• Clinical and Experimental Pediatrics
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• v.53 no.1
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• pp.72-79
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• 2010

Purpose: Left ventricular (LV) hypertrophy and impaired diastolic function may occur early in systemic hypertension. Diastolic dysfunction is associated with increased cardiovascular risk. Tissue Doppler imaging (TDI)-derived tissue velocity and strain rate are new parameters for assessing diastolic dysfunction. The aim of this study is to determine whether TDI and strain rate imaging (SRI) would improve the ability to recognize early impaired diastolic and systolic functions compared with conventional echocardiography in hypertensive adolescents. Methods: We included 38 hypertensive patients with systolic blood pressure above 140 mmHg or diastolic blood pressure above 90 mmHg. Ejection fraction and myocardial performance index (MPI) were estimated by conventional echocardiography. Peak systolic myocardial velocity, early diastolic myocardial velocity (Em), and peak late diastolic myocardial velocity (Am) were obtained by using TDI and SRI. Results: In the hypertensive group, interventricular septal thickness was significantly increased on M-mode echocardiography. Em/Am was significantly decreased at the mitral valve annulus. Among hypertensive subjects, the E strain rate at basal, mid, and apex was significantly decreased. Systolic strain was significantly decreased at the septum in the hypertensive group. Conclusion: Strain rate might be a useful new parameter for the quantification of both regional and global LV functions and could be used in long-term follow up in hypertensive patients. Early identification by SRI of subjects at risk for hypertensive and ventricular dysfunction may help to stratify risk and guide therapy. Further studies, including serial assessment of LV structure and function in a larger number of adolescents with hypertension, is necessary.

• Clinical and Experimental Pediatrics
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• v.61 no.2
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• pp.59-63
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• 2018

Purpose: Cardiomyopathy is becoming the leading cause of death in patients with Duchenne muscular dystrophy because mechanically assisted lung ventilation and assisted coughing have helped resolve respiratory complications. To clarify cardiopulmonary function, we compared cardiac function between the home ventilator-assisted and non-ventilator-assisted groups. Methods: We retrospectively reviewed patients with Duchenne muscular dystrophy from January 2010 to March 2016 at Gangnam Severance Hospital. Demographic characteristics, pulmonary function, and echocardiography data were investigated. Results: Fifty-four patients with Duchenne muscular dystrophy were divided into 2 groups: home ventilator-assisted and non-ventilator-assisted. The patients in the home ventilator group were older ($16.25{\pm}1.85years$) than those in the nonventilator group ($14.73{\pm}1.36years$) (P=0.001). Height, weight, and body surface area did not differ significantly between groups. The home ventilator group had a lower seated functional vital capacity ($1,038{\pm}620.41mL$) than the nonventilator group ($1,455{\pm}603.2mL$). Mean left ventricular ejection fraction and fractional shortening were greater in the home ventilator group, but the data did not show any statistical difference. The early ventricular filling velocity/late ventricular filling velocity ratio ($1.7{\pm}0.44$) was lower in the home ventilator group than in the nonventilator group ($2.02{\pm}0.62$. The mitral valve annular systolic velocity was higher in the home ventilator group (estimated ${\beta}$, 1.06; standard error, 0.48). Patients with Duchenne muscular dystrophy on a ventilator may have better systolic and diastolic cardiac functions. Conclusion: Noninvasive ventilator assistance can help preserve cardiac function. Therefore, early utilization of noninvasive ventilation or oxygen may positively influence cardiac function in patients with Duchenne muscular dystrophy.

• Korean Journal of Veterinary Research
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• v.55 no.4
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• pp.221-225
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• 2015

This study evaluated the effects of alfaxalone (3 mg/kg, intravenously) on echocardiographic examination in healthy dogs using echocardiography. Six adult Beagle dogs were used for this study. Left ventricular dimensions with systolic indexes, trans-blood flow at all cardiac valvular annulus and trans-mitral tissue Doppler values were measured from routine transthoracic echocardiography. Although the changes were not statistically significant, heart rate, left ventricular end-systolic diameter, left ventricular end-diastolic diameter, peak velocities of tricuspid A-wave and transpulmonic flow were increased after alfaxalone induction, while systolic blood pressure, fractional shortening, left ventricular ejection fraction, peak velocities of mitral E-wave, mitral A wave, tricuspid E-wave, transaortic flow and medial e'-, a'- and s'-peaks decreased after alfaxalone induction. No dogs showed hypoxemia during sedation, regardless of intubation and oxygen supply. Although alfaxalone showed mild cardiovascular depression, this protocol could be a good alternative sedative protocol for echocardiographic examination in healthy dogs because the cardiovascular depression was statistically and clinically insignificant. However, further studies in dogs with heart diseases should be conducted to confirm these findings after alfaxalone induction.

• 순환기질환의공학회:학술대회논문집
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• 2002.11a
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• pp.46-47
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• 2002

• The Korean Journal of Nuclear Medicine
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• v.39 no.2
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• pp.94-99
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• 2005

Electrocardiogram-gated single photon omission computed tomography (SPECT) provides valuable information in the assessment of both myocardial perfusion and ventricular function. Tl-201 is a suboptimal isotope for gating. Tl-201 images are more blurred compared with Tc-99m tracers due to the increased amount of scattered photons and use of a smooth filter. The average myocardial count densities are approximately one-half those of conventional technetium tracers. However, Tl-201 is still widely used because of its well-established utility for assessing myocardial perfusion, viability and risk stratification. Gated SPECT with Tl-201 enables us to assess both post-stress and rest left ventricular volume and function. Previous studies with gated Tl-201 SPECT measurements of ejection fraction (EF), end-diastolic volume (EDV), end-systolic volume (ESV) have shown high correlation with first-pass radionuclide angiography, gated blood pool scan, Tc-99m-MIBI gated SPECT, contrast ventriculography, echocardiography, and 3-dimensional magnetic resonance imaging. However, problems related to these studies include few agreement data of EDV and ESV, use of a reference method that is likely to have the same systemic errors (gated Tc-99m-MIBI SPECT), and other technical factors related to the count density of gated SPECT. With optimization of gated imaging protocols and more validation studies, gated Tl-201 SPECT would be an accurate method to provide perfusion and function information in patients with coronary artery disease.

• Biomolecules & Therapeutics
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• v.6 no.2
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• pp.199-203
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• 1998

Acute hemodynamic effects of CJ-18513, a non-peptide angiotensin IIreceptor antagonist, were examined in mongrel dogs treated with high frequency ventricular pacing for one week. Rapid ventricular pacing reduced mean blood pressure (mBP), Lvdp/dt and cardiac output (CO), and increased the left ventricular end-diastolic pressure (LVEDP) and pulmonary capillary wedge pressure (PCWP). Continuous infusion of CJ-10513 at doses of 10 and 20$\mu$g/kg/min, respectively, for 30 minutes reduced mBP, LVEDP and myocardial oxygen consumption rate (MVO,) and shifted the cardiac function curve (CO-LVEDP ourve) to the left in this dog model. In conclusion, CJ-10513 decreased the preload and afterload and increased the cardiac function in dogs with pacing-induced heart failure.

• Korean Journal of Radiology
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• v.20 no.6
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• pp.956-966
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• 2019

Objective: To characterize the changes in right ventricular (RV) volume, volume load, and function measured with cardiac computed tomography (CT) over the entire time course of tetralogy of Fallot (TOF). Materials and Methods: In 374 patients with TOF, the ventricular volume, ventricular function, and RV volume load were measured with cardiac CT preoperatively (stage 1), after palliative operation (stage 2), after total surgical repair (stage 3), or after pulmonary valve replacement (PVR) (stage 4). The CT-measured variables were compared among the four stages. After total surgical repair, the postoperative duration (POD) and the CT-measured variables were correlated with each other. In addition, the demographic and CT-measured variables in the early postoperative groups were compared with those in the late postoperative and the preoperative group. Results: Significantly different CT-based measures were found between stages 1 and 3 (indexed RV end-diastolic volume [EDV], 63.6 ± 15.2 mL/m² vs. 147.0 ± 38.5 mL/m² and indexed stroke volume (SV) difference, 7.7 ± 10.3 mL/m² vs. 32.2 ± 16.4 mL/m²; p < 0.001), and between stages 2 and 3 (indexed RV EDV, 72.4 ± 19.7 mL/m² vs. 147.0 ± 38.5 mL/m² and indexed SV difference, 5.7 ± 13.1 mL/m² vs. 32.2 ± 16.4 mL/m²; p < 0.001). After PVR, the effect of RV volume load (i.e., indexed SV difference) was reduced from 32.2 mL/m² to 1.7 mL/m². Positive (0.2 to 0.8) or negative (-0.2 to -0.4) correlations were found among the CT-based measures except between the RV ejection fraction (EF) and the RV volume load parameters. With increasing POD, an early rapid increase was followed by a slow increase and a plateau in the indexed ventricular volumes and the RV volume load parameters. Compared with the preoperative data, larger ventricular volumes and lower EFs were observed in the early postoperative period. Conclusion: Cardiac CT can be used to characterize RV volume, volume load, and function over the entire time course of TOF.

• The Journal of Pediatrics of Korean Medicine
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• v.14 no.2
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• pp.1-32
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• 2000

It has long been known that SOAT is effective for sudden palpitation occurring unexpectedly in Oriental Medicine. However, effect of SOAT on the isolated heart has not been studied yet. The purpose of this study is to investigate the effect of SOAT on hemodynamics and ECG of isolated rat hearts induced by electrical stimulation using Langendorff perfusion apparatus for nonworking heart. SOAT extract was manufactured by water-alcohol precipitated method. Sprague-Dawley rats weighting $120{\sim}150g$ were used for the experiments, Subject animals were divided into four groups, which are consisted of 1) control(Group orally administered by normal saline 1ml for 14days), 2) sample A(Group orally administered by SOAT extract 1ml for 14days), 3) sample C(Group injected by SOAT extract 0.5ml after stimulation, 4) sample C(Group injected by SOAT extract 1ml after stimulation. To evluate the effects of SOAT on hemodynamics and ECG of isolated rat heart induced by stimulation, heart rate, left ventricular pressure, systolic power, diastolic power, coronary artery perfusion volume and ECG were measured using Langendorff apparatus in both stimulation mode(5 volts, 450 beats/min) and arrythmic mode(5 volts, 420 beats/min including 60 beats/min) The results obtained are as follows : 1. After receiving stressful electrical stimuli, isolated heart showed the heart rate, left ventricular pressure, systolic power, diastolic power, coronary artery perfusion volume were all decreased temporarily, but perfusion continued longer recovery to the control state appeared. However, the coronary artery perfusion volume diminished continuously. 2. The heart rates did not change significantly with both stimulation mode and arrhythmic mode, among experimental groups. 3. The left ventricular pressure showed with both stimulation mode and arrhythmic mode, the significant changes(p<0.05) especially in the injection sample group. In case of stimulation mode, low concentration injection group(0.5ml) was more significantly increased rather than high concentration group(1ml) and in case of arrhythmic mode, high density group(1ml) was so increased than the other(0.5ml). 4. For the systolic power and diastolic power, no significant changes were noticed in the stimulation mode, but in the arrhythmic mode of injection sample groups, significant change(p<0.05) was noticed in both systolic power and diastolic power. Specially the high concentration group(1ml) showed more significant increase than the low concentration group. 5. For the coronary artery perfusion volume, no significant change difference among sample groups was observed in both the stimulation mode and the arrhythmic mode. 6. For the ECG recordings, arrhythmia was induced by electrical stimulus of arrythmia mode and after the stimulus was removed, irregular wave appeared temporarily, but as perpusion continued, recovery to the control state was abtained like the stimulation mode. According to the above results, SOAT significantly changed the hemodynamic data from the electrically stressed, isolated hearts of connected Langendorff perfusion apparatus and we propose SOAT has the direct effects on the muscular function of heart.

• Korean Journal of Radiology
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• v.20 no.1
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• pp.102-113
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• 2019

Objective: To assess the accuracy and potential bias of computed tomography (CT) ventricular volumetry using semiautomatic three-dimensional (3D) threshold-based segmentation in repaired tetralogy of Fallot, and to compare them to those of two-dimensional (2D) magnetic resonance imaging (MRI). Materials and Methods: This retrospective study evaluated 32 patients with repaired tetralogy of Fallot who had undergone both cardiac CT and MRI within 3 years. For ventricular volumetry, semiautomatic 3D threshold-based segmentation was used in CT, while a manual simplified contouring 2D method was used in MRI. The indexed ventricular volumes were compared between CT and MRI. The indexed ventricular stroke volumes were compared with the indexed arterial stroke volumes measured using phase-contrast MRI. The mean differences and degrees of agreement in the indexed ventricular and stroke volumes were evaluated using Bland-Altman analysis. Results: The indexed end-systolic (ES) volumes showed no significant difference between CT and MRI (p > 0.05), while the indexed end-diastolic (ED) volumes were significantly larger on CT than on MRI (93.6 ± 17.5 mL/m² vs. 87.3 ± 15.5 mL/m² for the left ventricle [p < 0.001] and 177.2 ± 39.5 mL/m² vs. 161.7 ± 33.1 mL/m² for the right ventricle [p < 0.001], respectively). The mean differences between CT and MRI were smaller for the indexed ES volumes (2.0-2.5 mL/m²) than for the indexed ED volumes (6.3-15.5 mL/m²). CT overestimated the stroke volumes by 14-16%. With phase-contrast MRI as a reference, CT (7.2-14.3 mL/m²) showed greater mean differences in the indexed stroke volumes than did MRI (0.8-3.3 mL/m²; p < 0.005). Conclusion: Compared to 2D MRI, CT ventricular volumetry using semiautomatic 3D threshold-based segmentation provides comparable ES volumes, but overestimates the ED and stroke volumes in patients with repaired tetralogy of Fallot.

• The Korean Journal of Nuclear Medicine
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• v.20 no.2
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• pp.39-45
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• 1986

Resting gated blood pool scan was used to derive left ventricular functional changes in normals (N=13, mean age=43) and in patients with coronary artery disease (N=50, mean age=53). Peak filling rates, average filling rates, and ejection fractions were significantly depressed in coronary artery disease. (p<0.0005, each other). And in coronary artery disease with normal ejection fraction (N=21), peak filling rates and average filling rates were depressed also, and peak filling rates of coronary artery disease with normal ejection fraction were abnormal in 61.2% and average fillin rates were abnormal in 71.4%. It appears that (1) resting peak filling rates and average filling rates were sensitive and easily obtainable parameters of the diastolic dysfunction assosiated with coronary artery disease, (2) a significant proportion of coronary artery disease patients without any evidence of abnormal systolic function have depressed resting peak filling rates and average filling rates of the left ventricle.