Manatomo Toyono

Comparison of the right ventricular Tei index by tissue Doppler imaging to that obtained by pulsed Doppler in children without heart disease.

This study demonstrated that the TDI-Tei index correlates well with the Tei index determined by pulsed Doppler, and thus represents a simple method of assessing RV myocardial performance. Moreover, the TDI-Tei index has the advantage of simultaneous recording of systolic and diastolic velocity patterns, suggesting that the TDI-Tei index is a feasible approach to assess global RV function in children.

Geometry of the proximal isovelocity surface area in mitral regurgitation by 3-dimensional color Doppler echocardiography: Difference between functional mitral regurgitation and prolapse regurgitation

BACKGROUND The geometry of the proximal isovelocity surface area (PISA) of functional mitral regurgitation (MR), which is conventionally assumed to be a hemisphere, remains to be clarified. We investigated the 3-dimensional (3D) geometry of PISA of functional MR as opposed to that of MR due to mitral valve prolapse (MVP) by real-time 3D echocardiography with color Doppler capability. METHODS Twenty-seven patients with functional MR and 27 patients with MVP were examined. The horizontal PISA length in the commissure-commissure plane and each PISA radius in 3 anteroposterior planes (medial, central, and lateral) were measured by real-time 3D echocardiography with 3D software. The effective regurgitant orifice (ERO) area was calculated with the maximum PISA radius and compared to that by 2D quantitative Doppler method. RESULTS En-face 3D color Doppler images showed an elongated and slightly curved PISA geometry along the leaflet coaptation in functional MR, whereas the geometry was rounder in MVP. The PISA horizontal length in functional MR was longer than that in MVP (2.3 +/- 0.4 vs 1.2 +/- 0.2 cm, P < .001). The PISA method with the maximum radius underestimated the ERO area by 2D quantitative Doppler method (by 24%) in functional MR, but not in MVP. CONCLUSIONS The geometry of PISA in functional MR was elongated, distinctly different from the more focal pathology of MVP, leading to underestimation of the ERO area by PISA method.

Doppler Echocardiographic Evaluation of Left Ventricular Output and Left Ventricular Diastolic Filling Changes in the First Day of Life

ABSTRACT: The aim of this study was to evaluate the changes in Doppler transmitral flow patterns during the 1st d of life. Doppler echocardiography of the ascending aorta and mitral valve was performed serially in 20 normal neonates at 2, 12, and 24 h of age. A computer-interfaced digitizer pad was used to measure the following: ascending aorta flow velocity-time integral, total diastolic filling flow velocity-time integral, flow velocity-time integral of early diastolic filling, and flow velocity-time integral of atrial contraction. The inner diameter of the ductus arteriosus was 4.2 ± 0.6 mm at 2 h of age, 2.3 ± 0.5 mm at 12 h of age, and had closed in 17 of 20 neonates (85%) by 24 h of age. The ascending aorta flow velocity-time integral and total diastolic filling flow velocity-time integral, which were high at 2 h of age, decreased significantly at 12 h of age [12.2 ± 2.1 cm versus 9.6 ± 1.7 cm (p < 0.001) and 8.0 ± 1.1 versus 7.1 ± 1.4 (p < 0.01), respectively] but remained constant thereafter. Although no significant changes in flow velocity-time integral of atrial contraction and peak velocity of atrial contraction were noted during the first 24 h of birth, the flow velocity-time integral of early diastolic filling and peak velocity of early diastolic filling that were high at 2 h of age were reduced significantly at 12 h of age [5.0 ± 0.9 cm versus 4.1 ± 1.1 cm (p < 0.005) and 60.9 ± 9.0 cm/s versus 50.3 ± 9.0 cm/s (p < 0.001), respectively], resulting in significant reductions in the ratio of flow velocity-time integral of early diastolic filling/flow velocity-time integral of atrial contraction and the ratio of peak velocity of early diastolic filling/peak velocity of atrial contraction at 12 h of age. The size of the ductus arteriosus was found to be correlated with the peak velocity of early diastolic filling (r = 0.42, p < 0.05). Our results clearly demonstrate that the pattern of early diastolic filling was dependent on preload, whereas that of late diastolic filling was independent of preload in the early neonatal period.

The role of nitric oxide in dilating the fetal ductus arteriosus in rats.

Prostaglandin E is a major dilator of the fetal ductus arteriosus (DA), but the role of nitric in fetal ductal dilation has not been established. We studied the effects of a potent nitric oxide synthase inhibitor. Nω-nitro-L-arginine methyl ester (L-NAME), on the fetal DA in rats. L-NAME was injected into the dorsum of pregnant rats, and fetal DA was studied 4 h later with a rapid whole body freezing method. The inner diameters of the DA and the main pulmonary artery were measured on a freezing microtome. The inner diameter ratio of DA to main pulmonary artery (DA/PA) was 1.02 ± 0.03 (mean ± SEM; number of fetuses [n], 21) in normal near-term fetuses. The effect of prostaglandin synthesis inhibition was studied after orogastric administration of indomethacin to pregnant rats. In near-term rats on the 21st day of gestation (term, 21.5 d), a large dose of L-NAME (100 mg/kg) caused only mild ductal constriction, with DA/PA reduced to 0.83 ± 0.05 (n = 20). Indomethacin (1 mg/kg) caused moderate ductal constriction, and DA/PA was decreased to 0.65 ± 0.05 (n = 21). Combined administration of L-NAME (10 mg/kg) and indomethacin (1 mg/kg) caused severe ductal constriction, with DA/PA of 0.26 ± 0.03 (n = 16). In preterm rats on the 19th day of gestation, a moderate dose of L-NAME (10 mg/kg) caused severe ductal constriction, with a DA/PA of 0.32 ± 0.05 (n = 24). Indomethacin (1 mg/kg) alone caused only mild ductal constriction, with DA/PA 0.86 ± 0.02 (n = 16). In conclusion, prostaglandin has a major role and nitric oxide has a minor role in dilating the DA in the near-term fetal rat. In contrast, nitric oxide has a major role and prostaglandin has a minor role in dilating the DA in preterm fetal rats.

A comparison of tissue doppler imaging and velocities of transmitral flow in children with elevated left ventricular preload

Compared with transmitral velocities of flow, myocardial wall velocities obtained by tissue Doppler imaging are less influenced by left atrial pressure. The data supporting this assumption, however, are limited in patients with congenital cardiac disease. The aim of this study was to compare the effects of left ventricular preload on transmitral inflow and velocities assessed by tissue Doppler imaging. Tissue Doppler imaging, and conventional Doppler echocardiography with simultaneous invasive hemodynamic studies, were performed in 33 patients with a simple ventricular septal defect or patency of the arterial duct. Transmitral velocities (E, A) and mitral annular velocities (Ea, Aa) were measured, permitting calculation of the ratio of E to Ea. The ratio of pulmonary to systemic flows, and mean left atrial pressure, were also measured. In 10 of 33 patients, echocardiographic and hemodynamic studies were performed 4 to 5 months after surgery. The E and A values in the patients were greater than those in the controls (p < 0.01). In contrast, neither Ea nor Aa differed between the two group. The ratio of E to Ea in the patients increased significantly compared with that in the controls (8.9+/-2.1 vs 7.3+/-1.3, p < 0.01). The E value was directly related to mean left atrial pressure and the ratio of pulmonary to systemic flows. The velocities measured by Tissue Doppler imaging, however, had no significant relationship to either of these measurements. The ratio of E to Ea correlated well with mean left atrial pressure (r = 0.75, p < 0.01). In 10 post-operative patients, the values for E and A decreased from 119+/-14 to 89+/-10 cm/sec (p < 0.01) and from 91+/-22 to 61+/-9 cm/sec (p < 0.01), respectively. No significant changes were noted in the values of Ea and Aa. The ratio of E to Ea, and mean left atrial pressure, decreased from 10.3+/-1.9 to 8.2+/-1.5 (p < 0.01) and from 11.0+/-1.8 to 7.4+/-1.0 mmHg (p < 0.01), respectively. The percentage change in left atrial pressure correlated with the percent change in the ratio of E to Ea (r = 0.64, p < 0.05). The present study showed that the velocities obtained with tissue Doppler imaging are less dependent on mean left atrial pressure in children with elevated left ventricular preload caused by a left-to-right shunt.

Echocardiographic predictors for persistent functional mitral regurgitation after aortic valve replacement in patients with aortic valve stenosis.

Moderate functional mitral regurgitation (MR) in patients with aortic valve stenosis (AS) is often left unaddressed at the time of aortic valve replacement (AVR) because it is expected to decrease after AVR. However, some patients have persistent moderate MR after AVR. We sought to determine the preoperative echocardiographic predictor for persistent functional MR after AVR in patients with AS. Pre- and postoperative echocardiograms were reviewed in 110 patients with severe AS and functional MR who underwent AVR without mitral valve (MV) surgery. Fifty-eight patients received concomitant coronary artery bypass graft surgery. In patients with MV tenting, defined as apical displacement of mitral leaflets in the apical 4-chamber view, MV tenting area and tenting height were measured at midsystole. Eighty patients had MV tenting (mean MV tenting area 1.4 +/- 0.5 cm(2), mean MV tenting height 0.8 +/- 0.2 cm) and 30 did not have it before AVR. MR severity decreased in 51 of 80 patients (64%) with MV tenting after AVR and in 25 of 30 patients (83%) without MV tenting (p <0.05). In patients with MV tenting, multivariate analysis revealed that presence of long-term atrial fibrillation and MV tenting area were independent predictors of postoperative MR severity (all p values <0.05). The sensitivity and specificity in predicting persistent moderate MR after AVR were 72% and 82% for MV tenting area >1.4 cm(2). In conclusion, preoperative MV tenting predicts persistent functional MR after AVR in patients with severe AS.

Noninvasive estimation of left ventricular end-diastolic pressure using tissue Doppler imaging combined with pulsed-wave Doppler echocardiography in patients with ventricular septal defects: a comparison with the plasma levels of the B-type natriuretic Peptide.

Background: There are limited data regarding whether the ratio of the peak transmitral flow velocity during early diastole (E) to the peak mitral annular velocity during early diastole (Ea) obtained by tissue Doppler imaging (TDI) and the plasma levels of the B‐type natriuretic peptide (BNP) are useful for evaluating the left ventricular end‐diastolic pressure (LVEDP) in children with ventricular septal defects (VSD). We investigated the validity of noninvasive estimation of the LVEDP in VSD infants. Methods: We studied 48 patients (mean age, 9 ± 6 months). Using pulsed‐wave Doppler echocardiography and TDI, E and Ea were measured to calculate the E/Ea ratio. The LVEDP and the ratio of pulmonary to systemic blood flow (Qp/Qs) were determined invasively. Results: There were significant positive correlations between E and both the LVEDP value and the Qp/Qs ratio. In contrast, Ea showed significant negative correlations with the LVEDP value and Qp/Qs ratio. The E/Ea ratio correlated significantly with the LVEDP value and Qp/Qs ratio. The plasma BNP levels correlated significantly with the Qp/Qs ratio, although they did not show a significant correlation with the LVEDP. An E/Ea ratio of >9.8 indicated patients with a LVEDP of >10 mmHg with a sensitivity of 92% and specificity of 80%. Conclusion: TDI combined with pulsed‐wave Doppler echocardiography predicted the LVEDP of VSD infants, whereas the plasma BNP value did not have a significant association with the LVEDP.

Persistent tricuspid regurgitation and its predictor in adults after percutaneous and isolated surgical closure of secundum atrial septal defect.

The fate of functional tricuspid regurgitation (TR) after closure of a secundum atrial septal defect (ASD) without any corrective tricuspid valve (TV) surgery remains unclear. We investigated this and the predictors of persistent TR after ASD closure. Thirty-two consecutive patients with moderate or severe TR before ASD closure were examined. Of these, 23 underwent percutaneous ASD closure, and 9 underwent isolated surgical ASD closure. The left ventricular end-diastolic volume, left ventricular ejection fraction, right ventricular end-diastolic area, right ventricular fractional area change, right ventricular spherical index, right atrial area, TV annular diameter, TV tethering height, pulmonary artery systolic pressure, and pulmonary/systemic blood flow ratio were determined by echocardiography before and early after ASD closure. The color Doppler maximal jet area was used to assess the severity of TR. After ASD closure, the jet area decreased for all patients (p = 0.009); however, 16 patients (50%) had persistent TR. Multivariate analysis revealed that only pulmonary artery systolic pressure before ASD closure was related to the TR jet area after ASD closure (p = 0.003). A pulmonary artery systolic pressure of >60 mm Hg predicted persistent TR with 100% sensitivity and 63% specificity. In conclusion, functional TR was ameliorated after percutaneous and isolated surgical ASD closure, although persistent TR was common. The presence of pulmonary hypertension before ASD closure predicted persistent TR; therefore, corrective TV surgery should be considered at ASD closure in adult patients with moderate or severe TR and concomitant pulmonary hypertension.

Diagnostic Value of Left Ventricular Outflow Area in Patients with Hypertrophic Cardiomyopathy: A Real-Time Three-Dimensional Echocardiographic Study

BACKGROUND Earlier studies demonstrated the ability of real-time 3-dimensional (3D) echocardiography (3DE) to measure left ventricular outflow tract (LVOT) area (A(LVOT)) in patients with hypertrophic cardiomyopathy (HCM). However, its clinical value is unknown. OBJECTIVE We sought to investigate the feasibility and accuracy of real-time 3DE-derived A(LVOT) to diagnose significant LVOT obstruction in a large number of patients with HCM. METHODS A total of 162 patients with HCM had 3DE by using a volumetric system. The smallest A(LVOT) during systole was determined by moving a 2-dimensional plane in 3D space. The pressure gradient across LVOT was assessed by continuous wave Doppler method. Provocation was performed in patients without significant LVOT obstruction (pressure gradient across LVOT < 50 mm Hg) at rest. RESULTS Twenty (12%) patients with poor image quality of 3DE were excluded; 16 (28%) patients with a volumetric system, but only 4 (4%) patients with commercial equipment (P < .001). In the remaining 142 patients, A(LVOT) inversely correlated with pressure gradient across LVOT both at rest (r = 0.82, P < .001) and after provocation (r = 0.60, P < .001). The value of A(LVOT) less than 0.85 cm(2) and less than 2.0 cm(2) predicted resting and provokable LVOT obstruction with sensitivity of 87% and 81%, and specificity of 77% and 90%, respectively. CONCLUSIONS Real-time 3DE measurement of A(LVOT) was successful in diagnosing and quantifying LVOT obstruction at rest and after provocation in a large number of patients with HCM.

Maturational changes in left ventricular contractile state

It has been suggested from animal and human studies that age-related alterations in left ventricular contractility occur. However, there is little information about growth-related changes in left ventricular performance from preterm infants to older children. In 22 preterm infants, 23 fullterm infants, and 35 children, left ventricular contractility was evaluated by two-dimensional and M-mode echocardiography. The rate-corrected mean velocity of fiber shortening (mVcfc)-end-systolic wall stress (ESS) relation was used as an index of contractility. There were significant inverse linear correlations between ESS and mVcfc in the three groups (all P<0.01). The slopes and y-intercepts of the regression lines of mVcfc-ESS relation were both significantly greater in the premature infants (mVcfc=-0.0133 ESS+1.62) and neonates (mVcfc=-0.0107 ESS+1.55) than those in the children (mVcfc=-0.0047+1.29). However, there were no significant differences between the premature and fullterm infants. Thus, these findings suggest that the contractility and afterload sensitivity of the left ventricle in the premature infants may be similar to those in the fullterm infants. In addition, our serial study in the premature infants showed that the ESS increased significantly with growth while the mVcfc did not change, suggesting that the left ventricular performance in the premature infants during early life was preserved in the setting of a lower afterload.