• Journal of Chest Surgery
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• v.34 no.6
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• pp.441-446
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• 2001

Background: Electrical breathing pacing has many advantages over mechanical ventilation. However, clinically permanent diaphragmatic pacing has been applied to limited patients and few temporary pacing has been reported. Our purpose is to investigate the feasibility of temporary electrical diaphragm pacing in explothoracotomy canine cases. Methods: Five dogs were studied under the general anesthesia. Left 5th intercostal space was opened. Self designed temporary pacing leads were placed around the left phrenic nerve and connected to the myostimulator. Chest wall was closed after tube insertion with underwater drainage. Millar catheter was introduced to the aorta and right atrium. Swan-Ganz catheter was introduced to the pulmonary artery. When the self respiration was shallow with deep anesthesia, hemodynamic and tidal volume were measured with the stimulator on. Results: Tidal volume increased from 143.3$\pm$51.3 ml to 272.3$\pm$87.4 ml(p=0.004). Right atrial diastolic pressure decreased from 0.7$\pm$4.0 mmHg to -10.5$\pm$4.7 mmHg(p=0.005). Pulmonary arterial diastolic pressure decreased from 6.1+2.5 mmHg to 1.2$\pm$4.8 mmHg(p<0.001). The height of water level in chest tube to show intrathoracic pressure change was from 10.3$\pm$6.7cmH$_{2}$O to 20.0$\pm$5.3 cmH$_{2}$O. Conclusion: Temporary electrical diaphragmatic pacing is a simple method to assist respiration in explothoracotomy canine cases. Self designed pacing lead is implantable and removable. Negative pressure ventilation has favorable effects on the circulatory system. Therefore, clinical application of temporary breathing pacing is feasible in thoracotomy patients to assist cardiorespiratory function.

• Journal of Chest Surgery
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• v.31 no.4
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• pp.393-397
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• 1998

A 25-year-old man with viral cardiomyopathy and chronic active hepatitis successfully underwent dynamic cardiomyoplasty for the first time in Korea on July 30, 1996. The patient had been intermittently dyspneic for 5 years and was admitted to our center twice because of heart failure. For the past 2 years, he was NYHA functional class III status with a left ventricular ejection fraction(LVEF) of around 30%. The patient was born with scoliosis and showed a short stature. The liver function showed elevated liver enzymes, and hepatitis B antigen was positive. The liver biopsy revealed chronic active hepatitis. The preoperative echocardiogram showed decreased left ventricular function with grade II mitral and grade II tricuspid regurgitation with dilated left and right atrium. Recently his symptoms worsened and we decided to perform a dynamic cardiomyoplasty. The left latissmus dorsi muscle(LDM) was mobilized and tested with lead placement on his right lateral decubitus position. The patient was positioned into supine and, after median sternotomy, the heart was wrapped with the mobilized muscle. The Russian made cardiomyostimulator(EKS-445) and leads (Myocardial PEMB for heart and PEMP-1 for LDM) were used. The total operation time was 8 hours and there were no perioperative episodes. Postoperatively the LDM had been trained for a 10 week period and currently the stimulation ratio is maintained at 1:4. The postoperative LVEF did not increase with the value of 30-35%. However, the patient feels better postoperatively with slightly increased activity.

• Journal of Preventive Medicine and Public Health
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• v.31 no.2 s.61
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• pp.183-198
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• 1998

In order to determine the prevalence rate and find out the sexual difference of abnormal electrocardiographic findings manifested by computerized EKG, which is equipped with auto-analyzing function, a total of 2,083 electrocardiograms that were taken from population over 20 years-old from October 1996 to February 1997 were studied according to their age, gender and blood pressure. 1. Using the electrocardiography with auto-analyzing function, 33 kinds of abnormal findings were manifested. The prevalence rate of abnormal findings was 52.8% in male and 43.7% in female. Among them, the most common finding was sinus brady-cardia found in 17.6% of male and 15.4% of female. Left ventricular hypertrophy by voltage criteria, minimal voltage of left ventricular hypertrophy, left axis deviation and atrial fibrillation were more common in male than in female statistically. Both of nospecific T wave and ST segment abnormality were more common in female than in male statistically. 2. Thirty-three kinds of abnormal findings were manifested. They revealed one abnormal finding alone or combined with some other ones making 128 kinds of abnormal finding. The most common abnormal finiding that manifested alone was right axis deviation (100%), then myocardial ischemia (95.7%) the next. The most common abnormal finding that complexed with other abnormal findings were left anterior fascicular block(percentage of single manifestation, 26.2%) and nonspecific T wave abnormality(percentage of single manifestation; 32.9%). Also, combination of sinus bradycardia and minimal voltage of left ventricular hypertrophy, and combination of sinus bradycardia and left ventricular hypertrophy were included in 25th sequences of abnormal findings. 3. The prevalence rate of abnormal electrocardiographic findings were higher in older group, hypertensive group, and the group of higher systolic or diastolic pressure in both sexes. 4. Abnormal findings that commonly manifested with sinus bradycardia were voltage criteria or minimal voltage of left ventricular hypertrophy(38.6%): sinus arrhythmia(10.5%): nonspecific T wave or ST segment abnormality(18.4%) and first degree AV block(7.2%) in descending order. 5. The most common site which manifested myocardial ischemia was posterior and inferior wall with equal percentage of 23.4%. And then anterior wall(19.1%), and antero-lateral wall and septum with equal percentage of 10.6% was noted in descending order.

• Clinical and Experimental Pediatrics
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• v.50 no.5
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• pp.476-483
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• 2007

Purpose : The objective of this study was to assess ventricular function by tissue Doppler imaging (TDI) in children with congenital heart disease (CHD) who have been undergoing open heart surgery (OHS) using cardiopulmonary bypass. We tried to compare the parameters of tissue Doppler imaging before and after OHS in patients with congenital heart disease. Methods : This study was conducted on 32 patients with CHD after OHS from January 2005 to December 2005 at Kyungpook National University hospital. Patients who underwent 2-D echocardiography before and after their OHS. All patients were divided into three groups, left ventricular volume overloading group (group 1), and right ventricular volume overloading group (group 2), and right ventricular pressure overloading group (group 3). The TDIs were examined before and 1 to 3 months after OHS. Peak early diastolic (E), and peak late diastolic (A) velocity of transmitral flow were measured by pulsed wave Doppler examination. Peak systolic (Sm), peak early diastolic (Em), and peak late diastolic (Am) velocity in apical 4-chamber and 2-chamber views were measured by TDI. The author calculated E/Em ratio. Results : The patients were 14 boys and 18 girls and the average age of patients was 2 years and 3 months. The congenital heart diseases which have to get OHS were ventricular septal defect (13 cases), atrial septal defect (7), atrioventricular septal defect (3), isolated pulmonary stenosis (2) and tetralogy of Fallot (7). There were significant decrease of Sm, Em, Am measured on tricuspid annulus and E/Em measured on mitral annulus in apical 4 chamber view (P<0.05). Conclusion : This study showed significant decrease of Sm, Em, Am measured on tricuspid annulus and E/Em measured on mitral annulus in apical 4 chamber view after OHS. These changes might be due to the effects of cardiopulmonary bypass in OHS and/or hemodynamic changes after correction of congenital heart disease. To clarify these changes, further study on more patients is needed.

• Journal of Cardiovascular Imaging
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• v.31 no.3
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• pp.125-132
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• 2023

BACKGROUND: There is limited data on the residual echocardiographic findings including strain analysis among post-coronavirus disease (COVID) patients. The aim of our study is to prospectively phenotype post-COVID patients. METHODS: All patients discharged following acute COVID infection were systematically followed in the post-COVID-19 Recovery Clinic at Vancouver General Hospital and St. Paul's Hospital. At 4-18 weeks post diagnosis, patients underwent comprehensive echocardiographic assessment. Left ventricular ejection fraction (LVEF) was assessed by 3D, 2D Biplane Simpson's, or visual estimate. LV global longitudinal strain (GLS) was measured using a vendor-independent 2D speckle-tracking software (TomTec). RESULTS: A total of 127 patients (53% female, mean age 58 years) were included in our analyses. At baseline, cardiac conditions were present in 58% of the patients (15% coronary artery disease, 4% heart failure, 44% hypertension, 10% atrial fibrillation) while the remainder were free of cardiac conditions. COVID-19 serious complications were present in 79% of the patients (76% pneumonia, 37% intensive care unit admission, 21% intubation, 1% myocarditis). Normal LVEF was seen in 96% of the cohort and 97% had normal right ventricular systolic function. A high proportion (53%) had abnormal LV GLS defined as < 18%. Average LV GLS of septal and inferior segments were lower compared to that of other segments. Among patients without pre-existing cardiac conditions, LVEF was abnormal in only 1.9%, but LV GLS was abnormal in 46% of the patients. CONCLUSIONS: Most post-COVID patients had normal LVEF at 4-18 weeks post diagnosis, but over half had abnormal LV GLS.

• Journal of Chest Surgery
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• v.32 no.3
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• pp.224-236
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• 1999

Background: To evaluate the short-term effect of dynamic cardiomyoplasty on circulatory function and detect the related factors that can affect it, experimental cardiomyoplasties were performed under the state of normal cardiac function and heart failure. Material and Method: A total of 10 mongrel dogs weighing 20 to 30kg were divided arbitrarily into two groups. Five dogs of group A underwent cardiomyoplasty with latissimus dorsi(LD) muscle mobilization followed by a 2-week vascular delay and 6-week muscle training. Then, hemodynamic studies were conducted. In group B, doxorubicin was given to 5 dogs in an IV dose of 1 mg/kg once a week for 8 weeks to induce chronic heart failure, and simultaneous muscle training was given for preconditioning during this period. Then, cardiomyoplasties were performed and hemodynamic studies were conducted immediately after these cardiomyoplasties in group B. Result: In group A, under the state of normal cardiac function, only mean right atrial pressure significantly increased with the pacer-on(p<0.05) and the left ventricular hemodynamic parameters did not change significantly. However, with pacer-on in group B, cardiac output(CO), rate of left ventricular pressure development(dp/dt), stroke volume(SV), and left ventricular stroke work(SW) increased by 16.7${\pm}$7.2%, 9.3${\pm}$3.2%, 16.8${\pm}$8.6%, and 23.1${\pm}$9.7%, respectively, whereas left ventricular end-diastole pressure(LVEDP) and mean pulmonary capillary wedge pressure(mPCWP) decreased by 32.1${\pm}$4.6% and 17.7${\pm}$9.1%, respectively(p<0.05). In group A, imipramine was infused at the rate of 7.5mg/kg/hour for 34${\pm}$2.6 minutes to induce acute heart failure, which resulted in the reduction of cardiac output by 17.5${\pm}$2.7%, systolic left ventricular pressure by 15.8${\pm}$2.5% and the elevation of left ventricular end-diastole pressure by 54.3${\pm}$15.2%(p<0.05). With pacer-on under this state of acute heart failu e, CO, dp/dt, SV, and SW increased by 4.5${\pm}$1.8% and 3.1${\pm}$1.1%, 5.7${\pm}$3.6%, and 6.9${\pm}$4.4%, respectively, whereas LVEDP decreased by 11.7${\pm}$4.7%(p<0.05). Comparing CO, dp/dt, SV, SW and LVEDP that changed significantly with pacer-on, both under the state of acute and chronic heart failure, augmentation widths of these left ventricular hemodynamic parameters were significantly larger under the state of chronic heart failure(group B) than acute heart failure(group A)(p<0.05). On gross inspection, variable degrees of adhesion and inflammation were present in all 5 dogs of group A, including 2 dogs that showed no muscle contraction. No adhesion and inflammation were, however, present in all 5 dogs of group B, which showed vivid muscle contractions. Considering these differences in gross findings along with the following premise that the acute heart failure state was not statistically different from the chronic one in terms of left ventricular parameters(p>0.05), the larger augmentation effect seen in group B is presumed to be mainly attributed to the viability and contractility of the LD muscle. Conclusion: These results indicate that the positive circulatory augmentation effect of cardiomyoplasty is apparent only under the state of heart failure and the preservation of muscle contractility is important to maximize this effect.