Correlation of pulse wave velocity with left ventricular mass in patients with hypertension once blood pressure has been normalized

Vascular stiffness has been proposed as a simple method to assess arterial loading conditions of the heart which induce left ventricular hypertrophy (LVH). There is some controversy as to whether the relationship of vascular stiffness to LVH is independent of blood pressure, and which measurement of arterial stiffness, augmentation index (AI) or pulse wave velocity (PWV) is best. Carotid pulse wave contor and pulse wave velocity of patients (n=20) with hypertension whose blood pressure (BP) was under control (<140/90 mmHg) with antihypertensive drug treatment medications, and without valvular heart disease, were measured. Left ventricular mass, calculated from 2D echocardiogram, was adjusted for body size using two different methods: body surface area and height. There was a significant (P<0.05) linear correlation between LV mass index and pulse wave velocity. This was not explained by BP level or lower LV mass in women, as there was no significant difference in PWV according to gender (1140.1+67.8 vs 1110.6+57.7 cm/s). In contrast to PWV, there was no significant correlation between LV mass and AI. In summary, these data suggest that aortic vascular stiffness is an indicator of LV mass even when blood pressure is controlled to less than 140/90 mmHg in hypertensive patients. The data further suggest that PWV is a better proxy or surrogate marker for LV mass than AI and the measurement of PWV may be useful as a rapid and less expensive assessment of the presence of LVH in this patient population

Intense laser field effect on impurity states in a semiconductor quantum well: transition from the single to double quantum well potential

In this work are studied the intense laser effects on the impurity states in GaAs-Ga1-xAlxAs quantum wells under applied electric and magnetic fields. The electric field is taken oriented along the growth direction of the quantum well whereas the magnetic field is considered to be in-plane. The calculations are made within the effective mass and parabolic band approximations. The intense laser effects have been included through the Floquet method by modifying the confinement potential associated to the heterostructure. The results are presented for several configurations of the dimensions of the quantum well, the position of the impurity atom, the applied electric and magnetic fields, and the incident intense laser radiation. The results suggest that for fixed geometry setups in the system, the binding energy is a decreasing function of the electric field intensity while a dual monotonic behavior is detected when it varies with the magnitude of an applied magnetic field, according to the intensity of the laser field radiation

Central blood pressure, arterial stiffness, and wave reflection: New targets of treatment in essential hypertension

Central blood pressure is dependent on the stiffness of large arteries and pulse wave reflection. These parameters are very important in the development of hypertensive target organ disease. Moreover, recent clinical studies have shown their independent predictive value for cardiovascular morbidity and mortality. Therefore, 2007 guidelines for the management of hypertension inserted the evaluation of central arterial stiffness as an important component for assessing total cardiovascular risk. Differences in the way various antihypertensive drugs affect arterial stiffness and central hemodynamics may explain the greater cardio-vascular protection provided by newer drugs (eg, renin-angiotensin system blockers or calcium channel blockers) independent of peripheral blood pressure reduction, as shown by recent clinical studies. However, the predictive value of the attenuation of arterial stiffness, wave reflections, and central blood pressure still needs to be confirmed in prospective, long-term, large-scale therapeutic trials. Thus, whether these measurements should be routinely performed as a diagnostic or therapeutic indicator remains debatable