• Title/Summary/Keyword: significant wave period

Search Result 215, Processing Time 0.021 seconds

Evaluation of short-term cardiac function by tissue Doppler imaging in pre and postoperative period of congenital heart disease (조직 도플러 영상을 이용한 선천성 심장병 수술 전후의 단기 심기능 평가)

  • Lee, Jun-Hwa;Kim, Yeo-Hyang;Hyun, Myung-Chul;Lee, Sang-Bum
    • Clinical and Experimental Pediatrics
    • /
    • v.50 no.5
    • /
    • pp.476-483
    • /
    • 2007
  • Purpose : The objective of this study was to assess ventricular function by tissue Doppler imaging (TDI) in children with congenital heart disease (CHD) who have been undergoing open heart surgery (OHS) using cardiopulmonary bypass. We tried to compare the parameters of tissue Doppler imaging before and after OHS in patients with congenital heart disease. Methods : This study was conducted on 32 patients with CHD after OHS from January 2005 to December 2005 at Kyungpook National University hospital. Patients who underwent 2-D echocardiography before and after their OHS. All patients were divided into three groups, left ventricular volume overloading group (group 1), and right ventricular volume overloading group (group 2), and right ventricular pressure overloading group (group 3). The TDIs were examined before and 1 to 3 months after OHS. Peak early diastolic (E), and peak late diastolic (A) velocity of transmitral flow were measured by pulsed wave Doppler examination. Peak systolic (Sm), peak early diastolic (Em), and peak late diastolic (Am) velocity in apical 4-chamber and 2-chamber views were measured by TDI. The author calculated E/Em ratio. Results : The patients were 14 boys and 18 girls and the average age of patients was 2 years and 3 months. The congenital heart diseases which have to get OHS were ventricular septal defect (13 cases), atrial septal defect (7), atrioventricular septal defect (3), isolated pulmonary stenosis (2) and tetralogy of Fallot (7). There were significant decrease of Sm, Em, Am measured on tricuspid annulus and E/Em measured on mitral annulus in apical 4 chamber view (P<0.05). Conclusion : This study showed significant decrease of Sm, Em, Am measured on tricuspid annulus and E/Em measured on mitral annulus in apical 4 chamber view after OHS. These changes might be due to the effects of cardiopulmonary bypass in OHS and/or hemodynamic changes after correction of congenital heart disease. To clarify these changes, further study on more patients is needed.

The Effects of Pergola Wisteria floribunda's LAI on Thermal Environment (그늘시렁 Wisteria floribunda의 엽면적지수가 온열환경에 미치는 영향)

  • Ryu, Nam-Hyong;Lee, Chun-Seok
    • Journal of the Korean Institute of Landscape Architecture
    • /
    • v.45 no.6
    • /
    • pp.115-125
    • /
    • 2017
  • This study was to investigate the user's thermal environments under the pergola($L\;7,200{\times}W\;4,200{\times}H\;2,700mn$) covered with Wisteria floribunda(Willd.) DC. according to the variation of leaf area index(LAI). We carried out detailed measurements with two human-biometeorological stations on a popular square Jinju, Korea($N35^{\circ}10^{\prime}59.8^{{\prime}{\prime}}$, $E\;128^{\circ}05^{\prime}32.0^{{\prime}{\prime}}$, elevation: 38m). One of the stations stood under a pergola, while the other in the sun. The measurement spots were instrumented with microclimate monitoring stations to continuously measure air temperature and relative humidity, wind speed, shortwave and longwave radiation from the six cardinal directions at the height of 0.6m so as to calculate the Universal Thermal Climate Index(UTCI) from $9^{th}$ April to $27^{th}$ September 2017. The LAI was measured using the LAI-2200C Plant Canopy Analyzer. The analysis results of 18 day's 1 minute term human-biometeorological data absorbed by a man in sitting position from 10am to 4pm showed the following. During the whole observation period, daily average air temperatures under the pergola were respectively $0.7{\sim}2.3^{\circ}C$ lower compared with those in the sun, daily average wind speed and relative humidity under the pergola were respectively 0.17~0.38m/s and 0.4~3.1% higher compared with those in the sun. There was significant relationship in LAI, Julian day number and were expressed in the equation $y=-0.0004x^2+0.1719x-11.765(R^2=0.9897)$. The average $T_{mrt}$ under the pergola were $11.9{\sim}25.4^{\circ}C$ lower and maximum ${\Delta}T_{mrt}$ under the pergola were $24.1{\sim}30.2^{\circ}C$ when compared with those in the sun. There was significant relationship in LAI, reduction ratio(%) of daily average $T_{mrt}$ compared with those in the sun and was expressed in the equation $y=0.0678{\ln}(x)+0.3036(R^2=0.9454)$. The average UTCI under the pergola were $4.1{\sim}8.3^{\circ}C$ lower and maximum ${\Delta}UTCI$ under the pergola were $7.8{\sim}10.2^{\circ}C$ when compared with those in the sun. There was significant relationship in LAI, reduction ratio(%) of daily average UTCI compared with those in the sun and were expressed in the equation $y=0.0322{\ln}(x)+0.1538(R^2=0.8946)$. The shading by the pergola covered with vines was very effective for reducing daytime UTCI absorbed by a man in sitting position at summer largely through a reduction in mean radiant temperature from sun protection, lowering thermal stress from very strong(UTCI >$38^{\circ}C$) and strong(UTCI >$32^{\circ}C$) down to strong(UTCI >$32^{\circ}C$) and moderate(UTCI >$26^{\circ}C$). Therefore the pergola covered with vines used for shading outdoor spaces is essential to mitigate heat stress and can create better human thermal comfort especially in cities during summer. But the thermal environments under the pergola covered with vines during the heat wave supposed to user "very strong heat stress(UTCI>$38^{\circ}C$)". Therefore users must restrain themselves from outdoor activities during the heat waves.

Mid-Term Results of 292 cases of Coronary Artery Bypass Grafting (관상동맥 우회술 292례의 중기 성적)

  • 김태윤;김응중;이원용;지현근;신윤철;김건일
    • Journal of Chest Surgery
    • /
    • v.35 no.9
    • /
    • pp.643-652
    • /
    • 2002
  • As the prevalence of coronay artery disease is increasing, the surgical treatment has been universalized and operative outcome has been improved. We analyzed the short and mid-term results of 292 CABGs performed in Kangdong Sacred Heart Hospital. Material and Method: From June 1994 to December 2001, 292 patients underwent coronary artery bypass grafting. There were 173 men and 119 women and their ages ranged from 39 to 84 years with a mean of $61.8{\pm}9.1$ years. We analyzed the preoperative risk factors, operative procedures and operative outcome. In addition, we analyzed the recurrence of symptoms, long-term mortality and complications via out-patient follow-up for discharged patients. Result: Preoperative clinical diagnoses were unstable angina in 137(46.9%), stable angina in 34(11.6%), acute myocardial infarction in 40(13.7%), non-Q myocardial infarction in 25(8.6%), postinfarction angina in 22(7.5%), cardiogenic shock in 30(10.3%) and PTCA failure in 4(1.4%) patients. Preoperative angiographic diagnoses were three-vessel disease in 157(53.8%), two-vessel disease in 35 (12.0%), one-vessel disease in 11(3.8%) and left main disease in 89(30.5%) patients. We used saphenous veins in 630, internal thoracic arteries in 257, radial arteries in 50, and right gastoepiploic arteries in 2 distal anastomoses. The mean number of distal anastomoses per patient was $3.2{\pm}1.0$ There were 18 concomitant procedures ; valve replacement in 8(2.7%), left main coronary artery angioplasty in 6(2.1%), patch closure of postinfarction ventricular septal defect(PMI-VSD) in 2(0.7%), replacement of ascending aorta in 1(0.3%) and coronary endarterectomy in 1(0.3%) patient. The mean ACC time was $96.6{\pm}35.3 $ minutes and the mean CPB time was $179.2{\pm}94.6$ minutes. Total early mortality was 8.6%, but it was 3.1% in elective operations. The most common cause of early mortality was low cardiac output syndrome in 6(2.1%) patients. The stastistically significant risk factors for early mortality were hypertension, old age($\geq$ 70 years), poor LV function(EF<40%), congestive heart failure, preoperative intraaortic balloon pump, emergency operation and chronic renal failure. The most common complication was arrhythmia in 52(17.8%) patients. The mean follow-up period was $39.0{\pm}27.0$ months. Most patients were free of symptoms during follow-up. Fourteen patients(5.8 %) had recurrent symptoms and 7 patients(2.9%) died during follow-up period. Follow-up coronary angiography was performed in 13 patients with recurrent symptoms and they were managed by surgical and medical treatment according to the coronary angiographic result. Conclusion: The operative and late results of CABG in our hospital, was acceptable. However, There should be more refinement in operative technique and postoperative management to improve the results.

Availability of Cardiac Troponin T as a Marker for Detecting Perioperative Myocardial Damage in Patients with Open Heart Surgery (개심술후 발생한 심근손상에서 진단 표지자로서의 Troponin T의 임상적 유용성)

  • 김태이;정태은;이동협;이정철;한승세
    • Journal of Chest Surgery
    • /
    • v.31 no.1
    • /
    • pp.20-27
    • /
    • 1998
  • It is well known that troponin T(below TnT) is present in the myocardial cells and released during myocardial damage, so it`s very specific enzyme to myocardium. Availability of cardiac specific TnT in assessing perioperatively myocardial damage was evaluated from 34 open heart surgery patients. They consisted of 11 ischemic heart, 13 acquired valvular heart and 10 congenital heart cases. Patients were divided into two groups, group A(patients with myocardial damage) and group B(patients without myocardial damage), according to the symptom of chest pain suspecting angina and the ECG findings of ST segment and T wave changes which show myocardial ischemia and injury. Serum TnT levels were measured by enzyme immunoassay method preoperatively, immediately postoperatively, postoperative day 1, day 2, day 3, and day 7. We observed and analyzed the changes of serum TnT levels in two groups and compared the serum TnT levels with CK-MB levels measured at the same time. In group A, serum TnT levels showed 1.37$\pm$0.26$\mu$g/L, 3.16$\pm$0.66$\mu$g/L, 2.39$\pm$0.74$\mu$g/L, 2.49$\pm$0.76$\mu$g/L, and 1.23$\pm$0.60$\mu$g/L, immediate postoperatively, postoperatively day1, day2, day3, and day7, respectively. It was observed there were significant differences compared with those of group B(0.38$\pm$0.04$\mu$g/L, 0.34$\pm$0.05$\mu$g/L, 0.25$\pm$0.03$\mu$g/L, 0.24$\pm$0.04$\mu$g/L, and 0.11$\pm$0.03$\mu$g/L) during identical periods(P<0.01). Serum CK-MB level in group A significantly elevated to 145.04$\pm$35.08 IU/L on the postoperative day 1 compared to group B(31.28$\pm$5.87 IU/L, P<0.05), However, it stiffly decreased from day 2 and returned to preoperative level at day 3. When serum TnT level more than 1.0$\mu$g/L is thought to reflect myocardial damage, serum TnT had 100% of sensitivity and 87% of specificity in diagnosing the postoperative myocardial damage(p<0.01). I conclusion, serum TnT levels increased significantly at very early stage of myocardial damage and persisted much longer period than CK-MB. This suggests that serum TnT has more advantage and availability in assessing the perioperatively myocardial damage than any other tests.

  • PDF

A Case Study of Strong Wind Event over Yeongdong Region on March 18-20, 2020 (2020년 3월 18일-20일 영동지역 강풍 사례 연구)

  • Ahn, Bo-Yeong;Kim, Yoo-Jun;Kim, Baek-Jo;Lee, Yong-Hee
    • Journal of the Korean earth science society
    • /
    • v.42 no.5
    • /
    • pp.479-495
    • /
    • 2021
  • This study investigates the synoptic (patterns of southern highs, northern lows, and lows rapidly developed by tropopause folding), thermodynamic, and kinematic characteristics of a strong wind that occurred in the Yeongdong region of South Korea on March 18-20, 2020. To do so, we analyzed data from an automatic weather station (AWS), weather charts, the European Centre for Medium-range Weather Forecasts (ECMWF) reanalysis, rawinsonde, and windprofiler radars. The daily maximum instantaneous wind speed, exceeding 20 m s-1, was observed at five weather stations during the analysis period. The strongest instantaneous wind speed (27.7 m s-1) appeared in the Daegwallyeong area. According to the analysis of weather charts, along with the arrangement of the north-south low-pressure line, the isobars were moved to the Yeongdong area. It showed a sine wave shape, and a strong wind developed owing to the strong pressure gradient. On March 19, in the northern part of the Korean Peninsula, with a drop in atmospheric pressure of 19 hPa or more within one day, a continuous strong wind was developed by the synoptic structure of the developing polar low. In the adiabatic chart observed in Bukgangneung, the altitude of the inversion layer was located at an altitude of approximately 1-3 km above the mountaintop, along with the maximum wind speed. We confirmed that this is consistent with the results of the vertical wind field analysis of the rawinsonde and windprofiler data. In particular, based on the thermodynamic and kinematic vertical analyses, we suggest that strong winds due to the vertical gradient of potential temperature in the lower layer and the development of potential vorticity due to tropopause folding play a significant role in the occurrence of strong winds in the Yeongdong region.