Acute Cigarette Smoking-Induced Hemodynamic Alterations in the Common Carotid Artery-A Transcranial Doppler Study-

Abstract

moking is known as a major risk factor in the development and progression of cardiovascular disease; 1 but despite extensive research, the pathophysiological mechanisms that are responsible for smoking-related vascular damage have not been elicited. In addition to alterations in hemostatic factors, endothelial function and blood lipids, the dynamic properties of the arterial wall may play an important role. 2 There is evidence that the compliance of both large and medium-sized arteries decreases immediately after smoking a cigarette. 3,4 It has also been shown that smoking increases cerebral blood flow velocity and reduces vasomotor reactivity for 10-30 min as revealed by transcranial Doppler sonography. 5 Ultrasound and Doppler methods are ideally suited for bedside examinations; Doppler and duplex techniques have been used to estimate cerebral blood flow in healthy adults by measuring flow volumes of the common carotid artery (CCA). 6,7 The aim of the present study was to determine the instantaneous effects of smoking a cigarette on CCA hemodynamics such as flow velocity and waveform parameters in healthy nonsmokers. Circulation Journal Vol.68, December 2004 MethodsSixteen healthy nonsmokers (12 males, 4 females; mean age 27±4 years), who had undergone a prior complete physical and echocardiographic examination to determine that they did not have a medical history or physical signs of cerebrovascular disease, comprised the study group. All subjects were asked to refrain from food intake and caffeine-containing beverages for at least 8 h before participating in the study, which was carried out between 09.00 h and 12.00 h. Written informed consent was obtained from each participant.Each subject rested in the supine position for at least 15 min on a comfortable bed in the test room to stabilize heart rate. Color duplex sonography of the entire extracranial carotid system was performed using a 7.0-MHz linear array transducer of a combined sonography system (Toshiba, Nemio 20, Tokyo, Japan). All participants were examined while supine with the head hyperextended and turned away from the side being scanned. The site of measurement was approximately 1.5 cm below the carotid bulb in the CCA. The B-mode image was magnified to achieve a higher resolution of detail and enable the luminal diameter of the vessels to be measured optimally. Because the CCA expanded markedly during a cardiac cycle, M-mode registration, noting minimum and maximum diameters, was used. In the color Doppler mode, the velocity range of the color scale was set slightly higher than the Nyquist limit to enable easy detection of flow disturbances. Pulsed Doppler measurement was done using a sample volume covering the entire luminal width. Flow velocities were recorded Background Cigarette smoking has been shown to temporarily alter cerebral flow velocity and vasomotor reactivity, so the aim of this study was to assess the acute effects of smoking a single cigarette on the common carotid artery (CCA) hemodynamics in healthy nonsmokers. Method and Resul...

Relationship Between Endothelial Function and Coronary Risk Factors in Patients With Stable Coronary Artery Disease

“…11,27,28 Both passive and active smoking causes endothelial dysfunction. 8,29,30 In contrast to previous studies we found no relationship between smoking and endothelial dysfunction; however, almost all of the present patients had quit smoking after clinical and/or angiographic diagnosis of CAD. Benjamin et al 10 found that FMD% was better in smokers who did not smoke within the 6 h prior to the study hours than in those who did smoke.…”

The Effects of Smoking on Carotid Artery Hemodynamics

“…The data showed a strong linear association between the duration of smoking and the percentage of carotid stenosis, which increased 0.34% per year, as well as between the frequency of smoking and the degree of carotid narrowing, which increased 0.31% per unit frequency. These findings are consistent with those of Barutcu et al, 5 whose results based on transcranial Doppler measurements suggested that smoking causes acute hemodynamic alterations in the common carotid artery. The data presented also agree with those of Tell et al, 6 who showed that among all participants, the prevalence of clinically significant (≥50%) internal carotid stenosis increased from 4.4% in never smokers to 7.3% in former smokers to 9.5% in current smokers (P < .0001).…”

Predictive value of noninvasively determined endothelial dysfunction for long-term cardiovascular events and restenosis in patients undergoing coronary stent implantation: a prospective study

“…The reason is multifactorial and may in part be associated with oxidative stress and systemic inflammation. In our study population, the patients in the lower FMD tertile were older, had higher BMI levels, and were more likely to have There are also many studies showing a connection between hypertension, elevated cholesterol levels, tobacco use, and endothelial function [26,33,34]. In our study, we did not find a relationship between those parameters and FMD, which might have resulted from the patients having appropriate antihypertensive, antihypercholesterolemic treatment and smoking cessation before FMD measurement.…”