Acute cigarette smoking-induced hemodynamic alterations in the common carotid artery--a transcranial Doppler study--.

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 RESULTS: Using a 7.0 MHz linear transducer of a computed sonography system, the CCA hemodynamics, including the diameter of the left and right CCA, peak systolic velocity, maximum end-diastolic velocity, time-averaged maximum velocity pulsatility index, resistivity index, flow volume, diameter and area of the CCAs, were measured in 16 healthy nonsmokers before and immediately after smoking a cigarette. Compared with the baseline, heart rate and blood pressure significantly increased, the diameter, flow volume and area of each CCA were unchanged, and the pulsatility index and resistivity index were significantly altered after smoking. In addition, the peak systolic velocity, maximum end-diastolic velocity and time-averaged maximum velocity were significantly altered after smoking. CONCLUSIONS: Cigarette smoking significantly altered the CCA hemodynamics in nonsmokers, probably as a consequence of enhanced adrenergic activity.