A Clinical and Echocardiographic Score to Identify Pulmonary Hypertension Due to HFpEF.

Background: Heart failure with preserved ejection fraction (HFpEF) is a frequent cause of pulmonary hypertension (PH) that is not easy to differentiate from precapillary PH. We aimed to determine whether the characteristic features of the patients may help differentiate between HFpEF and precapillary PH.

Methods And Results: Clinical and echocardiographic parameters were analyzed in 156 patients referred to our PH referral center.

Acute exposure to diesel exhaust impairs nitric oxide-mediated endothelial vasomotor function by increasing endothelial oxidative stress.

Exposure to diesel exhaust was recently identified as an important cardiovascular risk factor, but whether it impairs nitric oxide (NO)-mediated endothelial function and increases production of reactive oxygen species (ROS) in endothelial cells is not known. We tested these hypotheses in a randomized, controlled, crossover study in healthy male volunteers exposed to ambient and polluted air (n=12). The effects of skin microvascular hyperemic provocative tests, including local heating and iontophoresis of acetylcholine and sodium nitroprusside, were assessed using a laser Doppler imager.

L-NAME iontophoresis: a tool to assess NO-mediated vasoreactivity during thermal hyperemic vasodilation in humans.

Background: Decreased endothelial Nitric oxide (NO) bioavailability is one of the earliest events of endothelial dysfunction. Assessment of microvascular blood flow using a Laser Doppler Imager during local noninvasive administration of L-N-Arginine-Methyl-Ester (L-NAME) by skin iontophoresis may help discriminate the relative contributions of NO and non-NO pathways during a skin thermal hyperemic test.

Methods: In healthy nonsmokers, the effects of thermal vasodilation and sodium nitroprusside-mediated vasodilation were tested on skin pretreated with 0.

Vascular oxidative stress induced by diesel exhaust microparticles: synergism with hypertension.

Background: Epidemiological and clinical studies have shown that traffic-related air pollution and, particularly, diesel exhaust particles (DEP) are strongly linked to cardiovascular mortality.

Methods: Vascular toxicity was studied by assessing vasomotor responses of aortas isolated from normotensive Wistar rats exposed in vitro to DEP (DEP suspension and aqueous DEP extract). In vivo experiments were performed on Wistar rats and spontaneously hypertensive rats (SHRs) exposed for 4 weeks via intratracheal instillation to either DEP or saline vehicle.

Nicotine increases chemoreflex sensitivity to hypoxia in non-smokers.

Background: The peripheral chemoreflex contributes to cardiovascular regulation and represents the first line of defence against hypoxia. The effects of nicotine on chemoreflex regulation in non-smoking humans are unknown.

Method: We conducted a prospective, randomized, crossover, and placebo-controlled study in 20 male non-smokers to test the hypothesis that nicotine increases chemoreflex sensitivity.

Effects of enoximone on peripheral and central chemoreflex responses in humans.

cAMP plays an important role in peripheral chemoreflex function in animals. We tested the hypothesis that the phosphodiesterase inhibitor and inotropic medication enoximone increases peripheral chemoreflex function in humans. In a single-blind, randomized, placebo-controlled crossover study of 15 men, we measured ventilatory, muscle sympathetic nerve activity, and hemodynamic responses to 5 min of isocapnic hypoxia, 5 min of hyperoxic hypercapnia, and 3 min of isometric handgrip exercise, separated by 1 wk, with enoximone and placebo administration.