The correlation of arteriosclerosis obliterans with lipoproteins in insulin-dependent and non-insulin-dependent diabetes.
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Adult↗
Biomedical subjects
K W Beach
Publications and source records attributed to K W Beach.
Diagnostic reliability of M-mode echocardiography for detecting mitral valve prolapse in 50 consecutive panic patients.
Fifty consecutive panic patients had M-mode echocardiographs read independently by two cardiologists with expertise in echocardiography. In this prospective study, there was poor interrater reliability (22 of 50; K = 0.11) for diagnosis of mitral valve prolapse (MVP). On repeat evaluation 10 months later there was also unacceptable intrarater reliability for each reader: 22 of 35 (K = 0.41) and 22 of 35 (K = 0.45). We conclude that M-mode echocardiography is clinically unreliable for establishing the diagnosis of mitral valve prolapse. These findings suggest that the variable reporting of M-mode-determined mitral valve prolapse in psychiatric populations may reflect differences among echocardiologists rather than differences in cardiac pathology. The clinical implications of these findings are discussed.
Agoraphobia↗
Evaluating carotid artery disease. The concordance between pulsed Doppler/spectrum analysis and angiography.
The results of ultrasonic pulsed Doppler duplex scanning with spectral analysis and computer pattern recognition are compared with the results of contrast arteriography in patients screened for extracranial carotid artery disease. The intraangiographer variability (one radiologist reading the same films twice) and the interangiographer variability (two radiologists reading the same film independently) were also studied. To calculate degrees of agreement corrected for chance, the Kappa statistic was computed for all the evaluation methods employed. At the present time, the concordance between spectral analysis and cerebral contrast angiography reaches a Kappa value of 0.682 +/- 0.064. This level of agreement compares favorably with the interangiographer agreement level (K = 0.568 +/- 0.058) and the intraangiographer agreement (K = 0.711 +/- 0.054). The computer pattern recognition program predicted the degree of stenosis by angiography with an agreement of K = 0.721 +/- 0.059. This concordance compares favorably to that observed when the radiologists are compared with themselves and is greater than that reached by two different radiologists. The continuous improvement in precision and accuracy of duplex scanning offers the promise of its usefulness in clinical and epidemiological studies.
Blood Flow Velocity↗
Post-endarterectomy carotid ultrasonic duplex scanning concordance with contrast angiography.
The results of ultrasonic duplex scanning combined with spectral analysis are compared with the results of contrast angiography in patients after endarterectomy in which recurrence of carotid arterial disease was suspected. Thirty-six patients underwent a duplex scan study within 3 months of their post-operative angiogram, performed at their physician's discretion (44 studies). The overall accuracy of the method was 80%. Our ability to predict a greater than 50% diameter reduction along with total occlusion was 94%. The measure of agreement corrected for chance between arteriography and duplex scanning as expressed by the Kappa statistic was 0.675 +/- SE (K) 0.096. This level of agreement compared favorably to that of inter- and intra-observer variability in reading cerebral angiograms. The accuracy reported justifies the clinical use of ultrasonic duplex scanning in the detection of recurrent stenosis after carotid endarterectomy.
Blood Flow Velocity↗
Computer based pattern recognition of carotid artery Doppler signals for disease classification: prospective validation.
A computer based pattern recognition method has been developed to classify the percent diameter reduction in nonoccluded internal carotid arteries. Using a combined B-mode/pulsed Doppler unit, the system utilizes spectral waveforms obtained from the low common and proximal internal carotid artery locations. The ECG-R wave is used as a time reference to synchronize the averaging of Doppler spectra from 20 heart cycles. An averaged waveform is generated and represents the spectral data from which features are extracted for analysis. A stepwise selection algorithm identifies a feature subset for partitioning the entire range of disease into two states, less than and greater than a decision point. Three such partitions are made, leading to the following categories: Normal, 1-20, 21-50 and 51-99% dia. reduction. A classifier was trained, tested prospectively against unknown data and the results compared to angiography. Of the 170 vessels tested, 141 (82%) were classified in the same category by angiography and the computer system. Agreement for each category was 93% (27/29) for the normals, 81.5% (44/54) for the 1-20% lesions, 78% (29/37) for the 21-50% lesions and 82% (41/50) for the 51-99% lesions. The computer method and angiography differed by more than one category in only one of the 170 tests. The level of agreement corrected for chance (Kappa +/- SE(K] was 0.769 +/- 0.039. Future efforts will be directed toward dividing classification of disease further (especially in the 51-99% category), developing a dedicated microprocessor for on-line analysis of the signals and using the system for prospective epidemiological studies of various populations.
Adult↗
Sources of variability in carotid duplex examination: a prospective study.
Interobserver and intraobserver variability of ultrasonic, duplex carotid artery examinations was studied in a prospective, randomized, and blinded clinical trial. Forty-eight patients were examined by two technologists, yielding 96 carotid artery examinations. The kappa statistic was calculated to determine the degree of agreement corrected for chance. The kappa value between examinations by different technologists was 0.476. Variability occurred at both steps in the examination procedure: (1) obtaining the velocity waveforms (kappa = 0.536); and (2) using these waveforms to classify the extent of carotid disease (kappa = 0.609 for interobserver variability in reading waveforms). Minimal to moderate disease categories accounted for most of the variability. There was little disagreement in categorizing lesions as greater than or less than 50% diameter reduction. Intraobserver variability in rereading spectral waveforms was minimal (kappa = 0.842 and 0.894). Recognition of disturbed flow patterns in normal carotid bulbs may reduce variability.
Carotid Artery Diseases↗
Pseudocolor displays in B-mode imaging applied to echocardiography and vascular imaging: an update.
Cardiac and vascular ultrasound systems incorporting colorized gray-scale display options to supplement the standard B-mode gray-scale image have recently reappeared on the market from several manufacturers. As yet, the clinical benefit of this "new" technology is unknown, and recommendations and protocols for its best application are not available. This article reviews the limitations of the gray-scale displays currently used, the rationale of the color-supplemented B-mode image, and some of the potential applications to cardiac and vascular ultrasound.
Color↗
Prevalence of severe arteriosclerosis obliterans in patients with diabetes mellitus. Relation to smoking and form of therapy.
Noninvasive methods were used to determine the prevalence and severity of arteriosclerosis obliterans associated with diabetes in 674 subjects including 153 recruited as controls. A resting ankle systolic blood pressure that was less than 90% of the arm pressure indicated severe arteriosclerosis obliterans. Of the 71 subjects with severe disease, 64 (90%) had a history of smoking, which is significantly greater than the 60% overall smoking rate (p less than 0.001). In non-insulin-dependent diabetic smokers, the diet-treated subjects had 2.5 times the prevalence of severe arteriosclerosis obliterans as those treated with insulin (p = 0.01); the sulfonylurea-treated subjects had twice the prevalence of severe disease as those treated with insulin (p = 0.015).
Adult↗
The natural history of carotid arterial disease in asymptomatic patients with cervical bruits.
A prospective study was initiated in January 1980 to follow with Duplex scanning a consecutive series of 167 asymptomatic patients with cervical bruits. Patients were seen at six month intervals for the first year and yearly thereafter. Based on previously validated criteria, disease at the carotid bifurcation was classified into 6 categories: Normal, 1-15% diameter reduction, 16-49%, 50-79%, 80-99%, and occlusion. Patients were evaluated to assess: the occurrence of new neurological symptoms, the stability of the lesions at the carotid bifurcation, and the possible role of risk indicators on disease changes. During follow-up, ten patients became symptomatic (6 with TIA's and 4 with stroke). The development of symptoms was accompanied by disease progression in 8 patients. By life table analysis, the annual rate occurrence of symptoms was 4%. The mean annual rate of disease progression to a greater than 50% stenosis was 8%. When progression in all categories was considered, 60% of the sides showed some disease aggravation. The presence of or progression to a greater than 80% stenosis was highly correlated (p = 0.00001) with either the development of a total occlusion of the internal carotid artery or new symptoms. The major risk factors associated with disease progression were cigarette smoking, diabetes mellitus, and age. Those patients under 65 years of age were most likely to show progression. Despite high rates of disease progression, this study further supports the contention that it is prudent to follow a conservative course in the management of asymptomatic patients presenting with a cervical bruit.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Carotid artery disease in NIDDM diabetes.
A prospective study of 135 controls, 286 non-insulin-dependent diabetic patients, and 31 subjects with an elevated fasting plasma glucose was performed to assess the prevalence of high-grade carotid artery stenosis. The carotid artery evaluation was performed using an ultrasonic duplex scanner. When those patients with an elevated fasting plasma glucose and non-insulin-dependent diabetes were considered together, the prevalence was 8.2% as compared with 0.7% for the controls (P = 0.0007). Those risk factors found to be significantly related to the higher prevalence of carotid disease in the combined groups of patients included age, ratio of systolic blood pressure to diastolic blood pressure, plasma cholesterol, and cigarette smoking. These findings may be an explanation for the greater incidence of stroke in patients with diabetes mellitus.
Adult↗
Vascular disease of the lower extremities.
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Arteriosclerosis Obliterans↗