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Dive into the research topics where Tetsuzo Wakatsuki is active.

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Featured researches published by Tetsuzo Wakatsuki.


American Journal of Cardiology | 1997

Clinical application of pulsed Doppler tissue imaging for assessing abnormal left ventricular relaxation.

Takashi Oki; Tomotsugu Tabata; Hirotsugu Yamada; Tetsuzo Wakatsuki; Hisanori Shinohara; Akiyoshi Nishikado; Arata Iuchi; Nobuo Fukuda; Susumu Ito

Conventional assessment of left ventricular (LV) relaxation by calculating the time constant of LV pressure decay during the isovolumic diastole requires an invasive approach. Conversely, noninvasive parameters obtained by measuring isovolumic relaxation time and transmitral flow velocity often give inaccurate information. Using LV pressure curve, pulsed Doppler echocardiography, and pulsed Doppler tissue imaging in 38 patients with heart disease and 12 control subjects, we calculated the time constant and recorded transmitral flow velocity and motion velocities at the endocardial portions of the ventricular septum and LV posterior wall. Compared with the controls, patients exhibited a prolonged time constant, a decreased peak early diastolic velocity of the LV posterior wall, and a prolonged time interval from the second heart sound to the peak of the early diastolic wave. The time constant correlated well with the isovolumic relaxation time and various parameters calculated from the transmitral flow velocity, except in patients with elevated LV end-diastolic pressure. In all subjects, the time constant correlated negatively with the peak early diastolic velocity of the posterior wall and positively with the time from the second heart sound to the peak of the early diastolic wave. Thus, early diastolic parameters derived from the motion velocity of the LV posterior wall by pulsed Doppler tissue imaging were closely related to the time constant. This technique may allow noninvasive evaluation of abnormal LV relaxation in patients with various heart diseases.


Journal of The American Society of Echocardiography | 1999

PULSED TISSUE DOPPLER IMAGING OF LEFT VENTRICULAR SYSTOLIC AND DIASTOLIC WALL MOTION VELOCITIES TO EVALUATE DIFFERENCES BETWEEN LONG AND SHORT AXES IN HEALTHY SUBJECTS

Takashi Oki; Tomotsugu Tabata; Yuichiro Mishiro; Hirotsugu Yamada; Miho Abe; Yukiko Onose; Tetsuzo Wakatsuki; Arata Iuchi; Susumu Ito

Our objective was to evaluate in healthy subjects the left ventricular (LV) wall motion velocities along the long and short axes by means of pulsed tissue Doppler imaging (TDI) to clarify the differences in the LV systolic and diastolic function between both axes. Wall motion velocities were recorded at the mid-wall portion of the middle site of the LV posterior wall in the parasternal long-axis view, and at the subendocardial portion of the middle site of the LV posterior wall in the apical long-axis view by pulsed TDI in 35 healthy subjects (mean age 26 +/- 10 years, mean heart rate 72 +/- 7 bpm). In all subjects, the LV pressure curve, its first derivative (dP/dt), the LV wall motion velocity, the phonocardiogram, and the electrocardiogram were simultaneously recorded. The systolic wave of the LV posterior wall motion velocity exhibited 2 peaks: the first and second systolic waves (Swl and Sw2, respectively). The diastolic wave also exhibited 2 peaks, the early diastolic and atrial systolic waves. The Swl along the long axis was greater than either the Sw1 and Sw2 along the short axis or the Sw2 along the long axis. The peak Sw1 along the long axis coincided with the peak dP/dt and was slightly earlier than the peak Swl along the short axis. The onset of Sw1 along the long axis coincided with the onset of the first heart sound. The Sw2 along the short axis was greater than that along the long axis. The early diastolic wave along the short axis was greater than that along the long axis, whereas the atrial systolic wave along the long axis was greater than that along the short axis. Thus, in healthy subjects, shortening of the longitudinal fibers predominated over that of the circumferential fibers during early systole, whereas shortening of the circumferential fibers predominated over the longitudinal fibers during the ejection phase. During diastole, the circumferential fibers predominated in the LV wall expansion at early diastole, whereas the longitudinal fibers predominated at atrial systole. In conclusion, pulsed TDI provided information that is useful in understanding the characteristics of LV wall motion along the long and short axes.


Journal of The American Society of Echocardiography | 1999

Effect of aging on diastolic left ventricular myocardial velocities measured by pulsed tissue Doppler imaging in healthy subjects.

Hirotsugu Yamada; Takashi Oki; Yuichiro Mishiro; Tomotsugu Tabata; Miho Abe; Yukiko Onose; Tetsuzo Wakatsuki; Susumu Ito

We evaluated the effect of aging on diastolic left ventricular (LV) wall motion velocity in 80 healthy persons with the use of pulsed tissue Doppler imaging. The wall motion velocity patterns were recorded at the middle regions of the LV posterior wall and ventricular septum in the parasternal (along the short axis) and apical (along the long axis) LV long-axis views. In the posterior wall, the peak early diastolic wall motion velocities (Ews) along both axes correlated inversely with age (long axis: r = -0.61, P <. 0001; short axis: r = -0.55, P <.0001), and the peak atrial systolic wall motion velocities(Aws) along both axes correlated directly with age (long axis: r = 0.59, P <.0001; short axis: r = 0.65, P <.0001). In the ventricular septum, the Ew along the long axis correlated inversely with age (r = -0.51, P <.0001), and the Aws along both axes correlated directly with age (long axis: r = 0.57, P <.0001; short axis: r = 0.53, P <.0001). The Ews along both axes at the posterior wall correlated directly with the peak early diastolic transmitral flow velocity. The Aws along both axes at the ventricular septum and posterior wall correlated directly with the peak atrial systolic transmitral flow velocity. The times from the second heart sound to the peak of the early diastolic waves of the ventricular septum and posterior wall along both axes significantly increased with age. The times from the aortic component of the second heart sound to the peak of the early diastolic motion velocities along both axes were significantly longer at the ventricular septum than at the posterior wall. Pulsed tissue Doppler imaging may be useful for evaluating the effect of aging on diastolic LV function in healthy persons.


Journal of The American Society of Echocardiography | 1998

Left ventricular diastolic properties of hypertensive patients measured by pulsed tissue Doppler imaging.

Takashi Oki; Tomotsugu Tabata; Hirotsugu Yamada; Tetsuzo Wakatsuki; Yuichiro Mishiro; Miho Abe; Yukiko Onose; Arata Iuchi; Susumu Ito

Examination of left ventricular (LV) diastolic dysfunction in hypertensive patients has been based on parameters obtained from the transmitral flow velocity during pulsed Doppler echocardiography. However, these parameters are affected by loading conditions. We evaluated LV diastolic function along the longitudinal and transverse axes by pulsed tissue Doppler imaging (TDI) in 50 hypertensive (HT) patients and 36 age-matched healthy volunteers (N). Transmitral flow velocity was recorded by pulsed Doppler echocardiography. LV posterior wall motion velocity along the longitudinal and transverse axes also was recorded by pulsed TDI. In both groups, peak early diastolic velocity of the LV posterior wall (Ew) along the transverse axis (N: 15.8+/-5.2 cm/s, HT: 12.2+/-4.4 cm/s) was higher than that along the longitudinal axis (N: 12.7+/-3.1 cm/s, HT: 9.5+/-3.3 cm/s). Peak atrial systolic velocity of the LV posterior wall (Aw) along the longitudinal axis (N: 9.1+/-1.8 cm/s, HT: 9.7 +/-2.6 cm/s) significantly exceeded that along the transverse axis (N: 8.0+/-2.2 cm/s, HT: 8.4+/-2.4 cm/s) in both groups. The Ews were lower and the Aws were higher along both axes in the patient group than in the control group. The time intervals from the aortic component of the second heart sound to the peak of the early diastolic wave (IIA-Ews) along both the transverse (N: 142+/-18 ms, HT: 154+/-19 ms) and longitudinal (N: 151 16 ms, HT: 162+/-20 ms) axes were longer in the patient group. In 29 patients, Ews along both axes correlated negatively (transverse: r = -0.80, P < .0001; longitudinal: r = -0.71, P < .0001) and IIA-Ews correlated positively (transverse: r = 0.81, P < .0001; longitudinal: r = 0.74, P < .001) with the time constant of the LV pressure decay during isovolumic diastole. The Aws along both axes in the 24 patients without pseudonormalization in transmitral flow velocity correlated positively (transverse: r = 0.60, P < .001; longitudinal: r = 0.74, P < .0001) with the LV end-diastolic pressure. In conclusion, LV relaxation and filling along the longitudinal and transverse axes were impaired in many patients with hypertension. Pulsed TDI was useful for evaluating LV diastolic dynamics in this disease.


Journal of The American Society of Echocardiography | 2003

Prognostic value of the atrial systolic mitral annular motion velocity in patients with left ventricular systolic dysfunction

Takashi Yamamoto; Takashi Oki; Hirotsugu Yamada; Hideji Tanaka; Takeo Ishimoto; Tetsuzo Wakatsuki; Tomotsugu Tabata; Susumu Ito

BACKGROUND Transmitral flow velocity variables are powerful predictors of poor prognosis in patients with left ventricular (LV) systolic dysfunction. However, these variables may not accurately reflect the severity of pulmonary congestion. This study was designed to determine whether the peak atrial systolic mitral annular motion velocity (MA-Aw) measured by pulsed Doppler tissue imaging can predict cardiac death or hospitalization for worsening heart failure in patients with LV systolic dysfunction. METHODS MA-Aw was recorded in 96 patients with LV systolic dysfunction who were followed up for 29 +/- 10 months. All patients underwent Doppler echocardiography on entry into the study, and cardiac catheterization was performed in 45 patients. Patients were divided into 3 groups on the basis of the ratio of early (E) to late (A) diastolic filling (E/A) of the transmitral flow velocity: group 1 (n=31; E/A < 1); group 2 (n=37; 1 < or = E/A < 2); and group 3 (n=28; E/A > or = 2). RESULTS During follow-up, 36 patients (38%) died of cardiac causes and 34 (35%) were hospitalized for worsening heart failure. There were 2 cardiac deaths (6%) in group 1, 14 (39%) in group 2, and 20 (56%) in group 3. The MA-Aw correlated closely with the mean pulmonary capillary wedge pressure. Univariate Cox model analysis showed that MA-Aw < or = 5 cm/s was the most powerful predictor of cardiac death or hospitalization for worsening heart failure compared with clinical, hemodynamic, and the other echocardiographic variables. Furthermore, MA-Aw < or = 5 cm/s was clearly discernible as a good predictor of cardiac mortality on multivariate Cox model and as assessed by Kaplan-Meier method. CONCLUSION The MA-Aw obtained by pulsed Doppler tissue imaging is a sensitive index of pulmonary congestion in patients with LV systolic dysfunction. It is a simple and noninvasive outcome measure and can be used to monitor treatment.


Journal of The American Society of Echocardiography | 1999

Evaluation of Left Ventricular Contraction Abnormalities in Patients with Dilated Cardiomyopathy with the Use of Pulsed Tissue Doppler Imaging

Yuichiro Mishiro; Takashi Oki; Hirotsugu Yamada; Tetsuzo Wakatsuki; Susumu Ito

The left ventricular (LV) systolic wave, as recorded by pulsed tissue Doppler imaging, usually consists of 2 components (Sw(1) and Sw(2)). However, the clinical significance of these waves has not been studied in patients with dilated cardiomyopathy (DCM) and sinus rhythm. We studied 25 patients with DCM (DCM group) and 22 age-matched normal subjects (control group). The LV posterior wall motion velocities along the short and long axes were recorded by pulsed tissue Doppler imaging, and the peak velocities of the Sw(1) and Sw(2) and the times from the electrocardiographic Q wave to the peak Sw(1) and Sw(2) (Q-Sw(1) and Q-Sw(2), respectively) were determined. In all patients cardiac catheterization was performed immediately after the noninvasive examination, and the LV end-diastolic pressure and peak dP/dt were determined. The LV end-diastolic pressure and peak dP/dt were significantly greater and lower, respectively, in the DCM group. The peak Sw(1) along the long axis was significantly greater than Sw(1) and Sw(2) along the short axis and Sw(2) along the long axis in the control group. The peak Sw(1) and Sw(2) along the long and short axes were all significantly lower in the DCM group than in the control group. The Q-Sw(1) along the long axis was significantly shorter than that along the short axis, whereas no significant difference was seen in the Q-Sw(2) in either axis in any patient. The Q-Sw(1) and Q-Sw(2) along both axes were significantly longer in the DCM group than in the control group. All systolic pulsed tissue Doppler imaging variables, particularly the peak Sw(1) along the long axis, correlated well with the peak dP/dt in all patients. LV contractility along both the short and long axes is commonly impaired in patients with DCM. In particular, peak Sw(1) along the long axis is a useful parameter for evaluating LV myocardial contractility during isovolumic contraction.


Journal of The American Society of Echocardiography | 1999

Influence of Aging on Systolic Left Ventricular Wall Motion Velocities Along the Long and Short Axes in Clinically Normal Patients Determined by Pulsed Tissue Doppler Imaging

Yukiko Onose; Takashi Oki; Yuichiro Mishiro; Hirotsugu Yamada; Miho Abe; Kazuyo Manabe; Yoshimi Kageji; Tomotsugu Tabata; Tetsuzo Wakatsuki; Susumu Ito

Our objective was to evaluate the influence of aging on left ventricular (LV) regional systolic function along the long and short axes in clinically normal patients. We recorded LV wall motion velocity patterns at the mid-wall portion of the middle of the LV posterior wall in the parasternal long-axis view (short-axis direction) and at the endocardial portion of the middle of the LV posterior wall in the apical long-axis view (long-axis direction) with pulsed tissue Doppler imaging in 80 normal patients (age range 15 to 78 years). In all patients the LV pressure curve and its first derivative (dP/dt) were recorded. The systolic wave of the LV posterior wall motion velocity pattern exhibited 2 peaks, the first (Sw(1)) and second (Sw(2)) systolic waves. No significant changes were seen with aging in the percent LV fractional shortening determined by M-mode echocardiography, LV ejection fraction determined by left ventriculography, the peak Sw(1) and Sw(2) along the short axis, the peak Sw(2) along the long axis, and the peak dP/dt. The peak Sw(1) along the long axis correlated inversely with age (P <.0001) but did not correlate significantly with the peak dP/dt. These results suggest that shortening of the longitudinal fibers in early systole is impaired with increased age in healthy individuals. This impairment results in insufficient spherical change in the LV cavity, although global LV pump function and myocardial contractility are maintained.


Journal of The American Society of Echocardiography | 1999

Effect of an Acute Increase in Afterload on Left Ventricular Regional Wall Motion Velocity in Healthy Subjects

Takashi Oki; Kazuyo Fukuda; Tomotsugu Tabata; Yuichiro Mishiro; Hirotsugu Yamada; Miho Abe; Yukiko Onose; Tetsuzo Wakatsuki; Arata Iuchi; Susumu Ito

We recorded left ventricular (LV) wall motion velocities before and after angiotensin II infusion by pulsed tissue Doppler imaging in 20 healthy subjects, and evaluated the responses of systolic and diastolic LV function along the long and short axes during an acute increase in afterload. Angiotensin II was administered intravenously to obtain a 30% increase in mean blood pressure. After angiotensin II infusion, LV end-systolic dimension and end-systolic circumferential wall stress increased significantly, and the percentage of LV fractional shortening decreased significantly. Peak first systolic LV wall motion velocity (Sw1 ) along the long axis decreased markedly compared with that along the short axis, and peak second systolic LV wall motion velocity (Sw2 ) along the short axis decreased significantly compared with that along the long axis. Early diastolic LV wall motion velocities along both the long and short axes decreased significantly, whereas atrial systolic LV wall motion velocity did not change. In conclusion, an acute increase in afterload caused a significant decrease in longitudinal fiber shortening during the isovolumic contraction phase (Sw1 along the long axis), circumferential fiber shortening during the ejection phase (Sw2 along the short axis), and LV relaxation during early diastole (early diastolic LV wall motion velocities along both axes) in healthy subjects. Pulsed tissue Doppler imaging may be useful for detecting the effect of various loading conditions on LV wall motion velocities along the long and short axes.


Journal of the American College of Cardiology | 2000

Coronary Flow Velocity Immediately After Primary Coronary Stenting as a Predictor of Ventricular Wall Motion Recovery in Acute Myocardial Infarction

Tetsuzo Wakatsuki; Masato Nakamura; Taro Tsunoda; Hiroko Toma; Toshiyuki Degawa; Takashi Oki; Tetsu Yamaguchi

OBJECTIVES The purpose of this study was to examine the relationship between the pattern of coronary blood flow velocity immediately after successful primary stenting and the recovery of left ventricular (LV) wall motion in patients with acute myocardial infarction (AMI). BACKGROUND It is difficult to predict the recovery of LV wall motion immediately after direct angioplasty in AMI. Recent reports indicate that dysfunctional coronary microcirculation is an important determinant of prognosis for AMI patients after successful reperfusion. METHODS We measured left anterior descending coronary flow velocity variables using a Doppler guide wire immediately after successful primary stenting in 31 patients with their first anterior AMI. The patients were divided into two groups: those with and those without early systolic reverse flow (ESRF). Changes in LV regional wall motion (RWM) and ejection fraction (EF) at admission and at discharge were compared between the two groups. Coronary flow velocity variables immediately after primary stenting were compared with changes in left ventriculographic indexes. RESULTS The change in RWM was significantly greater in the non-ESRF group than it was in the ESRF group (0.9 +/- 0.7 vs. -0.1 +/- 0.3 standard deviation/chord, respectively, p < 0.001). The change in EF was also significantly greater in the non-ESRF group than it was in the ESRF group (10 +/- 10 vs. 1 +/- 6%, respectively, p < 0.05). In the non-ESRF group (diastolic to systolic velocity ratio [DSVR] <3.0), the DSVR correlated positively with the change in RWM (r = 0.60, p < 0.005, n = 24) and the change in EF (r = 0.52, p < 0.01). CONCLUSIONS The coronary flow velocity pattern measured immediately after successful primary stenting is predictive of the recovery of regional and global LV function in patients with AMI.


American Heart Journal | 2000

Detection of left ventricular regional relaxation abnormalities and asynchrony in patients with hypertrophic cardiomyopathy with the use of tissue Doppler imaging

Oki T; Yuichiro Mishiro; Hirotsugu Yamada; Yukiko L. Onose; Masako Matsuoka; Tetsuzo Wakatsuki; Tabata T; Susumu Ito

BACKGROUND It is well known that the distribution and magnitude of left ventricular (LV) hypertrophy are not uniform in patients with hypertrophic cardiomyopathy (HCM), which results in regional heterogeneity of LV early diastolic function. The advent of tissue Doppler imaging (TDI) has allowed the noninvasive evaluation of regional LV wall motion velocities. The aim of this study was to evaluate regional LV relaxation abnormalities and asynchrony noninvasively in patients with HCM by using pulsed and color-coded TDI. METHODS AND RESULTS We studied 20 patients with asymmetric septal hypertrophy (HCM group) and 18 age-matched normal patients (control group). The peak early diastolic motion velocity (Ew) and time from the aortic component of the second heart sound to the peak of the Ew (II(A)-Ew) were measured by pulsed TDI. The myocardial velocity gradient during early diastole (MVG-Ew) also was measured by color-coded TDI. Mean values for these parameters were determined on the basis of measurements made at 2 sites of the ventricular septum or posterior wall at the levels of chordae tendineae and papillary muscles. The mean Ew and mean MVG-Ew for the ventricular septum and posterior wall were significantly lower, and mean II(A)-Ew was significantly prolonged in the HCM group compared with the control group. This difference was most pronounced in the hypertrophied ventricular septum of the HCM group. The standard deviations of II(A)-Ew for the ventricular septum and posterior wall were significantly greater in the HCM group than in the control group. The time constant of LV pressure decay during isovolumic diastole (tau) correlated inversely with Ew and MVG-Ew and correlated directly with II(A)-Ew. Furthermore, tau correlated directly with the standard deviation of the II(A)-Ew. CONCLUSIONS LV early diastolic function in patients with HCM may be mediated by an augmentation of regional LV relaxation abnormalities and asynchrony.

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Shusuke Yagi

University of Tokushima

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Takayuki Ise

University of Tokushima

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