• Proceedings of the KOSOMBE Conference
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• v.1996 no.05
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• pp.88-90
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• 1996

The right and left atrial pressures are important parameters in automatic control of a total artificial heart (TAH) within normal physiological ranges. Our TAH is composed of a moving actuator, right and left ventricles and the interventricular space enclosed by a semi-rigid housing. During operation of the TAH, the jnterventpicular space's volume is changed dynamically by the difference between the ejection volume of one ventricle and the inflow volume of the other. Therefore, the changes in pressure of the interventricular space is related to both atrial pressures. We measured the interventricular pressure (IVP) waveform using a pressure sensor and attempted to indirectly estimate the changes of atrial pressures. This method has an advantage that the sensor does not contact the blood directly. Furthermore, the IVP waveforms have its zero baseline in each pump cycle, thus the pressure measurements are free from the transducer drift problems by measuring the peak pressure from these baseline values. From the In vitro experiments, we found that the IVP waveform contained several useful parameters such as negative peak, dP/dT on the initial break, the area enclosed by the profile in each stroke, which are associated with atrial pressures and the filling conditions of the ventricles. The measured atrial pressures were linearly related to the negative peak of the interventricular pressure.

• The Journal of Internal Korean Medicine
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• v.27 no.3
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• pp.784-790
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• 2006

Most of the atrial flutter occurs in patients who have an organic disease of the heart. The symptoms of atrial flutter include anxiety with palpitation. sleep disorder and fatigue. For a long time, oriental medicine has clinically treated these symptoms, and the diagnosis has been usually based on the doctor's judgment on the subjective clinical symptoms. However, if oriental medicine includes new diagnostic aids like electrocardiogram or other various methods or combinations of techniques, the accuracy and objectivity of diagnosis and clinical data can be improved. In this case, a 65 year-old male patient who had anxiety with palpitation and abnormal P wave (atrial flutter) on the EKG was treated with Xiaofengbusindaotantang (疎風補心導痰湯) and Shengmaisan (生脈散). Significant improvement in the clinical symptoms and EKG results was observed. This result suggests that oriental medical treatment can be used for treatment of organic heart disease like an atrial flutter. In addition, subsequent studies should be followed to ensure the appropriateness of new diagnostic aids, such as EKG, and other various modalities.

• Journal of Veterinary Clinics
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• v.37 no.1
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• pp.9-14
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• 2020

Left atrial enlargement (LAE) is an important diagnostic factor in dogs with myxomatous mitral valve disease (MMVD). It is associated with the onset of congestive heart failure (CHF). Recently, a new radiographic left atrial measurement called vertebral left atrial size (VLAS) was introduced. This can be considered as a left atrial enlargement above 2.3. It appears to be related to the severity of MMVD. However, serial changes in VLAS in relation to disease progression and improvement in patients have yet to be studied. This study aims to assess the value of VLAS as a left atrial size monitoring indicator by examining correlations with VHS, LA/Ao ratio and LVIDDN, and comparing serial changes in dogs. A total of 126 dogs were studied with their owners' consent. The dogs were classified into four MMVD groups (Control, B1, B2, C-D) following the ACVIM Guideline by performing a physical examination, radiography and echocardiography. Besides, 24 and 17 dogs were reevaluated to compare values in relation to the progression and improvement of MMVD. VLAS showed significant increase according to the progress of the MMVD stage. This was the same in the Maltese breed group. A strong positive correlation was found between LVIDDN, VHS, LA/Ao ratio, and VLAS. The results of this study found VLAS to be significantly different according to left atrium size, and there was a correlation between disease progression and VLAS levels in each dog. Therefore, VLAS may be used to detect changes in left atrium size as an additional monitoring index of MMVD.

• Journal of Chest Surgery
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• v.24 no.9
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• pp.843-852
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• 1991

We prospectively studied postoperative cardiac arrhythmia after open heart surgery to analyze the types and incidence of cardiac arrhythmia and to predict preoperative risk factors. And also we evaluated the effectiveness of atrial and ventricular epicardial electrodes which were placed during operation Between March 1990 and August 1990, We had operated on in 211 patients and we studied 201 consecutive patients excluding 10 patients. The study group included 99 males and 102 female patients, ages 1 month to 75 years[Mean$\pm$SD=28.0$\pm$21.7 years]. Postoperatively, all patients were regularly seen by the cardiac surgeon and cardiologist, They had continuous electrocardiographic monitoring for the first 3 days, initially in the intensive care unit and were checked routine electrocardiography on the postoperative 7 days, The postoperative cardiac arrhythmia were analyzed and possible associations of this arrhythmia with various pre, intra, and postoperative factors were studied by univariate and multivariate discriminant analysis, The overall incidence of postoperative cardiac arrhythmia except relative sinus bradycardia was 36.8%;[74/201], The incidence of postoperative cardiac arrhythmia in acyanotic congenital heart disease: 19.4%, cyanotic congenital heart disease: 20.8%, cardiac arrhythmia surgery: 33.3%, acquired valvular heart disease: 60.9% and coronary artery occlusive disease: 38.9%. Both univariate and multivariate studies indicated the pre operative symptom duration[p = 0013], the duration of medication[p=0.003], presence of preoperative arrhythmia[p<0.001] and pre-operative left atrial dimension in echocardiography to be the factor promoting postoperative cardiac arrhythmia. Multivariate discriminant analysis showed that the presence of preoperative cardiac arrhythmia, bypass time and the duration of preoperative symptom duration conveyed considerable risk factor on post-operative arrhythmia. The atrial wire electrodes were used diagnostically in 36 and were used therapeutically in 89 among 201 patients. Atrial pacing were used to treat relative sinus bradycardia, accelerated junctional tachycardia or premature atrial or ventricular contractions in 51 patients. Atrioventricular sequential pacing were used in 16 patients and ventricular pacing were used in 20 patients. Hemodynamics were evaluated in 2 patients of relative sinus bradycardia before and after atrial pacing. The atrial pacing increased the amount of cardiac output to 15% more. Because of their great utility in the diagnosis and treatment of arrhythmias, we conclude that routine placement of atrial and ventricular electrodes at the time of operation is indicated regardless of the nature of the open-heart procedure.

• The Korean Journal of Physiology and Pharmacology
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• v.21 no.3
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• pp.293-300
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• 2017

Prostaglandin $D_2$ ($PGD_2$) may act against myocardial ischemia-reperfusion (I/R) injury and play an anti-inflammatory role in the heart. Although the effect of $PGD_2$ in regulation of ANP secretion of the atrium was reported, the mechanisms involved are not clearly identified. The aim of the present study was to investigate whether $PGD_2$ can regulate ANP secretion in the isolated perfused beating rat atrium, and its underlying mechanisms. $PGD_2$ (0.1 to $10{\mu}M$) significantly increased atrial ANP secretion concomitantly with positive inotropy in a dose-dependent manner. Effects of $PGD_2$ on atrial ANP secretion and mechanical dynamics were abolished by AH-6809 ($1.0{\mu}M$) and AL-8810 ($1.0{\mu}M$), $PGD_2$ and prostaglandin $F2{\alpha}$ ($PGF2{\alpha}$) receptor antagonists, respectively. Moreover, $PGD_2$ clearly upregulated atrial peroxisome proliferator-activated receptor gamma ($PPAR{\gamma}$) and the $PGD_2$ metabolite 15-deoxy-${\Delta}12$, 14-$PGJ_2$ (15d-$PGJ_2$, $0.1{\mu}M$) dramatically increased atrial ANP secretion. Increased ANP secretions induced by $PGD_2$ and 15d-$PGJ_2$ were completely blocked by the $PPAR{\gamma}$ antagonist GW9662 ($0.1{\mu}M$). PD98059 ($10.0{\mu}M$) and LY294002 ($1.0{\mu}M$), antagonists of mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) and phosphatidylinositol-3-kinase (PI3K)/protein kinase B (Akt) signaling, respectively, significantly attenuated the increase of atrial ANP secretion by $PGD_2$. These results indicated that $PGD_2$ stimulated atrial ANP secretion and promoted positive inotropy by activating $PPAR{\gamma}$ in beating rat atria. MAPK/ERK and PI3K/Akt signaling pathways were each partially involved in regulating $PGD_2$-induced atrial ANP secretion.

• Progress in Superconductivity
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• v.7 no.1
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• pp.28-35
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• 2005

We propose a method to measure atrial arrhythmias (AA) such as atrial fibrillation (Afb) and atrial flutter (Afl) with a SQUID magnetocardiograph (MCG) system. To detect AA is one of challenging topics in MCG. As the AA generally have irregular rhythm and atrio-ventricular conduction, the MCG signal cannot be improved by QRS averaging; therefore a SQUID MCG system having a high SNR is required to measure informative atrial excitation with a single scan. In the case of Afb, diminished f waves are much smaller than normal P waves because the sources are usually located on the posterior wall of the heart. In this study, we utilize an MCG system measuring tangential field components, which is known to be more sensitive to a deeper current source. The average noise spectral density of the whole system in a magnetic shielded room was $10\;fT/{\surd}Hz(a)\;1\;Hz\;and\;5\;fT/{\surd}Hz\;(a)\;100\;Hz$. We measured the MCG signals of patients with chronic Afb and Afl. Before the AA measurement, the comparison between the measurements in supine and prone positions for P waves has been conducted and the experiment gave a result that the supine position is more suitable to measure the atrial excitation. Therefore, the AA was measured in subject's supine position. Clinical potential of AA measurement in MCG is to find an aspect of a reentry circuit and to localize the abnormal stimulation noninvasively. To give useful information about the abnormal excitation, we have developed a method, separative synthetic aperture magnetometry (sSAM). The basic idea of sSAM is to visualize current source distribution corresponding to the atrial excitation, which are separated from the ventricular excitation and the Gaussian sensor noises. By using sSAM, we localized the source of an Afl successfully.

• Asian-Australasian Journal of Animal Sciences
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• v.2 no.3
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• pp.264-266
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• 1989

• Journal of Chest Surgery
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• v.19 no.3
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• pp.429-432
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• 1986

Cardiac myxoma is most significant benign tumors constituting nearly 50% of all primary cardiac tumors. Its diagnosis is important because prognosis is excellent by surgical therapy and is usually fatal if unrecognized and untreated. Recently the development of diagnostic procedure and cardiac surgery increased the accuracy of diagnosis and the opportunity of successful treatment. Two cases of left atrial myxoma removed successfully were presented.

• Journal of Chest Surgery
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• v.42 no.2
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• pp.244-247
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• 2009

A left atrial appendage aneurysm is a very rare medical condition which can develop by an inflammatory reaction or a degenerative change. If there is no accompanying anomaly, a left atrial appendage is considered a congenital disease. The majority of left atrial appendage aneurysms are detected incidentally because they usually do not cause any symptoms. Surgery is indicated, even for asymptomatic patients, because of the risk of life-threatening complications, such as atrial fibrillation, supraventricular tachycardia, systemic embolization, and cardiac arrest. Left atrial appendage aneurysms are usually treated by a median sternotomy with extracorporeal circulation, especially if the aneurysm has a broad base or contains a thrombus, but can treated by thoracotomy without extracorporeal circulation. We report a case of a successfully treated left atrial appendage aneurysm that was misdiagnosed as a partial pericardial defect without extracorporeal circulation in a 13-year old child.

• The Korean Journal of Physiology and Pharmacology
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• v.9 no.2
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• pp.87-94
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• 2005

It is not clear whether $Ca^{2+}-induced$ $Ca^{2+}$ release from the sarcoplasmic reticulum (SR) is involved in the regulation of atrial natriuretic peptide (ANP) release. Previously, we have shown that nifedipine increased ANP release, indicating that $Ca^{2+}$ entry via voltage-gated L-type $Ca^{2+}$ channel activation decreases ANP release. The purpose of the present study was two-fold: to define the role of SR $Ca^{2+}$ release in the regulation of ANP release and whether $Ca^{2+}$ entry via L-type $Ca^{2+}$ channel is prerequisite for the SR-related effect on ANP release. Experiments were performed in perfused beating rabbit atria. Ryanodine, an inhibitor of SR $Ca^{2+}$ release, increased atrial myocytic ANP release ($8.69{\pm}3.05$, $19.55{\pm}1.09$, $27.31{\pm}3.51$, and $18.91{\pm}4.76$% for 1, 2, 3, and $6{\mu}M$ ryanodine, respectively; all P<0.01) with concomitant decrease in atrial stroke volume and pulse pressure in a dose-dependent manner. In the presence of thapsigargin, an inhibitor of SR $Ca^{2+}$ pump, ryanodine-induced increase in ANP release was not observed. Thapsigargin attenuated ryanodine-induced decrease in atrial dynamic changes. Blockade of L-type $Ca^{2+}$ channel with nifedipine abolished ryanodine-induced increase in ANP release ($0.69{\pm}5.58$% vs. $27.31{\pm}3.51$%; P＜0.001). In the presence of thapsigargin and ryanodine, nifedipine increased ANP release and decreased atrial dynamics. These data suggest that $Ca^{2+}$-induced $Ca^{2+}$ release from the SR is inversely involved in the regulation of atrial myocytic ANP release.