Doppler study of cerebral arteries in hypercholesterolemia

Influence of visceral fat and blood pressure on changes in blood flow velocity in non-obese individuals

INTRODUCTION

The aim of this study was to evaluate the impact of different visceral fat (VF) and blood pressure (BP) levels on changes in blood flow velocity (BFV) among non-obese subjects, using a cross-sectional study approach.

METHODS

A total of 110 putatively healthy and non-obese subjects were divided into three groups according to their level of VF and BP. Common carotid artery BFV was measured using a developed portable Doppler ultrasound measurement system.

RESULTS

The most pronounced peak systolic velocity (S1) was lower (p < 0.05) in the hypertensive group and the peak diastolic velocity (D) was significantly lower in the pre-hypertensive group than in the normotensive group. There were differences in velocity reflection and resistive indices between the hypertensive and other two BP groups. The higher VF group had significantly lower S1 and D velocities and resistive and vascular elasticity indices. By contrast, the velocity reflection index was larger in the higher VF group.

CONCLUSIONS

We confirmed that there were significant differences in the BFV among non-obese subjects who differed in level of VF and BP. This study confirms that a putatively increasing VF and BP level is associated with the development of hypertension.

Searching the perfect ultrasonic classification in assessing carotid artery stenosis: comparison and remarks upon the existing ultrasound criteria

Doppler ultrasound scanning is the first line investigation for quantifying the internal carotid artery stenosis. Nevertheless, the lack of internationally accepted ultrasound criteria for describing the degree of stenosis has contributed to the different and confusing measurements ranges. The use of two different angiographic methods, the North American Symptomatic Carotid Endoarterectomy Study and the European Carotid Surgery Trial was probably the major initial source of confusion in deriving valid and reliable duplex ultrasound criteria worldwide. The consensus proposed in 2003 by the Society of Radiologists in Ultrasound has been a great attempt to create a conformity document, establishing grey scale and Doppler criteria in considering the different degrees of stenosis. According to this attempt, in 2010, the multi-parametric Deutsche Gesellschaft für Ultraschall in der Medizin ultrasound criteria have been proposed with a precise differentiation between main and additional criteria and depicted a different peak systolic velocity (PSV) threshold. In 2012, these criteria have been implemented, focusing on the multi-parametric approach, re-defining the PSV values and clearly introducing the concept of PSV average. Despite these attempts, a wide range of practice patterns still exists, with consistent disparities in patients' care. This paper collects these previous experiences and summarizes their strengths and weaknesses, to give a contribution in the carotid artery stenosis grading standardization using ultrasonic methods. Carotid ultrasound as the only diagnostic tool for the selection of patients for carotid surgery or stenting will be possible only with internationally accepted criteria.

Prevalence of significant carotid artery stenosis in Iranian patients with peripheral arterial disease

BACKGROUND

Generalized screening for carotid artery stenosis with carotid duplex ultrasonography in patients with peripheral arterial disease is controversial.

OBJECTIVES

The aim of the present study was to determine the prevalence of significant internal carotid artery (ICA) stenosis in a group of Iranian patients with peripheral arterial disease.

METHODS

We prospectively screened 120 patients with a known diagnosis of peripheral vascular disease for carotid artery stenosis. Based on the angiographic assessment of abdominal aorta and arteries of the lower extremities, patients with stenosis greater than 70% in the lower extremity arteries were included. A group of healthy individuals aged ≥ 50 years was recruited as a control. Risk factors for atherosclerosis including smoking, diabetes mellitus, hyperlipidemia, ischemic heart disease, and cerebrovascular disease were recorded. Common carotid arteries (CCAs) and the origins of the internal and external arteries were scanned with B-mode ultrasonography. Significant ICA stenosis, > 70% ICA stenosis but less than near occlusion of the ICA, was diagnosed when the ICA/CCA peak systolic velocity ratio was ≥ 3.5.

RESULTS

Ninety-five patients, with a mean age of 58.52 ± 11.04 years, were studied. Twenty-five patients had a history of smoking, six patients had a history of coronary artery disease, six patients had hypertension, and ten patients had diabetes mellitus. Significant ICA stenosis was present in four patients (4.2%) with peripheral arterial disease in one healthy individual (1%) of the control group (P > 0.05). In terms of the risk factors for atherosclerosis, no statistically significant relationship was found between individual atherosclerotic risk factors and significant ICA stenosis (P > 0.05).

CONCLUSION

The prevalence of significant ICA stenosis in Iranian patients with peripheral arterial disease is low. In addition, there is no relationship between individual atherosclerotic risk factors and significant ICA stenosis.