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W Lane Duvall

Publications and source records attributed to W Lane Duvall.

7 recordsLinked to original sources
PubMed2006

A pilot study of the clinical impact of hand-carried cardiac ultrasound in the medical clinic.

BACKGROUND: Small, hand-carried ultrasound devices have become widely available, making point-of-care echocardiograms (echos) accessible to all medical personnel as a means to augment and improve the increasingly inefficient physical examination. This study was designed to determine the clinical utility of hand-carried echo by medical residents in clinical decision making. METHODS: Nine residents underwent brief, practical echo training to perform and interpret a limited hand-carried echo as an integral component of their office examination. The residents' hand-carried echo consisting of four basic views to define left ventricular (LV) function and wall thickness, valvular disease, and any pericardial effusions was compared to one performed by a level III echocardiographer. RESULTS: Seventy-two consecutive medical clinic patients were enrolled with an average image acquisition time of 4.45 minutes. Residents obtained diagnostic images in 94% of the cases and interpreted them correctly 93% of the time. They correctly identified 92% of the major echo findings and 78% of the minor findings. Their diagnosis of LV dysfunction, valvular disease, and LV hypertrophy improved by 19%, 39%, and 14% with hand-carried echo compared to history and physical alone. Management decisions were reinforced in 76% and changed in 40% of patients with the use of hand-carried echo. CONCLUSION: This study demonstrates that it is possible to train medical residents to perform an effective and reasonably accurate hand-carried echo during their physical examination, which can impact clinical management.

Chi-Square Distribution↗
PubMed2005

Endothelial dysfunction and antioxidants.

The vascular endothelium plays a crucial role in the physiology of blood vessels and the pathological processes of atherosclerotic disease and acute coronary syndromes. Endothelial dysfunction is the core problem; it is an impairment of endothelium-dependent vasorelaxation caused by a loss of nitric oxide activity in the vessel wall, which results in impairment in the regulation of vascular homeostasis. Further understanding of its mechanisms of action and possible therapeutic targets will be of great importance. The group of antioxidant vitamins, A, C and E, would seem uniquely situated to reduce cardiovascular events by improving endothelial function by reducing the concentration of reactive oxygen species in the vessel wall and by preventing oxidative modification of low-density lipoprotein. Unfortunately, despite extensive studies in both observational and randomized trials, the weight of evidence points to little or no benefit from antioxidant therapy.

Antioxidants↗
PubMed2003

Can hand-carried ultrasound devices be extended for use by the noncardiology medical community?

Echocardiography (echo) is a powerful, noninvasive, inexpensive diagnostic imaging technique that provides important information in a variety of cardiovascular diseases. Echo provides rapid information regarding ventricular and valvular function in the clinical management of patients. Smaller, relatively inexpensive hand-carried cardiac ultrasound (HCU) devices have become commercially available, which can be used for diagnostic cardiac imaging. Because of their relative ease of use, portability, and affordable cost, these new hand-held systems have made point-of-care (bedside) echocardiography available to all medical personnel. The rate-limiting step to the widespread use of this technology is the lack of personnel with echo training at the immediate contact point with patients. Although extensive training and experience are needed to acquire and interpret a complete echo, training medical personnel to perform and interpret a limited echo (defined as a brief, diagnosis focused exam) may fully exploit the potential of echo as a point-of-care diagnostic tool and may be accomplished in a short period of time. Presently there are guidelines for independent competency in echocardiography and HCU echo established by several professional organizations and as a result of these rigorous guidelines, other noncardiology medical professionals who could practically derive the greatest benefit are discouraged and virtually precluded from utilizing echo during the initial encounter with the patient. However, there is now a growing body of literature in a diverse group of noncardiology medical personnel that demonstrates that it is possible to quickly and effectively train them to perform and interpret limited echocardiograms. Medical students, medical residents, cardiology fellows with limited experience, emergency department physicians, and surgical intensive care unit staff have all been evaluated after only brief, focused training periods, and investigators found that HCU echo provided important new information, changed therapeutic management, and was vastly superior to the physical exam alone with an acceptable overall level of accuracy. The contribution of echocardiography to the field of cardiovascular disease since its invention has been significant and the newer compact, portable, ultrasound systems have the potential to revolutionize the utilization and availability of echocardiography. To maximize integration of echo into medical practice, physicians and physician extenders could be trained to perform and interpret limited echo to complement their clinical examination and improve their diagnostic skills. The challenge is to provide practical training programs to assure competency in performing point of care echocardiograms.

Emergency Service, Hospital↗
PubMed2003

Cardiovascular disease in women.

Almost 62 million Americans have one or more types of cardiovascular disease and, of these, more than 32 million are female. This translates into an average of 1 in 5 women, making cardiovascular disease the leading killer of women in the U.S., responsible for more than half a million deaths a year. While it has been known for some time that differences exist between the sexes regarding coronary heart disease, it has only been in the last 10 years that these disparities in incidence, morbidity, mortality, risk factors, diagnosis, and treatment have been explored. Research has shown a gap in the utilization of medical therapy, diagnostic studies, and revascularization procedures involving women. In addition, women s outcomes after myocardial infarction have been consistently demonstrated to be poorer than those of men. Another important issue that has just started to be addressed is that the predominantly male-focused cardiovascular research has been generalized to women. Only in recent years have women been included in clinical trials or databases in sufficient numbers for sex-based analysis of the data. The topic of cardiovascular disease in women is diverse and complex. In this article, some of the important issues will be introduced and discussed, highlight our current understanding of the problem and to emphasize the areas in which further study and progress is needed. These issues include the epidemiology of coronary heart disease, the diagnosis of coronary heart disease, the medical therapy of acute coronary syndromes, coronary revascularization, and hormone replacement therapy.

Cardiovascular Diseases↗
PubMed2002

Targeting cardiovascular risk associated with both low density and high density lipoproteins using statin-niacin combination therapy.

BACKGROUND: Cardiovascular risk might be reduced by targeted changes in both low density and high density lipoprotein cholesterol (LDL-C and HDL-C). This dual strategy will require a well tolerated, effective regimen, as well as a better understanding of how HDL-C may be targeted. DESIGN: An open-label, uncontrolled, retrospective cohort study of combined statin-niacin therapy. METHODS: We reviewed all patients ( n= 132) started on this combination in a referral lipid clinic over a 6.5-year period for tolerability, safety and effectiveness. RESULTS: Combined therapy was tolerated by 77% of patients. No serious adverse events attributable to medication were encountered. In drug-naive patients (n = 37), moderate doses of statin and niacin (mean 1180 mg/day) reduced LDL-C 31% and increased HDL-C 29% ( P< 0.002, both comparisons). At niacin doses >or= 1000 mg/day (mean 1480) added to a constant statin regimen (n=29), HDL-C increased 20% ( P< 0.001). Even at niacin doses < 1000 mg/day (mean 580, n= 23), HDL-C increased 13% ( P< 0.05). Although mean HDL-C increased, the initial and final HDL-C distributions were broad and largely overlapping. Any chosen cutpoint for HDL-C goal would apply to only a minority of patients. The total/HDL cholesterol ratio had narrower distributions, as the percentage of patients with ratio < 5.0 increased from 17% to 67%. CONCLUSION: Combined statin-niacin therapy lowers LDL-C and raises HDL-C with acceptable tolerance and safety. If treating LDL-C is the primary goal, consistent with current guidelines, then a strategy of targeting the total/HDL cholesterol ratio as a secondary goal is applicable to more patients than targeting HDL-C itself.

Anticholesteremic Agents↗
PubMedDate not supplied

SPECT myocardial perfusion imaging in morbidly obese patients: image quality, hemodynamic response to pharmacologic stress, and diagnostic and prognostic value.

BACKGROUND: Obesity is a growing epidemic in the United States, and little is known about the characteristics of the morbidly obese population (body mass index [BMI] > or = 40 kg/m2) undergoing stress myocardial perfusion imaging (MPI). METHODS AND RESULTS: We retrospectively reviewed all consecutive morbidly obese patients without known coronary artery disease presenting for a clinically indicated technetium 99m (Tc-99m) gated stress single photon emission computed tomography imaging study over a 42-month period. Studies were analyzed for image quality, for the contribution of attenuation correction to image interpretation, and for the hemodynamic response to pharmacologic stress. In patients who subsequently had cardiac catheterization, the results were compared with those from the initial MPI study, and the Social Security Death Index and hospital medical records were searched to the assess survival rate in the entire cohort. A total of 433 patients were identified with a mean BMI of 47.3 +/- 8 kg/m2 and a mean Tc-99m stress dose of 35.6 +/- 5.4 mCi. Image quality was good in 61% of the patients, adequate in 37%, and poor in 2%. It was found to be dependent on the stressor used (better with exercise) but did not correlate with increasing weight or BMI. Attenuation correction was used in 95% of the studies reviewed and was helpful for image interpretation in 60%. The heart rate response to dipyridamole and adenosine was more pronounced and the blood pressure response to dipyridamole was less pronounced in morbidly obese patients compared with nonobese control patients. In the 43 patients who underwent catheterization, stress MPI had a sensitivity of 95% and negative predictive value of 80%. Kaplan-Meier survival analysis at 1 year showed a significant difference in survival rate of 98.3% for normal MPI studies and 94.0% for abnormal MPI studies (P = .02). CONCLUSION: Diagnostic-quality single photon emission computed tomography imaging is feasible in the majority (98%) of morbidly obese patients with the use of a dual-head camera, attenuation correction, and high stress Tc-99m tracer doses. Exercise stress was associated with better image quality. The prognostic value of a normal MPI study in this population appears to be less favorable than in non-morbidly obese patients.

Cohort Studies↗