Error in the Invasive Assessment of Severity Estimation of the End of Ejection in Aortic Stenosis: An Unreported Source of Estimation of the End of Ejection in Aortic Stenosis An Unreported Source of Error in the Invasive Assessment of Severity

Background-All indices of aortic stenosis (AS) rely on measurements of mean transvalvular pressure gradient (⌬P) and flow rate. Because the gradient is reversed during late ejection, the late systolic left ventricular (LV)-aortic pressure crossover may be an erroneous landmark of end-ejection. The aortic incisura should be a better reference to calculate indices of AS invasively. Methods and Results-The accuracy of the pressure crossover and the incisura to define end-ejection was assessed in a chronic AS experimental model (9 dogs) with the use of an implantable flowmeter and Doppler echocardiography as reference. In 288 hemodynamic recordings analyzed (aortic valve area [AVA]: 0.74Ϯ0.46 cm 2 ), ejection ended 37Ϯ29 ms after the pressure crossover but almost simultaneously with the incisura (2Ϯ17 ms). Pressure crossover error accounted for significant errors in the measurement of ⌬P (95% limits of agreement, ϩ0 to ϩ7 mm Hg) and AVA (Ϫ0.1 to ϩ0.2 cm 2 ). These errors were reduced to less than half with the use of the incisura to define end-ejection. Additionally, the agreement with Doppler-derived AS indices was best with use of the incisura. Pressure crossover error was maximal in situations of higher output, moderate orifice narrowing, higher arterial compliance, and lower vascular resistance. In 32 consecutive patients undergoing cardiac catheterization for AS, the pressure crossover induced a clinically important overestimation of the ⌬P from ϩ22 to ϩ50%. Errors in AVA estimation were considerably smaller (Ϫ2% to ϩ6%) because of simultaneous and offsetting errors in the measurements of ⌬P and flow. Conclusions-The aortic incisura and not the second pressure crossover should be used to obtain invasive indices of AS

Chronic Exposure of Cat Odor Enhances Aggression, Urinary Attractiveness and Sex Pheromones of Mice

To test whether predator odor exposure negatively affects the behavior of prey, we exposed three groups of male house mice (Mus musculus) to the odors of cat (Felis catus) urine, rabbit (Oryctolagus cuniculus) urine and water (control), respectively, for consecutive 58 days and investigated how the treatments affected the response, aggressiveness, dominance, urinary attractiveness to females and pheromone composition of male mice. Compared to mice exposed to rabbit urine or water, those exposed to cat odor did not show any response habituation to the cat odor and became more aggressive, increased mark urine production and were more attractive to females when the latter were tested with their urine. Furthermore, gas chromatography coupled with mass spectrometry analysis revealed coincident elevations of the well-known male pheromones, E,E-α-farnesene, E-β-farnesene, R,R-dehydro-exo-brevicomin or S-2-sec-butyl-dihydrothiazole. In addition, rabbit urine exposure increased urinary attractiveness to females and pheromonal levels of the males in comparison with the mice exposed to water. This could be related to olfactory enrichment of heterospecific chemosignals, suggesting that predator odors were more beneficial. In light of these anti-intuitional findings in the chemical interaction between cats and mice, we conclude that predator odor affects prey more profoundly than previously believed and that its impact may not always be negative