共查询到20条相似文献,搜索用时 15 毫秒
1.
D.M.L. Prado E.A. Rocco A.G. Silva D.F. Rocco M.T. Pacheco P.F. Silva V. Furlan 《Brazilian journal of medical and biological research》2016,49(2)
The oxygen uptake efficiency slope (OUES) is a submaximal index incorporating
cardiovascular, peripheral, and pulmonary factors that determine the ventilatory
response to exercise. The purpose of this study was to evaluate the effects of
continuous exercise training and interval exercise training on the OUES in patients
with coronary artery disease. Thirty-five patients (59.3±1.8 years old; 28 men, 7
women) with coronary artery disease were randomly divided into two groups: continuous
exercise training (n=18) and interval exercise training (n=17). All patients
performed graded exercise tests with respiratory gas analysis before and 3 months
after the exercise-training program to determine ventilatory anaerobic threshold
(VAT), respiratory compensation point, and peak oxygen consumption (peak
VO2). The OUES was assessed based on data from the second minute of
exercise until exhaustion by calculating the slope of the linear relation between
oxygen uptake and the logarithm of total ventilation. After the interventions, both
groups showed increased aerobic fitness (P<0.05). In addition, both the continuous
exercise and interval exercise training groups demonstrated an increase in OUES
(P<0.05). Significant associations were observed in both groups: 1) continuous
exercise training (OUES and peak VO2 r=0.57; OUES and VO2 VAT
r=0.57); 2) interval exercise training (OUES and peak VO2 r=0.80; OUES and
VO2 VAT r=0.67). Continuous and interval exercise training resulted in
a similar increase in OUES among patients with coronary artery disease. These
findings suggest that improvements in OUES among CAD patients after aerobic exercise
training may be dependent on peripheral and central mechanisms. 相似文献
2.
Santa-Clara H Fernhall B Mendes M Sardinha LB 《European journal of applied physiology》2002,87(6):568-575
Weight-training is recommended as a complement to conventional aerobic-training for most low to moderate risk patients suffering
from coronary artery disease (CAD). The purpose of this study was to evaluate the effect of a 1 year exercise programme combining
weight- and aerobic-training on peak oxygen uptake (VO2,peak) and ventilatory threshold (VT). We studied 40 men suffering CAD who were divided into three groups: 14 subjects to weight-training
plus aerobic-training [mean (SD] [combined exercise group, age 55 (10) years], 14 to aerobic-training only [aerobic-training
group, age 57 (11) years], and 12 to a control group [standard care, age 57 (11) years]. A symptom-limited graded exercise
test using the standard Bruce protocol was performed using a 12-lead electrocardiogram, and gas analysis techniques. Muscle
strength was determined only in the combined exercise group using the one-repetition maximum method on each of eight weight
exercises. Arm and leg strength increased by 21.9% and 27.8% respectively (P<0.0001) from pre to post-tests. The VO2,peak did not differ between the combined and aerobic-training groups but their adjusted means were greater than those of the control
group [39 (1.8) and 35.3 (1.8) compared to 26.2 (2.7) ml·kg–1·min–1 (P<0.001)]. The oxygen uptake at VT was higher in the combined group [24.7 (1.4) ml·kg–1·min–1] compared to aerobic [18.7 (1.4) ml·kg–1·min–1] and control [13.6 (1.7) ml·kg–1min–1] groups (P<0.001). Similar results were found for exercise tolerance (treadmill time to peak and at VT). Combined exercise training
increased the VT more than aerobic-training alone. Combined exercise training did not improve the VO2,peak or the functional capacity more than aerobic-training alone.
Electronic Publication 相似文献
3.
Danilo M L Prado Enéas A Rocco Alexandre G Silva Priscila F Silva Jaqueline M Lazzari Gabriela L Assump??o Sheyla B Thies Claudia Y Suzaki Raphael S Puig Valter Furlan 《Clinics (S?o Paulo, Brazil)》2015,70(1):46-51
OBJECTIVE:
To test the hypotheses that 1) coronary artery disease patients with lower aerobic fitness exhibit a lower ventilatory efficiency and 2) coronary artery disease patients with lower initial aerobic fitness exhibit greater improvements in ventilatory efficiency with aerobic exercise training.METHOD:
A total of 123 patients (61.0±0.7 years) with coronary artery disease were divided according to aerobic fitness status into 3 groups: group 1 (n = 34, peak VO2<17.5 ml/kg/min), group 2 (n = 67, peak VO2>17.5 and <24.5 ml/kg/min) and group 3 (n = 22, peak VO2>24.5 ml/kg/min). All patients performed a cardiorespiratory exercise test on a treadmill. Ventilatory efficiency was determined by the lowest VE/VCO2 ratio observed. The exercise training program comprised moderate-intensity aerobic exercise performed 3 times per week for 3 months. Clinicaltrials.gov: NCT02106533RESULTS:
Before intervention, group 1 exhibited both lower peak VO2 and lower ventilatory efficiency compared with the other 2 groups (p<0.05). After the exercise training program, group 1 exhibited greater improvements in aerobic fitness and ventilatory efficiency compared with the 2 other groups (group 1: ▵ = -2.5±0.5 units; group 2: ▵ = -0.8±0.3 units; and group 3: ▵ = -1.4±0.6 units, respectively; p<0.05).CONCLUSIONS:
Coronary artery disease patients with lower aerobic fitness status exhibited lower ventilatory efficiency during a graded exercise test. In addition, after 3 months of aerobic exercise training, only the patients with initially lower levels of aerobic fitness exhibited greater improvements in ventilatory efficiency. 相似文献4.
5.
背景:B型脑钠肽已成为心血管疾病诊断重要的血清标志物,作为心血管疾病危险因素分层的重要因子。
目的:分析冠状动脉旁路移植前后B型脑钠肽与各项血流动力学参数的关系。
方法:选择30例冠心病行冠脉旁路移植患者,分为左室射血分数≥ 50%心功能正常患者13例;左室射血分数< 50%心功能不全患者17例。观察患者移植前1 d、移植后7 h、移植后1,3,5,7 d血浆B型脑钠肽水平变化趋势,分析移植前后B型脑钠肽与心功能各项指标的相关关系。
结果与结论:左室射血分数≥ 50%组患者冠脉旁路移植前后血浆B型脑钠肽水平显著低于左室射血分数< 50%组;组内比较移植后血浆B型脑钠肽水平均显著高于移植前(P < 0.05或P < 0.001)。患者冠脉旁路移植前B型脑钠肽水平与纽约心脏病协会心功能分级、左房内径、左室内径呈正相关(r=0.61;r=0.34;r=0.67);与左室射血分数、心排血量呈负相关(r=-0.75;r=-0.70)。患者移植后B型脑钠肽峰值浓度与出院前纽约心脏病协会心功能分级、超声心动图左室舒张末期内径、肺动脉压力呈正相关(r=0.72;r=0.70;r=0.45)。结果说明冠心病患者冠脉旁路移植前血浆B型脑钠肽质量浓度与左心室射血分数及左心室舒张末期内径有很好的相关性,能准确反映冠脉旁路移植前后的心功能状态。
中国组织工程研究杂志出版内容重点:组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程全文链接: 相似文献
6.
Jidong Sung Jeong Hoon Yang Soo Jin Cho Sun Hee Hong Eun Hee Huh Seung Woo Park 《Journal of Korean medical science》2009,24(5):795-799
Arterial stiffness is an important contributor to the development of cardiovascular disease. We investigated the effect of short duration exercise using the treadmill test on arterial stiffness in the presence of coronary artery disease. We enrolled patients with and without coronary artery diseases (CAD and control group, 50 patients each) referred for treadmill testing. Brachial-ankle pulse wave velocity (baPWV) were measured before and after treadmill testing. Values of baPWV were significantly reduced at 10 min after exercise in both groups, more in the CAD group than in the control group (baseline baPWV and post-exercise change [cm/sec]: 1,527±245 and -132±155 in the CAD group, 1,439±202 and -77±93 in the control group, respectively, P for change in each group <0.001, P for difference in changes between the two groups <0.001). These findings persisted after adjusting for age, body mass index, systolic blood pressure, mean arterial pressure (MAP), MAP decreases, and baseline baPWV. Significant post-exercise baPWV reductions were observed in both groups, and more prominently in the CAD group. This finding suggests that short-duration exercise may effectively improve arterial stiffness even in patients with stable coronary artery disease. 相似文献
7.
Effect of ageing on the ventilatory response and lactate kinetics during incremental exercise in man
Jacques Prioux Michèle Ramonatxo Maurice Hayot Patrick Mucci Christian Préfaut 《European journal of applied physiology》2000,81(1-2):100-107
We investigated the effects of age on breathing pattern, mouth occlusion pressure, the ratio of mouth occlusion pressure
to mean inspiratory flow, and venous blood lactate kinetics during incremental exercise. Mouth occlusion pressure was used
as an index of inspiratory neuromuscular activity, and its ratio to mean inspiratory flow was used as an index of the “effective
impedance” of the respiratory system. Nine elderly male subjects [mean (SD) age: 68.1 (4.8) years] and nine young male subjects
[mean (SD) age: 23.4 (1.3) years] performed an incremental exercise test on a bicycle ergometer. After a warm-up at 30 W,
the power was increased by 30 W every 1.5 min until exhaustion. Our results showed that at maximal exercise, power output,
breathing pattern, and respiratory exchange values, with the exception of tidal volume and the “effective impedance” of the
respiratory system, were significantly higher in the young subjects. The power output and oxygen consumption values at the
anaerobic threshold were also significantly higher in the young men. At the same power output, the elderly subjects showed
significantly higher values for minute ventilation, respiratory equivalents for oxygen uptake and carbon dioxide output (CO2), mean inspiratory flow, occlusion pressure and lactate concentration than the young subjects. At the same CO2 below the anaerobic threshold (0.5, 0.75, 1.00 and 1.25 l · min−1), minute ventilation and lactate concentration were also significantly higher in the elderly subjects. We observed a significantly
higher minute ventilation at CO2 values of 0.5, 0.75, 1.00 (P < 0.001) and 1.25 l · min−1 (P < 0.05) in the elderly men, and a significantly higher lactate concentration at CO2 values of 1.00 (P < 0.05) and 1.25 l · min−1 (P < 0.01). In conclusion, the ventilatory response in elderly subjects is elevated in comparison with that in young subjects,
both below and above the anaerobic threshold. This study demonstrates for the first time that this ventilatory increase, both
below and above the threshold, is partly due to an increased lactate concentration.
Received: 30 March 1999 / Accepted: 24 June 1999 相似文献
8.
Ahn S Park YJ Min SI Kim SY Ha J Kim SJ Kim HS Yoon BW Min SK 《Journal of Korean medical science》2012,27(6):625-629
This prospective study surveyed the prevalence of peripheral arterial disease (PAD) in Korean patients with coronary arterial disease (CAD) or cerebrovascular disorder (CVD). From March 2010, 576 hospitalized patients in cardiovascular or stroke center were enrolled as the study group. Ankle-brachial index (ABI) was measured and the cut-off point for diagnosing PAD was ≤ 0.9 at rest. A total of 424 hospitalized patients in the Department of Surgery and aged ≥ 50 yr was enrolled as the control group. The prevalence of PAD was significantly higher in the study group than the control group (7.6% vs 1.7%; P < 0.001). To analyze the relationship of other vascular diseases and PAD, the patients were regrouped; group A (no CAD or CVD), group B (CAD only), group C (CVD only), and group D (CAD and CVD). Compared with group A, those with other vascular diseases (group B, C, D) had significantly higher prevalence of PAD, diabetes, dyslipidemia, renal insufficiency and claudication. The trend that patients with CAD or CVD are at risk of PAD is observed in this cross-sectional study in Koreans. Routine ABI measurement is recommended in these high-risk groups for early detection and proper management of PAD. 相似文献
9.
Eduardo D. E. Papa Izo Helber Manes R. Ehrlichmann Claudia Maria Rodrigues Alves Marcia Makdisse Livia N. Matos Jairo Lins Borges Renato D. Lopes Edson Stefanini Antonio Carlos Carvalho 《Clinics (S?o Paulo, Brazil)》2013,68(12):1481-1487
OBJECTIVES:
To correlate the importance of the ankle-brachial index in terms of cardiovascular morbimortality and the extent of coronary arterial disease amongst elderly patients without clinical manifestations of lower limb peripheral arterial disease.METHODS:
We analyzed prospective data from 100 patients over 65 years of age with coronary arterial disease, as confirmed by coronary angiography, and with over 70% stenosis of at least one sub-epicardial coronary artery. We measured the ankle-brachial index immediately after coronary angiography, and a value of <0.9 was used to diagnose peripheral arterial disease.RESULTS:
The patients'' average age was 77.4 years. The most prevalent risk factor was hypertension (96%), and the median late follow-up appointment was 28.9 months. The ankle-brachial index was <0.9 in 47% of the patients, and a low index was more prevalent in patients with multiarterial coronary disease compared to patients with uniarterial disease in the same group. Using a bivariate analysis, only an ankle-brachial index of <0.9 was a strong predictive factor for cardiovascular events, thereby increasing all-cause deaths and fatal and non-fatal acute myocardial infarctions two- to three-fold.CONCLUSION:
In elderly patients with documented coronary disease, a low ankle-brachial index (<0.9) was associated with the severity and extent of coronary arterial disease, and in late follow-up appointments, a low index was correlated with an increase in the occurrence of major cardiovascular events. 相似文献10.
11.
Objective
To determine whether a transtheoretical model-based exercise stage-matched intervention (ESMI) has positive effects on the exercise behavior of sedentary patients with coronary heart disease (CHD).Methods
The study was a randomized controlled trial with a repeated measures design. Participants (N = 196) were randomly allocated to either a conventional (C) group, a patient education (PE) group, or an ESMI group. Exercise behavior was measured by exercise stages of change, exercise self-efficacy, exercise decisional balance, and duration of moderate exercise at baseline, immediate post-intervention, and at 3- and 6-month follow-up.Results
Our results showed that the ESMI group demonstrated a more positive shift in exercise stages of change (p < 0.01), higher exercise self-efficacy (p < 0.01), greater exercise benefits (p < 0.01), fewer exercise barriers (p < 0.01), and longer moderate exercise duration (minutes/week) (p < 0.01) after completion of the 8-week intervention compared with the C and PE groups. These significantly positive effects were maintained at 3- and 6-month follow-up.Conclusion
The transtheoretical model-based ESMI had significantly positive effects on the exercise behavior of sedentary CHD patients.Practice implications
It is important to provide a structured education program for CHD patients, preferably guided by the transtheoretical model. 相似文献12.
Glutathione S-transferase (GST) plays a key role in the detoxification of xenobiotic atherogen generated by smoking. To analyze the effect of GSTM1/T1 gene polymorphisms on the development of smoking-related coronary artery disease (CAD), 775 Korean patients who underwent coronary angiography were enrolled. The subjects were classified by luminal diameter stenosis into group A (>50%), B (20-50%), or C (<20%). GSTM1 and GSTT1 gene polymorphisms were analyzed using multiplex polymerase chain reaction (PCR) for GSTM1/T1 genes and CYP1A1 gene for internal control. Of 775 subjects, 403 patients belonged to group A. They had higher risk factors for CAD than group B (N=260) and group C (N=112). The genotype frequencies of null GSTM1 and GSTT1 showed no significant differences among 3 groups. Considering the effect of GSTM1 gene polymorphisms on the smoking-related CAD, smokers with GSTM1 null genotype had more increased risk for CAD than non-smoker with GSTM1 positive genotype (odds ratios [OR], 2.07, confidence interval [CI], 1.06-4.07). Also the effect of GSTT1 gene polymorphism on smoking-related CAD showed the same tendency as GSTM1 gene (OR, 2.00, CI, 1.05-3.84). This effect of GSTM1/T1 null genotype on smoking-related CAD was augmented when both gene polymorphisms were considered simultaneously (OR, 2.76, CI, 1.17-6.52). We concluded that GSTM1/T1 null genotype contributed to the pathogenesis of smoking-related CAD to some degree. 相似文献
13.
Although numerous studies have validated the efficacy of intracoronary shunt on reducing left ventricular dysfunction during off-pump coronary artery bypass surgery (OPCAB), there is lack of evidence supporting its role on right ventricular (RV) function during right coronary artery (RCA) revascularization. Therefore, we studied the effect of intracoronary shunt during grafting of dominant RCA without visible collateral supply on global RV function using thermodilution method. Forty patients scheduled for multivessel OPCAB with right dominant coronary circulation without collateral supply confirmed by angiography were randomized to RCA revascularization either with a shunt (n=20) or soft snare occlusion (n=20). RV ejection fraction (RVEF) was recorded at baseline, during RCA grafting, and 15 min after reperfusion. Corresponding RV stroke work index (RVSWI) was calculated. RVEF and RVSWI decreased significantly during RCA grafting and returned to baseline values after reperfusion in both groups without any significant differences between the groups. Intracoronary shunt did not exert any beneficial effect on global RV function during RCA grafting, even in the absence of visible collateral supply. Regarding the possibility of graft failure by intracoronary shunt-induced endothelial damage, routine use of intracoronary shunt during RCA grafting is not recommended in patients with preserved biventricular function. 相似文献
14.
Radial basis function neural network approach for the diagnosis of coronary artery disease based on the standard electrocardiogram exercise test 总被引:2,自引:0,他引:2
Lewenstein K 《Medical & biological engineering & computing》2001,39(3):362-367
The purpose of the paper is the evaluation of a radial basis function neural network as a tool for computer aided coronary
artery disease diagnosis based on the results of the traditional ECG exercise test. The research was performed using 776 data
records from an exercise test (297 records from healthy patients and 479 from ill patients) confirmed by coronary arteriography
results. Each record described the state of the patient, provided input data for the neural network, included the level and
slope of an ST segment of a 12-lead ECG signal made at rest and after effort, heart rate, blood pressure, load during the
test, and occurrence of coronary pain, coronary arteriography, correct output pattern for the neural network, and verified
the existence (or not) of more than 50% stenosis of the particular coronary vessels. Radial basis function neural networks
for coronary artery disease diagnosis were optimised by choosing the type of radial function, the method of training (setting
the number of centres and their dimensions), and regularisation. The best network correctly recognised over 97% of cases from
a 400-element test set, diagnosing not only the patients' condition (simple ‘sane-sick’ diagnosis), but also pointing out
individual sick/stenosed vessels. 相似文献
15.
16.
Effect of exercise on coronary endothelial function in patients with coronary artery disease 总被引:36,自引:0,他引:36
Hambrecht R Wolf A Gielen S Linke A Hofer J Erbs S Schoene N Schuler G 《The New England journal of medicine》2000,342(7):454-460
BACKGROUND: Studies of the cardioprotective effects of exercise training in patients with coronary artery disease have yielded contradictory results. Exercise training has been associated with improvement in myocardial perfusion even in patients who have progression of coronary atherosclerosis. We therefore conducted a prospective study of the effect of exercise training on endothelial function in patients with coronary artery disease. METHODS: We randomly assigned 19 patients with coronary endothelial dysfunction, indicated by abnormal acetylcholine-induced vasoconstriction, to an exercise-training group (10 patients) or a control group (9 patients). To reduce confounding, patients with coronary risk factors that could be influenced by exercise training (such as diabetes, hypertension, hypercholesterolemia, and smoking) were excluded. In an initial study and after four weeks, the changes in vascular diameter in response to the intracoronary infusion of increasing doses of acetylcholine (0.072, 0.72, and 7.2 microg per minute) were assessed. The mean peak flow velocity was measured by Doppler velocimetry, and the diameter of epicardial coronary vessels was measured by quantitative coronary angiography. RESULTS: In the initial study, the two groups had similar vasoconstrictive responses to acetylcholine. After four weeks of exercise training, coronary-artery constriction in response to acetylcholine at a dose of 7.2 microg per minute was reduced by 54 percent (from a mean [+/-SE] decrease in the luminal diameter of 0.41+/-0.05 mm in the initial study to a decrease of 0.19+/-0.07 mm at four weeks; P<0.05 for the comparison with the change in the control group). In the exercise-training group, the increases in mean peak flow velocity in response to 0.072, 0.72, and 7.2 microg of acetylcholine per minute were 12+/-7, 36+/-11, and 78+/-16 percent, respectively, in the initial study. After four weeks of exercise, the increases in response to acetylcholine were 27+/-7, 73+/-19, and 142+/-28 percent (P<0.01 for the comparison with the control group). Coronary blood-flow reserve (the ratio of the mean peak flow velocity after adenosine infusion to the resting velocity) increased by 29 percent after four weeks of exercise (from 2.8+/-0.2 in the initial study to 3.6+/-0.2 after four weeks; P<0.01 for the comparison with the control group). CONCLUSIONS: Exercise training improves endothelium-dependent vasodilatation both in epicardial coronary vessels and in resistance vessels in patients with coronary artery disease. 相似文献
17.
Deniz ELK Mustafa DURAN aban KELEOLU Zeki ETNKAYA Sibel BOYLU Rdvan YURT Ali DOAN Mehmet Turul NAN Nihat KALAY 《Turkish Journal of Medical Sciences》2021,51(3):1273
Background/aimIt has been suggested that there is a significant progress in coronary artery disease (CAD) by many pathophysiological mechanisms. Nondipper hypertension (NDH) has been shown to have higher target organ damage and have a higher rate of cardiovascular mortality and morbidity. In this study, we investigated the effect of nondipper hypertension on the progression of coronary atherosclerosis.Materials and methodsA total of 186 patients who underwent coronary angiography twice between 6 months and 3 years were included in the study. Coronary angiography was repeated on the admission day due to angina or positive exercise test and the patients were divided into groups.ResultsProgression of coronary artery disease was detected in 58 of 186 patients. Seventy-one of the total patients were found to be nondipper hypertensive. Nondipper hypertension, hypertension, diabetes mellitus, low-density lipoprotein, and total cholesterol were found to be effective in the progression of CAD. Among these parameters, it was seen that nondipper hypertension and hyperlipidemia were the most important independent risk factors.Conclusion Coronary artery disease is a progressive disease, and this progression depends on many reasons. In our study, we showed that nondipper hypertension is a new parameter that is effective in CAD progression. 相似文献
18.
Antonio P. Mansur Julio Y. Takada Célia M. C. Strunz Solange D. Avakian Luiz Antonio M. César José A. F. Ramires 《Clinics (S?o Paulo, Brazil)》2013,68(12):1502-1508
OBJECTIVE:
To examine the association of atherogenic and thrombogenic markers and lymphotoxin-alfa gene mutations with the risk of premature coronary disease.METHODS:
This cross-sectional, case-control, age-adjusted study was conducted in 336 patients with premature coronary disease (<50 years old) and 189 healthy controls. The control subjects had normal clinical, resting, and exercise stress electrocardiographic assessments. The coronary disease group patients had either angiographically documented disease (>50% luminal reduction) or a previous myocardial infarction. The laboratory data evaluated included thrombogenic factors (fibrinogen, protein C, protein S, and antithrombin III), atherogenic factors (glucose and lipid profiles, lipoprotein(a), and apolipoproteins AI and B), and lymphotoxin-alfa mutations. Genetic variability of lymphotoxin-alfa was determined by polymerase chain reaction analysis.RESULTS:
Coronary disease patients exhibited lower concentrations of HDL-cholesterol and higher levels of glucose, lipoprotein(a), and protein S. The frequencies of AA, AG, and GG lymphotoxin-alfa mutation genotypes were 55.0%, 37.6%, and 7.4% for controls and 42.7%, 46.0%, and 11.3% for coronary disease patients (p = 0.02), respectively. Smoking, dyslipidemia, family history, and lipoprotein(a) and lymphotoxin-alfa mutations in men were independent variables associated with coronary disease. The area under the curve (C-statistic) increased from 0.779 to 0.802 (p<0.05) with the inclusion of lipoprotein(a) and lymphotoxin-alfa mutations in the set of conventional risk factors.CONCLUSIONS:
The inclusion of lipoprotein(a) and lymphotoxin-alfa mutations in the set of conventional risk factors showed an additive but small increase in the risk prediction of premature coronary disease. 相似文献19.
Effect of increased blood fluidity through hemodilution on coronary circulation at rest and during exercise in dogs 总被引:5,自引:0,他引:5
Wulf von Restorff Bertold Höfling Jürgen Holtz Eberhard Bassenge 《Pflügers Archiv : European journal of physiology》1975,357(1-2):15-24
Summary Coronary flow and myocardial oxygen consumption were measured in conscious dogs at rest and during two levels of submaximal treadmill exercise (3 and 7 km/h at 15% grade, respectively) during adaptation to progressive hemodilution with dextran 60. At rest coronary flow increased to more than seven-fold with diminishing hematocrit to 12.5% in order to cover myocardial oxygen consumption which increased from 6.5±0.3 ml/min· 100 g at hematocrit 47.5% to 13.5±0.8 ml/min· 100 g at hematocrit 12.5%. The dilatory capacity of the coronary vessels, estimated from the reactive hyperemia after a 12 sec occlusion of the left circumflex coronary artery, dropped from 602% at control to 45% at lowest hematocrit levels.During the superimposed stress of exercise coronary flow and myocardial oxygen consumption increased further, so that the dilatory capacity of the coronaries was exhausted at hematocrit levels between 16 and 22%.Myocardial oxygen consumption per unit of oxygen delivered to peripheral tissues increased substantially with progressive hemodilution. In the presence of the reduced arterial oxygen content the augmented myocardial oxygen demand limits the overall adaptability to hemodilution by an exhaustion of the coronary dilatory capacity.Supported by Deutsche Forschungsgemeinschaft. 相似文献
20.
目的探讨增强型体外反搏(enhancedexternalcouterpulsationEECP)对冠心病经皮冠状动脉介入治疗患者的疗效。方法经选择性冠状动脉造影确诊为冠心病且介入治疗成功的患者共469例,其中85例在药物治疗的基础上行体外反搏治疗(EECP组),另384例予单纯药物治疗(药物组)。临床随访6~72个月,部分行超声心动图和冠脉造影复查,比较两组随访病例临床终点事件、左室功能和造影结果的差异。结果(1)基线资料:对EECP组81例(95%)和药物组350例(91%)成功进行了随访,两组在临床资料、造影特征和介入治疗等方面差异均无统计学意义(P>0.05)。⑵临床终点事件:EECP组心绞痛复发率显著低于药物组(8·6%比17.4%,P<0.05);EECP组总的临床终点事件发生率明显低于药物组(18.5%比35.4%,P<0.01)。(3)超声心动图:两组基线室壁运动指数和左室射血分数相似,但复查时EECP组明显优于药物组(P<0.01)。⑷冠状动脉造影:两组再狭窄发生率差异无统计学意义P>0.05,但EECP组出现侧支循环患者数明显多于药物组(17.9%比5·1%,P<0.05),复查时病变血管参考内径[(3.29±0.61)mm比(3.06±0.50)mm,P<0.05]和支架内最小腔径[(3.02±0.59)mm比(2.67±0.62)mm,P<0.01]均显著大于药物组。结论对于介入治疗成功的冠心病患者,增强型体外反搏可减少心绞痛复发,改善预后和心功能,并可能有预防再狭窄的作用。 相似文献