass ratio and WR reflect the severity. These parameters may be useful for the noninvasive assessment of the myocardial metabolic abnormalities caused by hemodynamic overload.

Adult↗

PubMed2002

Low-dose amiodarone for patients with advanced heart failure who are intolerant of beta-blockers.

The tolerability and effectiveness of amiodarone in patients with advanced heart failure (HF) who are intolerant of beta-blockers was investigated in 22 patients (13 with and 9 without 180+/-26 mg/day of amiodarone). Heart rate (HR), blood pressure (BP), left ventricular diastolic dimension and fractional shortening (FS) using echocardiography, plasma atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP) and norepinephrine concentrations were determined at baseline and after 1 and 3 months of therapy. Although 9 patients tolerated amiodarone without any signs of HF, it was exacerbated in 4 patients. In 10 patients taking amiodarone who could be followed medically for 3 months, HR decreased after 1 month and remained unchanged until after 3 months (81+/-12 vs 65+/-7 vs 65+/-7beats/min), accompanied by decreased concentration of BNP (688+/-485 vs 392+/-203 vs 261+/-192pg/ml). FS increased significantly only after 3 months (0.12+/-0.05 vs 0.14+/-0.05 vs 0.16+/-0.04). Amiodarone may be used in patients with advanced HF who are intolerant of beta-blockers.

Adrenergic beta-Antagonists↗

PubMed2002

Huge saccular aneurysm in a coronary-pulmonary fistula fed by the left and right coronary arteries.

A 62-year-old woman was referred because of an abnormal mediastinal shadow that had first been noted 4 years ago on the left cardiac border on plain chest roentgenogram and which had gradually increased in size since. A huge saccular aneurysm in coronary-pulmonary fistula into which both the left and right coronary arteries drained was revealed by computed tomography and coronary angiography. The patient underwent aneurysmal resection and ligation of the fistulas. Histological study of the aneurysmal wall did not reveal atherosclerotic change but instead cystic medial necrosis, although there was no other clinical manifestation associated with this.

Angiography, Digital Subtraction↗

PubMed2002

[Intractable infective endocarditis associated with supraaortic stenosis in Williams syndrome: a case report].

A 17-year-old man with supravalvular aortic stenosis associated with Williams syndrome was admitted to our hospital for intensive treatment for intractable infective endocarditis. The patient had a history of percutaneous balloon valvuloplasty for aortic stenosis in 1992. He was well until late in 1999, when he had a high temperature after dental work-up. The diagnosis was infective endocarditis but antibiotic therapy was not effective. He was transferred to our clinic. Transthoracic echocardiography demonstrated bicuspid aortic valve, supraaortic stenosis, mitral valve prolapse with severe regurgitation and scattered vegetations on the anterior mitral and aortic valves. In addition, transesophageal echocardiography showed innumerable mobile vegetations located from Valsalva's sinus to the descending aorta. Aortic root and arch replacement with a homograft and mitral valve replacement with an artificial valve were successfully performed to eliminate the infective endocarditis. In the present patient, the flow jet across the supraaortic stenosis seemed to cause a predisposition to severe endocarditis.

Adolescent↗