Gender differences in autonomic cardiovascular regulation: spectral, hormonal, and hemodynamic indexes.

The autonomic nervous system drives variability in heart rate, vascular tone, cardiac ejection, and arterial pressure, but gender differences in autonomic regulation of the latter three parameters are not well documented. In addition to mean values, we used spectral analysis to calculate variability in arterial pressure, heart rate (R-R interval, RRI), stroke volume, and total peripheral resistance (TPR) and measured circulating levels of catecholamines and pancreatic polypeptide in two groups of 25 +/- 1.2-yr-old, healthy men and healthy follicular-phase women (40 total subjects, 10 men and 10 women per group). Group 1 subjects were studied supine, before and after beta- and muscarinic autonomic blockades, administered singly and together on separate days of study. Group 2 subjects were studied supine and drug free with the additional measurement of skin perfusion. In the unblocked state, we found that circulating levels of epinephrine and total spectral power of stroke volume, TPR, and skin perfusion ranged from two to six times greater in men than in women. The difference (men > women) in spectral power of TPR was maintained after beta- and muscarinic blockades, suggesting that the greater oscillations of vascular resistance in men may be alpha-adrenergically mediated. Men exhibited muscarinic buffering of mean TPR whereas women exhibited beta-adrenergic buffering of mean TPR as well as TPR and heart rate oscillations. Women had a greater distribution of RRI power in the breathing frequency range and a less negative slope of ln RRI power vs. ln frequency, both indicators that parasympathetic stimuli were the dominant influence on women's heart rate variability. The results of our study suggest a predominance of sympathetic vascular regulation in men compared with a dominant parasympathetic influence on heart rate regulation in women.

Contemporary models of change in the health professions.

This article reviews the special position that health professionals have occupied and the ways in which changes threaten the foundations of professional work. The application of modern management principles to health care runs the risk of overriding the "action orientation" that is a defining component of professional work. One goal of health workforce design should be the engineering of opportunities for the preservation of "professional voice" as a countervailing force to ensure high quality health care. Contemporary models of change applied to health care workforce include: (1) the system of professions models in which securing and maintaining jurisdiction are the mechanisms that professions employ to sustain their position, (2) a strategic adaptation model by which professions attempt to adjust to changing environments, (3) a model of redesigning patient care which applies Total Quality Management (TQM) and other "industrial techniques" to the health care workplace, and, (4) model of "consumer sovereignty" in which groups of citizens come together to determine the nature of care services and professional work, with the participation of the organizations and providers.