• Journal of the Korean Society of Manufacturing Process Engineers
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• v.12 no.4
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• pp.22-28
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• 2013

It is important to begin left ventricular assist device (LVAD) treatment at appropriate time for heart failure patients who expect cardiac recovery after the therapy. In order to predict the optimal timing of LVAD implantation, we predicted pumping efficacy of LVAD according to the severity of heart failure theoretically. We used LVAD-implanted cardiovascular system model which consist of 8 Windkessel compartments for the simulation study. The time-varying compliance theory was used to simulate ventricular pumping function in the model. The ventricular systolic dysfunction was implemented by increasing the end-systolic ventricular compliance. Using the mathematical model, we predicted cardiac responses such as left ventricular peak pressure, cardiac output, ejection fraction, and stroke work according to the severity of ventricular systolic dysfunction under the treatments of continuous and pulsatile LVAD. Left ventricular peak pressure, which indicates the ventricular loading condition, decreased maximally at the 1st level heart-failure under pulsatile LVAD therapy and 2nd level heart-failure under continuous LVAD therapy. We conclude that optimal timing for pulsatile LVAD treatment is 1st level heart-failure and for continuous LVAD treatment is 2nd level heart-failure when considering LVAD treatment as "bridge to recovery".

• Journal of Chest Surgery
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• v.18 no.2
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• pp.193-204
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• 1985

During the period from February to March, 1984, we employed a partial left heart bypass [left atrium to ascending aorta] in 2 patients who could not weaned from cardiopulmonary bypass with inotropic agents and cardiac pacing after coronary bypass surgery. These two patients showed significant improvement in ventricular function 18 to 47 hours after inserting the left heart bypass and were able to wean from the left heart bypass under using inotropic agents. Two patients died of multiple organ failures 11 days and 15 days postoperatively. These results indicate that early institution of left heart bypass in ventricular failure patients after open heart surgery can provide satisfactory long-term result.

• Korean Journal of Veterinary Service
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• v.46 no.1
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• pp.75-79
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• 2023

An eight-year-old, 28-kg male bull terrier who showed signs of lethargy and cough was referred for further evaluation of congestive heart failure. On presentation, physical examination revealed a systolic murmur at the left apex of the heart. Moreover, chest radiograph evaluation confirmed the mild alveolar and interstitial patterns in the caudal lung lobes and a grossly enlarged left atrium and left ventricle. Electrocardiography showed atrial fibrillation with a wide QRS complex, and transthoracic echocardiography revealed marked enlargement of the left atrium with abnormal morphology of the mitral valve. The thickened, hammer-like appearance and abnormal diastolic motion of the mitral valve leaflets were characterized by decreased leaflet separation and doming of the valve. The diagnosis was mitral stenosis with congestive heart failure and atrial fibrillation. The owner declined interventional valvuloplasty. Medical treatment included furosemide, pimobendan and diltiazem. Regular health check-ups have shown that vitality and clinical signs have improved considerably, and the dog have remained stable for 6 months after the presentation.

• Tuberculosis and Respiratory Diseases
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• v.54 no.3
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• pp.320-329
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• 2003

Background : The serum B-type natriuretic peptide (BNP) is released from the ventricles as a response to volume or pressure overload of the ventricles. A few studies have reported that the BNP measurements are useful in differentiating between heart failure and pulmonary causes in patients who visited the emergency department with dyspnea as the chief complaint. It is difficult to differentiate a right heart failure from a left heart failure in the emergency room. However, there is no report on the application of a BNP assay to differentiate in right heart failure from left heart failure. In this study, the BNP levels were measured from dyspneic patients in the emergency department to determine whether or not the BNP level would be useful in differentiating the cause of the dyspnea from right ventricular failure and left ventricular failure. Method : 89 patients who visited emergency department of the Bundang Cha Hospital with dyspnea from June 2002 to March 2003 were selected. The 29 patients from the outpatient clinics and inpatients were randomly selected as the control. Results : The BNP levels of patients in the left heart failure group were significantly different from that of the patients in the right heart failure group ($682{\pm}314$ pg/mL vs. $149{\pm}94$ pg/mL, p=0.000). When the BNP cut-off level was designated as 219 pg/mL using the receiver operating characteristic curve, the sensitivity was 94.3%, and specificity was 92.9%. In addition, the positive predictive value was 97% and the negative predictive value was 86.7% in differentiating right heart failure from left heart failure. Conclusion : Measurements of the serum BNP levels is an accurate and rapid method that can aid in distinguishing between right heart failure and left heart failure.

• Journal of Chest Surgery
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• v.52 no.2
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• pp.105-108
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• 2019

Right heart failure is a relatively common complication after left ventricular assist device (LVAD) implantation. Severe right heart failure can be managed by temporary right ventricular assist device (RVAD) implantation. However, trans-sternal RVAD insertion requires a subsequent third sternotomy for cannula removal. Herein, we present a case of RVAD insertion via a left anterior mini-thoracotomy after LVAD implantation in a patient with alcohol-induced cardiomyopathy.

• Journal of Chest Surgery
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• v.49 no.4
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• pp.292-294
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• 2016

Cardiac resynchronization therapy (CRT) is a new treatment for refractory heart failure. However, most patients with heart failure treated with CRT are adults, middle-aged or older with idiopathic or ischemic dilated cardiomyopathy. We treated a 12-year-old boy, who was transferred after cardiac arrest, with dilated cardiomyopathy, left bundle-branch block, and ventricular tachycardia. We performed cardiac resynchronization therapy with a defibrillator (CRT-D). After CRT-D, left ventricular ejection fraction improved from 22% to 4 4% assessed by echocardiogram 1 year postoperatively. On electrocardiogram, QRS duration was shortened from 206 to 144 ms. The patient's clinical symptoms also improved. For pediatric patients with refractory heart failure and ventricular arrhythmia, CRT-D could be indicated as an effective therapeutic option.

• Journal of Chest Surgery
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• v.23 no.3
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• pp.438-451
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• 1990

Pneumatic total artificial heart[TAH] has been clinically applied for the purpose of permanent or temporary use followed by cardiac transplantation in the patients with end stage heart diseases. In spite of the good durability of the pneumatic TAH, thrombus formation, bleeding and infection resulted in death. The Tomasu heart, which is a type of pneumatic TAH, was used in this study. This model is a modified Jarvik heart and consists of atrial cuffs, outflow vascular grafts and thin-layer seamless diaphragm type of ventricles. Cardiac outputs of the left artificial heart were measured by Donovan`s mock circulation under variable conditions of driving parameters, and an experimental artificial heart implantation was performed in 4 calves to observe the changes of hemodynamic parameters in early postoperative period and hematologic and bio-chemical changes in a long-term survival case. In the mock circulation test, cardiac output of the heart was increased with the increase of the left atrial pressure and left driving pressure. Maximum cardiac output was obtained at the heart rate of 120 to 130/min and percent systole of 40 to 45Zo under the condition of a constant left driving pressure of 180mmHg and left atrial pressure of 10mmHg. During the first 24 hours of TAH pumping, driving pressure ranged from 178$\pm$5mmHg to 187$\pm$8mmHg for the left heart and from 58$\pm$6mmHg to 78$\pm$28mmHg for the right heart. The Mean arterial pressure significantly increased between 2 and 8 hours after the start of pumping. The survival time ranged from 27 hours to 46 days. The causes of death were respiratory failure in 2 cases, mechanical valve failure in one, and left ventricular outflow obstruction due to thrombus in a 46-day survival case. This study demonstrated that Tomasu artificial heart operated effectively during the first 24 hours of artificial heart pumping, but thrombus formation around the valve holding area was the main problem in long-term survival case.

• Journal of Chest Surgery
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• v.21 no.1
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• pp.116-120
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• 1988

From July 1986 to June 1987, five patients were underwent IABP [intra aortic balloon pulsation] because of sever left heart failure in spite of maximum medication. These patients were reviewed as prophylactic IABP [1 patient], During operation [3 patients] and postoperative IABP [1 patients]. All patients were showed stable hemodynamic status with improved LV function during and after IABP. there was no IABP related complication or mortality. Advanced disease needs more effective methods of mechanical circulatory assistance and heart replacement.

• Journal of Veterinary Clinics
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• v.21 no.1
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• pp.83-86
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• 2004

A 4 year old mixed female dog was presented dyspnea, anorexia and syncope. In blood smear test, a lot of heartworm larvae were observed. In thoracic radiography, "reverse D" shape was observed. So, this case was considered with heartworm disease. In echocardiography, marked left heart hypertrophy was presented. In M-mode view, aortic valvular stenosis was found. After mongrel dog died, aortic valvular stenosis was reconfirmed in necropsy. After all, the dog died of pulmonary edema because of aortic valvular stenosis caused left heart failure.t failure.

• Journal of Chest Surgery
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• v.45 no.2
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• pp.116-119
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• 2012

A 61-year-old female patient was diagnosed with dilated cardiomyopathy with severe left ventricle dysfunction. Two days after admission, continuous renal replacement therapy was performed due to oliguria and lactic acidosis. On the fifth day, an intra-aortic balloon pump was inserted due to low cardiac output syndrome. Beginning 4 days after admission, she was supported for 15 days thereafter with an extracorporeal left ventricular assist device (LVAD) because of heart failure with multi-organ failure. A heart transplant was performed while the patient was stabilized with the LVAD. She developed several complications after the surgery, such as cytomegalovirus pneumonia, pulmonary tuberculosis, wound dehiscence, and H1N1 infection. On postoperative day 19, she was discharged from the hospital with close follow-up and treatment for infection. She received follow-up care for 10 months without any immune rejection reaction.