Objective To study the differences in blood pressure (BP)levels and the main factors raising BP among the population in Guangdong province.Methods The data analyzed stem from the sampling survey of hypertension in Guangdong Province in 1991,covering 42,894 subjects over 15 years old.Individual characteristics included age,sex,occupation education,smoking,alcohol drinking and body mass indx(BMI).Results Systolic and diastolic BP increased with age.The hypertension prevalence rate in male is higher than in female.The age-adjusted prevalence rate in office personnel is the highest(12.9%)among all occupations.It was increased with educfation level and BMI (in people educated atuniversity and over is 13.1%),and higher in smokers and alcohol-drinkers than non -smokers and nonalcohol-drinkers.Conclusions Age,occupation,education,smoking,alcohol drinking and BMI all effect BP.These risk factors should be reduced in the Guangdong population.

作者： 刊期： 2001年第02期

作者： 刊期： 2001年第02期

Objective The study will explore effects of the autoantibodies against AT1 receptor and angiotensin Ⅱ on the refractory hypertension. Methods Seventy-seven patients (46 men and 31 women) with essential hypertension were divided into groups of refractory hypertension (RH) and hypertension (HT) according to the 1999 WHO -ISH Guidelines for the Management of Hypertension. Forty normotensives (22 men) were recruited as controls.The mean age was 54. 3 ± 13 years old in RH group,53.5±9 years old in HT group and 51.2±11.9years old in normotensives (NT) group. The mean blood pressure was 154.2 ± 9.4/98.4 ± 8.2 mmHg in RH group and 130.1 ±7.6/80.5 ±6.7 mmHg in HT group after combination drug therapy of hypertension for 4 weeks. Blood pressure in NT group was 120. 8 ± 11.7/76. 4 ± 7.2 mmHg. The epitope of the 2nd extracellular loops of AT1 receptor was synthesized and used as antigens to screen the autoantibodies by ELISA. Plasma angiotensin (Ang) Ⅱ were examined by a radioimmunoassay. Results The autoantibodies against AT1 receptor were positive in 18 (46. 15% ) patients with RH, in 4 (10. 5 % ) hypertension and in 3 (7.5 % ) normotensives, P ＜ 0.01. Ang Ⅱwas 57.01 ± 52.63 pmol/L in patients with RH. Both the autoantibodies positive and the Ang Ⅱ increasing were 4 (10. 3 %) cases, both normal were 7 (17.9% ) cases, the autoantibodies positive or Ang Ⅱ in creasing was all of 14 (35.9 % ) cases (χ2 =0. 09,P ＞ 0. 05) There was no relationship between the autoantibodies against AT1 receptor and the angiotensin Ⅱ in refractory hypertension. Conclusion The autoantibodies against AT1 receptor and Ang Ⅱ might be two independent factors in developing of refractory hypertension. The findings suggest that AT1 receptor antagnist used in the treatment of refractory hypertension might have an important value.

作者： 刊期： 2001年第02期

though an association between the group A beta hemolytic streptococcus and rheumatic fever has been recognized for more than half a century, many important issues about this relationship remain incompletely defined. The initiating pharyngeal throat infection and the difference between true infection and the relatively harmless streptococcal “carrier state” are not yet understood. Many properties of the organism itself largely remain a mystery. While much has been written about “rheumatogenecity” of certain streptococci, the precise mechanism for inducing “rheumatogenecity”is unknown. Nor is there sufficient evidence to understand the role of “antigenic mimicry” in the pathogenesis.With the introduction of molecular techniques into the basic science laboratory, the nurmer of different streptococcal types (based either on the M protein or the emm gene) has almost doubled during the past ten years, making the problem even greater since little is known about the relative importance or epidemiology of these newly described types.

作者： 刊期： 2001年第02期

Objective To study the changes of baroreflex sensitivity (BRS) during head -up tilt test (HUT) in patients with vasovagal syncope (VS),and to examine the relationship between baroreflex sensitivity and neurohormonal factors. Furthermore, to investigate the effects of the changes of BRS on VS.Methods Forty- two patients with unexplained syncope (Among the 42 patients, there were 22 patients with positive HUT and 20 patients with negative HUT respectively) and 20 healthy volunteers (with negative HUT) underwent passive head-up tilt testing, Antecubital vein blood samples were taken before and after HUT, or at syncope. The fasting plasma endothelin ,serum nitric oxide (NO), serum NE were measured. The BRS was assessed on the basis of the linear regression slope the RR interval versus systolic arterial blood pressure during the increment in blood pressure after intravenous administration of phenylephrine. Results ( 1 )During the syncope, the BRS significantly reduced in HUT( + ) group than baseline. At the end of tilt, the level of plasma ET, serum NO in patients with positive HUT significantly increased compared with baseline or normal controls, and the plasma concentration of NE also had the trend of increase. ( 2 ) By multiple regression analysis, a significant negative correlation was found between baroreceptor sensitivity and the plasma ET, NO at the end of HUT in patients with positive HUT, but there was no relationship between BRS and NE. Conclusions During the syncope occure, the BRS in patients with VS decreased significantly compared with normal controls. The abnormal plasma ET, NO concentration might contribute to the mechanism of VS.

作者： 刊期： 2001年第02期

BSTRACT Atrial natriuretic peptide (ANP) is a peptide hormone that has potent natriuretic, diuretic,vasodilator, sympatholytic, and renin- and aldosterone- suppressing activities and is involved in the regulation of volume and electrolyte balance and blood pressure. Further, ANP has also been shown to inhibit cellular growth, proliferation and induce apoptosis in a variety of cell lines, including vascular smooth muscle cells and cardiac myocytes. Recent studies have demonstrated that ANP is not only involved in blood pressure and volume homeostasis but also in the direct regulation of cardiac growth. We and other investigators have demonstrated the existence of natriuretic peptide receptors in the heart and cardiac cells, suggesting that ANP has direct actions on cardiac tissue. Several recent in vivo studies have suggested that statement of ANP is inversely related to cardiac growth/hypertrophy. Transgenic mice overexpressing ANP have lower heart weight and blood pressure than wild type mice.

作者： 刊期： 2001年第02期

Background Myocardial blood flow(MBF) can be quantified with myocardial contrast echocardiography (MCE) during a venous in fusion of microbubble. A minimal MBF is required to maintain cell membrane integrity and myocardial viability in ischemic condition. Thus, we hypothesized that MCE could be used to assess myocardial viability by the determination of MBF. Methods and Results MCE was performed at 4 hours after ligation of proximal left anterior descending coronary artery in 7dogs with constant venous infusions of microbubbles.The video intensity versus pulsing interval plots derived from each myocardial pixel were fitted to an exponential function: y=A(1-e-βt), where y is Ⅵ at pulsing interval t, A reflects rnicrovascular cross- sectional area (or myocardial blood volume), and β reflects mean myocardial microbubble velocity. The product of A · β represents MBF. MBF was also obtained by radiolabeled microsphere method servered as reference.MBF derived by radiolabeled microsphere- method in the regions of normal, ischemia and infarction was 1.5±0.3, 0.7±0.3, 0.3±0.2mL·min-1· g-1respectively. The product of A · β obtained by MCE in those regions was 52. 46 ± 15.09, 24.36 ± 3.89, 3.74± ± 3.80 respectively. There was good correlation between normalized MBF and the normalized A · β (r =0. 81, P = 0. 001 ). Conclusions MCE has an ability to determine myocardial viability in myocardial in farction canine model.

作者： 刊期： 2001年第02期

The 3rd South China Cardiovascular Scientific Sessions was held on August 4th ～ 6th, 2001 in Guangzhou.There were a total of 119 papers published, 13 lectures given by well- known cardiologists from inland and other parts of the world and 13 satellite conferences.These sessions were characterized by abundant updated information and advance in research on cardiovascular diseases in basic and clinical sciences. They are summarized as follows:

作者： 刊期： 2001年第02期

atients with Acute Coronary Syndrome (ACS)are a clinical continuum-with patients presenting with unstable angina on one end, with patients with ST elevation myocardial infarction (STEMI) at the other end of the spectrum. In between are those with non- ST elevation myocardial infarction (NSTEMI) The pathophysiology is similar in these patients, namely isruption and fissuring of an atheromatous plaque,leading to enhanced platelet activation and local vasohyperactivity, with reduced flow and thrombus formation. While medical experts have reached consensus in the management of STEMI patients (thrombolysis nd / or percutaneous coronary intervention), optimalmanagement of patients with UA/NSTEMI remainsunclear.

作者： 刊期： 2001年第02期

作者： 刊期： 2001年第02期

eart failure is a disease with high morbidity and mortality. It is also the commonest cause of medical ward admission. The incidence of heart failure has been increasing world-wide in the past decade.Studies observed that about 25 - 50 % of patients with heart failure had evidence of electromechanical delay,commonly in the form of left bundle branch block or intraventricular conduction delay on surface electrocardiogram. This condition results in dyssynchronous contraction, mitral regurgitation and was associated with a worse prognosis. These patients may therefore benefit from cardiac resynchronization therapy.

作者： 刊期： 2001年第02期

Objective To compare the acute hemodynamic effects of five different pacing modes in patients with cardiac function NYHA class to Ⅱ without bundle branch block (BBB). Methods This study included 12 patients (SSS 7, Ⅲ°AVB 5) undergoing pacemaker implantation. Right ventricular apex (RVA), right ventricular outflow tract (RVOT),right ventricular bifocal (RV-Bi), left ventricular base (LVB) and bi - ventricular (Bi - V) pacing at 60～ 80 ppm were done in VVI mode prior to implantation of DDD pacemaker. The cardiac index (CI), mean pulmonary artery pressure (mPAP) and pulmonary capillary wedge pressure (PCWP) were measured with Swan - Ganz thermodilution catheter after 5 minutes of each pacing mode. Results ( 1 ) Comparing to pacing at RVA (CI: 2. 41 ±0. 38 L/min per m2, PCWP: 16. 7± 3.3 mmHg), the CI increased and the PCWP decreased significantly in pacing at RVOT(CI: 2.63 ±0.46, PCWP: 13.8±2.3), LVB(CI: 2.78±0.52,PCWP: 14.4±3.1), RV-Bi(CI: 2.83±0.57,PCWP: 12.8±2.5) and Bi-Vpacing(CI: 2.94±0. 60, PCWP: 12. 7 ±2.5), P ＜ 0. 01, respectively.(2) The CI of RV- Bi and Bi- V pacing was higher than that of RVOT and LVB pacing, the PCWP was lower, P ＜ 0.05, respectively. (3) There was no significant difference between RV- Bi pacing and Bi- V pacing in CI and PCWP. Conclusion There is no significant difference between RV - Bi pacing and Bi V pacing in the acute hemodynamic effects; however,dual - site pacing is much better than single site pacing in that aspect for patients with cardiac function NYHA class Ⅰ to Ⅱ without BBB. Among single site pacing, the RVOT and LVB pacing is better than RVA pacing in cardiac function.

作者： 刊期： 2001年第02期

Objectives The purpose of this study was to determine if the ultrasonic integrated backscatter and echo intensity could be used in clinical diagnosis of acute myocardial infarction. Methods and Results Within 2 weeks after acute myocardial infarction, 35 patients underwent ultrasonic tissue characterization from the papillary short- axis view.The cyclic variation of integrated backscatter and echo intensity of three different myocardial regions perfused by left anterior descending coronary artery, left cir cumflex coronary and right coronary were measured .The value of cyclic variation of integrated backscatter and integrated backscatter and echo intensity ≤ half of the highest value of three different myocardial regions on a same view were define as the criteria for diag nosing acute myocardial infarction , and the results were compared with coronary angiography. The sensitivity of diagnosing acute myocardial infarction by both Ultrasonic tissue characterization with integrated backscatter and echo intensity were 91.43 % . The location of myocardial infarction detected by this technique corresponded with the damaged myocardial region determined by coronary angiography. Conclusions Ultrasonic tissue characterization with integrated backscatter and echo intensity could clinically be used as a noninvasive approach in the diagnosis of acute myocardial infarction.

作者： 刊期： 2001年第02期

Objective To investigate the influences of previous angina pectoris on coronary collateral circulation and left ventricular function in patients with acute myocardial infarction. Methods 307 patients with a first episode acute myocardial infarction underwent selective coronary angiography and left ventriculography. The relation of previous angina pectoris to coronary collateral circulation, peak creatine kinase and left ventricular function were analyzed.Results ① In the 307 patients, there were 192(62.5 % ) with previous angina [PA ( + ) group] and 115 (37.5 % ) without [PA ( - ) group]. ②The peak creatine kinase (CK) and CK- MB were significantly higher in PA (-) group than in PA (+) group ( P ＜ 0.05 for both comparisons) . ③ Collateral circulation to infarct- related artery was more likely to be present in PA (+) group than in PA (-) group ( P ＜ 0.05) . ④ The left ventricular ejection fraction was significantly increased, and the left ventricular wall motion Cortina score decreased, in PA ( + ) group than in PA ( - ) group ( P ＜ 0.01 for both comparisons) .Conclusion In patients with acute myocardial infarction, previous angina pectoris may have beneficial effects on coronary collateral circulation and left ventricular unction.

作者： 刊期： 2001年第02期