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Tomoko Tani

Publications and source records attributed to Tomoko Tani.

13 recordsLinked to original sources
PubMed2006

Left atrial volume in normal Japanese adults.

BACKGROUND: Two-dimensional (D) echocardiography-derived left atrial (LA) volume has been shown to provide a more accurate assessment of LA size than the M-mode LA dimension. Our objective was to provide reference ranges of LA volume in healthy Japanese adults. METHODS AND RESULTS: The study subjects consisted of 105 Japanese adults, with a mean age of 39+/-13 years (range 20-63 years old). All subjects had normal ejection fraction (>55%), no wall motion abnormalities, normal diastolic function, no valvular disease, and normal sinus rhythm. The maximum LA volume, at left ventricular end-systole just before the opening of the mitral valve, was measured by using the bi-apical (4- and 2-chamber views) Simpson's rule. Both the absolute LA volume and the volume corrected by body surface area (LA volume index) were obtained. The LA volume ranged from 21 to 53 ml (mean 37+/-8 ml) and the LA volume index ranged from 13 to 30 ml/m(2) (mean 22+/-4 ml/m(2)). The mean LA volume index + 2SDs was 30 ml/m(2). CONCLUSIONS: Recognition of the upper limits of LA volume in normal Japanese subjects is of particular clinical relevance because it offers the opportunity of pathological LA remodeling diagnosis.

Adult↗
PubMed2005

Annular geometry in patients with chronic ischemic mitral regurgitation: three-dimensional magnetic resonance imaging study.

BACKGROUND: Although animal studies showed that annular remodeling may be related to the pathogenesis of chronic ischemic mitral regurgitation (CIMR), little was known in humans. A better understanding of the precise 3D geometry of the mitral valvular-ventricular complex in CIMR is needed to devise a better surgical technique. The purpose of the study was to elucidate mitral annular geometry in patients with CIMR using cardiac MRI. METHODS AND RESULTS: Thirty-eight patients with previous inferior or posterior myocardial infarction were studied. With the 3D reconstruction of the mitral annulus and subvalvular apparatus from a series of longitudinal cine MRIs, end-systolic mitral annulus dimensions and 3D geometry were calculated. Patients were grouped by mitral regurgitation grade using echocardiography (> or =2+, n=15 versus < or =1+, n=23). Both septal-lateral and commissure-commissure mitral annular diameters were significantly greater in CIMR(+) patients (35+/-5 versus 30+/-4 mm, P=0.005; 46+/-6 versus 39+/-4 mm, P<0.001, respectively). The length of the fibrous annulus was significantly larger in CIMR(+) patients (28+/-3 versus 24+/-3 mm; P<0.001). The height of the annular "saddle horn" above a best-fit plane was lower in CIMR(+) patients (4.2+/-1.2 versus 6.0+/-1.8 mm; P=0.002), and the annular height to commissural width ratio was significantly lower in CIMR(+) patients (12+/-3 versus 21+/-5%; P<0.001). CONCLUSIONS: Patients with CIMR had greater septal-lateral and commissure-commissure mitral annular dimension, larger intertrigonal distance, and flattened saddle shape of mitral annulus. These associated geometric alterations may be important in the pathogenesis of CIMR.

Adult↗
PubMed2005

Quantitative assessment of harmonic power doppler myocardial perfusion imaging with intravenous Levovist in patients with myocardial infarction: comparison with myocardial viability evaluated by coronary flow reserve and coronary flow pattern of infarct-related artery.

BACKGROUND: Myocardial contrast echocardiography and coronary flow velocity pattern with a rapid diastolic deceleration time after percutaneous coronary intervention has been reported to be useful in assessing microvascular damage in patients with acute myocardial infarction. AIM: To evaluate myocardial contrast echocardiography with harmonic power Doppler imaging, coronary flow velocity reserve and coronary artery flow pattern in predicting functional recovery by using transthoracic echocardiography. METHODS: Thirty patients with anterior acute myocardial infarction underwent myocardial contrast echocardiography at rest and during hyperemia and were quantitatively analyzed by the peak color pixel intensity ratio of the risk area to the control area (PIR). Coronary flow pattern was measured using transthoracic echocardiography in the distal portion of left anterior descending artery within 24 hours after recanalization and we assessed deceleration time of diastolic flow velocity. Coronary flow velocity reserve was calculated two weeks after acute myocardial infarction. Left ventricular end-diastolic volumes and ejection fraction by angiography were computed. RESULTS: Pts were divided into 2 groups according to the deceleration time of coronary artery flow pattern (Group A; 20 pts with deceleration time > or = 600 msec, Group B; 10 pts with deceleration time < 600 msec). In acute phase, there were no significant differences in left ventricular end-diastolic volume and ejection fraction (Left ventricular end-diastolic volume 112 +/- 33 vs. 146 +/- 38 ml, ejection fraction 50 +/- 7 vs. 45 +/- 9 %; group A vs. B). However, left ventricular end-diastolic volume in Group B was significantly larger than that in Group A (192 +/- 39 vs. 114 +/- 30 ml, p < 0.01), and ejection fraction in Group B was significantly lower than that in Group A (39 +/- 9 vs. 52 +/- 7%, p < 0.01) at 6 months. PIR and coronary flow velocity reserve of Group A were higher than Group B (PIR, at rest: 0.668 +/- 0.178 vs. 0.248 +/- 0.015, p < 0.0001: during hyperemia 0.725 +/- 0.194 vs. 0.295 +/- 0.107, p < 0.0001; coronary flow velocity reserve, 2.60 +/- 0.80 vs. 1.31 +/- 0.29, p = 0.0002, respectively). CONCLUSION: The preserved microvasculature detecting by myocardial contrast echocardiography and coronary flow velocity reserve is related to functional recovery after acute myocardial infarction.

Blood Flow Velocity↗
PubMed2004

Left atrial volume and the risk of paroxysmal atrial fibrillation in patients with hypertrophic cardiomyopathy.

Paroxysmal atrial fibrillation (PAF) is a common complication of patients with hypertrophic cardiomyopathy, often leading to acute or progressive heart failure and cerebral infarction. We assessed the echocardiographic data of 141 consecutive patients with hypertrophic cardiomyopathy, with and without PAF. In all, 31 patients (22%) had a history of PAF with spontaneous conversion to in sinus rhythm. Left atrial volume and left atrial volume indexed to body surface area were significantly increased for patients with PAF compared with those without PAF. Maximum left atrial volume was the most sensitive and specific parameter for the occurrence of PAF in patients with hypertrophic cardiomyopathy.

Atrial Fibrillation↗
PubMed2004

Detecting viable myocardium and predicting functional improvement: comparisons of positron emission tomography, rest-redistribution thallium-201 single-photon emission computed tomography (SPECT), exercise thallium-201 reinjection SPECT, I-123 BMIPP SPECT and dobutamine stress echocardiography.

BACKGROUND: Low-dose dobutamine stress echocardiography (LDDE) has become a useful and safe method for identifying hibernating or stunned myocardium and for predicting improvement in wall motion after coronary revascularization. METHODS AND RESULTS: In the present study, fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET), rest-redistribution thallium-201 ((201)Tl) single-photon emission computed tomography (RR-Tl SPECT), (123)I-15-(p-iodophenyl)-3-(R,S)-methyl pentadecanoic acid (BMIPP) and LDDE were performed in 30 patients with acute myocardial infarction (AMI) at 10+/-3 days after the onset of AMI. Also, exercise (201)Tl reinjection SPECT (RI-Tl SPECT) was performed at 14+/-2 days. Follow-up echocardiography was performed 5+/-3 months later in all patients after interventional therapy for the assessment of functional recovery. Of the 390 segments analyzed by echocardiography, 110 (28%) had abnormal wall motion. There were no significant differences between RR-Tl SPECT and LDDE in sensitivity, specificity, positive predictive value and negative predictive value using the chi(2)-test; however, in akinetic segments, there was a significant difference in sensitivity. Among FDG-PET, RI-Tl SPECT, BMIPP and LDDE, there were significant differences in 3 variables. In akinetic segments, LDDE is superior to RR-Tl SPECT in sensitivity and to FDG-PET in specificity. In hypokinetic segments, LDDE is superior to RI-Tl SPECT and BMIPP in sensitivity, and to FDG-PET and BMIPP in specificity. CONCLUSIONS: LDDE could detect functional recovery of viable myocardium in the early period of AMI and can be performed easily and safely.

Aged↗
PubMed2004

[Chordal cutting for the treatment of ischemic mitral regurgitation: two case reports].

The surgical treatment for ischemic mitral regurgitation remains controversal. Ring annuloplasty results in recurrent mitral regurgitation in some cases. Strut chordal cutting is a new surgical procedure in addition to ring annuloplasty for ischemic mitral regurgitation. Two patients (63-year-old woman, 53-year-old man) with severe ischemic mitral regurgitation were treated with this procedure. The patients had congestive heart failure due to mitral regurgitation, associated with inferior myocardial infarction. Regurgitant fraction of mitral regurgitation was 70% and 52% before surgery. Mitral leaflet tethering caused by apical displacement of the papillary muscle was observed. Mitral valve repair was performed by ring annuloplasty and chordal cutting. Intraoperative echocardiography showed that chordal cutting improved the configuration of the anterior leaflet, resulting in good mitral valve coaptation without regurgitation.

Cardiac Surgical Procedures↗
PubMed2003

Pioglitazone reduces neointimal tissue proliferation after coronary stent implantation in patients with type 2 diabetes mellitus: an intravascular ultrasound scanning study.

BACKGROUND: It has been reported that pioglitazone reduces neointimal hyperplasia after balloon-induced vascular injury in an experimental model. METHODS: To determine whether pioglitazone reduces neointimal tissue proliferation after coronary stent implantation in patients with type 2 diabetes mellitus, we studied 44 stented lesions in 44 patients with diabetes mellitus who underwent successful coronary stent implantation. Study patients were randomized into 2 groups: the pioglitazone group (23 patients with 23 lesions) and the control group (21 patients with 21 lesions). All patients underwent serial quantitative coronary angiography and serial intravascular ultrasound scanning studies. With a motorized pullback system, multiple image slices within the stent were obtained at every 1 mm. The stent area and lumen area were measured, and the neointimal area was calculated. Measurements were averaged over the number of selected image slices. The neointimal index was calculated as the averaged neointimal area divided by the averaged stent area multiplied by 100 (%). RESULTS: After 6 months of treatment, angiographic in-stent restenosis (17% vs 43%, respectively, P =.0994) and target lesion revascularization (13% vs 38%, respectively, P =.0835) were less frequent in the pioglitazone group than the control group; however, these differences did not reach significance. The intravascular ultrasound scanning study demonstrated that the neointimal index in the pioglitazone group was significantly smaller than that in the control group (28% +/- 9% vs 48% +/- 15%, respectively, P <.0001). CONCLUSION: A serial intravascular ultrasound scanning assessment demonstrated that pioglitazone reduces neointimal tissue proliferation after coronary stent implantation in patients with type 2 diabetes mellitus.

Aged↗
PubMed2003

Single-beat determination of Doppler-derived aortic flow measurement in patients with atrial fibrillation.

The clinical assessment of left ventricular systolic function in patients with atrial fibrillation is unreliable and difficult because of beat-to-beat variation. We initially evaluated an index that is on the basis of the ratio of preceding R-R (RR1) to pre-preceding R-R (RR2) intervals (RR1/RR2) for the measurement of Doppler aortic flow (peak flow velocity [Vp] and time-velocity integral [TVI] proportional to stroke volume) in 20 patients (aged 65 +/- 9.6 years) with atrial fibrillation. We obtained each parameter for >13 cardiac cycles, and the relationship between each parameter at a given cardiac beat and the RR1/RR2 ratio were evaluated by linear regression analysis. The value of each parameter at RR1/RR2 = 1 was calculated from the equation of linear regression line and compared with measured average value over all cardiac cycles. Both parameters showed a significant positive correlation with the RR1/RR2 ratio (Vp, r = 0.98, y = 1.01x + 0.61; TVI, r = 0.99, y = 1.01x + 0.26). The calculated value of each parameter at RR1/RR2 = 1 was quite similar to the average value (Vp, 97.4 +/- 30.8 vs 95.7 +/- 29.8 cm/s; TVI, 17.7 +/- 6.8 vs 17.3 +/- 6.7 cm, respectively). In the additional 20 patients (aged 77.4 +/- 15.2 years), Doppler aortic flow parameters of a single beat with identical RR1 and RR2 intervals were compared with measured average value over all cardiac cycles and showed similar results (Vp, r = 0.99, y = 0.99x + 3.4, P <.0001, bias -0.5 cm/s; TVI, r = 0.99, y = 0.92x + 1.5, P <.0001, bias 0.1 cm). In conclusion, the Doppler aortic flow at RR1/RR2 = 1 allows the left ventricular systolic parameters to be accurately evaluated during atrial fibrillation and obviates the less reliable process of averaging multiple irregular beats.

Aged↗
PubMed2003

Noninvasive assessment of flow velocity and flow velocity reserve in the right gastroepiploic artery graft by transcutaneous Doppler echocardiography: comparison with an invasive technique.

BACKGROUND: The measurement of flow velocity (FV) in coronary artery bypass grafts using a Doppler guidewire has provided useful clinical and physiologic information. The recently developed transcutaneous Doppler echocardiography is a noninvasive technique to measure FV and FV reserve (FVR) in the right gastroepiploic artery (GEA) graft. The purpose of this study was to evaluate whether transcutaneous Doppler echocardiography accurately measures FV and FVR in the right GEA graft in a clinical setting. METHODS: In 33 patients who underwent graft angiography for the assessment of the right GEA graft, FV in the right GEA graft was measured by transcutaneous Doppler echocardiography under the guidance of color flow Doppler imaging at the time of examination using a Doppler guidewire. FV in the midportion of the right GEA graft was measured at baseline and during hyperemic conditions using both transcutaneous Doppler echocardiography and a Doppler guidewire. RESULTS: There were excellent correlations between the value of FV obtained by transcutaneous Doppler echocardiography and those obtained with the Doppler guidewire (averaged peak velocity: y = 0.95 x + 1.46, r = 0.98, standard error of the estimate [SEE] = 2.94 cm/s; averaged systolic peak velocity: y = 0.94 x + 1.18, r = 0.97, SEE = 3.15 cm/s; diastolic peak velocity: y = 0.97 x + 1.62, r = 0.98, SEE = 4.40 cm/s; averaged diastolic peak velocity: y = 0.95 x + 1.75, r = 0.98, SEE = 3.60 cm/s). The FVR as determined by transcutaneous Doppler echocardiography showed a good correlation with that determined using the Doppler guidewire method (y = 0.90 x + 0.21, r = 0.92, SEE = 0.31). CONCLUSIONS: Transcutaneous Doppler echocardiography proved to be an accurate noninvasive method to measure FV and FVR in the right GEA graft.

Aged↗
PubMed2003

[Assessment of the clinical feasibility of OptiGo for hand-held echocardiography].

OBJECTIVES: Hand-held ultrasound devices are becoming available for clinical examination, but the accuracy and precision of such devices are unclear. This study compared the accuracy of a hand-held echo device to a standard echo system. METHODS: Twenty-two patients were examined with the OptiGo (Phillips Medial Systems) hand-held ultrasound system with a 2.5 MHz transducer and SONOS 5500 (Phillips Medial Systems) standard ultrasound system with a 2 to 4 MHz wideband transducer. Patients with cardiac arrhythmia and tachycardia were excluded. Image quality, chamber size (left ventricle, left atrium), global and regional left ventricular function, valve morphology and severity of valve regurgitation were assessed. RESULTS: There was good agreement between the two imaging devices for image quality (77.3%), left ventricular ejection fraction (90.5%), regional wall motion score (> 90%), valve morphology (> 90%), severity of valve regurgitation (> 81.0%) and there was good correlation and agreement for left ventricular and left atrial size. CONCLUSIONS: Although the OptiGo has limitations, the hand-held examination appropriately estimates global and regional left ventricular function, valve morphology, valve regurgitation and chamber size.

Adult↗
PubMed2003

[Validation of a new hand-carried ultrasound device equipped with directional color power Doppler and continuous wave Doppler].

OBJECTIVES: This study evaluated the accuracy of the directional color power Doppler (DCPD) and continuous wave Doppler (CWD) methods incorporated in the new hand-carried SonoSite 180PLUS ultrasound device. METHODS: The hand-held ultrasound system with 2.5 MHz transducer and SONOS 5500 was used as a standard ultrasound system with a 2 to 4 MHz wideband transducer. The experimental study used a Doppler wire phantom to evaluate the influence of target wire speed and angle of transducer on DCPD imaging. The clinical study included 48 consecutive patients. DCPD assessment of valvular regurgitation measured the distances of DCPD signals of mitral, aortic and tricuspid valve regurgitation using the apical four-chamber view for comparison with standard echocardiography. CWD assessment measured the peak velocities of the aortic flow and tricuspid valve regurgitant flow for comparison with standard echocardiography. RESULTS: In the experimental study, DCPD signals were not influenced by target wire speed changes and transducer incident angles. In the clinical study, agreements for mitral, aortic and tricuspid regurgitation between the two methods were 89.6%, 81.8% and 78.7%, respectively. The distances of DCPD valve regurgitant signals by the hand-carried ultrasound device showed good correlation (mitral regurgitation: y = 0.84x + 0.55; r = 0.93, aortic regurgitation: y = 0.95x + 0.27; r = 0.94, tricuspid regurgitation: y = 0.86x + 0.61; r = 0.90) with those by standard echocardiography. Evaluation of CWD velocity measurements showed good agreement for the lower flow velocities (< 2.0 m/sec). However, underestimation occurred for the high flow velocities (> 2.0 m/sec) compared with those by standard echocardiography (aortic flow: y = 0.80x + 0.11; r = 0.95, tricuspid regurgitation: y = 1.00x - 0.23; r = 0.90). CONCLUSIONS: The new hand-carried ultrasound device (SonoSite 180PLUS equipped with DCPD and CWD) is clinically useful for evaluating valvular regurgitations and flow velocities. Further studies are needed to determine the mechanism of the underestimation of high flow velocities by CWD.

Aortic Valve Insufficiency↗