• The Korean Journal of Nuclear Medicine
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• v.28 no.1
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• pp.52-61
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• 1994

Background : The demand for refinement in noninvasive and quantitative assessment of left ventricular (LV) function is increasing. Purpose : To assess normal values of left ventricular functional parameters during both systole and diastole by scintigraphic method using computerized triple-head gamma camera and to evaluate correlations between these parameters. Methods : ECG gated blood pool scan with $^{99m}Tc$-Human serum albumin was performed in 94 normal Korean subjects. Ejection fraction (EF), systolic parameters [peak emptying rate (PER), average emptying rate (AER), time to peak emptying rate (TPER)], and diastolic parameters [peak filling rate (PFR), average filling rate (AFR), time to peak filling rate (TPFR)] were obtained by analysis of LV time-activity curve, the correlation of these parameters to the age and sex, and the correlation between these parameters were evaluated. Results : 1) Mean value of ejection fraction in study subjects was $59.6{\pm}5.25%$ and showed no significant correlation to age (r=-0.08) and sex but showed most pronounced correlation to PFR (r=0.46, p<0.001), PER (r=0.41, p<0.001), AFR (r=0.34, p<0.001) and AER (r=0.28, p<0.01). 2) Mean values of systolic parameters were as follows: $PER=3.22{\pm}0.50$ end-diastolic volume/sec, $AER=2.22{\pm}0.45$ end-diastolic volume/sec, $TPER=103.5{\pm}29.30$ msec. They showed no significant correlation to age and sex. 3) Mean values of diastolic parameters were as follows: $PFR=2.71{\pm}0.51$ end-diastolic volume/sec, $AFR=1.83{\pm}0.44$ end-diastolic volume/sec, $TPFR=132.1{\pm}33.45$ msec. They showed strong correlation to age (r=0.70, -0.64, 0.37, p<0.001). Conclusions : Left ventricular functional parameters in normal Korean subjects were obtained reliably by computerized scintigraphic method and may be applied to the evaluation of cardiac function in diseased patients.

• Advances in biomechanics and applications
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• v.1 no.1
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• pp.23-40
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• 2014

This paper examines the blood chamber of a left ventricular assist device (LVAD) under static loading conditions and standard operating temperatures. The LVAD's walls are made of a temperature-sensitive polymer (ChronoFlex C 55D) and are covered with a titanium nitride (TiN) nano-coating (deposited by laser ablation) to improve their haemocompatibility. A loss of cohesion may be observed near the coating-substrate boundary. Therefore, a micro-scale stress-strain analysis of the multilayered blood chamber was conducted with FE (finite element) code. The multi-scale model included a macro-model of the LVAD's blood chamber and a micro-model of the TiN coating. The theories of non-linear elasticity and elasto-plasticity were applied. The formulated problems were solved with a finite element method. The micro-scale problem was solved for a representative volume element (RVE). This micro-model accounted for the residual stress, a material model of the TiN coating, the stress results under loading pressures, the thickness of the TiN coating and the wave parameters of the TiN surface. The numerical results (displacements and strains) were experimentally validated using digital image correlation (DIC) during static blood pressure deformations. The maximum strain and stress were determined at static pressure steps in a macro-scale FE simulation. The strain and stress were also computed at the same loading conditions in a micro-scale FE simulation.

• Biomolecules & Therapeutics
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• v.7 no.2
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• pp.170-177
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• 1999

PEG-hemoglobin SB1 (SB1), which is a hemoglobin-based oxygen carrier, is intended to use as a safe blood substitute against brain ischemia and stroke. The general pharmacological profiles of SB1 were studied. The doses given were 0, 5, 10, 20 ml/kg and drugs were administered intravenously. The animals used for this study were mouse, rat and guinea pig. SB1 showed no effects on general behavior, motor coordination, spontaneous locomotor activity, hexobarbital sleeping time, anticonvulsant activity, analgesic activity, blood pressure and heart rate, left ventricular peak systolic pressure, left ventricular end diastolic pressure, left ventricular developing pressure, double product, heart rate, coronary flow rate, smooth muscle contraction using guinea pig ileum, gastrointestinal transport, gastric secretion, urinary volume and electrolyte excretion at all doses tested except the decrease of body temperature. These findings demonstrated that SB1 possesses no general pharmacological effects at all doses tested.

• Journal of Chest Surgery
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• v.36 no.9
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• pp.683-686
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• 2003

Isolated right ventricular hypoplasia is a rare clinical entity. We describe a case of right ventricular hypoplasia, single atrium and spongy myocardium of left ventricle. The volume of right ventricle was half the volume of left ventricle and z-value of tricuspid valve was -4 preoperatively The patient, 6-year-old boy, underwent atrial partitioning with 3 mm fenestration, Postoperative course was smooth and he tolerated the biventricular state well during follow-up. Follow-up catherterization was done 27 months later The tricuspid valve grew well (z-value= -0.4) and atrial septal fenestration is closed spontaneously. This article reports a case of successful biventricular repair in a patient with isolated right ventricular hypoplasia.

• The Korean Journal of Nuclear Medicine
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• v.16 no.2
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• pp.29-36
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• 1982

Quantification of the regurgitation amount is important before and after valvular replacement surgery. Until now cardiac catheterization with cineventriculography, echocardiography have been used to measure the regurgitation amount, but also have many limitations. EKG gated cardiac blood pool scan provides a simple, non-invasive -method for quantify the regurgitation amount. By calculating the ratio of left ventricular to right ventricular stroke counts (stroke volume ratio) in gated bood pool scan, we measured the left ventricular regurgitation amount in 28 cases of valvular regurgitation and 25 cases of normal group. 1. Stroke volume ratio was higher in cases of valvular regurgitation $(2.11{\pm}0.58)$ than in cases of normal control $(1.15{\pm}0.31)$. (p<0.01). 2. Stroke volume ratio was classified by regurgitation grade using X-ray cineventriculography. In grades of mild regurgitation $(Grade\;I{\sim}II)$, stroke volume ratio was $2.02{\pm}0.29$, and in grades of severe regurgitation $(Grade\;III{\sim}IV)$, stroke volume ratio was $2.55{\pm}0.34$, so stroke volume ratio was well correlated with the grade of X-ray cineventriculography. 3. Stroke volume ratio was classfied by functional class made in New York Heart Association. In classes of mild regurgitation $(class\;I{\sim}II)$, stroke volume ratio was $2.08{\pm}0.26$, and in classes of severe regurgitation $(class\;III{\sim}IV)$, stroke volume ratio was $2.55{\pm}0.38$, Stroke volume ratio well represented the functional class. 4. After aortic and mitral valve replacement in 28 patients, the stroke volume ratio, decreased from $2.11{\pm}0.58\;to\;1.06{\pm}0.26$. Gated blood pool scan provides a noninvasive method of qnantifying valvular regurgitation and assessing the result of surgical interventions.

• 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.

• Korean Journal of Radiology
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• v.19 no.6
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• pp.1042-1052
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• 2018

Objective: To determine the utility of computed tomography (CT) ventricular volumes and morphometric parameters for deciding the treatment strategy in children with a hypoplastic left ventricle (LV). Materials and Methods: Ninety-four consecutive children were included in this study and divided into small LV single ventricle repair (SVR) (n = 28), small LV biventricular repair (BVR) (n = 6), disease-matched control (n = 19), and control (n = 41) groups. The CT-based indexed LV volumes, LV-to-right-ventricular (LV/RV) volume ratio, left-to-right atrioventricular valve (AVV) area ratio, left-to-right AVV diameter ratio, and LV/RV long dimension ratio were compared between groups. Proportions of preferred SVR in the small LV SVR group suggested by the parameters were evaluated. Results: Indexed LV end-systolic (ES) and end-diastolic (ED) volumes in the small LV SVR group ($6.3{\pm}4.0mL/m^2$ and $14.4{\pm}10.2mL/m^2$, respectively) were significantly smaller than those in the disease-matched control group ($16.0{\pm}4.7mL/m^2$ and $37.7{\pm}12.0mL/m^2$, respectively; p < 0.001) and the control group ($16.0{\pm}5.5mL/m^2$ and $46.3{\pm}10.8mL/m^2$, respectively; p < 0.001). These volumes were $8.3{\pm}2.4mL/m^2$ and $21.4{\pm}5.3mL/m^2$, respectively, in the small LV BVR group. ES and ED indexed LV volumes of < $7mL/m^2$ and < $17mL/m^2$, LV/RV volume ratios of < 0.22 and < 0.25, AVV area ratios of < 0.33 and < 0.24, and AVV diameter ratios of < 0.52 and < 0.46, respectively, enabled the differentiation of a subset of patients in the small LV SVR group from those in the two control groups. One patient in the small LV biventricular group died after BVR, indicating that this patient might not have been a good candidate based on the suggested cut-off values. Conclusion: CT-based ventricular volumes and morphometric parameters can suggest cut-off values for SVR in children with a hypoplastic LV.

• Korean Journal of Radiology
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• v.20 no.6
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• pp.1001-1002
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• 2019

• Korean Journal of Radiology
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• v.20 no.8
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• pp.1311-1312
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• 2019

• Journal of Chest Surgery
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• v.23 no.6
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• pp.1174-1179
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• 1990

Forty-five patients with double-outlet right ventricle[DORV] underwent complete intracardiac repair between July, 1983 and June, 1989. Patients with complete atrioventricular canal, atrioventricular discordance and uni-ventricular heart were excluded. The 32 male and 13 female patients ranged in age from 3 months to 15 years[mean 4 years]. Thirty-two patients had pulmonary stenosis. The early mortality was 11.ltd[5 /45] None of 27 died after a completely intraventricular repair. The mortality was 20%[1/5] for repair using transannular patch, 20% [1/5] for REV operation, 33.3%[1/3] for repair including extracardiac valved conduit, and 50% [1/2] for Jatene operation, respectively. Two modified Fontan procedures were performed without mortality. One died after Senning operation. Causes of early deaths included high residual right ventricular pressure[one patient] small left atrial and left ventricular volume[one patient], persisting severe pulmonary hypertension [one patient] and low cardiac output of unknown cause [two patients]. Complete heart block developed in one patient. Two late deaths occurred among the 40 operative survivors [5.0Po] from persisting severe pulmonary hypertension and bleeding at reoperation. Our results indicate that significant defects can be repaired with low mortality and morbidity.