This award supports the development of a mathematical model predicting short-term cardiovascular regulation during orthostatic stress and hypovolemia. The model to be derived will contain three sub-models: A cardiovascular model predicting blood pressure and flow in the cardiovascular system, a model predicting sympathetic and parasympathetic activity of the autonomic nervous system, and a model predicting concentrations of carbon dioxide and oxygen. These models will be combined through models for autonomic regulation and autoregulation. In addition, formal statistical and computational methods will be used to estimate parameters in the models with emphasis on accounting for and exploring variability underlying mechanisms across different individuals. In particular, the mathematical model will be validated against already existing data from hypovolemia and orthostatic stress tests, obtained during postural change from sitting to standing, head up tilt, and lower body negative pressure.
This research project is a collaborative effort between the PIs, J. Ottesen of Denmark, and J. Batzel and F. Kappel of Austria. In the past, each group has conducted successful research projects in related areas. With the attention and expertise of the US and foreign groups focused on this project, the collaboration will make significant progress in this area of research.
In order to enhance antihypertensive therapy, further knowledge of the effects of aging and hypertension on the cerebral circulation is essential. Since recent studies show a relationship between hypertension and development of cognitive dysfunction, it is crucial to understand the effect of hypertension on cerebral perfusion. Despite the importance of these clinical questions, progress towards answering them has been impeded by inadequate non-invasive methods to measure cerebral autoregulation, and inadequately tested assumptions about cerebral vasomotion. This award will support research designed to aid in the detection and remediation of these and other potentially life threatening injuries or conditions.
