Biomedical subjects

Ulf Schminke

Publications and source records attributed to Ulf Schminke.

11 recordsLinked to original sources

PubMed2006

Hemodynamic effects of subclavian steal phenomenon on contralateral vertebral artery.

PURPOSE: Increased blood flow velocity in the contralateral vertebral artery (VA) is a common finding in subclavian steal syndrome, but its clinical relevance is not known. The aim of this study was to investigate whether the degree of velocity increase in the contralateral VA correlated with the severity of the steal. METHODS: In a retrospective study of 62 patients with subclavian steal phenomenon and 62 sex- and age-matched controls, we analyzed the peak systolic velocity (PSV), end diastolic velocity (EDV), mean velocity (MV), resistance index (RI), and pulsatility index (PI) of the Doppler spectrum of the VA contralateral to the subclavian steal phenomenon. Clinical information including sex, age, comorbidities and Doppler data were recorded from the sonography registration form. RESULTS: In patients with subclavian steal syndrome, Doppler spectral analysis showed a complete reversal of flow in the VA in 29 patients (group A) and an alternating flow in 33 patients (group B). The PSV, MV, RI, and PI of the contralateral VA of patients from both groups were higher than in controls (p < 0.01 for both comparisons). The PSV, EDV, and MV in the contralateral VA were higher in patients with reversed flow compared with those with alternating flow (p < 0.05). Comparisons of clinical symptoms and comorbidities between the two groups did not yield significant findings. CONCLUSIONS: The degree of flow velocity increase in the contralateral VA artery correlates well with the severity of subclavian steal phenomenon.

Aged↗

PubMed2005

Association between alcohol consumption and subclinical carotid atherosclerosis: the Study of Health in Pomerania.

BACKGROUND AND PURPOSE: Epidemiologic studies have shown a J-shaped association between alcohol consumption and vascular diseases. However, only few studies have reported on the association between alcohol intake and subclinical atherosclerosis. The aim of the study was to investigate the relation between alcohol intake and carotid intima-media thickness (IMT) in participants of the population-based Study of Health in Pomerania. METHODS: In 1230 men and 1190 women, the mean IMT of the right and left common carotid arteries was measured by B-mode ultrasonography. Alcohol consumption was assessed with a computer-assisted face-to-face interview. RESULTS: In men, carotid IMT as a function of alcohol intake was depicted as a J-shaped curve with a nadir for the alcohol intake category of 61 to 80 g/d. Linear regression models controlled for age, diabetes, systolic blood pressure, leisure time physical activity, food frequency patterns, smoking status, and education revealed a significant inverse association between IMT and alcohol intake < or =80 g/d in men (beta=-0.009, P<0.02), which became insignificant after further controlling for HDL cholesterol and fibrinogen (beta=-0.007, P=NS). In women, neither a J-shaped relation nor significant differences in IMT between the drinking and nondrinking groups were found. CONCLUSIONS: Alcohol consumption is inversely correlated with carotid IMT in men but not in women. However, the total daily level of alcohol intake that shows a maximum protective effect against atherosclerosis is above the threshold where severe alcohol related comorbidity and organ damage have been reported.

Adult↗

PubMed2005

Hepatic steatosis is associated with an increased risk of carotid atherosclerosis.

AIM: Although an association between hepatic steatosis and vascular risk factors has been described, direct relationships between fatty liver and atherosclerosis have not yet been investigated. The aim of the present study has been to investigate those relationships. METHODS: The Study of Health in Pomerania examined a random population sample aged between 20 and 79 years. A study population of 4 222 subjects without hepatitis B and C infections and without liver cirrhosis was available for the present analysis. Hepatic steatosis was defined sonographically and intima-media thickness (IMT) as well as plaque prevalence were estimated by carotid ultrasound. RESULTS: The prevalence rate of hepatic steatosis was 29.9%. Among subjects aged > or =45 years, an association between hepatic steatosis and IMT of the carotid arteries was found in bivariate analysis, but not after adjustment for atherosclerotic risk factors. Individuals with fatty liver had more often carotid plaques than persons without fatty liver (plaque prevalence rate 76.8% vs 66.6%; P<0.001). This association persisted after adjustment for confounding factors and was predominantly present in subjects with no to mild alcohol consumption. CONCLUSION: There is an independent association between hepatic steatosis and carotid atherosclerotic plaques. Metabolic changes due to nonalcoholic fatty liver disease may explain this relationship.

Adult↗

PubMed2005

Prevalence of carotid artery stenosis in Taiwanese patients with one ischemic stroke.

PURPOSE: Ethnic differences in the distribution of atherosclerosis in the brain-supplying vessels are well described. However, only scarce data exist on the prevalence of extracranial carotid artery stenosis in Taiwanese patients who have had a single ischemic stroke. METHODS: Color-coded duplex sonography was used to evaluate the carotid arteries in a hospital-based study on 276 consecutive first-time Taiwanese stroke patients. Significant atherosclerotic lesions of the internal carotid arteries (ICA) were defined as a stenosis of more than 50% or an occlusion. RESULTS: The prevalence of significant carotid lesions was 6% (35/552) in the entire cohort and 8% (17/224) in patients with hemispheric strokes. Among patients with large-artery atheroscleroses, according to criteria of the Trial of Org 10172 in Acute Stroke Treatment, only 27% had significant extracranial ICA disease whereas 69% had intracranial vessel stenoses. Older patients tended to have more severe ICA lesions, while other risk factors were not correlated with carotid stenosis. CONCLUSION: The prevalence of more than 50% ICA stenosis was low in Taiwanese patients with first hemispheric ischemic strokes, indicating that it is not a major cause of ischemic stroke in this population.

Aged↗

PubMed2004

Asymptomatic carotid atherosclerosis is associated with circulating chlamydia pneumoniae DNA in younger normotensive subjects in a general population survey.

OBJECTIVE: Chlamydia pneumoniae infection has been associated with atherosclerosis, but serodiagnosis is unreliable in predicting vascular infection. Direct detection of circulating chlamydial DNA in peripheral blood mononuclear cells (PBMCs) was thus evaluated as a marker for cardiovascular risk in a general population survey using the common carotid intima-media thickness (IMT) as surrogate marker of asymptomatic atherosclerosis. METHODS AND RESULTS: C pneumoniae DNA in PBMCs was determined by nested polymerase chain reaction and associated with IMT for 1032 healthy participants of a general population survey who were within the highest or lowest IMT distribution quartile. C pneumoniae DNA was more prevalent in those with increased IMT (13.4% versus 10.7%), but this was not significant in univariate and of borderline significance in multivariate analysis. Testing for potential effect modifications by known strong determinants of an increased IMT in group interaction analysis revealed an independent association between C pneumoniae DNA and IMT in normotensive subjects (odds ratio [OR], 2.06; 95% CI, 1.05 to 4.03; P=0.04) and in those <70 years old (OR, 1.84; 95% CI, 1.06 to 3.19; P=0.03). CONCLUSIONS: Asymptomatic atherosclerosis is associated with circulating C pneumoniae DNA independently of classical cardiovascular risk factors in normotensive subjects and those <70 years old. C pneumoniae has been implicated in atherogenesis. We determined the association of chlamydial DNA in peripheral blood mononuclear cells with the carotid intima-media thickness from 1032 healthy subjects from a general population survey. A stratified group interaction analysis revealed an independent association in normotensive subjects and those <70 years old.

Adult↗

PubMed2004

Echo-enhanced duplex sonography of extracranial vertebral arteries.

We sought to investigate the potential benefit in examining extracranial vertebral arteries (ExVA) with an echo contrast agent. A total of 26 patients with insufficiently assessable ExVA underwent extracranial duplex sonography without and with an echo contrast medium. All examinations were recorded and analysed independently by two experienced sonographers. Interrater agreement was fair in assessment of B-mode quality, colour-coding, blooming artefacts, change of vmax, good to very good in all other rated categories. Using an echo contrast medium reduced overall inassessable ExVA by 48% and 36% according to the two raters, respectively. After contrast enhancement, diagnosis was clarified in ExVA formerly inassessable for hypoplasia in 60% vs. 56%, extracranial occlusion in 67% vs. 56% and resistance signal in 63% vs. 45%, respectively. Application of an echo contrast agent leads to clarification of ExVA sonographic diagnosis in approximately one third of poorly examinable patients (35% and 30%, respectively), and contributes in ruling out extracranial occlusion, hypoplasia and resistance signal.

Arterial Occlusive Diseases↗

PubMed2004

Thyroid function and carotid wall thickness.

Decreased serum TSH levels predict vascular mortality in older people. There is a need to investigate mechanisms that could explain this association. This study was designed to investigate the relationship between thyroid function and the carotid intima-media thickness (IMT). The Study of Health in Pomerania is a population-based survey in Germany. Data from 2086 individuals at least 45 yr old with carotid ultrasound and without known thyroid disorders were analyzed. Twenty-nine participants (1.4%) had elevated serum TSH levels, 300 (14.4%) had decreased serum TSH levels, and 12 (0.6%) participants were hyperthyroid. A linear relationship between thyroid function and IMT was found. The highest IMT values were observed in participants with hyperthyroidism, the lowest in subjects with elevated serum TSH levels (P < 0.01). A multivariable regression analysis identified thyroid function as an independent risk factor for increased IMT. Other risk factors for increased IMT included male gender, advanced age, diabetes mellitus, current smoking, and the use of antihypertensive medication; increased pulse pressure, serum low-density cholesterol, and total cholesterol/high-density lipoprotein ratio; as well as a decreased heart rate and a positive history of myocardial infarction. We conclude that there is an independent association between thyroid function and the IMT of the carotid artery.

Carotid Arteries↗

PubMed2002

Hemodynamic effects of innominate artery occlusive disease on anterior cerebral artery.

Stenoses of the innominate artery (IA) may affect flow conditions in the carotid arteries. However, alternating flow in ipsilateral anterior cerebral artery (ACA) due to IA stenosis is extremely rare. A 49-year-old woman who was evaluated for symptomatic cerebrovascular disease presented with right latent subclavian and right carotid system steal. Transcranial Doppler examination displayed systolic deceleration wave-forms in the right terminal internal carotid artery and alternating flow in the right ACA. Magnetic resonance angiography demonstrated tight stenosis of the right IA. For a thorough study of the hemodynamic effects of IA stenosis, a combination of duplex and transcranial Doppler examination is required.

Anterior Cerebral Artery↗

PubMed2002

Subclavian steal syndrome: can the blood pressure difference between arms predict the severity of steal?

BACKGROUND AND PURPOSE: A side-to-side difference in systolic brachial arterial blood pressure is a common finding in subclavian artery stenosis and is frequently used as a screening tool for subclavian steal syndrome (SSS). It was the goal of this retrospective study to investigate the relationship between different vertebral artery waveform types and the side-to-side difference in systolic blood pressure in patients with sonographically proven SSS. METHODS: The records of 1860 patients from the Neuroultrasound Laboratory between January 2000 and December 2000 were screened for the diagnosis of SSS in the final ultrasound report. In all patients, bilateral brachial arterial blood pressure was measured in a sitting position prior to the ultrasound examination. Vertebral artery waveforms were classified as (1) systolic deceleration, (2) alternating flow, and (3) complete reversal at rest. Blood pressure difference as calculated by normal-side blood pressure minus lesion-side blood pressure was compared with the 3 Doppler waveform types. RESULTS: SSS was found in 51 of 1860 (2.7%) ultrasonography studies of 49 patients (17 men, 32 women; mean age 65.3 +/- 10.5 years). Two patients (4%) had bilateral SSS. In 3 patients (6%), SSS was related to an innominate artery stenosis. Waveform analysis showed a completely reversed flow in 16 (31%), an alternating flow in 24 (47%), and a systolic deceleration in 11 (22%) cases. Systolic blood pressure difference was significantly higher in the complete reversal and alternating groups than in the systolic deceleration group (P < .001). CONCLUSION: Brachial systolic blood pressure difference is related to the severity of SSS and can be used as a screening tool for SSS. However, it performed better in severe steal than milder steal phenomena.

Aged↗

PubMed2002

Extracranial internal carotid artery occlusion: the role of common carotid artery volume flow.

BACKGROUND AND PURPOSE: Quantitative measurement of blood flow volume in the common carotid artery (CCA) is now possible using the color velocity imaging quantification (CVI-Q) ultrasound technique. The aim of this study was to evaluate the cerebral hemodynamic effects of unilateral internal carotid artery (ICA) occlusion on CCA blood flow volumes (FVs) using CVI-Q. METHODS: Records of ultrasound studies in our neurosonology laboratory were retrospectively reviewed to identify patients with unilateral ICA occlusions who at a minimum received both a routine color duplex carotid ultrasound examination and quantitative measurement of FV in the CCA, bilaterally, using the CVI-Q method. A total of 71 patients met criteria and were included in the cohort. A side to side comparison was performed for FV, peak systolic velocities (PSV), end-diastolic velocities (EDV), and resistance indices (RIs) in the CCA. Results correlated with any other available data such as flow direction in the ophthalmic artery and the presence of intracranial collateralization. RESULTS: The FV, PSV, and EDV were significantly reduced, and the RI was significantly increased in the CCA on the side of the occlusion. A subgroup analysis in patients who also had an examination of the ophthalmic (n = 61) and the intracranial arteries of the Circle of Willis (n = 50), showed significantly higher FV in the CCA on the side of the occlusion if there was also reversed flow in the ophthalmic artery on the side of the occlusion (344 +/- 144 ml/min versus 169 +/- 53 ml/min). CONCLUSION: Quantitative FV measurement using CVI-Q ultrasound can identify clear alterations in volume flow, collateral pathways, and cerebral hemodynamics in patients with unilateral ICA occlusion. It is a complementary tool, providing additional objective information about the cerebral hemodynamic effects of ICA occlusion that goes beyond what is available using routine flow velocity data.

Aged↗

PubMed2002

Association between behavior-dependent cardiovascular risk factors and asymptomatic carotid atherosclerosis in a general population.

BACKGROUND AND PURPOSE: Physical inactivity and unfavorable dietary and lifestyle patterns are related to cardiovascular disease and premature death. Their relationship to atherosclerosis of the carotid arteries and subsequent stroke is unclear. The objective of this study was to investigate the association between those behavioral cardiovascular risk factors and asymptomatic atherosclerosis of the carotid arteries in a population of former East Germany. METHODS: The Study of Health in Pomerania (SHIP) is a cross-sectional survey in northeast Germany. In 1632 individuals aged 45 to 70 years, high-resolution B-mode ultrasound was used to assess the mean intima-media thickness of the right and left common carotid arteries. Carotid plaques and stenosis were recorded. Physical activity, dietary patterns, and cardiovascular risk factors were assessed in interviews with the use of standardized scales. Physically active participants with optimal dietary patterns were classified in the optimal lifestyle group, and those inactive with unfavorable diet were classified in the unfavorable group. RESULTS: After adjustment for sex and age, significant decreasing trends were found for both intima-media thickness and severe asymptomatic atherosclerosis from unfavorable to optimal lifestyle patterns in never smokers but not in smokers. Regression analysis revealed an increased risk of severe asymptomatic atherosclerosis in subjects with an unfavorable lifestyle pattern compared with those with an optimal pattern (odds ratio 2.68; 95% CI, 1.13 to 6.37), following a significant linear trend. CONCLUSIONS: Physical activity and optimal diet are associated with reduced risk of early atherosclerosis in subjects who never smoked, while no benefit of an otherwise optimal lifestyle is observed in smokers.

Aged↗