DIABETIC MEDICINE, Issue 5 2006
M. P. Hermans
Abstract Objective Individuals with Type 2 diabetes are at increased risk of stroke. Plasma homocysteine (tHcy) is an independent risk factor for cardiovascular (CV) disease. The methylene,tetrahydrofolate reductase (MTHFR) gene polymorphism (thermolabile variant C677T) is associated with CV risk, partly as a result of increased Hcy, especially in homozygous subjects. Aim To relate the occurrence of the MTHFR polymorphism with stroke prevalence by examining allelic frequency and genotype distribution in 165 subjects with Type 2 diabetes studied for the presence of thermolabile C677T MTHFR mutation. Results Mean age was 67.7 years, and tHcy 18.2 µmol/l. T allele frequency was 38.5%. MTHFR genotypes were: normal (CC) 40%; heterozygous (CT) 43%; homozygous (TT) 17%. Serum levels of folic acid and B12 vitamin were within normal limits. Stroke prevalence was 14%. Sixty-four per cent of stroke-free subjects had the normal C allele vs. 46% in stroke subjects. The frequencies of genotypes (CC-CT-TT) were (%): 44-41-15 in stroke-free vs. 17-57-26 in stroke patients. Coronary (CAD) and peripheral artery disease (PAD) were common in all groups, with no differences according to genotypes. Stroke prevalence was markedly higher in genotypes CT and TT (18 and 21%) compared with CC (6%). Mean tHcy levels were higher in TT subjects. Conclusion The allelic frequency of C677T MTHFR mutation in Type 2 diabetes subjects with stroke is markedly different from that of subjects without stroke. Genotypic characteristics suggest that C677T MTHFR mutation confers a higher risk for stroke to both homozygous and heterozygous T allele carriers that cannot be ascribed solely to raised tHcy and/or lower folate status in CT subjects, nor to phenotypic expression of conventional risk factors for stroke. The impact of the MTHFR polymorphism on stroke may result from T allele-linked deleterious effects, or C allele-linked protection. Confirmatory studies are warranted, as this cohort was not randomly selected, and a type 1 error cannot be ruled out. [source]

The Relation between the Color M-Mode Propagation Velocity of the Descending Aorta and Coronary and Carotid Atherosclerosis and Flow-Mediated Dilatation

ECHOCARDIOGRAPHY, Issue 3 2010
Yilmaz Gunes M.D.
Background: To improve clinical outcomes, noninvasive imaging modalities have been proposed to measure and monitor atherosclerosis. Common carotid intima-media thickness (CIMT) and brachial artery flow-mediated dilatation (FMD) have correlated with coronary atherosclerosis. Recently, the color M-mode-derived propagation velocity of descending thoracic aorta (AVP) was shown to be associated with coronary artery disease (CAD). Methods: CIMT, FMD, and AVP were measured in 92 patients with CAD and 70 patients having normal coronary arteries (NCA) detected by coronary angiography. Patients with acute myocardial infarction, renal failure or hepatic failure, aneurysm of aorta, severe valvular heart disease, left ventricular ejection fraction <40%, atrial fibrillation, frequent premature beats, left bundle branch block, and inadequate echocardiographic image quality were excluded. Results: Compared to patients with normal coronary arteries, patients having CAD had significantly lower AVP (29.9 ± 8.1 vs. 47.5 ± 16.8 cm/sec, P < 0.001) and FMD (5.3 ± 1.9 vs. 11.4 ± 5.8%, P < 0.001) and higher CIMT (0.94 ± 0.05 vs. 0.83 ± 0.14 mm, P < 0.001) measurements. There were significant correlations between AVP and CIMT (r =,0.691, P < 0.001), AVP and FMD (r = 0.514, P < 0.001) and FMD and CIMT (r =,0.530, P < 0.001). Conclusions: The transthoracic echocardiographic determination of the color M-mode propagation velocity of the descending aorta is a simple practical method and correlates well with the presence of carotid and coronary atherosclerosis and brachial endothelial function. (Echocardiography 2010;27:300-305) [source]

Reverse Flow in Left Coronary Artery as the Clue to Diagnosis of an Anomalous Origin of the Left Coronary into Pulmonary Artery in an Infant with Dilated Cardiomyopathy

ECHOCARDIOGRAPHY, Issue 6 2008
Rodrigo Estévez M.D.
No abstract is available for this article. [source]

Concomitant Coronary and Peripheral Arterial Disease: Single-Stage Revascularization

JOURNAL OF CARDIAC SURGERY, Issue 3 2008
Onur S. Goksel M.D.
Coexistence of two entities is usually managed with a staged approach; however, decision to treat which entity first may be difficult clinically. We present a 49-year-old man with acute infrarenal aortic occlusion and cardiac ischemia who was treated with single-stage ascending aorta-bifemoral bypass following saphenous vein grafting to left anterior descending artery. Concomitant coronary and peripheral vascular revascularization is a practical method with a high flow inflow source as ascending aorta. We believe that a single-stage approach may be performed in the unstable patient as presented in this report. [source]

Coronary and systemic hemodynamic effects of clevidipine, an ultra-short-acting calcium antagonist, for treatment of hypertension after coronary artery surgery

ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 2 2000
N. Kieler-Jensen
Background: The aim was to evaluate the use of clevidipine, a new vascular selective, ultra-short-acting calcium antagonist for blood pressure control after coronary artery bypass grafting (CABG). Methods: The effects of clevidipine on central hemodynamics, myocardial blood flow and metabolism were studied at two different phases after CABG. In phase 1 (n=13), the hypertensive phase, the effects of clevidipine were compared to those of sodium nitroprusside (SNP) when used to control postoperative hypertension. In phase 2 (n=9), the normotensive phase, a clevidipine dose-response relationship was established. Results: At a target mean arterial pressure (MAP) of 75 mmHg, systemic vascular resistance (SVR) and heart rate (HR) were lower, preload, stroke volume (SV) and pulmonary vascular resistance (PVR) were higher, while there were no differences in myocardial lactate metabolism or oxygen extraction with clevidipine compared to SNP. In the normotensive phase, clevidipine induced a dose-dependent decrease in MAP (,19%), SVR (,27%) and PVR (,15%), accompanied by an increase in SV (10%), but no reflex increase in HR or changes in cardiac preload. Clevidipine caused a direct coronary vasodilation, as indicated by a decrease in myocardial oxygen extraction from 54% to 45%. Myocardial lactate metabolism was unaffected by clevidipine. The blood clearance of clevidipine was 0.05 l ,· ,min,1 ,· ,kg,1, the volume of distribution at steady state was 0.08 l ,· ,kg,1 and the initial and terminal half-lives were <1 min and 4 min, respectively. Conclusions: Clevidipine rapidly reduced MAP and induced a systemic, pulmonary and coronary vasodilation with no effect on venous capacitance vessels or HR. Clevidipine caused no adverse effects on myocardial lactate metabolism. Clevidipine thus appears suitable to control blood pressure after CABG. [source]

One-year Outcomes Following Coronary Computerized Tomographic Angiography for Evaluation of Emergency Department Patients with Potential Acute Coronary Syndrome

ACADEMIC EMERGENCY MEDICINE, Issue 8 2009
Judd E. Hollander MD
Abstract Objectives:, Coronary computerized tomographic angiography (CTA) has high correlation with cardiac catheterization and has been shown to be safe and cost-effective when used for rapid evaluation of low-risk chest pain patients from the emergency department (ED). The long-term outcome of patients discharged from the ED with negative coronary CTA has not been well studied. Methods:, The authors prospectively evaluated consecutive low- to intermediate-risk patients who received coronary CTA in the ED for evaluation of a potential acute coronary syndrome (ACS). Patients with cocaine use, known cancer, and significant comorbidity reducing life expectancy and those found to have significant disease (stenosis , 50% or ejection fraction < 30%) were excluded. Demographics, medical and cardiac history, labs, and electrocardiogram (ECG) results were collected. Patients were followed by telephone contact and record review for 1 year. The main outcome was 1-year cardiovascular death or nonfatal acute myocardial infarction (AMI). Results:, Of 588 patients who received coronary CTA in the ED, 481 met study criteria. They had a mean (±SD) age of 46.1 (±8.8) years, 63% were black or African American, and 60% were female. There were 53 patients (11%) rehospitalized and 51 patients (11%) who received further diagnostic testing (stress or catheterization) over the subsequent year. There was one death (0.2%; 95% confidence interval [CI] = 0.01% to 1.15%) with unclear etiology, no AMI (0%; 95% CI = 0 to 0.76%), and no revascularization procedures (0%; 95% CI = 0 to 0.76%) during this time period. Conclusions:, Low- to intermediate-risk patients with a Thrombosis In Myocardial Infarction (TIMI) score of 0 to 2 who present to the ED with potential ACS and have a negative coronary CTA have a very low likelihood of cardiovascular events over the ensuing year. [source]

Coronary Flow Reserve by Transthoracic Echocardiography Predicts Epicardial Intimal Thickening in Cardiac Allograft Vasculopathy

AMERICAN JOURNAL OF TRANSPLANTATION, Issue 7 2010
F. Tona
Cardiac allograft vasculopathy (CAV) is the leading cause of morbidity and mortality in heart transplantation (HT). We sought to investigate the role of coronary flow reserve (CFR) by contrast-enhanced transthoracic echocardiography (CE-TTE) in CAV diagnosis. CAV was defined as maximal intimal thickness (MIT) assessed by intravascular ultrasound (IVUS) ,0.5 mm. CFR was assessed in the left anterior descending coronary artery in 22 HT recipients at 6 ± 4 years post-HT. CAV was diagnosed in 10 patients (group A), 12 had normal coronaries (group B). The mean MIT was 0.7 ± 0.1 mm (range 0.03,1.8). MIT was higher in group A (1.16 ± 0.3 mm vs. 0.34 ± 0.07 mm, p < 0.0001). CFR was 3.1 ± 0.8 in all patients and lower in group A (2.5 ± 0.6 vs. 3.7 ± 0.3, p < 0.0001). CFR was inversely related with MIT (r =,0.774, p < 0.0001). A cut point of ,2.9, identified as optimal by receiver operating characteristics analysis was 100% specific and 80% sensitive (PPV = 100%, NPV = 89%, Accuracy = 91%). CFR assessment by CE-TTE is a novel noninvasive diagnostic tool in the detection of CAV defined as MIT ,0.5 mm. CFR by CE-TTE may reduce the need for routine IVUS in HT. [source]

Left coronary artery thrombus characterized by a fully automatic three-dimensional gated reconstruction,

CATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue 1 2009
Gert A.F. Schoonenberg MSc
Abstract Rotational coronary angiography and subsequent automatic modeling or reconstruction can result in clinically valuable three-dimensional (3D) representations of the coronaries. From these 3D representations information can be derived for specific coronary segments, such as lesion length, vessel diameter, bifurcation angles, and optimal viewing angles. In this case report, we highlight the characterization of a left coronary artery thrombus by a fully automatic 3D gated reconstruction. This case also shows that detailed 3D morphology of a lesion can be assessed during percutaneous coronary interventions using rotational coronary angiography and subsequent automated image processing. © 2009 Wiley-Liss, Inc. [source]

New parameters in the interpretation of exercise testing in women: QTC dispersion and QT dispersion ratio difference

CLINICAL CARDIOLOGY, Issue 4 2002
Kurtulu, Özdemr M.D.
Abstract Background: It has been reported that the increase of QT dispersion (QTD) that occurs due to increased inhomogeneity of the ventricular repolarization because of transient ischemia obtained by standard 12-lead electrocardiogram (ECG), the changes during exercise, and the differences between exercise and rest increase the accuracy of exercise test in the diagnosis of coronary artery disease (CAD). Hypothesis: This study was designed to investigate the value of QTD parameters, which are reported to increase the diagnostic accuracy of exercise test in women. Methods: Ninety-seven women who had undergone coronary angiography and exercise test were evaluated for diagnosis of chest pain. QT dispersion was calculated using the measurements of the highest and lowest values of QT interval obtained by ECG during peak exercise. The QTc using Bazett's equation, and the QTD ratio (QTDR) using QT/RR were calculated, and QTcD and QTD ratios were obtained. The difference between QTcD and QTDR was determined by extracting the rest values from the exercise values. Results: The groups with normal coronaries (n = 48), single-vessel CAD (n= 24), and multivessel CAD (n= 25) were compared. The obtained QTD parameters at peak exercise and their differences between exercise and rest were found to be significantly increased in patients with CAD (p<0.001). Furthermore, these parameters were found to be higher in the patients with multivessel CAD than in those with single-vessel disease (p < 0.05). With the parameters QTcD > 60 ms and QTDR > 10%, greater sensitivity and specificity were obtained compared with ST-segment depression. The highest diagnostic accuracy was obtained with the QTD parameters calculated from the differences between rest and exercise values. The diagnostic accuracy of the difference of QTcD > 15 ms and the difference of QTDR > 5% was relatively higher than the other parameters (sensitivity, specificity, and negative and positive predictor values are 84,88,84, 87% and 84, 96, 85, 95%, respectively). Conclusion: The use of QTD parameters as variables of ECG, which is easily obtainable in the evaluation of exercise ECG in women, increases the diagnostic accuracy of the exercise test. In addition, the evaluation of QTD variables may provide information about the incidence of CAD. [source]

Variations in high-density lipoprotein cholesterol in relation to physical activity and Taq 1B polymorphism of the cholesteryl ester transfer protein gene

CLINICAL GENETICS, Issue 5 2004
M Mukherjee
The aim of the study was to determine any association of physical activity and Taq 1B polymorphism in the cholesteryl ester transfer protein gene on high-density lipoprotein (HDL) cholesterol. Five hundred and four subjects, 390 males and 114 females consisting of an equal number of age- and sex-matched healthy controls and patients with coronary artery disease, were included. The mean age (±SD) of the patients and controls were 57.5 ± 10.6 years and 56.8 ± 11.0 years, respectively. All the patients underwent coronary angiography; 33, 58, 63, and 98 patients had normal coronaries, single-, two-, or triple-vessel disease, respectively. A third of the patients had suffered from a myocardial infarction. The genotype distribution conforming to Hardy,Weinberg equilibrium was similar for cases and controls. The mean HDL cholesterol increased from B1B1 through B2B2 genotype in controls and sedentary male patients. Self-reported leisure time physical activity, consisting mostly of an hour of morning walk daily, was associated with a rise in mean HDL cholesterol in male controls (33.6 ± 7.9 mg/dl to 36.2 ± 8.9 mg/dl, p = 0.037) and patients (32.4 ± 7.9 mg/dl to 35.7 ± 11.0 mg/dl; p = 0.018). The exercise-associated rise in HDL cholesterol was most pronounced in controls (32.1 ± 9.1 mg/dl to 36.8 ± 9.3 mg/dl, p = 0.05) and male patients (30.5 ± 7.4 mg/dl to 37.2 ± 9.7 mg/dl, p = 0.007) with B1B1 rather than B1B2 or B2B2 genotype. The results suggest a possible gene-environment interaction in the regulation of HDL cholesterol that needs to be confirmed in other populations and larger samples to rule out a chance occurrence. [source]

Monitoring of monocyte functional state after extracorporeal circulation: A flow cytometry study

CYTOMETRY, Issue 1 2004
Silverio Sbrana
Abstract Background Cardiovascular surgery with cardiopulmonary bypass (CPB) induces systemic inflammation and postoperative complications depending on pro- and anti-inflammatory mechanisms. Activated polymorphonuclear cells and monocytes may be responsible for morbidity associated with CPB. Knowledge of the monocyte functional state in particular may help to develop protective interventions. Methods Samples were drawn from venous peripheral blood (basal condition, at 4 and 24 h after CPB) and coronary blood (before and after cardioplegic arrest) of 14 patients undergoing cardiac surgery. The following phenotypic and functional parameters of the monocyte population were studied by flow cytometry: surface molecules expression (CD18, CD11a, CD11b, CD14, CD15, CD45, HLA-DR, and Toll-like receptor [TLR]-4), myeloperoxidase (MPO) content, and intracellular cytokine production (tumor necrosis factor [TNF]-,, interleukin [IL]-1,, IL-6, and IL-8). Results Cardiac surgery with CPB induced down-modulation of surface molecules expression on peripheral monocytes, especially at 24 h after CPB, for CD18, CD11a, and CD11b (P < 0.003) and for the CD15 adhesive cluster (P = 0.0028) and HLA-DR (P < 0.001). At 4 h after CPB, downregulation was observed for CD14 (P = 0.004), CD45 (P = 0.014), and CD15 (P = 0.0056). A loss of MPO was detected in venous peripheral (at 24 h after CPB, P = 0.01) or coronary (at reperfusion, P < 0.02) blood. The CD15 cluster complex exhibited a down-modulation in coronary blood (at reperfusion, P = 0.0003). Spontaneous intracellular production of IL-1,, IL-6, and IL-8 decreased at 24 h after CPB (P < 0.05). Conclusions The down-modulation of integrins and adhesive receptor expression and the loss of MPO suggest a strong activation and shedding reaction of circulating monocyte after CPB, further exacerbated by contact with coronary ischemic vessels. The changes of differentiation antigens may reflect the appearance of a partially immature population immediately after CPB. The reduced proinflammatory cytokine production, observed at 24 h after CPB, suggests a functional polarization of circulating monocytes. © 2003 Wiley-Liss, Inc. [source]

How to identify patients with vulnerable plaques

DIABETES OBESITY & METABOLISM, Issue 10 2008
Salim S. Virani
Multiple strategies are available for clinicians to identify patients at high risk for cardiovascular events. Two commonly discussed strategies are the identification of vulnerable plaques and the identification of vulnerable patients. The strategy of identifying vulnerable patients is less invasive, easy to implement and not restricted primarily to one vascular bed (e.g. coronary or cerebral). This review discusses the utility as well as the limitations of global risk assessment tools to identify such patients. The utility of biomarkers [C-reactive protein, lipoprotein-associated phospholipase A2 and lipoprotein(a)] and non-invasive measures of atherosclerosis burden (coronary artery calcium scores, carotid intima,media thickness and ankle,brachial index) in identifying patients at high risk for cardiovascular events are also discussed. [source]

Insulin resistance and endothelial dysfunction: the road map to cardiovascular diseases

DIABETES/METABOLISM: RESEARCH AND REVIEWS, Issue 6 2006
Eugenio Cersosimo
Abstract Cardiovascular disease affects approximately 60% of the adult population over the age of 65 and represents the number one cause of death in the United States. Coronary atherosclerosis is responsible for the vast majority of the cardiovascular events, and a number of cardiovascular risk factors have been identified. In recent years, it has become clear that insulin resistance and endothelial dysfunction play a central role in the pathogenesis of atherosclerosis. Much evidence supports the presence of insulin resistance as the fundamental pathophysiologic disturbance responsible for the cluster of metabolic and cardiovascular disorders, known collectively as the metabolic syndrome. Endothelial dysfunction is an important component of the metabolic or insulin resistance syndrome and this is demonstrated by inadequate vasodilation and/or paradoxical vasoconstriction in coronary and peripheral arteries in response to stimuli that release nitric oxide (NO). Deficiency of endothelial-derived NO is believed to be the primary defect that links insulin resistance and endothelial dysfunction. NO deficiency results from decreased synthesis and/or release, in combination with exaggerated consumption in tissues by high levels of reactive oxygen (ROS) and nitrogen (RNS) species, which are produced by cellular disturbances in glucose and lipid metabolism. Endothelial dysfunction contributes to impaired insulin action, by altering the transcapillary passage of insulin to target tissues. Reduced expansion of the capillary network, with attenuation of microcirculatory blood flow to metabolically active tissues, contributes to the impairment of insulin-stimulated glucose and lipid metabolism. This establishes a reverberating negative feedback cycle in which progressive endothelial dysfunction and disturbances in glucose and lipid metabolism develop secondary to the insulin resistance. Vascular damage, which results from lipid deposition and oxidative stress to the vessel wall, triggers an inflammatory reaction, and the release of chemoattractants and cytokines worsens the insulin resistance and endothelial dysfunction. From the clinical standpoint, much experimental evidence supports the concept that therapies that improve insulin resistance and endothelial dysfunction reduce cardiovascular morbidity and mortality. Moreover, interventional strategies that reduce insulin resistance ameliorate endothelial dysfunction, while interventions that improve tissue sensitivity to insulin enhance vascular endothelial function. There is general agreement that aggressive therapy aimed simultaneously at improving insulin-mediated glucose/lipid metabolism and endothelial dysfunction represents an important strategy in preventing/delaying the appearance of atherosclerosis. Interventions that 1 correct carbohydrate and lipid metabolism, 2 improve insulin resistance, 3 reduce blood pressure and restore vascular reactivity, and 4 attenuate procoagulant and inflammatory responses in adults with a high risk of developing cardiovascular disease reduce cardiovascular morbidity and mortality. Whether these benefits hold when the same prevention strategies are applied to younger, high-risk individuals remains to be determined. Copyright © 2006 John Wiley & Sons, Ltd. [source]

Increased prevalence of cardiovascular disease in Type 2 diabetic patients with non-alcoholic fatty liver disease

DIABETIC MEDICINE, Issue 4 2006
G. Targher
Abstract Aims, To estimate the prevalence of cardiovascular disease (CVD) in Type 2 diabetic patients with and without non-alcoholic fatty liver disease (NAFLD), and to assess whether NAFLD is independently related to prevalent CVD. Methods, We studied 400 Type 2 diabetic patients with NAFLD and 400 diabetic patients without NAFLD who were matched for age and sex. Main outcome measures were prevalent CVD (as ascertained by medical history, physical examination, electrocardiogram and echo-Doppler scanning of carotid and lower limb arteries), NAFLD (by ultrasonography) and presence of the metabolic syndrome (MetS) as defined by the World Health Organization or Adult Treatment Panel III criteria. Results, The prevalences of coronary (23.0 vs. 15.5%), cerebrovascular (17.2 vs. 10.2%) and peripheral (12.8 vs. 7.0%) vascular disease were significantly increased in those with NAFLD as compared with those without NAFLD (P < 0.001), with no differences between sexes. The MetS (by any criteria) and all its individual components were more frequent in NAFLD patients (P < 0.001). In logistic regression analysis, male sex, age, smoking history and MetS were independently related to prevalent CVD, whereas NAFLD was not. Conclusions, The prevalence of CVD is increased in patients with Type 2 diabetes and NAFLD in association with an increased prevalence of MetS as compared with diabetic patients without NAFLD. Follow-up studies are necessary to determine whether this higher prevalence of CVD among diabetic patients with NAFLD affects long-term mortality. Diabet. Med. (2006) [source]

Comparison of Coronary Flow Velocities Between Patients with Obstructive and Nonobstructive Type Hypertrophic Cardiomyopathy: Noninvasive Assessment by Transthoracic Doppler Echocardiography

ECHOCARDIOGRAPHY, Issue 1 2005
Seden Celik M.D.
Background: We aimed to compare coronary flow velocity (CFV) measurements of patients with nonobstructive (NHCM) and obstructive hypertrophic cardiomyopathy (HOCM) by using transthoracic Doppler echocardiography (TTDE). Methods and Results: In 11 patients with NHCM and 26 with HOCM, CFV in the distal left anterior descending (LAD) coronary was measured by TTDE (3.5 MHz) under the guidance of color Doppler flow mapping in addition to standard 2D and Doppler echocardiography. The results were compared with 24 normal participants who had no evidence of cardiac disease. Peak diastolic velocity of LAD was also higher in NHCM and HOCM than controls (52 ± 14 cm/sec and 54 ± 20 cm/sec vs 41 ± 11 cm/sec, respectively, P < 0.01). The analysis of systolic velocities revealed abnormal flow patterns in 16 (61%) patients with HOCM (12 systolic-reversal flow and 4 no systolic flow) and 6 (54%) (5 reversal flow and 1 zero flow) patients with NHCM (,11 ± 30 cm/sec and ,13 ± 38 cm/sec, vs 24 ± 9 cm/sec, respectively, P < 0.001). Linear regression analysis demonstrated no correlation between intraventricular pressure gradient and coronary flow velocities in HOCM patients. However, there were significant positive and negative correlations between septal thickness and diastolic and systolic velocities, respectively (r = 0.50, P < 0.002, and r =,0.43, P < 0.005). Conclusion: We conclude that the coronary flow velocity abnormalities are independent from the type of hypertrophic cardiomyopathy. [source]

Magnetic resonance microscopy of the equine hoof wall: a study of resolution and potential

EQUINE VETERINARY JOURNAL, Issue 5 2006
M. D. KELLER
Summary Reasons for performing study: Obtaining magnetic resonance images of the inner hoof wall tissue at the microscopic level would enable early accurate diagnosis of laminitis and therefore more effective therapy. Objectives: To optimise magnetic resonance imaging (MRI) parameters in order to obtain the highest possible resolution of the structures beneath the equine hoof wall. Methods: Magnetic resonance microscopy (MRM) was performed in front feet from 6 cadaver horses using T2 -weighted fast spin echo (FSE-T2), and T1 -weighted gradient echo (GRE-T1) sequences. Results: In T2 weighted FSE images most of the stratum medium showed no signal, however the coronary, terminal and sole papillae were visible. The stratum lamellatum was clearly visible and primary epidermal lamellae could be differentiated from dermal lamellae. Conclusion: Most structures beneath the hoof wall were differentiated. Conventional scanners for diagnostic MRI in horses are low or high field. However this study used ultra-high field scanners currently not available for clinical use. Signal-to-noise ratio (S/N) increases as a function of field strength. An increase of spatial resolution of the image results in a decreased S/N. S/N can also be improved with better coils and the resolution of high field MRI scanners will increase as technology develops and surface array coils become more readily available. Potential relevance: Although MR images with microscopic resolution were obtained ex vivo, this study demonstrates the potential for detection of lamellar pathology as it occurs. Early recognition of the development of laminitis to instigate effective therapy at an earlier stage and may improve the outcome for laminitic horses. Clinical MR is now readily available at 3 T, while 4 T, 7 T and 9 T systems are being used for human whole body applications. [source]

Contribution of endothelium-derived hyperpolarizing factors to the regulation of vascular tone in humans

FUNDAMENTAL & CLINICAL PHARMACOLOGY, Issue 4 2008
Jeremy Bellien
Abstract Endothelium plays a crucial role in the regulation of cardiovascular homeostasis through the release of vasoactive factors. Besides nitric oxide (NO) and prostacyclin, increasing evidences show that endothelium-derived hyperpolarizing factors (EDHF) participate in the control of vasomotor tone through the activation of calcium-activated potassium channels. In humans, the role of EDHF has been demonstrated in various vascular beds including coronary, peripheral, skin and venous vessels. The mechanisms of EDHF-type relaxations identified in humans involved the release by the endothelium of hydrogen peroxide, epoxyeicosatrienoic acids (EETs), potassium ions and electronical communication through the gap junctions. The role of EETs could be particularly important because, in addition contributing to the maintenance of the basal tone and endothelium-dependent dilation of conduit arteries, these factors share many vascular protective properties of NO. The alteration of which might be involved in the physiopathology of cardiovascular diseases. The evolution of EDHF availability in human pathology is currently under investigation with some results demonstrating an increase in EDHF release to compensate the loss of NO synthesis and to maintain the endothelial vasomotor function whereas others reported a parallel decrease in NO and EDHF-mediated relaxations. Thus, the modulation of EDHF activity emerges as a new pharmacological target and some existing therapies in particular those affecting the renin,angiotensin system have already been shown to improve endothelial function through hyperpolarizing mechanisms. In this context, the development of new specific pharmacological agents especially those increasing EETs availability may help to prevent endothelial dysfunction and therefore enhance cardiovascular protection in patients. [source]

Sigma receptors: from discovery to highlights of their implications in the cardiovascular system

FUNDAMENTAL & CLINICAL PHARMACOLOGY, Issue 1 2002
Laurent Monassier
Sigma receptors are the targets of many ligands, of which some (the haloperidol for instance) are psychoactive, and of substances known to have antiarrhythmic effects (amiodarone and clofilium). They are involved in a variety of cardiovascular functions, such as the regulation of cardiac contractility and rhythm and the regulation of coronary and peripheral arterial vasomotricity. This short review will focus on some aspects regarding the ligands, the binding sites, the intracellular coupling and the cardiovascular functions of these enigmatic receptors. [source]

Survival to discharge among patients treated with CRRT

HEMODIALYSIS INTERNATIONAL, Issue 1 2005
R. Wald
Continuous renal replacement therapy (CRRT) is widely used in critically ill patients with acute renal failure (ARF). The survival of patients who require CRRT and the factors predicting their outcomes are not well defined. We sought to identify clinical features to predict survival in patients treated with CRRT. We reviewed the charts of all patients who received CRRT at the Toronto General Hospital during the year 2002. Our cohort (n = 85) represented 97% of patients treated with this modality in 3 critical care units. We identified demographic variables, underlying diagnoses, transplantation status, location (medical-surgical, coronary or cardiovascular surgery intensive care units), CRRT duration, baseline creatinine clearance (CrCl), and presence of oliguria (<400 ml/d) on the day of CRRT initiation. The principal outcome was survival to hospital discharge. Among those alive at discharge, we assessed whether there was an ongoing need for renal replacement therapy. Greater than one-third (38%, 32/85) of patients survived to hospital discharge. Three (9%) of the survivors remained dialysis-dependent at the time of discharge. Survivors were younger than non-survivors (mean age 56 vs 60 y.), were on CRRT for a shorter duration (7 vs 13 d.), and had a higher baseline CrCl (79 vs 68 ml/min). Patient survival varied among different critical care units (medical surgical 33%, coronary 38%, and cardiovascular surgery 45%). Multivariable logistic regression revealed that shorter duration of CRRT, non-oliguria, and baseline CrCl > 60 ml/min were independently associated with survival to hospital discharge (p < 0.05). Critically ill patients with ARF who require CRRT continue to have high in-hospital mortality. A shorter period of CRRT dependence, non-oliguria, and higher baseline renal function may predict a more favorable prognosis. The majority of CRRT patients who survive their critical illness are independent from dialysis at the time of hospital discharge. [source]

Regular or "Super-Aspirins"?

JOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 4 2001
A Review of Thienopyridines or Aspirin to Prevent Stroke
PURPOSE: To review the evidence for the effectiveness and safety of the thienopyridines (ticlopidine and clopidogrel) compared with aspirin for the prevention of vascular events among patients at high risk of vascular disease. BACKGROUND: Atherosclerosis and resultant cardiovascular disease are important causes of morbidity and mortality in older people. In particular, atherosclerosis of the cerebral arteries can lead to transient ischemic attacks (TIAs) and stroke. Stroke ranks as the third-leading cause of death in the United States and in 1997 was responsible for over 150,000 fatalities.1 In addition to the mortality associated with this disease, stroke is also a leading source of long-term disability in survivors. Nearly 4.5 million stroke survivors are alive today,1 highlighting the fact that primary, but also secondary, prevention are extremely important for minimizing the complications of this illness. DATA SOURCES: Specialized trial registers of the Cochrane Stroke Group and the Antithrombotic Trialist's Collaboration, MEDLINE, and Embase were searched. Additional unpublished information and data were sought from Sanofi, the pharmaceutical company that developed and manufactures ticlopidine and clopidogrel, as well as the principal investigators of the Clopidogrel versus Aspirin in Patients at Risk of Ischemic Events (CAPRIE) trial,7 the largest of the trials identified. STUDY SELECTION CRITERIA: All unconfounded randomized trials comparing either ticlopidine or clopidogrel with aspirin among patients at high risk of vascular disease (those with symptoms of ischemia of the cerebral, coronary, or peripheral circulations) who were followed for at least 1 month for the recurrence of vascular events were included. DATA EXTRACTION: Data were extracted from four completed randomized trials completed in the past 20 years, which included 22,656 patients.7,10 Two authors independently extracted the data from these trials for the following information: the types of patients enrolled; the entry and exclusion criteria; the randomization method; the number of patients originally allocated to the treatment and control groups; the method and duration of follow-up; the number of patients in each group lost to follow-up; information on compliance with the treatment allocated; the definitions of outcome events; the number of outcome events in each treatment group; and any method used for blinding patients, treating clinicians, and outcome assessors to treatment allocation. MAIN RESULTS: Four completed trials involving a total of 22,656 patients were identified. Aspirin was compared with ticlopidine in three trials (3,471 patients)8,10 and with clopidogrel in one trial (19,185 patients).7 A recent TIA or ischemic stroke was the qualifying event in 9,840 patients, a recent myocardial infarction in 6,302 patients, and symptomatic peripheral arterial disease in 6,514 patients. The average age of the patients was approximately 63, with approximately two-thirds of the patients being male and white. The duration of follow-up ranged from 12 to 40 months. CONCLUSIONS: This systematic review demonstrates that, compared with aspirin, thienopyridines are only modestly more effective in preventing serious vascular events in high-risk patients. For patients who are intolerant of, or allergic to aspirin, the available safety and efficacy data suggest that clopidogrel is an appropriate, but more-expensive, alternative antiplatelet drug. It appears safer than ticlopidine and as safe as aspirin but it should not replace aspirin as the first-choice antiplatelet agent for all patients. Further studies are necessary to determine which, if any, particular types of patients would benefit most and least from clopidogrel instead of aspirin. [source]

Concomitant Coronary and Peripheral Arterial Disease: Single-Stage Revascularization

The "Button Inside" Technique for the Aortic Root Replacement: A Modified Button Technique

JOURNAL OF CARDIAC SURGERY, Issue 4 2006
Carlo Canosa M.D.
Anastomosis of the coronary buttons is performed from the inside of the composite valve graft previously including the coronary buttons in the composite valve graft. Reduced tension is present between coronary arteries and the composite valve graft once the heart is beating and the systemic pressure is increasing. In this way coronary buttons are reinforced directly by the composite aortic wall graft prosthesis. The coronary ostia are perfused with lower tension at the site of the coronary anastomoses. No bleeding from the suture line of the coronary buttons occurs using this new surgical approach. [source]

Novel Use of a Magnetic Coupling Device to Repair Damage of the Internal Thoracic Artery

JOURNAL OF CARDIAC SURGERY, Issue 1 2006
Alexandros Charitou M.D., F.R.C.S.
The device has been primarily used to perform distal coronary anastomoses. We report for the first time the novel use of this magnetic coupling device as a technique to repair iatrogenic injury of the left internal thoracic artery conduit. Technical issues, advantages, disadvantages, and the use of computer tomography angiogram for assessment of the anastomosis are discussed. [source]

Optical Mapping of Transmural Activation Induced by Electrical Shocks in Isolated Left Ventricular Wall Wedge Preparations

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 11 2003
OLEG F. SHARIFOV Ph.D.
Introduction: It is believed that electrical shocks interrupt fibrillation by directly stimulating the bulk of ventricular myocardium in excitable states, but how shocks activate intramural tissue layers is not known. In this study, Vm responses and transmural activation patterns induced by shocks during diastole were measured in isolated coronary perfused preparations of porcine left ventricle. Methods and Results: Rectangular shocks (duration = 10 ms; field strength, E = 1,44 V/cm) were applied across preparations (thickness = 14.9 ± 2.5 mm, n = 9) via large mesh electrodes during diastole or action potential (AP) plateau. Vm responses at the transmural surface were measured using optical mapping technique (resolution = 1.2 mm). Depending on shock strength, three types of Vm responses were observed. (1) Weak shocks (E , 1,4 V/cm) applied in diastole induced APs with simple monophasic upstrokes. The latency and time of transmural activation (TTA) rapidly decreased with increasing shock strength. Earliest activation occurred predominantly at the cathodal side of preparations in the areas that exhibited maximal ,Vm during AP plateau. (2) Intermediate shocks (E , 4,23 V/cm) induced monophasic and biphasic upstrokes that were paralleled with predominantly negative plateau ,Vm. Activation was initiated at multiple transmural sites and rapidly spread across the myocardial wall (TTA = 0.6 ± 0.2 ms). (3) Very strong shocks (E , 23,44 V/cm) could cause triphasic upstrokes, likely reflecting occurrence of membrane electroporation, and delayed activation (TTA = 6.7 ± 3.8 ms) at sites of largest negative plateau ,Vm. Conclusion: Shocks applied during diastole cause direct and rapid (within 1 ms) activation of ventricular bulk over a wide range of shock strengths, supporting the excitatory hypothesis of defibrillation. Very strong shocks can cause multiphasic Vm responses and delayed activation. (J Cardiovasc Electrophysiol, Vol. 14, pp. 1215-1222, November 2003) [source]

Review of nursing care for patients undergoing percutaneous coronary intervention: a patient journey approach

JOURNAL OF CLINICAL NURSING, Issue 17 2009
John X Rolley
Aim., To evaluate the existing literature to inform nursing management of people undergoing percutaneous coronary intervention. Background., Percutaneous coronary intervention is an increasingly important revascularisation strategy in coronary heart disease management and can be an emergent, planned or rescue procedure. Nurses play a critical role in delivering care in both the independent and collaborative contexts of percutaneous coronary intervention management. Design., Systematic review. Method., The method of an integrative literature review, using the conceptual framework of the patient journey, was used to describe existing evidence and to determine important areas for future research. The electronic data bases CINAHL, Medline, Cochrane and the Joanna Briggs data bases were searched using terms including: (angioplasty, transulminal, percutaneous coronary), nursing care, postprocedure complications (haemorrhage, ecchymosis, haematoma), rehabilitation, emergency medical services (transportation of patients, triage). Results., Despite the frequency of the procedure, there are limited data to inform nursing care for people undergoing percutaneous coronary intervention. Currently, there are no widely accessible nursing practice guidelines focusing on the nursing management in percutaneous coronary intervention. Findings of the review were summarised under the headings: Symptom recognition; Treatment decision; Peri-percutaneous coronary intervention care, describing the acute management and Postpercutaneous coronary intervention management identifying the discharge planning and secondary prevention phase. Conclusions., Cardiovascular nurses need to engage in developing evidence to support guideline development. Developing consensus on nurse sensitive patient outcome indicators may enable benchmarking strategies and inform clinical trial design. Relevance to clinical practice., To improve the care given to individuals undergoing percutaneous coronary intervention, it is important to base practice on high-level evidence. Where this is lacking, clinicians need to arrive at a consensus as to appropriate standards of practice while also engaging in developing evidence. This must be considered, however, from the central perspective of the patient and their family. [source]

Forensic Considerations in Cases of Neurofibromatosis,An Overview

JOURNAL OF FORENSIC SCIENCES, Issue 5 2007
Roger W. Byard M.B.B.S.
Abstract:, Neurofibromatosis types 1 and 2 are inherited neurocutaneous disorders characterized by a variety of manifestations that involve the circulatory system, the central and peripheral nervous systems, the skin, and the skeleton. Significant reduction in lifespan occurs in both conditions often related to complications of malignancy and hypertension. Individuals with these conditions may also be the subject of medicolegal autopsy investigation if sudden death occurs. Unexpected lethal events may be associated with intracranial neoplasia and hemorrhage or brainstem compression. Vasculopathy with fibrointimal proliferation may result in critical reduction in blood flow within the coronary or cerebral circulations, and aneurysmal dilatation may be associated with rupture and life-threatening hemorrhage. An autopsy approach to potential cases should include review of the history/hospital record, liaison with a clinical geneticist (to include family follow-up), a full external examination with careful documentation of skin lesions and nodules, measurement of the head circumference in children, photography, possible radiologic examination, a standard internal autopsy examination, documentation of the effects of previous surgery and/or chemo/radiotherapy, examination for specific tumors, specific examination and sampling of vasculature (renal, cerebral, and cardiac), formal neuropathologic examination of brain and spinal cord, possible examination of the eyeballs, examination of the gastrointestinal tract, histology to include tumors, vessels, gut, and bone marrow, toxicological testing for anticonvulsants, and sampling of blood and tissue for possible cytogenetic/molecular evaluation if required. [source]

Who should receive a statin these days?

JOURNAL OF INTERNAL MEDICINE, Issue 4 2006
Lessons from recent clinical trials
Abstract. The 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors or statins are the most successful cardiovascular drugs of all time. By interrupting cholesterol synthesis in the liver, they activate hepatocyte low-density lipoprotein (LDL) receptors and produce consistent and predictable reductions in circulating LDL cholesterol with resulting reproducible improvements in cardiovascular risk by retarding or even regressing the march of atherosclerosis in all major arterial trees (coronary, cerebral and peripheral). Clinical trials have demonstrated their capacity not only to extend life, but also to improve its quality by retarding the progression of diabetes mellitus and chronic renal disease and by enhancing central and peripheral blood flow. They are amongst the most extensively investigated pharmaceutical agents in current clinical use. In cardiovascular end-point trials they have proven ability to help prevent that first and all important myocardial infarction and to reduce the likelihood of a recurrence in those who do succumb. They are equally effective in men and women of all ages and at all levels of cardiovascular risk, whether caused by hypercholesterolaemia, hypertension, cigarette smoking, diabetes mellitus or the metabolic syndrome. In addition, they improve the outlook of patients with familial hypercholesterolaemia whose LDL receptor function is deficient or defective; and all of this comes at minimal risk to the recipient. Their most important potential side effect is myopathy, which on very rare occasions may lead to rhabdomyolysis. Clinical experience shows that myopathic symptoms with creatine kinase levels raised to more than 10 times the upper limit of normal is seen in <0.01% of recipients and progression to fatal rhabdomyolysis because of renal failure has been recorded in only 0.15 cases per million prescriptions. Liver function abnormalities are also, rarely, seen. Again, the frequency of raised aspartate or alanine aminotransferase to more than three times the normal limit is encountered in no more than 1,2% of all treated patients and is completely reversible upon withdrawal of treatment. Progression to hepatitis or liver failure does not occur. This constellation of benefits with little side effect penalty has resulted in the comparison of statins with antibiotics in the global battle against cardiovascular disease. [source]

Microcoil Embolization for Treatment of a Right Coronary Arteriovenous Fistula

JOURNAL OF INTERVENTIONAL CARDIOLOGY, Issue 4 2003
MUBIN I. SYED M.D.
A patient initially presented with anginal symptoms and a positive stress thallium test. An arteriovenous malformation in the right coronary artery causing a suspected coronary "steal syndrome" was subsequently discovered. This was treated with a microcoil embolization technique in lieu of the traditional surgical approach and this technique is described in detail. The patient had successful clinical, nuclear, and angiographic outcomes. (J Interven Cardiol 2003;16:347,350) [source]

Successful Double Percutaneous Alcohol and Coil Embolization of Bilateral Coronary-to-Pulmonary Artery Fistulas

JOURNAL OF INTERVENTIONAL CARDIOLOGY, Issue 3 2000
GIUSEPPE SANGIORGI M.D.
We report the case of a 70-year-old man with recent myocardial infarction who was admitted for further evaluation of his effort angina. Cardiac catheterization and selective coronary angiography excluded significant coronary atherosclerotic disease of the coronary arteries. Double coronary-to-pulmonary artery fistulas, one originating from the proximal right, the other from the left anterior descending coronary arteries, and draining into the right and left branch of the pulmonary artery, respectively, were observed. A left-to-right shunt was visualized at angiography. The patient was successfully treated with percutaneous alcohol and coil embolization of both coronary artery fistulas with total resolution of clinical symptoms. At 6-month follow-up a coronary angiography confirmed complete disappearance of the fistulas. We conclude that a "coronary steal" phenomenon caused by the fistulas induced myocardial ischemia in this patient and that percutaneous transcatheter exclusion with chemical and mechanical devices is a safe. effective, and reasonable alternative to traditional cardiac surgery. [source]

Correction for heart rate variability during 3D whole heart MR coronary angiography

JOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 5 2008
Stijntje D. Roes MD
Abstract Purpose To evaluate the effect of a real-time adaptive trigger delay on image quality to correct for heart rate variability in 3D whole-heart coronary MR angiography (MRA). Materials and Methods Twelve healthy adults underwent 3D whole-heart coronary MRA with and without the use of an adaptive trigger delay. The moment of minimal coronary artery motion was visually determined on a high temporal resolution MRI. Throughout the scan performed without adaptive trigger delay, trigger delay was kept constant, whereas during the scan performed with adaptive trigger delay, trigger delay was continuously updated after each RR-interval using physiological modeling. Signal-to-noise, contrast-to-noise, vessel length, vessel sharpness, and subjective image quality were compared in a blinded manner. Results Vessel sharpness improved significantly for the middle segment of the right coronary artery (RCA) with the use of the adaptive trigger delay (52.3 ± 7.1% versus 48.9 ± 7.9%, P = 0.026). Subjective image quality was significantly better in the middle segments of the RCA and left anterior descending artery (LAD) when the scan was performed with adaptive trigger delay compared to constant trigger delay. Conclusion Our results demonstrate that the use of an adaptive trigger delay to correct for heart rate variability improves image quality mainly in the middle segments of the RCA and LAD. J. Magn. Reson. Imaging 2008;27:1046,1053. © 2008 Wiley-Liss, Inc. [source]