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At least 1,369 records · Page 76Linked to original sources
PubMed2005

[Perform analyse on the predictive model of ischemic cardiovascular diseases in Qingdao].

OBJECTIVE: To explore the clinical usage of the methods and tools of the 10-year's risk estimation of ischemic cardiovascular disease (ICVD) in Chinese. METHODS: The risk of ICVD in 2287 middle-aged Qingdao people was evaluated by the methods and tools of the 10-year's risk estimation of ICVD in Chinese, which was developed by Cardiovascular Institute, Chinese Academy of Medical Sciences. RESULTS: (1) 98.16% of male and 99.39% of female had a 10-year absolute risk of ICVD less than 10%. 0.19% of male and 0.15% of female had a 10-year absolute risk of ICVD higher than 20%. (2) In the low risk group (absolute risk < 10%) detection rate of abnormal SBP, FBG, TC, BMI was 100%, 20.8%, 75%, 87.5% respectively. While in the high risk group (absolute risk > or = 20%) detection rate of abnormal SBP, FBG, TC, BMI was 7.31%, 3.4%, 37.74%, 59.26% respectively. CONCLUSIONS: The prediction models and simplified tools for estimating 10-year-risk of ICVD in Chinese can predict satisfactorily the occurrence of cardiovascular disease in Qingdao area.

Adult↗
PubMed1991

[Computer simulation of the dynamics of the arterial system for various cardiovascular situations].

The simulation model describes the basic characteristics of the pulse in a wide range of arterial vessels. By comparison of simulated stenosis with photoplethysmographic registered curves of patients suffering from stenosis, it could be shown, that also pathologic hemodynamics can be adequately described. A new sight of dicrotic pulse generation was derived by the simulated removal of large arteries. This led to the hypothesis of decoupled, autonomous multiple reflections in the arteries of the arm, the leg and the head.

Arterial Occlusive Diseases↗
PubMed2006

Pharmacist-led cardiac risk reduction model.

The Cardiovascular Risk Reduction Clinic (CRRC) is a pharmacist-coordinated care model that incorporates the 4 major modifiable risk factors into a single treatment program. The authors aimed to assess the effectiveness of the CRRC model by comparing the Framingham point score before and after CRRC intervention. Retrospective data between 2001 and 2002 were analyzed for 375 veterans (age 65+/-10 years) with diabetes (88.8%) or coronary artery disease (44%) referred to the CRRC for intensive cardiac risk management. Total Framingham point score decreased from 14.5 at baseline to 13.6 after CRRC intervention (mean change 0.9+/-0.3). When considering only the patients not at target goals at baseline (n=200), significant improvements in guideline adherence was observed in low-density lipoprotein cholesterol, systolic blood pressure, hemoglobin A1c, and smoking. The CRRC model reduces the risk of cardiovascular events as assessed by Framingham point score in patients with established coronary artery disease and/or diabetes.

Aged↗
PubMed2000

A closed-loop model of the canine cardiovascular system that includes ventricular interaction.

A closed-loop model of cardiopulmonary circulation has been developed for the study of right-left ventricular interaction under physiologically normal and altered conditions. The core model provides insight into the effects of ventricular interaction and pericardial mechanics on hemodynamics. The complete model contains realistic descriptions of (a) the interacting ventricular free walls and septum, (b) the atria, (c) the pericardium, and (d) the systemic and pulmonary vascular loads. The current analysis extends previous work on ventricular interaction and pericardial influence under isolated heart conditions to loading conditions imposed by a closed-loop model of the circulation. A nonlinear least-squares parameter identification method (Levenberg-Marquardt algorithm) is used, together with parameter sensitivity analysis, to estimate the values of key parameters associated with the ventricular and circulation models. Pressure measurements taken at several anatomical locations in the circulation during open-chest experiments on dogs are used as data in the identification process. The complete circulatory model, including septal and pericardial coupling, serves as a virtual testbed for assessing the global affects of localized mechanical or hemodynamic alterations. Studies of both direct and series ventricular interaction, as well as the effect of the pericardium on cardiac performance, are accomplished with this model. Alterations in model parameter values are used to predict the impact of disease and/or clinical interventions on steady-state hemodynamic performance. Additionally, a software package titled CardioPV has been developed to integrate the complete model with data acquisition tools and a sophisticated graphical user interface. The complete software package enables users to collect experimental data, use the data to estimate model parameters, and view the model outputs in an online setting.

Animals↗
PubMed2001

Pharmacodynamic models for the cardiovascular effects of moxonidine in patients with congestive heart failure.

AIMS: To assess the pharmacodynamics of moxonidine in patients with functional NYHA Class II-III congestive heart failure (CHF). METHODS: A parallel population pharmacokinetic/pharmacodynamic (PK/PD) analysis was performed to assess the effect of moxonidine (0.1, 0.2, 0.3 mg twice daily) and placebo treatment on plasma noradrenaline (NA) levels, standing systolic blood pressure (SBP), and heart rate (HR) over 12 weeks in 97 patients with CHF using a parallel group design with dose escalation. A sequential analysis was also developed, where the relative changes in NA concentration were related to both SBP and HR. RESULTS: In the parallel PD analysis, an effect delay was shown for all three end points (NA, SBP, and HR). An inhibitory Emax model was used to characterize the concentration-effect relationships. For SBP and HR, the EC50 value increased over time. For NA, there was a positive baseline drift over the 12 weeks; this was interpreted as disease progression. Moxonidine delayed this increase by 9.8 weeks. For SBP, there was a circadian pattern at baseline. In the sequential PD analysis, the relationship between the drug response (NA) and SBP or HR was best described by an inhibitory Emax model. No effect delays between the response and effects were found. CONCLUSIONS: Effects of moxonidine on NA, SBP, and HR could be quantified by an effect compartment model in the presence of disease progression and circadian variations. Disease progression, as judged by increasing NA levels with time, was delayed by moxonidine. A direct relationship was found between NA and SBP/HR.

Adult↗
PubMed1995

Pyrrolo[2,1-c][1,4]benzothiazines: synthesis, structure-activity relationships, molecular modeling studies, and cardiovascular activity.

The synthesis and pharmacological evaluation of a series of pyrrolo[1,4]benzothiazine derivatives are described. These compounds, related to diltiazem, have been shown to be representative of a novel series of calcium channel antagonists. The IC50S for inhibition of [3H]nitrendipine binding calculated by radioreceptor assay on rat cortex and rat heart homogenates showed that some of the described compounds possess an affinity equal to or higher than those of the reference calcium antagonists verapamil and cis-(+)-diltiazem. Furthermore, the alteration of the benzothiazepinone system of diltiazem to the pyrrolo[1,4]benzothiazine system of the title compounds resulted in a clear-cut selectivity for cardiac over vascular tissue, as shown in functional studies. In fact comparison of calcium antagonist activity on guinea pig aorta strips with the negative inotropic activity, determined by using an isolated guinea pig left atrium, revealed that the compounds examined displayed higher selectivity than the reference standard, within a wide variation of data. A number of structure-activity relationship trends have been identified, and possible explanation is advanced in order to account for the observed differences in selectivity. Prerequisite for in vitro calcium channel-blocking activity is the presence of two pharmacophores, namely, the substitution at C-4 and the substitution on the pyrrole ring. Two of the tested compounds, 8b and 28a, were identified as potent calcium antagonists selective for cardiac over vascular tissue.

Animals↗
PubMed2002

Effectiveness of three models for comprehensive cardiovascular disease risk reduction.

Cost and accessibility contribute to low participation rates in phase 2 cardiac rehabilitation programs in the United States. In this study, we compared the clinical effectiveness of 2 less costly and potentially more accessible approaches to cardiovascular risk reduction with that of a contemporary phase 2 cardiac rehabilitation program. Low- or moderate-risk patients (n = 155) with coronary artery disease (CAD) were randomly assigned to 12 weeks of participation in a contemporary phase 2 cardiac rehabilitation program (n = 52), a physician supervised, nurse-case-managed cardiovascular risk reduction program (n = 54), or a community-based cardiovascular risk reduction program administered by exercise physiologists guided by a computerized participant management system based on national clinical guidelines (n = 49). In all, 142 patients (91.6%) completed testing at baseline and after 12 weeks of intervention. For patients with abnormal (i.e., not at the goal level) baseline values, statistically significant (p < or =0.05) improvements were observed with all 3 interventions for multiple CAD risk factors. No statistically significant risk factor differences were observed among the 3 programs. For patients with a baseline maximal oxygen uptake < 7 metabolic equivalents, cardiorespiratory fitness increased to a greater degree in patients in the cardiac rehabilitation program and the community-based program versus the physician-supervised, nurse- case-managed program. These data have important implications for cost containment and increasing accessibility to clinically effective comprehensive cardiovascular risk reduction services in low- or moderate-risk patients with CAD.

Coronary Disease↗
PubMed1997

Intraoperative monitoring of IMA flow: what does it mean?

BACKGROUND: This study examines whether the measurement of internal thoracic artery (ITA) graft flow can determine the adequacy of the ITA-left anterior descending coronary artery (LAD) anastomosis. METHODS: To study a wide range of clinical problems, we used a computer simulation of the cardiovascular system. The model included a time-varying elastance model of the heart, a systemic circulation represented by a multielement nonlinear model of the aorta and its major branches, a nonlinear model of the LAD circulation, and a model of the ITA bypass graft. RESULTS: With a mild LAD stenosis, ITA graft flow was low and flow reversal occurred. As the percent stenosis increased, ITA flow and the percentage of ITA-to-total LAD flow increased. The ITA graft helped to maintain resting LAD blood flow. A partial obstruction (40%) at the ITA-LAD anastomosis reduced ITA graft flow at similar levels of LAD stenosis. However, overlap in flow values comparing a normal with a partially obstructed anastomosis occurred. CONCLUSIONS: Flow patterns in the ITA are highly dependent on the degree of stenosis of the LAD as well as the integrity of the anastomosis. The predictive power of ITA flow measurement increases with severe stenosis or total occlusion of the proximal LAD and with high coronary blood flow demands.

Anastomosis, Surgical↗
PubMed2002

Accelerated atherogenesis in autoimmune rheumatic diseases.

The observation that systemic inflammatory rheumatic diseases such as rheumatoid arthritis (RA) are associated with a significantly increased rate of cardiovascular disease, which often occurs at a younger age than in the normal population, is particularly important given the increasing interest in the role of inflammation in atherogenesis in the general population. This review examines the accumulating evidence for accelerated atherogenesis of RA and updates the hypothesis that vasculitis plays a major role in this. Endothelial dysfunction (ECD), widely regarded as initial lesion in atherogenesis, has been shown to occur commonly in primary vasculitis. This ECD is a diffuse event, demonstrable in more than one vascular bed. It is not simply due to scarring in the vessel wall, related to the focal inflammation of the underlying vasculitis, since it may be reversed by suppression of the immune inflammation. However, the mechanisms for this ECD differ from that of the primary vasculitis. Preliminary evidence suggests that inflammatory mediators such as CRP, TNF, or sphingolipids may be involved. The diffuse ECD of vasculitis may have important consequences for both the progression of the primary disease and for cardiovascular events. A model for the role of vasculitis-induced ECD in the accelerated atherogenesis of rheumatic diseases is presented. These concepts are discussed together with the messages they suggest for 'idiopathic' atherosclerosis in the general population.

Arteriosclerosis↗
PubMed1999

Projecting coronary heart disease incidence and cost in Australia: results from the incidence module of the Cardiovascular Disease Policy Model.

OBJECTIVE: To project the incidence rates of coronary heart disease and the number of hospitalised incident coronary heart disease cases and hospital costs associated with the first hospital admission, for males and females aged 45-69, up to 2014 in Australia. METHOD: A computer simulation model using a microsimulation technique was developed to simulate individuals' coronary heart disease history over time for a sampled Australian population characterised by major coronary risk factors. Using the simulated incidence rates, population and hospital cost data, the number of hospitalised incident coronary heart disease events and hospital costs associated with the first hospital admission were projected. RESULTS AND CONCLUSIONS: If current cohort-specific coronary risk factor distributions change only by a location shift and the availability and efficacy of current treatment patterns prevail, the model projects declines of 13% and 24% in incidence rates for males and females aged 45-69 respectively by 2014. However, because the population aged 45-69 is projected to increase over the same period, the number of projected hospitalised coronary heart disease events and the hospital costs associated with the first admission will increase by more than 40%. IMPLICATIONS: A modeling strategy which integrates information on coronary risk factor distributions, epidemiologic, demographic and economic data can provide comprehensive projections that assist future health care planning in the area of coronary heart disease.

Adult↗
PubMed2004

Role of impaired myocardial relaxation in the production of elevated left ventricular filling pressure.

Although present in many patients with heart failure and a normal ejection fraction, the role of isolated impairments in active myocardial relaxation in the genesis of elevated filling pressures is not well characterized. Because of difficulties in determining the effect of prolonged myocardial relaxation in vivo, we used a cardiovascular simulated computer model. The effect of myocardial relaxation, as assessed by tau (exponential time constant of relaxation), on pulmonary vein pressure (PVP) and left ventricular end-diastolic pressure (LVEDP) was investigated over a wide range of tau values (20-100 ms) and heart rate (60-140 beats/min) while keeping end-diastolic volume constant. Cardiac output was recorded over a wide range of tau and heart rate while keeping PVP constant. The effect of systolic intervals was investigated by changing time to end systole at the same heart rate. At a heart rate of 60 beats/min, increases in tau from a baseline to extreme value of 100 ms cause only a minor increase in PVP of 3 mmHg. In contrast, at 120 beats/min, the same increase in tau increases PVP by 23 mmHg. An increase in filling pressures at high heart rates was attributable to incomplete relaxation. The PVP-LVEDP gradient was not constant and increased with increasing tau and heart rate. Prolonged systolic intervals augmented the effects of tau on PVP. Impaired myocardial relaxation is an important determinant of PVP and cardiac output only during rapid heart rate and especially when combined with prolonged systolic intervals. These findings clarify the role of myocardial relaxation in the pathogenesis of elevated filling pressures characteristic of heart failure.

Blood Pressure↗
PubMed1993

A comparison of propofol with other injectable anaesthetics in a rat model for measuring cardiovascular parameters.

Prolonged, stable, non-recovery anaesthesia is required for the assessment of the effects of novel compounds on the cardiovascular system. A comparison of injectable anaesthetic agents and combinations (thiobarbital, fentanyl-fluanisone and midazolam, propofol, fentanyl-fluanisone and propofol, and alphaxalone/alphadolone) was made in laboratory rats and the following parameters assessed over 3 h: blood pressure, heart rate and rhythm, respiration rate and depth, analgesia, ease of induction and maintenance of anaesthesia. It was found that propofol, with fentanyl-fluanisone premedication, provided stress-free induction, easily controlled anaesthesia, good analgesia and muscle relaxation for surgery, for up to 3 h duration. Heart rate, blood pressure and respiration remained stable and within normal limits during this time. The other anaesthetics/combinations assessed did not rate as highly in these respects. Propofol, following fentanyl-fluanisone premedication, would appear to be a useful and safe anaesthetic for use in rodents, which avoids significant effects on heart rate or blood pressure.

Anesthesia, Intravenous↗
PubMed1989

[The Belgian project for the prevention of cardiovascular diseases: a model of multifactorial prevention].

Résults are presented from the "belgian heart disease prevention project, part of the WHO european collaborative trial in the multifactorial prevention of coronary heart disease (CHD)". 19.409 men aged 40-59 yr took part; they were employed in thirty factories which formed the allocation units for a randomised controlled trial lasting 5-6 yr. The intervention package consisted largely of health education promoting a cholesterol-lowering diet, smoking cessation, weight control, physical activity, and treatment of arterial hypertension. A programme of information was supplemented by face-to-face counselling at the workplace by two physicians attached to the project. The coronary risk profile was reduced in the intervention group, compared with that in the control group, especially during the first 4 yr, by effects on serum cholesterol, number of cigarettes smoked daily, and arterial blood-pressure. Total mortality was 17.5% lower in the intervention group than in the control group (p = 0.038); coronary mortality was reduced by a non-significant 20.8% whereas CHD incidence (non-fatal myocardial infarction plus fatal myocardial infarction plus sudden deaths) was reduced by 24.5%, (P = 0.031). Non-fatal myocardial infarction (not a major end-point) was similarly reduced by 26.1% (p = 0.030).

Adult↗