• Korean Journal of Radiology
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• v.22 no.10
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• pp.1619-1627
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• 2021

Objective: This study used cardiac magnetic resonance imaging (MRI) to compare the characteristics of left ventricular remodeling in patients with primary aldosteronism (PA) with those of patients with essential hypertension (EH) and healthy controls (HCs). Materials and Methods: This prospective study enrolled 35 patients with PA, in addition to 35 age- and sex-matched patients with EH, and 35 age- and sex-matched HCs, all of whom underwent comprehensive clinical and cardiac MRI examinations. The analysis of variance was used to detect the differences in the characteristics of left ventricular remodeling among the three groups. Univariable and multivariable linear regression analyses were used to determine the relationships between left ventricular remodeling and the physiological variables. Results: The left ventricular end-diastolic volume index (EDVi) (mean ± standard deviation [SD]: 85.1 ± 13.0 mL/m² for PA, 75.9 ± 14.3 mL/m² for EH, and 77.3 ± 12.8 mL/m² for HC; p = 0.010), left ventricular end-systolic volume index (ESVi) (mean ± SD: 35.2 ± 9.8 mL/m² for PA, 30.7 ± 8.1 mL/m² for EH, and 29.5 ± 7.0 mL/m² for HC; p = 0.013), left ventricular mass index (mean ± SD: 65.8 ± 16.5 g/m² for PA, 56.9 ± 12.1 g/m² for EH, and 44.1 ± 8.9 g/m² for HC; p < 0.001), and native T1 (mean ± SD: 1224 ± 39 ms for PA, 1201 ± 47 ms for EH, and 1200 ± 44 ms for HC; p = 0.041) values were higher in the PA group compared to the EH and HC groups. Multivariable linear regression demonstrated that log (plasma aldosterone-to-renin ratio) was independently correlated with EDVi and ESVi. Plasma aldosterone was independently correlated with native T1. Conclusion: Patients with PA showed a greater degree of ventricular hypertrophy and enlargement, as well as myocardial fibrosis, compared to those with EH. Cardiac MRI T1 mapping can detect left ventricular myocardial fibrosis in patients with PA.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.8
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• pp.715-720
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• 2014

In order to maximize the effect of left ventricular assist device (LVAD) on ventricular unloading, the therapy should be begun at appropriate level of heart failure severity. We predicted pumping efficacy of LVAD according to the severity of heart failure theoretically. We used 3 dimensional finite element model of ventricle coupled with 6 Wind-kessel compartmental model of vascular system. Using the computational model, we predicted cardiac responses such as contractile ATP consumption of ventricle, left ventricular pressure, cardiac output, ejection fraction, and stroke work according to the severity of ventricular systolic dysfunction under the treatments of continuous LVAD. Contractile ATP consumption, which indicates the ventricular energetic loading condition decreased maximally at the $5^{th}$ level heart-failure under LVAD therapy. We conclude that optimal timing for LVAD treatment is $5^{th}$ level heart-failure when considering LVAD treatment as "bridge to recovery".

• Journal of Chest Surgery
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• v.19 no.2
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• pp.232-237
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• 1986

The intraventricular conduction disturbances have been documented after correction of ventricular septal defects by any surgical route but debated its etiology. And so the frequency of conduction disturbances following right ventriculotomy, right atriotomy and pulmonary arteriotomy for closure of ventricular septal defects was compared in various conditions. The present series consists of 218 patients with ventricular septal defects. They had the surgical repair at the Seoul National University Hospital from January 1983 to October 1984. Conduction disturbances were studied with conventional 12 leads electrocardiogram. Of the 218 VSD`s 139 patients were repaired via vertical right ventriculotomy, 45 patients via right atriotomy, 34 patients via pulmonary arteriotomy. 1] Of 218 patients the frequency of RBBB was 26.1% and the frequency of RBBB + LAH was 6.0%. 2] There is no statistical difference between right ventriculotomy group [30.2%] and right atriotomy group [24.4%]. But there is significant difference between right ventriculotomy group and pulmonary arteriotomy group [11.8%] [P<0.05]. 3] In respect to anatomical classification by Kirklin`s method, the frequency of RBBB was higher in type II [32.1%] than in type I [14.9%]. [P<0.05] But in each anatomical type, there is no influence of the various surgical approach on the incidence of postoperative RBBB. 4] The frequency of RBBB was 31.8% in patch closure group and 14.3% in direct closure group. [P<0.05] Although the result suggests that there is no significant difference in various surgical approaches on the incidence of postoperative conduction disturbances, it may be reduced by a new-ventricular approach or a limited incision at right ventricular outflow tract in right ventricular approach.

• Journal of Chest Surgery
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• v.21 no.5
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• pp.828-841
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• 1988

To predict the postoperative hemodynamic status of right ventricle preoperatively, a retrospective analysis was undertaken to determine the influence of pulmonary artery size on postoperative right ventricular pressure in 32 consecutive patients with tetralogy of Fallot who underwent total correction between July, 1987 to June, 1988 at the Department of Thoracic and Cardiovascular Surgery, Seoul National University Hospital. We have related the ratio of the postrepair peak systolic pressure in the right ventricle and the systemic systolic arterial pressure[PRV/Ao] to the preoperative cineangiographic measurement of pulmonary arterial tree, expressed as pulmonary artery index[PAI], the ratio of diameter of the right pulmonary artery to diameter of ascending aorta[r.PA/A.Ao], the ratio of right and left pulmonary artery to diameter of descending aorta[r.I.PA/D.Ao] There was tendency that the postrepair PRV/Ao seems to be related to the preoperative diameter of right and left pulmonary artery, but there were no statistically significant correlation with PAI, r.PA/A.Ao, r.l.PA/D. Ao to the ratio of the postoperative peak systolic right ventricular pressure and systemic systolic arterial pressure[PRV/Ao]. There was tendency to decrease the postoperative right ventricular pressure[PRV/Ao] about 11.2%[P < 0.025] within several hours than immediately after repair, but after then, there was no change of right ventricular pressure[PRV/Ao] significantly. There was good correlation of pressure change between the immediate and late postrepair right ventricular pressure[48 hour], and the derived linear regression line was; y=0.68534 0.1994[r=0.57294, P < 0.001]. There was no operative death due to residual high right ventricular pressure[PRV/Ao >0.75] related to hypoplastic pulmonary arterial development, thus we expect, for symptomatic patients even infants, that complete repair can be attempted when the pulmonary artery index[PAI] is over 108mm2/BSA, RPA/AAo is over 0.35, RPA LPA/D. Ao is over 1.36.

• Journal of Korean Neurosurgical Society
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• v.39 no.1
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• pp.26-31
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• 2006

Objective : The authors study on the clinical presentations and the surgical outcomes of the tumors in the ventricular system. Methods : 15 patients with ventricular tumor were studied. The clinical presentation, radiological findings, different surgical approaches, and outcome were analyzed. Tumors were classified into three groups based on their locations in MRI : lateral, third and fourth ventricle. Surgical methods were transcortical approach in eight patients, transcallosal approach in four, median suboccipital approach in two, and subfrontal approach in one. Gross total removal was achieved in 10 patients. Subtotal resections were performed in the rest. Glasgow outcome scale was used for evaluation of the surgical outcome. Results : Main clinical presentations were chronic headache in patients with the tumor in the lateral ventricular tumor and sudden onset of headache and consciousness change in patients with the tumor in the third and fourth ventricular tumor Development of hydrocephalus was more predominant in patients with the tumors in the third ventricle. Postoperatively, good outcome [Glasgow outcome scale IV, V] were in 73%, and better results was observed in patients with the tumors in the lateral ventricular tumor. The differences of outcome according to surgical approach were not recognized, even though it was not reliable statistically. Conclusion : In ventricular tumor, postoperative outcome is not good in patients with sudden development of headache, hydrocephalus, high grade tumor. Outcome is good in patients with the tumor in the lateral ventricle relatively. There is no difference in outcome according to the approach method to the tumors. And it is necessary to be aware of various approach methods to the tumors and anatomy surrounding the ventricle for avoidance of neurological complications.

• The Journal of the Korea Contents Association
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• v.9 no.7
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• pp.19-26
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• 2009

This paper presents an approach to classify normal and ventricular tachycardia/fibrillation(VT/VF) from the Creighton University Ventricular Tachyarrhythmia Database(CUDB) using the neural network with weighted fuzzy membership functions(NEWFM) and wavelet transforms. In the first step, wavelet transforms are used to obtain the detail coefficients at levels 3 and 4. In the second step, all of detail coefficients d3 and d4 are classified into four intervals, respectively, and then the standard deviations of the specific intervals are used as eight numbers of input features of NEWFM. NEWFM classifies normal and VT/VF beats using eight numbers of input features, and then the accuracy rate is 90.1%.

• Journal of Biomedical Engineering Research
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• v.38 no.6
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• pp.313-320
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• 2017

Myocardial infarction is a disease caused by stenosis of the coronary arteries. The high risk of sudden cardiac death due to myocardial infarction has triggered related researches that have been actively studied so far. However, these studies focused on the clinical results, which are mainly based on observations of symptoms due to infarction through electrocardiograms. Therefore, in this study, we tried to analyze the behavior of heart according to the position and volume of infarction lesion through the computer simulation study using three dimensional ventricular models. In order to implement infarction, commercial software was used to simulate cell necrosis due to blockage of a specific coronary. In addition, the conduction block due to infarction was mimicked by reducing the electrical conduction in the infarcted area, which was 100 times less than the electrical conduction of the whole ventricular lattice implemented by the finite element analysis method. Thus, this study classified the infarcted cases into the upper, middle, lower, and apex according to lattice data of eight different infraction areas. In other words, we assumed that myocardial infarction would have inherent electro-dynamic characteristics depending on the location and extent, and analyzed the ventricular electromechanical responses for infarction lesions using a three dimensional cardiac physiome model. The results showed that the volume of infarction did not directly affect the cardiac responses, but the location of the infarction lesions could influence the ventricular pumping efficiency. These suggest that the occlusion of specific coronary arteries may have a fatal effect on the decline in ventricular performance. In conclusion, although location of myocardial infarction lesions is considered to be an important variable to be considered clinically rather than lesion size, quantitative predictions should be made more in the future considering physiological factors such as lesion location and direction of myocardial fiber at that location.

• The Korean Journal of Physiology and Pharmacology
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• v.4 no.3
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• pp.253-261
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• 2000

Head-out water immersion induces marked increase in the cardiac stroke volume. The present study was undertaken to characterize the stroke volume change by analyzing the aortic blood flow and left ventricular systolic time intervals. Ten men rested on a siting position in the air and in the water at $34.5^{circ}C$ for 30 min each. Their stroke volume, heart rate, ventricular systolic time intervals, and aortic blood flow indices were assessed by impedance cardiography. During immersion, the stroke volume increased 56%, with a slight (4%) decrease in heart rate, thus cardiac output increased ${\sim}50%.$ The slight increase in R-R interval was due to an equivalent increase in the systolic and diastolic time intervals. The ventricular ejection time was 20% increased, and this was mainly due to a decrease in pre-ejection period (28%). The mean arterial pressure increased 5 mmHg, indicating that the cardiac afterload was slightly elevated by immersion. The left ventricular end-diastolic volume index increased 24%, indicating that the cardiac preload was markedly elevated during immersion. The mean velocity and the indices of peak velocity and peak acceleration of aortic blood flow were all increased by ${\sim}30%,$ indicating that the left ventricular contractile force was enhanced by immersion. These results suggest that the increase in stroke volume during immersion is characterized by an increase in ventricular ejection time and aortic blood flow velocity, which may be primarily attributed to the increased cardiac preload and the muscle length-dependent increase in myocardial contractile force.

• Journal of Veterinary Clinics
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• v.34 no.5
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• pp.353-355
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• 2017

A four month old, intact female Jindo dog presented to the Veterinary Teaching Hospital of Kangwon National University with collapse. Physical examination revealed a heart rate of more than 200 beats per minute. Blood tests showed mild anemia and mild neutrophilia, while thoracic radiography and ultrasonography revealed no remarkable findings. Electrocardiography showed ventricular premature complexes (VPCs). The dog was diagnosed with congenital ventricular tachyarrhythmia. The condition was improved by lidocaine infusion. After 10 days, the dog was discharged from the hospital with a prescription of atenolol, pimobendan, diltiazem, furosemide, spironolactone, and L-carnitine. This dog is still alive after 31 months. However, progressive cardiac remodeling was confirmed on radiography and ultrasonography. Congenital ventricular tachyarrhythmia is rare in dogs, and the prognosis of reported cases is poor. This report describes the long-term successful management of a dog with congenital ventricular tachyarrhythmia.

• Journal of Chest Surgery
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• v.10 no.1
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• pp.148-155
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• 1977

The clinical findings with cardioangiography and successful surgical treatment of a 10 year old girl with double-outlet right ventricle is reported at The Dept. of Thoracic and Cardiovascular Surgery, Korea University Hospital, College of Medicine. The patient has been suffered from intermittent cyanosis, palpitation, and exertional dyspnea since 1 year after NFSD, and a holosystolic ejection murmur of grade 4 at the left 3rd intercostal space with mild cyanosis of the lips was the only physical findings at the time of this admission. Cardiac catheterization revealed ventricular septal defect with left to right shunt of 43% and right to left shunt of 10.2%. On cardioangiography from the left ventricle revealed all of the left ventricular outflow shunted into the right ventricle through the large ventricular septal defect, and the aorta originated from the infundibular chamber of the right ventricle with left, anterior sided pulmonary artery. The atria, viscera, and ventricles were normally located, and right ventricular out-flow was narrowed with infundibular hypertrophy and pulmonary valvular stenosis. Surgical correction was accomplished by closure of the ventricular septal defect in such a way that left ventricular outflow was routed via a Teflon felt prosthetic tunnel to the aorta, and pulmonary valvulotomy with infundibulectomy Was done to pass Hegar`s dilator No. 15 for reconstruction of the right ventricular outflow tract. The patient tolerated complete repair and has continued to improve over a period of three months after operation with normal school life. Details of the disease and method of repair are presented with related references.