• The Korean Journal of Physiology and Pharmacology
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• v.2 no.3
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• pp.287-295
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• 1998

Diazepam is known to have cardiovascular depressive effects through a combined action on benzodiazepinergic receptor and the GABA receptor-chloride ion channel complex. Moreover, it is known that barbiturates also have some cardiovascular regulatory effects mediated by the central GABAergic system. Therefore, this study was undertaken to delineate the regulatory actions and interactions of these systems by measuring the responses of the cardiovascular system and renal nerve activity to muscimol, diazepam and pentobarbital, administered intracerebroventricularly in rabbits. When muscimol $(0.03{\sim}0.3\;{\mu}\;g/kg)$, diazepam $(10{\sim}100\;{\mu}\;g/kg)$ and pentobarbital $(1{\sim}10\;{\mu}\;g/kg)$ were injected into the lateral ventricle of the rabbit brain, there were similar dose-dependent decreases in blood pressure (BP) and renal nerve activity (RNA). The relative potency of the three drugs in decreasing BP and RNA was muscimol ＞ pentobarbital ＞ diazepam. Muscimol and pentobarbital also decreased the heart rate in a dose-dependent manner; however, diazepam produced a trivial, dose-independent decrease in heart rate. Diazepam $(30\;{\mu}g/kg)$ augmented the effect of muscimol $(0.1\;{\mu}g/kg)$ in decreasing blood pressure and renal nerve activity, but pentobarbital $(3\;{\mu}g/kg)$ did not. Bicuculline $(0.5\;{\mu}g/kg)$, a GABAergic receptor blocker, significantly attenuated the effect of muscimol in decreasing BP and RNA, either alone or with diazepam, and that of pentobarbital in decreasing BP and RNA, either alone or with muscimol. We inferred that the central benzodiazepinergic and barbiturate systems help regulate peripheral cardiovascular function by modulating the GABAergic system, which adjusts the output of the vasomotor center and hence controls peripheral sympathetic tone. Benzodiazepines more readily modulate the GABAergic system than barbiturates.

• The Korean Journal of Physiology
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• v.21 no.1
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• pp.13-22
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• 1987

Effects of synthetic atrial natriuretic peptide and furosemide on the cardiovascular and renal functions were examined in the freshwater turtle, Amyda japonica. Both atria and ventricle of turtle contained an immunoreactive atrial natriuretic peptide. Synthetic rat atrial natriuretic peptide (atriopeptin III) and turtle atrial extract caused a decrease in mean arterial blood pressure and the vasodepressor effect was dose-dependent. In hydrated turtles received either atriopeptin III or turtle atrial extract, no significant change in renal function was observed until 100 min except a slight natriuresis at 60 or 100 min after injection of 30 ug/kg atriopeptin III or atrial extract, respectively. However, furosemide, 2 mg/kg, caused marked diuresis, natriuresis and kaliuresis. In non-hydrated turtles, no significant change in renal function was observed until 6 hrs following injection of 30 ug/kg atriopeptin III. Plasma aldosterone decreased at 2 hr and increased at 24 hr after injection of atriopeptin III although plasma renin concentration did not change. But, furosemide caused persistent diuresis, natriuresis and kaliuresis. Additionally, plasma aldosterone and renin concentrations were significantly increased at 24 hrs after injection of furosemide. In conclusion, we suggest that the freshwater turtle may have an atrial natriuretic peptide in heart and vascular receptors for atrial natriuretic peptide, and that atrial natriuretic peptide is more important in the regulation of blood pressure rather than that of renal function in freshwater turtles. We also suggest that an increased plasma renin concentration caused by furosemide may not be due to the sodium concentration delivered to macula densa, but due to the dehydration caused by persistent diuresis and natriuresis.

• Journal of Chest Surgery
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• v.29 no.7
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• pp.689-699
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• 1996

An animal experiment was designed for the evaluation of in vivo performance of the newly developed electrohydraulic type ventricular assist device and its influence on the left ventricular function during pal- satile left ventricular assist. Eight adult sheep were incorporated into the study and data were collected from seven sheep. Total as- sist time ranged from 69 minutes to 7 days. The performance of the device was satisfactory both in asyn- chr nous and synchronous mode within the range of given native heart rate. More than 4 liters of device output could be reached within the range of normal left atral pressure without development of negative pressure in the left atrium. Moderate to severe degree of hemolysis was noted as evidenced by significant increase of plasma free hemoglobin level after 3 days of left ventricular support along with the presence of the small amount of thrombi around the floating disc type polymer valve apparatus reflecting that further study and refinement of the device need to be done in regard of biocompatibility and thromboresistance. The hemodynamics showed increase in heart rate (p < 0.05), cardiac output and left ventricular minute work (p < 0.05) after placement of the device at the flow rate of 2.0∼2.5 Llmin. The left atrial pressure, left ventricular pressure and LV dpldt were decreased after the device placement(p < 0.05). The endocardial viability ratio and oxygen contents of the mixed ven us blood and coronary venous blood were all increased (p < 0.05) after the device placement suggesting effective unloading of the left ventricle was accomplished. The myocardial perfusion was thought improved in synchronous counterpulsation as suggested by sig- nificant increase in endocardial viability ratio and coronary venous blood oxygen content in synchronous assist mode comparing with asynchronous mode.

• Journal of Chest Surgery
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• v.40 no.9
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• pp.593-599
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• 2007

Background: The correlation between levels of brain natriuretic peptide (BNP) and the effect of pulmonary resection on the right ventricle of the heart is not yet widely known. This study aims to assess the relationship between the change in hemodynamic values of the right ventricle and increased BNP levels as a compensatory mechanism for right heart failure following pulmonary resection and to evaluate the role of the BNP level as an index of right heart failure after pulmonary resection. Material and Method: In 12 non small cell lung cancer patients that had received a lobectomy or pnemonectomy, the level of NT-proBNP was measured using the immunochemical method (Elecsys $1010^{(R)}$, Roche, Germany) which was compared with hemodynamic variables determined through the use of a Swan-Garz catheter prior to and following the surgery. Echocardiography was performed prior to and following the surgery, to measure changes in right ventricular and left ventricular pressures. For statistical analysis, the Wilcoxon rank sum test and linear regression analysis were conducted using SPSSWIN (version, 11.5). Result: The level of postoperative NT-proBNP (pg/mL) significantly increased for 6 hours, then for 1 day, 2 days, 3 days and 7 days after the surgery (p=0.003, 0.002, 0.002, 0.006, 0.004). Of the hemodynamic variables measured using the Swan-Ganz catheter, the mean pulmonary artery pressure after the surgery when compared with the pressure prior to surgery significantly increased at 0 hours, 6 hours, then 1 day, 2 days, and 3 days after the surgery (p=0.002, 0,002, 0.006, 0.007, 0.008). The right ventricular pressure significantly increased at 0 hours, 6 hours, then 1 day, and 3 days after the surgery (p=0.000, 0.009, 0.044, 0.032). The pulmonary vascular resistance index [pulmonary vascular resistance index=(mean pulmonary artery pressure-mean pulmonary capillary wedge pressure)/cardiac output index] significantly increased at 6 hours, then 2 days after the surgery (p=0.008, 0.028). When a regression analysis was conducted for changes in the mean pulmonary artery pressure and NT-proBNP levels after the surgery, significance was evident after 6 hours (r=0.602, p=0.038) and there was no significance thereafter. Echocardiography displayed no significant changes after the surgery. Conclusion: There was a significant correlation between changes in the mean pulmonary artery pressure and the NT-proBNP level 6 hours after a pulmonary resection. Therefore, it can be concluded that changes in NT-proBNP level after a pulmonary resection can serve as an index that reflects early hemodynamic changes in the right ventricle after a pulmonary resection.

• Journal of Chest Surgery
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• v.41 no.3
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• pp.305-312
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• 2008

Background: Anatomic and functional abnormalities of the systemic atrioventricular (AV) valve are common in single ventricle. pathologies and continue to be associated with poor early and late outcomes in surgically palliated single. ventricle patients. We aggressively performed valvuloplasty for atrioventricular valve regurgitation (AVVR) during the course toward a Fontan operation. Material and Method: Between January 1995 and December 2004, 209 patients underwent a Fontan operation in our institution. We retrospectively evaluated the prevalence of AVVR and the influence of AV valve repair on outcome, and we analyzed the progression of AVVR after the Fontan operation for 168 patients where echocardiographic follow up results for more than 6 months after the Fontan operation were available. During the course toward a Fontan operation, 25 patients underwent 30 procedures for AVVR. These procedures. were. carried out during placement of a bidirectional cavopulmonary shunt (BCPS) for nine patients, between the time of placement of a BCPS and the Fontan operation for four patients, and during the Fontan operation for 17 patients. Five patients underwent procedures for AVVR twice. Result: The late mortality rate after the Fontan operation was 4.2% (n=7), with a median follow-up duration of 52 months (range, $6{\sim}123$ months). Seven patients (4%) had unfavorable outcomes such as significant (moderate or severe) AVVR in six patients, and significant AV valve stenosis in one patient was determined at the last follow up after the Fontan operation. Among the seven patients, four patients underwent AV valve repair after the Fontan operation, and one patient underwent subsequent AV valve replacement. Progression to AVVR of equal to or greater than grade 2 was noted in 30 patients (18%) at the last follow up after the Fontan operation, including 12 patients that underwent previous AV valve procedures. Initial grading of AVVR, a previous AV valve operation, and specific AV valve morphology such as a common AV valve or mitral atresia were significant risk factors for the progression of AVVR after the Fontan operation. Conclusion: In our surgical series, a small percentage of patients showed unfavorable outcomes. related to AVVR during the course toward a Fontan operation. However, a closer follow-up is required to evaluate the progression of the AVVR after a Fontan operation, especially for patients showing poor AV valve function at the first presentation and specific AV valve morphology.

• Journal of Chest Surgery
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• v.31 no.7
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• pp.650-659
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• 1998

Between August 1996 and August 1997, 22 patients underwent extracardiac Fontan operations. The basic diagnoses included univentricular heart of the right ventricular type (n=12); univentricular heart of the left ventricular type (n=4); tricuspid atresia (n=4); left isomerism, transposition of great arteries, ventricular septal defect and pulmonary stenosis (n=1); and criss-cross heart with uneven ventricle (n=1). The median age of the 14 men and 8 women was 29 months (range from 21 months to 26 years). Previous procedures included bidirectional cavopulmonary shunt (n=15, interval=15.6$\pm$3.4 months), Kawashima operation (n=4, interval=37.5$\pm$20 months), and classic Glenn shunt (n=1, interval=14 years). In 2 patients, extracardiac Fontan operations were done without any previous procedures. A 16- to 22-mm flexible Gore-Tex tube graft (n=18), Hemashield graft (n=3), or, alternatively, a nonvalved aortic allograft (n=1) was cut and anastomosed end-to-end between inferior vena cava and undersurface of pulmonary artery using Gore-Tex or Prolene suture in a running fashion. In risk Fontan patients (n=12), a communication between the extracardiac conduit and the right atrium was constructed. In the most 13 recent patients, the procedures were done without cross-clamping of the aorta and with a beating heart. Operative mortality was 9.1% (n=2). Complications included persistent chest tube drainage for more than 7 days (n=5), chorea (n=2), and low cardiac output (n=1). There were no late deaths. Follow-up echocardiogram (mean: 6 months) demonstrated satisfactory hemodynamic results in the surviving 20 patients. Potential advantages of this technique consist of minimization of surgical manipulation of atrial tissue, reduction or elimination of myocardial ischemia, creationof a uniform and stable inferior vena cava-to-pulmonary artery conduit, and increased flexibility and safety in certain high-risk patients such as those with increased pulmonary vascular resistance, pulmonary hypertension, and impaired ventricular function. Further investigations during a longer follow-up are needed to confirm the intermediate and long-term results, especially the reduction of late atrial arrhythmias.

• Korean Journal of Clinical Laboratory Science
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• v.48 no.4
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• pp.394-400
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• 2016

The b-type natriuretic peptide (BNP) values and increase on functional disorder in the ventricle, and are used as an index to diagnose heart failure and predict the prognosis. BNP values is known to be relevant to dyssystole in congestive heart failure. This study aimed to identify correlation between the BNP values and the items that indicate the diastolic function in echocardiography. The research divided 188 patients who went through the BNP test and echocardiography in the hospital into the groups with the BNP values; <100, 100-300, 301-600, 601-900, and >901 pg/mL. As the BNP values increase, there was relevance with the echocardiography items of ejection fraction, size of left atrium, E velocity, A velocity, Deceleration time, E/A ratio, E', A', S' and E/E'. In comparison on the groups divided based on the BNP values, E/E' had the highest relevance. The research also categorized 67 patients who diagnosed with heart failure. In comparison on the groups of the heart failure patients, the BNP values of the three groups of Grade I: $623.0{\pm}459.7pg/mL$, Grade II: $1013.2{\pm}1155.1pg/mL$ and Grade III: $1693.4{\pm}1544.0pg/mL$, respectively (p<0.01). As the grade was higher, there was a higher relevance with the echocardiography items of ejection fraction, size of left atrium, E velocity, A velocity, Deceleration time, E/A ratio, E', A', S' and E/E' (p<0.001). Higher BNP values had a higher relevance with the items that indicate the diastolic function in echocardiography and the BNP values of the Restrictive physiology group were the highest in echocardiography. So the BNP values was thought to be valuable to predict diastolic function of heart.

• Investigative Magnetic Resonance Imaging
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• v.12 no.1
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• pp.40-48
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• 2008

Purpose : We sought to determine the early change of ventricular geometry and function after concomitant surgeries of modified Dor procedure and mitral valve annuloplasty by using magnetic resonance imaging. Materials and Methods : We enrolled 21 patients with dilated heart failure who underwent modified Dor procedure (n=8), mitral valve annuloplasty (n=6), or both surgeries (n=7). Cine MRI was used to assess left ventricular dimensions and function before and after surgery. We measured the left ventricular end-diastolic and end-systolic volumes and the dimensions of the left ventricular long-axis and short-axis. Left ventricular stroke volume, ejection fraction, and sphericity index were calculated from these measurements. These parameters were analyzed and compared between three different surgery groups to explain the combined effect of the concomitant surgeries. Results : MRI was performed within average $12\;{\pm}\;15$ days (range 1-58 days) before and $38\;{\pm}\;50$ days (range 7- 231 days) after the surgery. The patients who underwent concomitant surgeries had more profound enlargement of left ventricle and decreased contractility prior to surgery than those in the patients who underwent single surgical procedure. Left ventricular end-diastolic volume and endsystolic volume significantly decreased in all patients regardless of surgery type after surgery. Ejection fraction significantly increased only in the patients who got modified Dor procedure without mitral valve annuloplasty (25.4% to 40.7%). Sphericity index increased in patients with modified Dor procedure but decreased in patients with mitral valve annuloplasty (0.65 to 0.78 vs. 0.75 to 0.65). In the patients who underwent concomitant surgeries showed no significant change in sphericity index after surgery. Conclusion : The early change of the left ventricular geometry and function after the concomitant surgeries with modified Dor procedure and mitral valve annuloplasty in patients with dilated heart failure includes a marked reduction in left ventricular volume and in stroke volume. The shape of the left ventricle does not change because the effect of sphericity index decrease from mitral valve annuloplasty is counteracted by the effect of sphericity index increase from modified Dor procedure. Improvement of left ventricular ejection fraction is not the early change after the concomitant surgeries.

• 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.

• The Korean Journal of Pharmacology
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• v.26 no.1
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• pp.7-12
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• 1990

Cyclobuxine D is a steroidal alkaloid, which was extracted from Buxus microphylla var. koreana Nakai. In our previous studies, we clarified several pharmacological actions of cyclobuxine D: an antiinflammatory action, hypotensive and bradycardiac effects, negative inotropic effects on the several smooth muscles and cardiac muscle. The present study was undertaken to elucidate possible mechanisms by protection of myocardial tells from ischemia and reperfusion induced derangement in cardiac function and metabolism by cyclobuxine D. For this purpose, the isolated rat heart was used. Rat hearts were perfused for 60 min under ischemia conditions in the presence and absence of cyclobuxine D and verapamil, and for 30 min under reperfusion conditions. Ischemia produced a marked decline in contractile force, an increase of resting tension, an immediate release of ATP metabolites and an accumulation of calcium in the left ventricle. Cyclobuxine D (100ng/ml) ameliorated the myocardial injury produced by ischemia.