• The Korean Journal of Pharmacology
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• v.26 no.2
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• pp.101-111
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• 1990

The effect of physostigmine (PS), which has been shown to act on the muscarinic receptors in the brains of the rat, dog and cat, on the arterial blood pressure (BP) was investigated in urethane-anesthetized rabbits. Intravenous (iv) PS, $25{\sim}300\;{\mu}g/kg$, caused little change in BP. However, after treatment of rabbits with either of chlorisondamine (CS), hexamethonium, intracerebroventricular (icv) clonidine, icv xylazine and icy reserpine iv PS produced a pressor response. Spinalization of the rabbit also caused iv PS to increase BP. The pressor effect of iv PS in CS-treated rabbits was markedly reduced after prazosin or pirenzepine. Iv PS inhibited the pressor response to McN-A-343 in CS-treated and in spinal rabbits; alternately during the infusion of McN-A-343 iv PS failed to produce the pressor response. The pressor response to DMPP was not affected by iv PS. Icv PS, $12{\sim}200\;{\mu}g/kg$, produced a pressor response which was accentuated after CS-treatment. This pressor effect was inhibited, though not complete, by prazosin or by pirenzepine. A simultaneous treatment of rabbits with both $[Sar^{1},\;Ala^{8}]-angiotensin$ II, an angiotensin II antagonist, and prazosin or pirenzepine almost completely abolished the pressor effect of icv PS, whereas the angiotensin II antagonist did not enhance the inhibitory effect of pirenzepine and prazosin on the pressor response to iv PS . Icv pirenzepine blocked the pressor response to icv PS without affecting that to iv PS. The present results show that the pressor response to iv PS in CS-treated and in spinal rabbits arises from stimulation of the muscarinic receptors in the sympathetic ganglia, whereas the pressor response by icv PS via activation of the muscarinic receptors in the brain which causes an enhancement in the outflow of sympathetic discharge and angiotensin. The results also suggest that iv PS is unable to produce a pressor response in the rabbit unless the sensitivity of the gangionic muscarinic receptors is altered by ganglionic nicotinic blockade, by the decrease of central sympathetic outflow on the sympathetic ganglia or by spinalization.

• Journal of Chest Surgery
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• v.38 no.10 s.255
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• pp.661-668
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• 2005

Background: We have hypothesized that, if a low resistant gravity-flow membrane oxygenator is used, then the twin blood sacs of TPLS can be located at downstream of the membrane oxyenator, which may double the pulse rate at a given pump rate and increase the pump output. The purpose of this study was to determine the optimal configuration for the ECLS circuits by using the concept of pulse energy and pump output. Material and Method: Animals were randomly assigned to 2 groups in a total cardiopulmonary bypass model. In the serial group, a conventional membrane oxygenator was located between the twin blood sacs. In the parallel group, the twin blood sacs were placed downstream of the gravity-flow membrane oxygenator. Energy equivalent pressure (EEP) and pump output were collected at pump-setting rates of 30, 40, and 50 BPM. Result: At the given pump-setting rate, the pulse rate was doubled in the parallel group. Percent changes of mean arterial pressure to EEP were $13.0\pm1.7,\; 12.0\pm1.9\;and\;7.6\pm0.9\%$ in the parallel group, and $22.5\pm2.4,\; 23.2\pm1.9,\;and\;21.8\pm1.4\%$ in the serial group at 30, 40, and 50 BPM of pump-setting rates. Pump output was higher in the parallel circuit at 40 and 50 BPM of pump-setting rates $(3.1\pm0.2,\;3.7\pm0.2L/min\;vs.\;2.2\pm0.1\;and\;2.5\pm0.1L/min,\;respectively,\;p=0.01)$. Conclusion: Either parallel or serial circuit configuration of the ECLS generates effective pulsatility. As for the pump out, the parallel circuit configuration provides higher flow than the serial circuit configuration.

• Journal of Chest Surgery
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• v.36 no.3
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• pp.123-130
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• 2003

Background: In order to develop the acute heart failure model for the animal experiment of the pneumatic ventricular assist device, we decided to use young pig whose coronary artery distribution is almost the same as humans and also very cheap in price. The purpose of this study is to develop stable, reproducible acute ischemic heart failure model in swine using coronary artery ligation method. Material and Method: Five young pigs whose weights are the same as adult humans are under experiment. Each pig was under endotracheal intubation and connected to a mechanical ventilator. Through left lateral thoracotomy, we exposed the heart and induced ischemic heart failure by coronary artery ligation. The ligation began at the distal part of the left anterior descending coronary artery. After 5 minutes of initial ligation we reperfused the artery and then re-ligated. Before and after each ligation-reperfusion procedure we assessed the left ventricular end-diastolic pressure, arterial pressure, and cardiac index. We also measured left ventricular end-diastolic dimension, end-systolic dimension, fractional shortening, ejection fraction using intraoperative epicardial echocardiography. After appropriate heart failure was established with sequential (from distal part of LAD to proximal location) ligation-reperfusion-ligation procedure, we inserted the ventricular assist device and operated. Result: We established stable acute ischemic heart failure in 3 of 5 young pigs with this sequential ligation-reperfusion-ligation procedure, and could maintained 50% less ejection fraction before the procedure according to intraoperative epicardial echocardiography. We also observed no ventricular arrhythmia usually associated with simple coronary artery ligation in large animals and no cardiac arrest associated with ventricular arrhythmia or myocardial stunning. In pathologic specimen, we observed scattered ischemic myocardium in all around the ischemic field induced by coronary artery ligation. Conclusion: Under the concept of ischemic preconditioning, we developed safe and reproducible acute ischemic heart failure model in swine using sequential coronary artery ligation-reperfusion-ligation method.

• Journal of Chest Surgery
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• v.31 no.8
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• pp.749-755
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• 1998

Background: Twelve patients with acyanotic tetralogy of Fallot(TOF), characterized by the combination of a malaligned ventricular septal defect(VSD) and infundibular pulmonic stenosis with the clinical finding of acyanosis at rest, underwent surgical correction between January 1988 and July 1997. Materials and methods: 9.92% of patients with the diagnosis of TOF were acyanotic TOF in the same period. Ages ranged from 12 to 42 months(mean 25.2 months). 2D-echocardiographic studies, cardiac catheterization, and angiocardiograms were performed in all patients before operation. The preoperative mean systemic arterial oxygen saturation was 93.5%. According to the 2D-echocardiographic analysis, there was Lt-to-Rt shunt through VSD in 4 patients, bidirectional shunt in 2 patients, and no shunt in 6 patients. Results: The preoperative mean right ventricle to pulmonary artery(RV-PA) pressure gradients were 52.3 mmHg on 2D- echocardiogram and 48.4 mmHg on cardiac catheterization. The repair of ventricular septal defect was performed through a right atrial approach and the hypertrophic infundibular muscle bundles were resected by the transatrial and transpulmonary approach. Six patients(50%) received a transannular patch. The mean cardiopulmonary bypass time was 135.0 minutes, and the aortic crossclamp time was 87.8 minutes. Postoperative complications included bleeding necessitating reentry in one and chylothorax in one. No patient died after operation and there were no late deaths. Postoperative 2D-echocardiograms revealed tiny patch dehiscence in 5 cases and a moderate RV-PA pressure gradients(mean 15.3 mmHg). All patients were in New York Heart Association functional class 1 after operation. Conclusions: acyanotic TOF is the uncommon form of TOF, and acyanotic TOF can be repaired with a good outcome.

• Journal of Chest Surgery
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• v.37 no.6
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• pp.492-498
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• 2004

Background: In this study, we investigated the risk factors for the development or progression of aortic regurgitation(AR) in patients with type I ventricular septal defect (VSD) to determine the optimal surgical timing and strategy. Material and Method: Three-hundred and ten patients with type I VSD with or without AR were included. The mean of age was 73.7$\pm$114.7 (1-737) months. One hundred and eighty six patients (60%) had no AR, 83 (27%) had mild AR, 25 (8%) had moderate AR and 16 (5%) had severe AR. Aortic valve was repaired in 5 patients and replaced in 11 patients with closure of VSD in the first operation. Four patients required redo aortic valve repair and 11 patients required redo aortic valve replacement. Age at operation, association with aortic valve prolapse, Qp/Qs, systolic pulmonary arterial pressure, VSD size and systolic pulmonary artery to aortic pressure ratio(s[PAP/AP］) were included as risk factors analysis for the development of AR. The long-term result of aortic valve repair and aortic valve replacement were compared. Result: Older age at operation, association with aortic valve prolapse, high Qp/Qs, and s[PAP/AP] were identified as risk factors for the development of AR (p<0.05, Table 2). The older the patient at the time of operation, the higher the severity of preoperative AR and the incidence of postoperative AR (p<0.05, Table 1, Fig. 1). For the older patients at operation, aortic valve repair had higher occurrence of AR compared to those who had aortic valve replacement (p<0.05, Fig. 2). Conclusion: From the result of this study, we can concluded that early primary repair is recommended to decrease the progression of AR. Aortic valve repair is not always a satisfactory option to correct the aortic valve pathology, which may suggest that aortic valve replacement should be considered when indicated.

• Clinical and Experimental Pediatrics
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• v.46 no.3
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• pp.259-264
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• 2003

Purpose : We have performed an analysis on patients who received Rastelli operation in our institute and reviewed their progress postoperatively. Various factors with suspected relationship to the outcome have been considered to help in future treatment and follow-up. Methods : We analyzed retrospectively 43 patients who either received Rastelli operation in Yonsei University Cardiovascular Center from March 1995 to April 1997 or who received post-procedural cardiac catheterization and follow-up echocardiography in the out-patient department after the procedure. Results : No statistically valid relationships were found between the age of the patient, their body weight, preoperative pulmonary arterial index and pressure, presence of pulmonary branchial stenosis and postoperative results. Cases with atrioventricular concordance showed lower age and body weight, and discordant cases exhibited lower ejection fraction 3 days postoperatively. Upon follow up, lower NYHA score was seen in patients with severe residual stenosis. In the group that received cardiac catheterization after the procedure, residual stenosis and right ventricular pressure measurement in echocardiography showed good correlation with the catheterization data. Conclusion : In cases where conduit insertions of the right ventricular outflow tract are required to achieve total correction in complex cardiac deformity, early operation does not seem to provide a clear risk to the patient. In patients with atrioventricular discordance, careful postoperative observation of the ventricular function seems to be needed. Also, echocardiography appears to be a sound method in follow-up of patients after the correctional procedure.

• Sleep Medicine and Psychophysiology
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• v.22 no.1
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• pp.30-34
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• 2015

Obesity hypoventilation syndrome (OHS) is characterized by severe obesity, excessive daytime sleepiness, hypoxemia and hypercapnea. Because OHS mimics pulmonary hypertension or cor pulmonale, clinicians should recognize and treat this syndrome appropriately. A 58-year-old female visited the emergency room because of dyspnea. She was obese and had kyphoscoliosis. The patient also experienced snoring, recurrent choking during sleep and daytime hypersomnolence which worsened after gaining weight in the recent year. The arterial blood gas analysis showed she experienced hypoxemia and hypercapnea not only during nighttime but also daytime. We suspected OHS and the patient underwent polysomnography to confirm whether obstructive sleep apnea was present. During the polysomnography test, sleep obstructive apnea was observed and apnea-hypopnea index was 9.2/hr. The patient was treated with bilevel positive airway pressure therapy (BiPAP). After BiPAP for 4 days, hypoxemia and hypercapnia were resolved and she is currently well without BiPAP. We report a case successfully treated with clinical improvement by presuming OHS early in a patient who had typical OHS symptoms, even while having other conditions which could cause hypoventilation.

• Tuberculosis and Respiratory Diseases
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• v.46 no.5
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• pp.628-635
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• 1999

Background : Maximal expiratory flow rate is determined by the size of airway, elastic recoil pressure and the collapsibility of airway in the lung. The obstruction of expiratory flow is one of the major functional impairments of emphysema, which represents COPD. Nevertheless, expiratory narrowing of upper airway may be recruited as a mechanism for minimizing airway collapse, and maintaining lung volume and hyperinflation by an endogenous positive end-expiratory pressure in patients with airflow obstruction. We investigated the physiologic role of trachea in respiration in emphysema. Method : We included 20 patients diagnosed as emphysema by radiologic and physiologic criteria from January to August in 1997 at Seoul Municipal Boramae Hospital. Chest roentgenogram, high resolution computed tomography(HRCT), and pulmonary function tests including arterial blood gas analysis and body plethysmography were taken from each patient. Cross-sectional area of trachea was measured according to the respiratory cycle on the level of aortic arch by HRCT and calibrated with body surface area. We compared this corrected area with such parameters of pulmonary function tests as $PaCO_2$, $PaO_2$, airway resistance, lung compliance and so on. Results : Expiratory cross-sectional area of trachea had significant correlation with $PaCO_2$ (r=-0.61, p<0.05), $PaO_2$ (r=0.6, p<0.05), and minute ventilation (r=0.73, p<0.05), but inspiratory cross-sectional area did not (r=-0.22, p>0.05 with $PaCO_2$, r=0.26, p>0.05 with $PaO_2$, and r=0.44, p>0.05 with minute ventilation). Minute ventilation had significant correlation with tidal volume (r=0.45, p<0.05), but it had no significant correlation with respiratory frequency (r=-0.31, p>0.05). Cross-sectional area of trachea had no significant correlation with other parameters of pulmonary function including $FEV_1$, FVC, $FEV_1$/FVC, peak expiratory flow, residual volume, diffusing capacity, airway resistance, and lung compliance, whether the area was expiratory or inspiratory. Conclusion : Cross-sectional area of trachea narrowed during expiration in emphysema, and its expiratory area had significant correlation with $PaCO_2$, $PaO_2$, and minute ventilation.

• Childhood Kidney Diseases
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• v.1 no.2
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• pp.101-108
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• 1997

Purpose : The clinical characteristics of renovascular hypertension (RVHT) in children were analyzed. Methods : Medical records of 16 children diagnosed as RVHT on the basis of angiography during Jan. '86 to Jun. 94 in our hospital were reviewed retrospectively. Results : The mean age at the onset was 8.5 yrs and the sex ratio(M:F) was 7:9. The causes of RVHT were Takayasu arteritis in 6, Moyamoya disease in 5, and fibromuscular dysplasia in 3 patients. Abdominal bruit was noted in 6 patients (38%). Peripheral renin activity was raised in all tested patients. Bilateral renal arterial involvemnent was found in 9 patients (56%). Captopril renal scans showed good correlation with angiographic findings. Five patients were treated with antihypertensives only, and blood pressure was controlled completely in 2 and incompletely in 3. Percutaneous transluminal angioplasty was performed in 10 patients with 50% of success rate. However, hypertension was recurred due to restenosis or accompaning aortic stenosis in 3 patients. Surgical treatment was performed in 4 patients, and the blood pressure was controlled partially in 1 and poorly in the remaining 3. Conclusions : Takayasu arteritis, Moyamoya disease and fibromuscular dysplasia are the major causes of childhood RVHT in our country. The diagnosis of RVHT in children should be based on a set of tests individually selected for case by case. For the low curability of the current treatment modalities available, RVHT in children should not be regarded as 'curable' so far. We expect, however, that the outcome will be improved by more extensive application of the newly developed surgical technique.

• Tuberculosis and Respiratory Diseases
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• v.44 no.1
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• pp.136-145
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• 1997

Background : Tracheal Gas Insufflation (TGI) is one of the newer ancillary measures in mechanical ventilation employed to enhance carbon dioxide elimination. TGI exerts its effect through reduction of deadspace ventilation, but the factors determining its effect are not well studied yet. Method : The subjects were seven mechanically-ventilated patients ($58.8{\pm}10.6$ yrs) who showed increased physiologic deadspace greater than 60%. After 30 nun of stabilization with 100% oxygen on pressure control ventilation, continuous flow TGI was administered via the insufflation lumen of Hi-Lo Jet Tracheal Tube (Mallincrodt, USA) for 15 min at 3 L/min and 5 L/min each. Results : $PaCO_2$ was decreased ($51.4{\pm}17.6$ at baseline, $49.1{\pm}18.9$ at TGJ 3 L/min $45.0{\pm}14.9$ mm Hg at TGI 5 L/min, p=0.050), and pH was increased ($7.37{\pm}0.12$, $7.38{\pm}0.13$, $7.39{\pm}0.12$, respectively, p=0.037) while mixed expired $CO_2$ ($P_ECO_2$) was not changed significantly from baseline (p=0.336) by TGI. Physiologic deadspace(Vdphy) was decreased ($73.0{\pm}7.9$% at baseline, $69.8{\pm}10.0$% at TGI 3 L/min, and $67.1{\pm}10.1$% at TGI 5 L/min, p=0.015). $AaDO_2$(p=0.147), Vt(p=0.2140), Pmean(p=0.7788) and mean arterial pressure(p=0.4169) were not changed. The correlation between % maximal decrease of Vdphy were r=0.790 with the ratio of baseline Vdana/Vdphy(p=0.035) and r=-0.754 with baseline Vdalv(p=0.050). Conclusion: TGI was effective in reducing $PaCO_2$ and deadspace, and the deadspace-reducing effect was best correlated with baseline anatomic/physiologic deadspace ratio.