The role of patient's profile and allogeneic blood transfusion in development of post-cardiac surgery infections: a retrospective study.

Objectives: We aimed to investigate the association of patient characteristics and allogeneic blood transfusion products in development of post-cardiac surgery nosocomial infections.

Methods: This retrospective study was conducted in 7888 patients undergoing cardiac surgery with median sternotomy and cardiopulmonary bypass. Multivariable logistic regression analysis was used for independent effect of variables on infections.

The onset of ventricular isovolumic contraction as reflected in the carotid artery distension waveform.

The blood pressure waveform carries information about the cardiac contraction and the impedance characteristics of the vascular bed. Here, we demonstrate that the start of isovolumic ventricular contraction is persistently reflected as an inflection point in the pressure wave as recorded in the aortic root (TP(IC)) as well as in the carotid artery distension waveform (TD(IC)) as it travels down the arterial tree. In a group of six patients with normal pressure gradients across the aortic valve after valve replacement, the TP(IC) had a small delay with respect to the onset of isovolumic ventricular contraction (<10 ms).

A ventricular-vascular coupling model in presence of aortic stenosis.

In patients with aortic stenosis, the left ventricular afterload is determined by the degree of valvular obstruction and the systemic arterial system. We developed an explicit mathematical model formulated with a limited number of independent parameters that describes the interaction among the left ventricle, an aortic stenosis, and the arterial system. This ventricular-valvular-vascular (V(3)) model consists of the combination of the time-varying elastance model for the left ventricle, the instantaneous transvalvular pressure-flow relationship for the aortic valve, and the three-element windkessel representation of the vascular system.

Pressure-volume loops in patients with aortic stenosis.

Background And Aim Of The Study: Preoperative left ventricular (LV) function is the strongest predictor of outcome after valve replacement for aortic stenosis (AS). Although pressure-volume analysis with the conductance catheter technique can provide detailed information on LV systolic and diastolic function, this technique has not yet been used in AS patients. The present study examined the potential use of LV function measurements using pressure-volume analysis with a conductance catheter during surgery for AS.