Identification of protein biomarkers associated with cardiac ischemia by a proteomic approach.

Angina is chest pain induced by ischemia of the heart muscle, generally due to obstruction or spasm of the coronary arteries. People that suffer from average to severe cases of angina have an increased percentage of death before the age of 55, usually around 60%. Therefore, prevention of major complications, optimizing diagnosis, prognosis and therapeutics are of primary importance. The main objective of this study was to uncover biomarkers by comparing serum protein profiles of patients suffering from stable or unstable angina and controls. We identified by non-targeted proteomic approach and confirmed by the means of independent techniques, the differential expression of several proteins indicating significantly increased vascular inflammation response, disturbance in the lipid metabolism and in atherogenic plaques stability.

Guidelines for quality improvement in cardiac surgery. The College of Cardiac Surgery : results of the 2007 survey.

Optimal delivery of health care is a common goal of individual physicians, professional organizations, hospital structures and governmental authorities. A growing concern has emerged from the public, media and third payer organizations concerning the quality of care and the amount of resources spending. In the United States, large databases, guidelines and performance evaluation have been elaborated by medical societies, particularly in the area of cardiac surgery. These tools are useful for improvement of patients' care, resources distribution, pay for performance and public and practitioners' awareness. The evaluation of quality is based on composite models combining structure, process and outcome indices. However, pitfalls such as patients' selection, and risk avoidance in order to improve results must been prevented by adjustment of the treated populations' risk factors by specific scores. The Belgian Health authorities have built a structure directed at delivery of care improvement based on "Care Programs", monitored by Colleges formed by delegates of professional organizations. The College of Cardiac Surgery has promoted several studies aimed at data collection and evaluation. In 2007, a survey was addressed to all the Belgian Cardiac surgeons to define their opinion as to the best indicators of care in their specialty. These results will serve to define further avenues of research. By maintaining the responsibility of care evaluation in the hands of the involved professionals, this kind of cooperation between governmental and physicians' organizations seems to serve the best interests of the public and the practitioners.

Standing waves in the FitzHugh-Nagumo model of cardiac electrical activity.

When excitable media are submitted to appropriate time dependent boundary conditions, a standing wavelike pattern can be observed in the system, as shown in recent experiments. In the present analysis, the physical mechanism explaining the occurrence of such space-time patterns is shown to be a competition between Ohmic diffusion and an action potential propagation across the system, coupled with the existence of refractory states for excitable media.

[Experimental study of systemic ventriculo-arterial coupling. Effects of modifications of thoracic aortic mechanical properties and myocardial ischemia on left ventricular performance]. / Contribution à l'étude expérimentale du couplage ventriculo-artériel systémique. Effets des modifications des propriétés mécaniques de l'aorte thoracique et de l'ischémie myocardique sur la performance ventriculaire gauche.

We quantified systemic ventriculo-arterial coupling in the pressure-volume (PV) plane, using a model of elastic chambers of the cardio-vascular system. In such a model, the ratio between left ventricular (LV) end-systolic elastance, and effective arterial elastance measures the coupling between the heart and the systemic vasculature, and the effects of cardiac diseases and of vasoactive agents on the coupling relationship can be independently evaluated in vivo. Furthermore, the analysis in the PV plane gives insights into LV mechanical efficiency, defined by the ratio between stroke work and pressure-volume area. Our results demonstrating that an augmentation of aortic compliance decreases the energetic cost of LV ejection should be considered when replacing the thoracic aorta by an artificial prosthesis. The homeometric autoregulation, suggesting a mechanism by which the heart can maintain a constant stroke volume, in the face of increased afterload, without using the Starling mechanism and independently of baroreflex integrity, is of paramount importance in heart transplant patients. Indeed, such patients, although lacking cardiac innervation, can adapt their cardiac output, stroke volume, end-systolic and end-diastolic pressures, without simultaneous changes in heart rate. Finally, our data demonstrate that the acutely ischemic LV must face an hostile hemodynamic environment, characterised by early vasoconstriction, later combined with decreased vascular compliance. These results are important when choosing vasoactive agents in the setting of acute myocardial infarction.