Arduino A. Mangoni

Acute effects of smoking on radial artery compliance in humans.

Objective To clarify whether the acute and marked increase in blood pressure associated with smoking is accompanied by an alteration in arterial compliance. Design Arterial compliance was measured in 13 subjects before and after smoking a cigarette with a nicotine content of 1.2mg, or before and after sham smoking. Measurements were obtained with the subjects at rest and after prolonged brachial artery occlusion (12min). Methods Compliance was measured using an echo-tracking system capable of continuously providing (300 readings/s) radial diameter data and, with the addition of a photoplesythmographic device, blood pressure measurement. Results Acute cigarette smoking caused a pressor and tachycardie response, and decreased markedly both resting radial artery diameter and compliance, at blood pressure values identical to those before smoking. The marked increase in radial artery diameter and compliance brought about by local ischaemia was unaffected by smoking, and no changes were observed both at rest and after ischaemia as a result of sham smoking. Conclusions Smoking causes a marked reduction in radial artery compliance, and the effect is independent of the increase in blood pressure. However, the marked increase in compliance due to ischaemia is not modified by smoking.

Alterations of radial artery compliance in patients with congestive heart failure

Congestive heart failure is accompanied by several hemodynamic alterations. To investigate whether these alterations include reduced arterial compliance, we studied 25 patients (age 57 +/- 2 years, mean +/- SE) with a mild or severe congestive heart failure based on clinical symptoms (New York Heart Association class II vs III or IV) and on echocardiographic alterations of left ventricular diastolic diameter and ejection fraction. Radial artery diameter and blood pressure were continuously measured by Doppler ultrasonography and a finger pressure device, respectively. Compliance was calculated by the Langewouters formula, and compliance values were derived throughout the systolic-diastolic pressure range. The area under the compliance-pressure curve normalized for pulse pressure was used to compare compliance values in the various groups. Data were obtained both in baseline condition and at the release from a 12-minute brachial artery occlusion. Fourteen healthy, age-matched subjects served as controls. Compared with the control group, patients with severe congestive heart failure showed a reduction of baseline compliance index (-48%, p < 0.01). Furthermore, while in control subjects compliance markedly increased after brachial artery occlusion (+43%, p < 0.01), in patients with severe congestive heart failure no increase occurred. No baseline compliance alteration was seen in patients with mild congestive heart failure in whom, however, the postischemic increase in compliance was also significantly blunted (-50% vs controls, p < 0.05). Thus, arterial compliance and arterial compliance modulation are impaired in congestive heart failure. Although more marked in severe congestive heart failure, the impairment is manifest in mild congestive heart failure as well.

Cardiac and vascular structural changes in normotensive subjects with parental hypertension

Objective To evaluate whether a predisposition to hypertension is associated with early cardiac and vascular alterations. Subjects Twenty-five normotensive subjects with both parents hypertensive (group 1) and 28 age- and sex-matched control subjects with both parents normotensive (group 2). Methods In the two groups the measurements included: clinic blood pressure; left ventricular end-diastolic diameter, septal wall thickness and posterior wall thickness (by echocardiography); minimal forearm and calf vascular resistances (i.e. resistance assessed immediately after prolonged ischaemia, which depends on arteriolar wall thickness); and baseline and postischaemic radial artery compliance-pressure curves over the systolodiastolic pressure range (by echotracking device and finger blood pressure). Results Group 1 had a slightly higher clinic blood pressure, and septal and posterior wall thickness, than group 2. Minimal forearm vascular resistance was clearly greater in group 1 than in group 2, whereas minimal calf vascular resistance was not significantly different in the two groups. Radial artery compliance was also similar in the two groups. Conclusions Parental predisposition to hypertension is accompanied by cardiac and arteriolar structural changes qualitatively similar to those found in hypertensive patients, although arteriolar structural changes do not involve all vascular beds. Arterial compliance is not altered in this condition. Vascular changes may be determined by mechanisms other than blood pressure elevation.

Evaluation of Arterial Compliance in Humans

Compliance is a measure of the elastic properties of arterial vessels and is a function of blood pressure. In recent years new techniques have been developed which allow to measure arterial compliance non invasively and continuously over the range of existing blood pressure values. It has been thus possible to investigate the alterations of arterial compliance in a variety of diseases and to address the physiological factors involved in arterial compliance modulation. This article will focus on the new data available on these issues.

Reproducibility of ultrasound assessment of common carotid and femoral artery compliance and distensibility in the anesthetized rat.

Objective To validate ultrasound assessment of common carotid and femoral artery compliance and distensibility in the anesthetized rat. Materials and methods A reproducibility study was performed by taking measurements twice on two different days in anesthetized Wistar-Kyoto (WKY) rats. The common carotid or femoral arterial diameter on one side and the contralateral arterial blood pressure were measured using a 10-MHz probe echo-Doppler device and an arterial catheter, respectively. The pressure and diameter data were stored in a computer programmed to calculate the arterial compliance and distensibility coefficients (Reneman formulas) and compliance and distensibility indices (arctangent model of Langewouters). A second experimental session was repeated 1 day later and mean values, day-to-day mean differences and repeatability coefficients were calculated for each parameter. Results For both the common carotid and the femoral artery, the mean values for heart rate, mean arterial pressure, arterial diameter, arterial compliance and arterial distensibility were similar on the first and second days; mean day-to-day differences were small and repeatability coefficients were in the range 5–10% of the mean value for diameter and mean arterial pressure and 10–20% of the mean value for compliance and distensibility. Conclusions In the anesthetized rat, ultrasound evaluation of the mechanical properties of the common carotid and femoral arteries is a reliable and reproducible technique.