Biomedical subjects

J Trevelyan

Publications and source records attributed to J Trevelyan.

At least 19 recordsLinked to original sources

PubMed2006

Comparison of transthoracic echocardiography with harmonic imaging with transoesophageal echocardiography for the diagnosis of patent foramen ovale.

The optimal diagnostic method for patent foramen ovale is currently unclear. This study compared bubble contrast second harmonic transthoracic (TTE) and transoesophageal echocardiography (TOE) on 87 consecutive patients referred for TOE for all indications. A right left shunt was diagnosed in 34 cases (39%), with TTE positive in 26 cases (sensitivity 76.5%), TOE positive in 27 cases (sensitivity 79.4%). Pitfalls of TTE included quality of echo and left sided valve lesions, and for TOE the ability to perform an adequate Valsalva manoeuvre. In conclusion, both tests have similar sensitivity and should be viewed as complementary modalities.

Adult↗

PubMed2005

Comparison of the effect of enalapril and losartan in conjunction with surgical coronary revascularisation versus revascularisation alone on systemic endothelial function.

OBJECTIVES: To investigate the effect of enalapril, losartan, and surgical coronary revascularisation on endothelial function, and the role of the angiotensin converting enzyme (ACE) insertion (I)/deletion (D) polymorphism. DESIGN: Randomised, controlled, blinded end point study. SETTING: University tertiary referral cardiac centre. PATIENTS AND INTERVENTIONS: 49 men awaiting coronary artery bypass grafting (CABG) were randomly assigned to treatment with losartan, enalapril, or control for two months before and three months after surgery. MAIN OUTCOME MEASURES: Endothelial function was blindly analysed by brachial artery flow mediated dilatation (FMD) and ACE I/D genotype was determined. RESULTS: FMD was impaired at baseline (1.0-1.7%) and after five months had improved to 5.2% with enalapril (p = 0.015), 5.0% with losartan (p = 0.0004), and 3.0% with CABG alone (p = 0.05). Patients with the II genotype had lower baseline FMD than those with DI or DD (0.1% v 1.7%, p = 0.038) and after enalapril or losartan treatment had greater improvement in FMD (mean (SEM) 7.1 (1.1)%) than patients with DI (3.1 (1.3)%, p = 0.024) or DD genotype (3.1 (1.1)%, p = 0.02). CONCLUSIONS: Enalapril and losartan, with surgical coronary revascularisation, significantly improve systemic endothelial function. Revascularisation alone produces a quantitatively smaller, but still significant, improvement. The ACE genotype significantly modulates this response. Patients with the II genotype have a more pronounced impairment in endothelial function at baseline and a greater improvement in response to treatment with these agents.

Angiotensin II Type 1 Receptor Blockers↗

PubMed2004

Plane-wave basis finite elements and boundary elements for three-dimensional wave scattering.

Classical finite-element and boundary-element formulations for the Helmholtz equation are presented, and their limitations with respect to the number of variables needed to model a wavelength are explained. A new type of approximation for the potential is described in which the usual finite-element and boundary-element shape functions are modified by the inclusion of a set of plane waves, propagating in a range of directions evenly distributed on the unit sphere. Compared with standard piecewise polynomial approximation, the plane-wave basis is shown to give considerable reduction in computational complexity. In practical terms, it is concluded that the frequency for which accurate results can be obtained, using these new techniques, can be up to 60 times higher than that of the conventional finite-element method, and 10 to 15 times higher than that of the conventional boundary-element method.

Journal Article↗

PubMed2003

Sources of diagnostic inaccuracy of conventional versus new diagnostic criteria for myocardial infarction in an unselected UK population with suspected cardiac chest pain, and investigation of independent prognostic variables.

OBJECTIVE: To assess the degree and sources of current diagnostic inaccuracy of serial conventional cardiac markers and ECGs compared with the new diagnostic criteria for myocardial infarction, with specific reference to physician specialty and the prognostic value of troponin T. DESIGN: Prospective, blinded observational study. SETTING: University hospital. PATIENTS AND INTERVENTIONS: All suspected cardiac chest pain admissions for six months, with additional blinded measurement of CK-MB mass and troponin T. World Health Organization and new criteria myocardial infarction diagnoses were made by an expert panel. MAIN OUTCOME MEASURES: Diagnostic adjustment by expert panel; completeness of serial measurements; six months prognosis. RESULTS: A complete set of serial cardiac markers was not taken in 38.7% of patients, this being twice as likely when managed by non-cardiologists than by cardiologists (p < 0.0001). The WHO myocardial infarction diagnosis was adjusted by the expert panel in 4% of cases, this being 90% more likely in patients admitted under non-cardiologists (p = 0.026). The new criteria for myocardial infarction identified an additional 27.3% of infarcts, with a diagnostic alteration in 12.0% of the cohort; 45.2% of these cases had a potentially preventable cause for diagnostic adjustment. Only troponin T (p = 0.0004), ST depression (p = 0.003), and heart failure (p = 0.016) were independently predictive of prognosis. CONCLUSIONS: Chest pain patients appear less likely to be fully and accurately assessed by non-cardiologists than by cardiologists. The new criteria for myocardial infarction identify approximately 25% of additional patients as MI, with potential additional advantages related to simplicity of diagnostic protocols. Troponin T was the most potent predictor of six month prognosis in an unselected cohort of chest pain admissions.

Adult↗

PubMed2002

Lipoprotein lipase gene variants relate to presence and degree of microalbuminuria in Type II diabetes.

AIMS/HYPOTHESIS: Lipids and lipoproteins, particularly triglyceride rich lipoproteins, could influence the development and progression of microalbuminuria in diabetes. Lipoprotein lipase gene variants have been found to correlate with lipid/lipoprotein concentrations, especially hypertriglyceridaemia. We assessed the influence of this gene on microalbuminuria in Type II (insulin-dependent) diabetes mellitus. METHODS: Microalbuminuria was determined quantitatively in 386 sequential Type II diabetic patients by measurement of the albumin-to-creatinine ratio (ACR). DNA was analysed for two common intronic LPL single nucleotide polymorphisms (Pvu II, intron 6, and Hind III, intron 8), and three common exonic mutations (Asp(9)-Asn, exon 2, Asn(291)-Ser, exon 6, and Ser(447)-Ter, exon 9). RESULTS: Individuals with P (2) P (2) (Pvu II) and H (2) H (2) (Hind III) genotypes had significantly greater ACRs ( P(2)P(2) vs P(1)P(1)+ P(1)P(2), 5.0+/-0.5 vs 3.4+/-0.3, p=0.0004 and H(2)H(2) vs H(1)H(1)+ H(1)H(2), 4.3+/-0.4 vs 3.4+/-0.3, p=0.04). Logistic regression analysis demonstrated that only the P(2)P(2) genotype ( p=0.0004), systolic BP ( p=0.008) and creatinine ( p=0.031) were independently associated with the presence of microalbuminuria/proteinuria. P(2) homozygotes were 170% more likely to have microalbuminuria or proteinuria, O.R. 2.7 (1.6-4.5, p=0.0001), 150% more likely to have microalbuminuria, O.R. 2.5 (1.5-4.3, p=0.001), and 330% more likely to have proteinuria, O.R. 4.3 (1.6-11.4, p=0.004). There were no associations of microalbuminuria with any of the exonic polymorphisms. CONCLUSION/INTERPRETATION: Genetic variants of lipoprotein lipase correlate with presence and severity of microalbuminuria in Type II diabetes, independent of effect on serum lipids. This association is only apparent in genetic variants demonstrating greatest heterozygosity.

Aged↗

PubMed2001

Evaluation of patient characteristics and utilisation of invasive cardiac procedures in a UK ethnic population with unstable angina pectoris.

OBJECTIVES: To evaluate patient characteristics and utilisation of invasive cardiac procedures in a UK ethnic population with unstable angina pectoris (UAP). DESIGN: Retrospective, observational study. SETTING: Tertiary referral cardiology centre in the United Kingdom serving a large Asian ethnic population. SUBJECTS: White and Asian patients undergoing PTCA for UAP over a 2.5-year period at a UK referral cardiology centre from a comprehensive PTCA database. Data were also collated for all emergency admissions with unstable angina, or angina (type unspecified), to our institute. MAIN OUTCOME MEASURES: Demographic and angiographic characteristics of patients undergoing PTCA. Frequency of usage of invasive cardiac procedures was determined in emergency angina admissions. RESULTS: From January 1997 to July 1999, 435 White and 36 Asian patients underwent PTCA for UAP at our institute. Asian patients were on average 4.4 years younger (P=0.015), had 19.3% more diabetes (P=0.003) and 19.7% less smoking (P=0.007). Trends to more single vessel disease in Whites and more double vessel disease in Asians were observed, with similar rates of triple vessel disease. Interestingly, Asians also had trends towards more left-sided coronary artery disease and revascularisation, smaller vessels and less bail-out stenting. Asian patients were significantly less likely to undergo coronary angiography, OR 0.64 (CI 0.45-0.91, P=0.012), during the index admission, and showed a trend to less PTCA. CONCLUSIONS: Asian patients with unstable angina pectoris appear to have clinical and angiographic differences from their White counterparts, and are less likely to have invasive cardiac procedures deployed. The reasons for these observations require elucidation and the prognostic significance of these findings is uncertain.

Aged↗

PubMed2001

The integration of complementary therapies into conventional medicine focuses primarily upon symptomatic care of the body with scant attention given to any interrelationship of the spirit and mind upon health and well-being.

We are pleased to continue our series of debates addressing topical issues currently under scrutiny in the field of complementary medicine. In selected issues, two people are invited to argue the case for or against a specific statement. In certain instances the position taken may not necessarily reflect the personal views of the authors. They have been asked to take a specific stance in order to stimulate debate and reflection about particular aspects of complementary and alternative medicine.

Attitude of Health Personnel↗

PubMed2001

Multiple coronary aneurysms in a patient with neurofibromatosis type 1: case report and intravascular ultrasound of aneurysm.

A 54 year old woman with neurofibromatosis type 1 (NF-1) was found to have multiple coronary aneurysms. Intraoperative intravascular ultrasound (IVUS) revealed severe coronary disease proximal to the aneurysm that had not been apparent angiographically. An IVUS picture of one of the giant coronary aneurysms is also shown. The vascular manifestations of neurofibromatosis and the causes of coronary aneurysms are reviewed.

Coronary Aneurysm↗

PubMed2000

Complications from Sinus of Valsalva aneurysm--a case of stable ischemia from compression of the left main stem and one of surgical recurrence.

Two cases of Sinus of Valsalva aneurysm with unusual complications are presented. Left main stem compression from an expanding Sinus of Valsalva aneurysm usually carries a poor prognosis and aggressive surgical management has been proposed. We describe a case with stable myocardial ischemia over four months from left main stem compression. Surgical repair of Sinus of Valsalva aneurysm is usually curative, but our second case demonstrates the pitfalls of inadequate surgical management.

Adult↗

PubMed1999

Intravascular ultrasound in the diagnosis of the no-reflow phenomenon after primary angioplasty for myocardial infarction.

Explore the source record for details and available documents.

Aged↗

PubMed1998

Future of complementary medicine: training, status and the European perspective (Part 2).

In her second paper on developments within complementary medicine, Joanna Trevelyan takes a look at current approaches to training; issues surrounding the status of complementary medicine; and the influence Europe may have on the availability of therapies, natural medicines and supplements.

Complementary Therapies↗

PubMed1998

Complementary therapies on the NHS: current practice, future developments (Part I).

Three major reports have been published within the past year on the status, use and development of complementary medicine within the UK. The NHS Confederation has undertaken a survey of usage within NHS services in Leicestershire, the Foundation for Integrated Medicine has explored how such services might be improved, and the University of Exeter was commissioned by the Department of Health to survey complementary medicine organisations. In Europe, complementary medicine has been the focus of considerable discussion, little of it very positive. This paper examines what we now know about the use of complementary medicine within the NHS, and explores the notion of 'integrated medicine'. A second paper, to be published in August, will look at the status of complementary medicine in the UK and Europe, and important developments regarding the future of practitioner training.

Complementary Therapies↗

PubMed1990