PubMed Health⌕ Search

Biomedical subjects

J Mayet

Publications and source records attributed to J Mayet.

At least 19 recordsLinked to original sources
PubMed2007

Reduced endothelial progenitor cells in European and South Asian men with atherosclerosis.

BACKGROUND: Circulating endothelial progenitor cells (EPCs) play a role in the repair and regeneration of the endothelium and may represent a novel cardiovascular risk factor. South Asian subjects have an increased risk of cardiovascular disease which is not fully explained by known risk factors. This study examined associations of EPCs with atherosclerosis and possible ethnic differences in EPCs. MATERIALS AND METHODS: A population sample of 58 European and South Asian adult men was enriched with the recruitment of an additional 59 European and South Asian men with known coronary disease. The coronary artery calcification score was measured by multi-slice computerized tomography (CT), carotid and femoral intima-media thickness (IMT), and femoral plaques were measured by ultrasound. The subjects were further subdivided into three categories of coronary artery disease on the basis of coronary artery calcification score and clinical history. Total EPCs and non-senescent EPCs (ns-EPCs) were quantified after 5 days cell culture and the number of late outgrowth colonies was measured over a 6-week test period. Circulating CD34+ haematopoietic precursor cells were measured by flow cytometry. RESULTS: Individuals with femoral plaques had reduced total and ns-EPCs. The number of ns-EPCs were reduced in individuals with the most coronary atheroma and were inversely related to the coronary calcification score and femoral IMT. These relationships persisted after multivariate adjustment for other risk factors. The numbers of late outgrowth colonies or circulating CD34+ cells were unrelated to the presence of atherosclerosis. There were no differences in the number of EPCs between European and South Asian subjects. CONCLUSION: The number of EPCs are reduced in subjects with atherosclerosis independent of other risk factors. Reduction in EPC numbers may be an independent risk factor for atherosclerosis but does not explain ethnic differences in cardiovascular risk.

Aged↗
PubMed2006

Haemodynamic effects of changes in atrioventricular and interventricular delay in cardiac resynchronisation therapy show a consistent pattern: analysis of shape, magnitude and relative importance of atrioventricular and interventricular delay.

OBJECTIVE: To assess the haemodynamic effect of simultaneously adjusting atrioventricular (AV) and interventricular (VV) delays. METHOD: 35 different combinations of AV and VV delay were tested by using digital photoplethysmography (Finometer) with repeated alternations to measure relative change in systolic blood pressure (SBP(rel)) in 15 patients with cardiac resynchronisation devices for heart failure. RESULTS: Changing AV delay had a larger effect than changing VV delay (range of SBP(rel) 21 v 4.2 mm Hg, p < 0.001). Each had a curvilinear effect. The curve of response to AV delay fitted extremely closely to a parabola (average R2 = 0.99, average residual variance 0.8 mm Hg2). The response to VV delay was significantly less curved (quadratic coefficient 67 v 1194 mm Hg/s2, p = 0.003) and therefore, although the residual variance was equally small (0.8 mm Hg2), the R2 value was 0.7. Reproducibility at two months was good, with the SD of the difference between two measurements of SBP(rel) being 2.5 mm Hg for AV delay (2% of mean systolic blood pressure) and 1.5 mm Hg for VV delay (1% of mean systolic blood pressure). CONCLUSIONS: Changing AV and VV delays results in a curvilinear acute blood pressure response. This shape fits very closely to a parabola, which may be valuable information in developing a streamlined clinical protocol. VV delay adjustment provides an additional, albeit smaller, haemodynamic benefit to AV optimisation.

Aged↗
PubMed2005

The Coronary Artery Revascularisation in Diabetes (CARDia) trial: background, aims, and design.

BACKGROUND: Patients with diabetes have an increased incidence and severity of ischemic heart disease, which leads to an increased requirement for coronary revascularization. Comparative information regarding mode of revascularization--coronary artery bypass graft surgery surgery (CABG) or percutaneous coronary intervention (PCI)--is limited, mainly confined to a subanalysis of the Bypass Angioplasty Revascularization (BARI) trial, suggesting a mortality benefit of CABG over PCI. No prospective trial has specifically compared these modes of revascularization in patients with diabetes. OBJECTIVE: The Coronary Artery Revascularisation in Diabetes (CARDia) trial is designed to address the hypothesis that optimal PCI is not inferior to modern CABG as a revascularization strategy for diabetics with multivessel or complex single-vessel coronary disease. The primary end point is a composite of death, nonfatal myocardial infarction, and cerebrovascular accident at 1 year. METHOD: A total of 600 patients with diabetes are to be randomized to either PCI or CABG, with few protocol restrictions on operative techniques or use of new technology. This gives a power of 80% to detect non-inferiority of PCI assuming that the PCI 1-year event rate is 9%. A cardiac surgeon and a cardiologist must agree that a patient is suitable for revascularization by either technique prior to recruitment into the study. Twenty-one centers in the United Kingdom and Ireland are recruiting patients. Data on cost effectiveness, quality of life, and neurocognitive function are being collected. Long-term (3-5 year) follow-up data will also be collected.

Angioplasty, Balloon, Coronary↗
PubMed2005

Stress echocardiography for the diagnosis and risk stratification of patients with suspected or known coronary artery disease: a critical appraisal. Supported by the British Society of Echocardiography.

Stress echocardiography today has matured into a robust and reliable technique not only for the diagnosis of suspected coronary artery disease (CAD) but also for the accurate risk stratification of patients with suspected and established CAD. This is mainly because of rapid advances in image acquisition, digital display, and the development of harmonic and contrast imaging. Stress echocardiography today is also utilised in patients with heart failure both for assessing the cause of heart failure and determining the extent of hibernating myocardium. With advances in myocardial perfusion imaging, stress echocardiography now allows simultaneous assessment of myocardial function and perfusion. Tissue Doppler imaging allows quantitation of wall motion. Ready availability and reliability makes stress echocardiography a cost effective technique for the assessment of CAD.

Aged↗
PubMed2005

Echocardiographic methods for selecting patients suitable for biventricular pacing therapy.

The large outcome studies of biventricular pacing to date have selected patients using electrocardiogram criteria (prolonged QRS and left bundle branch block morphology). However, 20-30% of patients do not appear to respond clinically, and as a result there has been much interest in developing more specific methods of detecting mechanical dyssynchrony. A number of different echocardiographic techniques have been developed which appear to offer greater sensitivity and specificity than ECG in selecting these patients. This paper reviews the most promising of the echocardiographic techniques and gives guidance for the clinical use of echocardiography in selecting patients for biventricular pacing.

Arrhythmias, Cardiac↗
PubMed2004

Cardioversion and the use of sedation.

Nurse led cardioversion services have achieved significant reductions in both cost and waiting time. However, the question of safety of the procedure raises several areas of concern.

Atrial Fibrillation↗
PubMed2004

Selection and optimisation of biventricular pacing: the role of echocardiography.

The quantification of ventricular dyssynchrony is a key factor in identifying patients with severe heart failure who may benefit from cardiac resynchronisation with biventricular pacing (BVP). Echocardiographic techniques appear to offer superior sensitivity and specificity than the ECG in selecting these patients. This paper reviews the scope of current echocardiographic techniques for guiding both patient selection and optimisation of device programming following implantation.

Bundle-Branch Block↗
PubMed2002

Anticoagulation for cardioversion of atrial fibrillation.

The cardioversion of chronic atrial fibrillation to sinus rhythm carries a thromboembolic risk of 1.5-6%. These events occasionally occur at the time of cardioversion, but more often happen hours or days later. These strokes and other embolic events may occur even where atrial thrombus has been excluded before cardioversion and it has become apparent that, although atrial electrical activity may be restored by cardioversion, normal mechanical atrial function may take longer to recover. Numerous studies have addressed the role of anticoagulation following cardioversion in patients with atrial fibrillation, however, the mechanism of embolic complications as well as the justification of a standard anticoagulation therapy are not fully established. In this review we will try to present an overview of the mechanisms of thrombosis following cardioversion and give an insight into current anticoagulation strategies.

Acute Disease↗
PubMed2001

QT intervals and QT dispersion as measures of left ventricular hypertrophy in an unselected hypertensive population.

Electrocardiographic (ECG) QT intervals and dispersion correlate with echocardiographic left ventricular mass index (LVMI) in groups of selected essential hypertensives. We tested the strength of this relationship in a large group of unselected hypertensives to assess whether QT measurements may be a simple screening test for LVH in clinical practice. In a cross-sectional study of 386 unselected hypertensive subjects, maximal QT intervals (QTmax), QT dispersion (QTdisp), and ECG voltages (Sokolow-Lyon and Cornell sex-specific voltages) were measured from 12-lead ECG. The LVMI correlated most strongly with Cornell voltage (linear regression r = 0.44, P < .001). The strongest relationship between LVMI and QT parameters was with QTmax, (r = 0.25, P < .001). This relationship weakened using heart rate-corrected QTmax. Correlations between LVMI and QTdisp were weak, whether or not they were corrected for heart rate. Sokolow-Lyon voltages, Cornell voltage and QTmax, but not QTdisp, were independently predictive of LVMI after adjustment for age, sex, race, and the other ECG parameters. Receiver operating characteristic (ROC) curve analyses demonstrated that no QT parameter performed better than simple ECG voltage criteria in the detection of LVH. In conclusion, QTmax, the QT parameter most strongly associated with LVMI, was independently associated with LVMI after adjustment for standard ECG voltage criteria. However, as an isolated measure it was no better than simple ECG voltage criteria as a screening test for LVH in clinical practice.

Adult↗
PubMed2001

Cardiac investigation and intervention prior to thoraco-abdominal aneurysm repair: coronary angiography in 35 patients.

OBJECTIVE: retrospective studies indicate a high risk of cardiac events in patients undergoing thoraco-abdominal aneurysm repair. We aimed to determine the prevalence of coronary disease in these patients, define the role of non-invasive cardiac testing and assess the short-term outcome of coronary re-vascularisation. DESIGN: a prospective cohort study of consecutive patients referred to a single surgeon. MATERIALS AND METHODS: forty patients recruited over 16 months (Type I, 6; II, 11; III, 8; IV, 15). Dobutamine stress echocardiography, coronary angiography and coronary re-vascularisation (PTCA or CABG) were performed according to a pragmatic protocol. Main outcome measures were the prevalence of coronary artery disease, sensitivity and specificity of clinical assessment and non-invasive cardiac testing, and adverse events associated with coronary investigation and intervention. RESULTS: seven patients (17.5%) were stratified as having high perioperative cardiac risk. The majority of patients (23, 57.5%) had no cardiac risk factor other than the operation type. Five patients (12.5%) had inducible ischaemia on non-invasive testing. Fourteen patients (40%) had haemodynamically significant coronary artery stenoses, of whom 12 (34%) underwent coronary revascularisation. Dobutamine stress echocardiography demonstrated 100% specificity and 71% sensitivity for the detection of significant coronary artery lesions. Coronary re-vascularisation by three-vessel bypass grafting was complicated by non-fatal stroke in one patient. Thirty-five patients (87.5%) proceeded to aneurysm repair. No patient who had been adequately investigated suffered a cardiac complication. CONCLUSIONS: the 40% prevalence of coronary artery disease in these patients is comparable to that of other patients undergoing arterial surgery. Non-invasive testing proved beneficial, both in screening low-risk patients and planning intervention in patients at higher risk. An aggressive approach to intervention was associated with an acceptable complication rate and favourable short-term outcome.

Adult↗