• Journal of Nutrition and Health
• /
• v.25 no.7
• /
• pp.597-607
• /
• 1992

The present study examined effects of caffeine on coronary circulation myocardial oxygen me-tabolism and calcium release in isolated perfused guinea pig hearts. Intracoronary caffeine({{{{ {10 }^{-5 } }}}}∼{{{{ { 10}^{-3 } }}}}M) was employed for 10 minutes to measure coronary perfusate flow(CF) and coronary vascular sresistance(CVR) at a constant coronary perfusion pressure of 80 cmH2O Perfusate myocardial oxygen consumption(MVO2) and percent oxygen extraction(%EC2) were calcula-ted. In addition calcium contents in both perfusate samples were measured to calculate calcium release in coronary venous effluent. Caffeine significantly decreased CF and increased CVR during 10 minutes of caffeine perfusion regardless of dose of caffeine perfused exhibiting time-response. While % EO2 was significantly enhanced with caffeine MVO2 was markedly reduced. The coronary venous perfusate pH dcreased during the perfusion with caffeine. These changes were consistent with caffeine-induced metabolic acidosis. Calcium release appeared to be dose-dependent and high dose of caffeine greatly increased venous calcium release even 2 minutes after perfusion with carffeine. These finding in dicate that caffeine produced coronary vasoconst-riction with increased calcium release in isolated perfused guinea pig hearts. Additionaly this vasoconstrictor response mignt be due tin part to the direct actions of caffeine.

• Journal of Mechanical Science and Technology
• /
• v.19 no.6
• /
• pp.1313-1320
• /
• 2005

Stenosed coronary artery may play an important role in various coronary heart diseases. However, it has not been known how much stenosed coronary artery affects coronary circulation system, quantitatively. The present study developed a mathematical model for microcirculation in the left common coronary artery (LCCA) with adopting a previously measured morphological data and mechanical properties of the coronary vessels. We examine the effect of percent diameter stenosis on blood flow rate and shear stress for two cases. Case I comprised of one-stenosed element at $10^{th}$ order ($\%$ diameter stenosis are 10, 30, and 50, respectively). Case II consisted of completely occluded element at $10^{th}$ order (number of occluded elements are 0, 1, and 2 out of 8, respectively). As the level of stenosis becomes severe, the shear stress increases significantly but the flow rate reduction was relatively small. However, for the occluded case, there was linearly proportional reduction of flow rate according to number of occluded elements. Either such high shear stress associated with coronary artery stenosis or reduced flow rate due to occlusion may cause atherosclerosis and myocardial ischemia.

• Journal of Chest Surgery
• /
• v.55 no.3
• /
• pp.243-245
• /
• 2022

True aneurysms of the coronary artery after aortic root replacement in Marfan syndrome patients are very rare. An anomalous origin of the right coronary artery (RCA) from the left sinus of Valsalva adds complexity during aortic root surgery. We present a case of a 37-year-old male patient with Marfan syndrome who had an RCA anomaly and a 4.5-cm true aneurysm of the common coronary button 14 years after a previous Bentall procedure. A redo Bentall operation and hemi-arch replacement were successfully performed. The anomalous origin of the RCA from the left sinus of Valsalva was safely divided and anastomosed as separate coronary buttons to the prosthetic composite valve graft. To prevent coronary button aneurysms after aortic root surgery in Marfan patients, the coronary buttons and the corresponding side holes on the prosthetic graft must be reduced to the maximum possible extent.

• Journal of the Korean Society of Radiology
• /
• v.17 no.7
• /
• pp.1033-1039
• /
• 2023

Low-dose chest CT, which is used as a lung screening test, also includes information on coronary artery calcification within the scan range. The purpose of this study was to investigate the usefulness of determining coronary artery calcification using Low-dose chest CT. Those who underwent low-dose chest CT and coronary artery calcification score CT on the same day were eligible. Coronary artery calcium score CT results were divided into 4 groups (Low: 1〈CACS〈10, Mild: 10〈CACS〈100, Moderate: 100〈CACS〈400, High: 400〈CACS) by referring to the Coronary artery calcium score categories and risks. After selecting 30 people each group, five radiotechnologists with more than 15 years of experience in coronary artery calcium measurement retrospectively analyzed the presence or absence of coronary artery calcification in low-dose chest CT images. The results of the five observers' uniform interpretation of the low-dose chest CT image were consistent with the coronary artery calcium score CT results in Low group: 56%, Mild group: 96.6%, Moderate group: 100%, and High group: 100%. appeared. In the Low group, all 5 observers observed calcification in 17 out of 30 cases, and in 7 cases all 5 observers decided that calcification could not be identified. Coronary artery calcification could be observed in 100% of asymptomatic adults with a calcium score of 15 or higher in low-dose chest CT scans. The minimum calcium score that can be identified is 1, and it was found that even very small calcifications can be identified when the subject's body size is small or the scan is performed at a time when heart movement is minimal.

• Journal of Chest Surgery
• /
• v.34 no.9
• /
• pp.720-723
• /
• 2001

A case of Marfan’s syndrome with atresia of right coronary artery is reported. A 45-year-old woman, who was diagnosed as Marfan’s syndrome 1 year ago, came to the hospital complaining of acute chest pain. The patient showed arachynodactyly, pectus carinatum, and long and slender extremities. In echocardiography there were severe aortic regurgitation measured grade IV and aortic dilatation of ascending aorta maximally 5.9 cm in diameter. Mitral regurgitation was mild, but there were also moderate left ventricular dilation and moderately decreased ejection fraction of left ventricle. At operation, atresia of right coronary artery was found. We performed Bentall type operation with SJM 27mm valved conduit for left coronary artery, and Piehler’s modification for right coronary artery bypass using 6mm PTFE graft. The atretic portion of right coronary artery from the suspected right coronary ostium to distal coronary flow was about 4 cm in length. The combination of right coronary artery atresia and Marfan’s syndrome is very rare. The author describes the rare case, which is treated with combined technique of Bentall and Piehler modification for reconstruction of coronary circulation.

• Journal of Chest Surgery
• /
• v.43 no.3
• /
• pp.296-299
• /
• 2010

A right coronary artery to left ventricular fistula with a giant right coronary artery aneurysm is a very rare condition. This requires surgical treatment because of the possibility of rupture of aneurysm, heart failure and infective endocarditis. A 47 years old male patient with dyspnea on exertion for 3 months was diagnosed as having a right coronary artery to left ventricular fistula with a giant right coronary artery aneurysm according to the CT and coronary artery angiography. We resected the aneurysm and performed a coronary artery bypass graft.

• Journal of the Korean Society of Radiology
• /
• v.85 no.2
• /
• pp.258-269
• /
• 2024

Treatment of patients with coronary artery disease commonly involves the use of balloon-expandable stent placements, currently recognized as the most prevalent approach for coronary artery revascularization. Nevertheless, the occurrence of restenosis remains a significant complication following percutaneous coronary interventions. The diagnostic role of coronary CT angiography (CCTA) in detecting stent restenosis has limitations primarily attributable to challenges in accurately discerning the lumen, due to issues such as blooming and motion artifacts. As a result, many cases often necessitate a transition to conventional coronary angiography. However, recent advancements in CT technology have led to notable improvements in both sensitivity and specificity, underscoring the growing significance of CCTA as a diagnostic tool. The consistent reporting of high negative predictive value is particularly noteworthy. This review aims to explore the historical context, current status, and recent trends in diagnosing coronary artery stent restenosis using CCTA.

• Journal of the Korean Society of Radiology
• /
• v.85 no.2
• /
• pp.270-296
• /
• 2024

Coronary CT angiography (CCTA) is recognized for its role as a gatekeeper for invasive coronary angiography in patients suspected of coronary artery disease because it can detect significant coronary stenosis with high accuracy. However, heavy plaque in the coronary artery makes it difficult to visualize the lumen, which can lead to errors in the interpretation of the CCTA results. This is primarily due to the limited spatial resolution of CT scanners, resulting in blooming artifacts caused by calcium. However, coronary stenosis with high calcium scores often requires evaluation using CCTA. Technological methods to overcome these limitations include the introduction of high-resolution CT scanners, the development of reconstruction techniques, and the subtraction technique. Methods to improve reading ability, such as the setting of appropriate window width and height, and evaluation of the position of calcified plaque and residual visibility of the lumen in cross-sectional images, are also recommended.

• Journal of Chest Surgery
• /
• v.24 no.11
• /
• pp.1133-1137
• /
• 1991

Congenital coronary arteriovenous fistula is relatively uncommon and often associated with additional congenital and acquired heart disease. If coronary arteriovenous fistula is suspected, the diagnosis can be made readily by cardiac catheterization and selective coronary arteriography. Surgical treatment is very satisfactory, with a low mortality and apparent good long term result. Recently, we experienced one case of congenital coronary arteriovenous fistula which was associated with aortic stenosis and regurgitation. The tortuous fistula tract was noted between the left anterior descending coronary artery and the main pulmonary artery. Under the cardiopulmonary bypass, aortic valve replacement[Carbomedics 23mm] and suture closure of the draining orifice of coronary arteriovenous fistula in the main pulmonary artery just above the pulmonary valve were performed, Postoperative hospital course was uneventful and the patient was discharged postoperative 9th day without any problems.

• Journal of Chest Surgery
• /
• v.24 no.5
• /
• pp.491-497
• /
• 1991

Coronary arteriovenous fistula is a relatively rare congenital heart disease and it drains into right atrium, right ventricle, pulmonary artery, coronary sinus or superior vena cava. We experienced one case of fistulous communication between right coronary artery and right ventricle which was most common condition. The patient was a 12 year old female and the only sign was continuous cardiac murmur. The cardiac catheterization and coronary angiography showed the fistulous communication between right coronary artery and right ventricle and aneurysmal dilatation of right coronary artery. Under the cardiopulmonary bypass with the hypothermic cardioplegia, fistula opening[7mm] which was located at right ventricle below the tricuspid valve annulus between septal and posterior leaflet was closed with 4 - 0 prolene continuous suture through right ventriculotomy. Her postoperative course was uneventful.