• Journal of Chest Surgery
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• v.14 no.3
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• pp.228-234
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• 1981

Measurement of cardiac output by thermodilution method is easy to perform and can be repeated at very short intervals and offers a number of theoretical and practical advantages. The purpose of this paper is to reevaluate the accuracy and reproducibility of the thermodilution cardiac output by comparing the results with those obtained by the direct Fick technique. From January through April 1981 [4 months], 26 simultaneous cardiac output measurements were made using thermodilution and direct Fick methods in 12 patients in the intensive care unit of Severance Hospital following open heart surgery. The average age of the patients was $34.8{\pm}12.0$ [SD] years [range; 17-57 years]. For cardiac output determination by thermodilution technique [$CO_TD$], a Swan-Ganz Thermodilution Catheter, Model 93A-131-7F [Edwards Laboratories], a Cardiac Output Computer, Model 9520A, and Strip Chart Recorder, Model 9810 [Edwards Laboratories] were used. For the determination of cardiac output by direct Fick principle [$CO_Fick$], a Van Slyke Manometric Apparatus [Thomas] for the measurements of arteriovenous oxygen content difference and a Collin`s Respirometer with Kymograph for the measurement of oxygen consumption were used. The correlation between the simultaneously measured $CO_TD$ and $CO_Fick$ was found to be $CO_Fick$ = 0.95.$CO_TD$ + 0.1073, [r= 0.9777, P < 0.001 ]. For 26 double or triple determinations of $CO_TD$, the values ranged from 1.77 L/min to 6.66 L/min, with a reproducibility of 2.18%. The maximum difference of $CO_TD$ for $CO_Fick$ was between +11.99% and -12,99% [$Mean{\pm}SD$ = $6.07{\pm}3.97$%]. Measurement of cardiac output by thermodilution method provides a simple, rapid, reproducible and highly accurate method for multiple cardiac output measurements suitable for use at the bedside. Comparison of Cardiac Output Determination by Direct Fick and Thermodilution Method in Man.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.7
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• pp.1591-1597
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• 2011

In this paper, on cardiopulmonary function in the intensive care unit over the direction of the state to define the diagnostic or therapeutic cardiac output Study on Implementation of measures as a platform, Swan-Ganz Catheter with sensor inserted into the body by inserting a saline solution Using temperature change caused by using thermodilution be used to obtain cardiac output. Swan-Ganz Catheter with temperature sensors and pressure sensors and sensor value which is entered through the acquisition more closely if the cardiac output CO, systemic and pulmonary vascular resistance, oxygen consumption and may be able to more accurately calculate the patient's condition than accurate diagnosis and treatment is possible.

• Journal of Biomedical Engineering Research
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• v.9 no.2
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• pp.165-170
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• 1988

The purpose of this study was to prove the accuracy of impedance cardiography by measuring cardiac outputs of patients simultaneously by thermodilution method, and impedance cardiography developed in our department. The subjects were eight patients with mitral stenosis admitted to the cathete rization laboratory in Severance Hospital. The correlation coefficient was 0.895, which is thought quite high considering the fact that accuracy of cardiac outputs of patients with valvular diseases measured by both methods was known to be low.

• Journal of the Korean Institute of Telematics and Electronics
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• v.27 no.3
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• pp.54-62
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• 1990

The thermodiluton is a standard method to measure cardiac output in clinical medicine. However it has many disadvantages such as expensive instrument and measurement, limited number of measurement, pain, safety problem, and side-effect due to insertion of catheter into heart. Electrical Impedance Cardiography has no such disadvantages and that it can continuously monitor stroke volume, contractility of cardiac muscle, and systolic time interval (STI) as well as cardiac output. While this impedance technique has been widely used and vigorously studied adroad, it is not introduced yet in Korea. Thus an Impedance Cardiograph has been developed in order to introduce this new technique. Its accuracy also has been verified by simultaneous measurement of cardiac output with the thermodilution technique. Finally changes of cardiac function during exercise were also measured.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.05a
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• pp.194-197
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• 2012

The purpose of the thesis is to develop a module which can measure precise Continuous Cardiac Output(CCO) better than existing equipments for the critical cardiopulmonary patient diagnosis purpose. This module enables more precise and effective diagnosis and treatment for the patient by compensating old method which injected cold liquid to inside of heart to measure the CCO.

• Journal of Biomedical Engineering Research
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• v.9 no.1
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• pp.109-116
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• 1988

In this paper, principles of impedance tenchinque and relationship between stroke volume and impedance change were theoretically explained. An impedance cardiograph was designed and constructed. Its reproducibility was verified by experiment. Until now, the peak point of dZ/dt waveform, first derivative of impedance change(${\Delta}$Z) , has been detected by software technique requiring considerable time to process. However in this paper its peak point was found using hardware for saving processing time. Useful cardiac parameters such as stroke volume and contractility of cardiac muscle were measured noninvasively. The reproducibility of the instrument was measured to be better(less than 10%) than that of clinical standard method such as thermodilution (more than 30%). Hence impedance cardiography was found to be better techique for monitoring stroke volume and myocardial contractility for pre and post operation, and pharmacological studies.

• Proceedings of the KIEE Conference
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• 1988.07a
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• pp.727-730
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• 1988

In this paper, cardiac parameters and relationship between stroke volume and impedance change were explained, and an impedance cardiograph was designed and constructed, and its accuracy was verified by experiment. Useful cardiac parameters such as stroke volume and contractility of cardiac muscle were measured noninvasively. The reproducibility of the instrument was measured to be better(less than 10%) than that of clinical standard method such as thermodilution. Hence impedance cardiography was found to be better technique for monitoring stroke volume and contractility of patients for pre and post operation, and pharmacological studies.

• Journal of Veterinary Clinics
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• v.29 no.5
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• pp.384-390
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• 2012

Echocardiographic measurements of cardiac output, including the modified Simpson's method, Automated Contour Tracking(ACT) method, and left ventricular outflow method are well described methods of evaluating cardiac function due to its reliability and the benefits of its non-invasive technique in human medicine. The purpose of this study was to evaluate the accuracy of an echocardiography estimate of cardiac output in isoflurane-anesthetized beagle dogs and was to compare the ACT method to the other methods used in measurement of cardiac output. In healthy beagle dogs, cardiac output results by echocardiography estimate methods showed an excellent correlations with those by the thermodilution method (The modified Simpson's method : r = 0.815, $r^2=0.665$, y = 0.434x + 0.311 ; ACT method : r = 0.86, $r^2=0.748$, y = 0.391x + 0.242 ; ventricular outflow method : r = 0.691, $r^2=0.478$, y = 0.593x + 0.242). Among the results obtained, the ACT method showed the highest correlation coefficient. In conclusion, our study demonstrated that echocardiography estimate methods did not prove to be suitable in accurately measuring absolute cardiac output values but showed an excellent correlation with thermodilution method. Therefore, by using the measurement of cardiac output as supplemental data, echocardiography estimate methods can be used for detection and correction of hemodynamic disturbances during emergency and anesthesia in veterinary practice.

• Journal of Chest Surgery
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• v.23 no.1
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• pp.22-32
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• 1990

Postoperative cardiac performance of cyanotic congenital heart disease is somewhat different from that of other cardiac diseases. For the evaluation of postoperative cardiac performance in the cyanotic congenital heart disease we measured cardiac output by thermodilution technique at 1, 4, 8, 12, 16, 20, 24, 36, 48 postoperative hours in 14 patients operated from Feb. 1989 to Nov. 1989 in The Department of Thoracic and Cardiovascular Surgery, Seoul National University Children`s Hospital. At the same time, we checked left atrial pressure [LAP], central venous pressure [CUP], and mixed venous oxygen saturation [SvO2] to detect correlation between them. Immediate postoperative cardiac index was 3.585 $\pm$ 0.945 L/min/m2, and it decreased maximally to 3.322$\pm$1.007 L/min/m2 at postoperative 16 hours. After then it increased and stabilized from 36 hours after operation, and its value was 4.426$\pm$1.358 L/min/m2. There were no correlations between cardiac index and left atrial pressure or central venous pressure. Between mixed venous oxygen saturation and cardiac index, there was no correlation in the early postoperative period but after postoperative 16 hours, there was significant correlation between them and correlation coefficients were 0.573 [16hrs], 0.743 [20hrs], 0.436 [24hrs], 0.560 [36hrs], 0.636 [48hrs], respectively. From these results, we concluded that in the corrective surgery of cyanotic congenital heart disease, cardiac performance was depressed in the early postoperative period. It improved from postoperative 16 hours, and stabilized from 36 hours after operation. During early postoperative period, mixed venous oxygen saturation should not be used as a predictor of cardiac performance but it could be used as a predictor of cardiac performance from 16 hours after operation.

• Journal of Chest Surgery
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• v.30 no.12
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• pp.1205-1213
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• 1997

This study reviewed useful aspects of the intraoperative transesophageal echocardiography among the patients in whom heart surgery were undertaken between January 1996 and July 1996 at St.Pauls hospital, Medical College of Catholic University, Seoul, Korea. During that period, 61 patients were operated on because of valvular heart disease(25 patients), coronary artery disease(22 patients), congenital heart disease(13 patients), and combined coronary artery disease and valvular heart disease(1 patient). Two patients(1 redo-VSD and 1 valvular heart diease) needed repeated aortic cross clamping and complementary procedures because of incomplete initial procedures. There was no incidence of air embolism. We could observe significant relationship of cardiac output monitoring methods either by thermodilution technique and transesophageal echocardiography by linear regression analysis(p<0.001). We tested myocardial response(percentage of systolic wall thickness, PSWT) with low dose dobutamine challenge to predict post-CABG myocardial perfusion. And the test showed statistically significant resp.onse(sensitivity 76%, specificity 94.7%, positive predictive value 95%, negative predictive value 75%). These results suggest that cardiac surgeon could draw more benefits by intraoperative transesophageal echocardiography.