Changes in Wave Reflection With Advancing Age in Normal Subjects To the Editor: From their study of a small selected group (521 of 2640 persons) within the Framingham cohort, Mitchell et al1 conclude that increase in central aortic stiffness rather than wave reflection is responsible for the increase in pulse pressure with advancing age in healthy men and women. The authors state that changes i...

Ion acoustic wave phenomena are studied and compared in two low-pressure argon discharges created by helicon sources. The wave amplitudes are spatially localized near the edge of a plasma column as the amplitudes of the “mirror waves” that are separated from the helicon source frequency by the ion wave frequency. Dependencies of the ion wave on radial position, pressure, input power, and magnet...

Information that can be derived from an assessment of the jugular venous pulse includes determination of the mean venous pressure, venous pulse contour, and presence and type of cardiac dysrhythmias . The jugular venous pressure is usually assessed by observing the right side of the patient's neck. The normal mean jugular venous pressure, determined as the vertical distance above the midpoint o...

In this paper, we investigated the corrected plasmon dispersion relation for graphene in presence of a constant magnetic field which it includes a quantum term arising from the collective electron density wave interference effects. By using quantum hydrodynamic plasma model which incorporates the important quantum statistical pressure and electron diffraction force, the longitudinal plasmons ar...

Arterial stiffening plays an important role in the development of hypertension and cardiovascular diseases. The intrinsically nonlinear (ie, pressure-dependent) elastic behavior of arteries may have serious consequences for the accuracy and interpretation of arterial stiffness measurements and, ultimately, for individual patient management. We determined aortic pressure and common carotid arter...

Arterial stiffening plays an important role in the development of hypertension and cardiovascular diseases. The intrinsically nonlinear (ie, pressure-dependent) elastic behavior of arteries may have serious consequences for the accuracy and interpretation of arterial stiffness measurements and, ultimately, for individual patient management. We determined aortic pressure and common carotid arter...

PURPOSE OF STUDY To compare magnetic resonance elastography (MRE) with ventricular pressure changes in an animal model. METHODS Three pigs of different cardiac physiology (weight, 25 to 53 kg; heart rate, 61 to 93 bpm; left ventricular [LV] end-diastolic volume, 35 to 70 ml) were subjected to invasive LV pressure measurement by catheter and noninvasive cardiac MRE. Cardiac MRE was performed i...

The effects of supine bicycle exercise on the input impedance of the ascending aorta were studied in thirteen male subjects undergoing cardiac catheterization, but in whom no cardiovascular disease was found. Ascending aortic flow velocity and pressure were recorded simultaneously from a multisensor catheter with an electromagnetic flow velocity probe and a pressure sensor mounted at the same l...

OBJECTIVE Beta-blocking therapy is the standard therapy in non-operated Marfan patients, however its efficacy after entire aortic replacement is unknown. The aim of this study was to describe the influence of (nearly) entire aortic replacement and beta-blocking therapy on blood pressure and wave reflections in Marfan patients. METHODS Four Marfan patients (mean age 31+/-3 years) and 8 age mat...