• Journal of the Korea Convergence Society
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• v.11 no.8
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• pp.269-278
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• 2020

The purpose of this study was to investigate the effect of left ventricular diastolic function on exercise capacity in hypertensive patients with obesity compared to the obese group. Adults who visited a general hospital in Gyeonggi-do from 2016 to 2019(man: 308, women: 192) were divided into 4 groups according to hypertension and obesity. In the hypertensive obesity group(IV), the A wave and E/E' wave were significantly higher than the normotensive obesity group(II), and the E' wave was significantly lower(respectively p<0.001). The group IV had significantly lower METS(metabolic equivalents) and exercise duration than the group II(respectively p<0.001). In group IV, E/A ratio was positively correlated with METS(p=0.025) and exercise duration(p=0.026). In contrast, E/E' wave in these groups showed a negative correlation with the exercise duration(p=0.046).

• Investigative Magnetic Resonance Imaging
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• v.23 no.2
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• pp.114-124
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• 2019

Purpose: We investigate biases in the assessments of left ventricular function (LVF), by compressed sensing (CS)-cine magnetic resonance imaging (MRI). Materials and Methods: Cardiovascular cine images with short axis view, were obtained for 8 volunteers without CS. LVFs were assessed with subsampled data, with compression factors (CF) of 2, 3, 4, and 8. A semi-automatic segmentation program was used, for the assessment. The assessments by 3 CS methods (ITSC, FOCUSS, and view sharing (VS)), were compared to those without CS. Bland-Altman analysis and paired t-test were used, for comparison. In addition, real-time CS-cine imaging was also performed, with CF of 2, 3, 4, and 8 for the same volunteers. Assessments of LVF were similarly made, for CS data. A fixed compensation technique is suggested, to reduce the bias. Results: The assessment of LVF by CS-cine, includes bias and random noise. Bias appeared much larger than random noise. Median of end-diastolic volume (EDV) with CS-cine (ITSC or FOCUSS) appeared -1.4% to -7.1% smaller, compared to that of standard cine, depending on CF from (2 to 8). End-systolic volume (ESV) appeared +1.6% to +14.3% larger, stroke volume (SV), -2.4% to -16.4% smaller, and ejection fraction (EF), -1.1% to -9.2% smaller, with P < 0.05. Bias was reduced from -5.6% to -1.8% for EF, by compensation applied to real-time CS-cine (CF = 8). Conclusion: Loss of temporal resolution by adopting missing data from nearby cardiac frames, causes an underestimation for EDV, and an overestimation for ESV, resulting in underestimations for SV and EF. The bias is not random. Thus it should be removed or reduced for better diagnosis. A fixed compensation is suggested, to reduce bias in the assessment of LVF.

• 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.

• Journal of Veterinary Clinics
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• v.32 no.2
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• pp.162-167
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• 2015

Tei-index has been reported as one of reliable echocardiographic factors for evaluating cardiac function in human and small animals. In this study, Tei-index were measured and evaluated with other echocardiographic parameters in normal thirteen beagle dogs and thirty-one dogs with mitral valve degeneration. Normal range of Tei index with tissue Doppler obtained at septum and left ventricular free wall was $0.58{\pm}0.07$ and $0.60{\pm}0.07$, respectively. The values between septum and left ventricular free wall did not show significant difference. Tissue Doppler derived tei index showed better reproducibility and significantly lower values than the results obtained by pulsed wave Doppler. Tei index obtained in either method increased with the progression of clinical signs. Therefore, the increase of Tei index in dogs with mitral regurgitation is thought to be an useful factor reflecting left ventricular dysfunction.

• 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.

• 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.

• Journal of Chest Surgery
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• v.20 no.2
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• pp.342-347
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• 1987

Complete occlusion of the main LCA is associated with a poor prognosis if the RCA becomes severely occluded. The functional role of collateral circulation is critical in this situation. This study lends support to the hypothesis that coronary collateral circulation can provide critically needed myocardial blood flow via right to left collaterals. Not surprisingly, left ventricular function was maintained in 4 of the 5 patients studied who had main LCA occlusion and well-developed collateral circulation.

• Journal of Chest Surgery
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• v.29 no.8
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• pp.867-874
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• 1996

This study was designed to assess the left ventricular peak systolic pressure/end-systolic volume (PSP/ESV) ratio in predicting symptomatic improvement with valve replacement in patients with aortic regurgitation and enlarged left von'lrlcular volume. We studied 21 patients (15 men and 6 women aged 15 to 60 years) with moderate or severe aortic regur- gitation, no other cardiovascular abnormalities and left ventricular end-systolic volume over 60 m11m2. In this group we assessed the preoperative variables which routinely were measured at cardiac catheterlzation to predict symptomatic improvement with valve replacement. Six months after operation, symptoms were alleviated in 13 patients(62%), and unchanged in 8()8%). By multivariate analysis, the PSP/ESV rati was a strong predictor for functional class 6 months after surgery(p=0.005) and also for change- in functional class prior to an operation to 6 months postoperatively(p=0.0)2). By 6 months after receiving valve replacement, all patients with a ratio over 1. 71 mmHglml/m'were in functional class I or II , in contrast, of those with a ratio < 1.71 mmHg/ml/m2, 40% were in functional class III. The PSP/ESV ratio may help to predict which patients with aortic regurgitation and enlarged left ven- tricular end-systolic volume will have symptomatic improvement with valve replacement.

• Proceedings of the KAIS Fall Conference
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• 2011.12a
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• pp.170-173
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• 2011

Therapeutic hypothermia(TH) improves neurological outcomes and reduces mortality among survivors of out-of-hospital cardiac arrest. Animal and human studies have shown that TH results in improved salvage of the myocardium, reduced infarct size, reduced left ventricular remodeling and better long-term left ventricular function in settings of regional myocardial ischemia. This study is to investigate the effect of TH on post-resuscitation myocardial dysfunction and survival time after cardiac arrest and resuscitation in a rat model of myocardial infarction (MI). Thoracotomies were performed in 10 Male Sprague-Dawley rats weighing 450-550 g. MI was induced by ligation of the left anterior descending coronary artery (LAD). Ninety min after LAD ligation, ventricular fibrillation induction and subsequent cardiopulmonary resuscitation was performed before defibrillation attempts. Animals were randomized to two groups: a) Acute MI-Normothermia b) Acute MI-Hypothermia ($32^{\circ}C$ for 4 h). Myocardial functions, including cardiac output, left ventricular ejection fraction, and myocardial performance index were measured echocardiographically together with duration of survival. Ejection fraction, cardiac output and myocardial performance index were $54.74{\pm}9.16$, $89.00{\pm}8.89$, $1.30{\pm}0.09$ respectively and significantly better in the TH group than those of the normothermic group at the first 4 h after resuscitation($32.20{\pm}1.85$,$41.60{\pm}8.62$,$1.77{\pm}0.19$)(p=0.00). The survival time of the hypothermic group ($31.8{\pm}14.8$ h) was greater than that of the normothermic group($12.3{\pm}6.5$ h, p<0.05). This study suggested that TH attenuated post resuscitation myocardial dysfunction in acute MI and would be a potential strategy in post resuscitation care.

• Journal of the Korean Society of Radiology
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• v.17 no.5
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• pp.761-766
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• 2023

In this paper, TI was measured to classify the presence or absence of mild left ventricular diastolic dysfunction. Of the total 306 data, 206 were used as training data and 100 were used as test data, and the machine learning models used for classification used SVM and KNN. As a result, it was confirmed that SVM showed relatively higher accuracy than KNN and was more useful in diagnosing the presence of left ventricular diastolic dysfunction. In future research, it is expected that classification performance can be further improved by adding various indicators that evaluate not only TI but also cardiac function and securing more data. Furthermore, it is expected to be used as basic data to predict and classify other diseases and solve the problem of insufficient medical manpower compared to the increasing number of tests.