Control of circulation by arterial baroreceptors and cardiopulmonary receptors in hypertension.

This article reviews observations made on reflex control of circulation in essential hypertension and in a few models of experimental hypertension. It is emphasized that a wide consensus exists on the fact that baroreceptor control of heart rate is impaired in essential hypertension and that this occurs not only in severe but also in mild and borderline hypertensive conditions. On the other hand, baroreceptor control of blood pressure is much less affected by chronic elevations in arterial blood pressure due to central or peripheral factors that differentially affect cardiac and vascular responses to the vagus and the sympathetic drive, respectively. Cardiopulmonary receptor control of peripheral circulation and renin release is also little affected by hypertension, and the suggestion has been made that its sensitivity may even be enhanced in early hypertensive stages and then undergoes a subsequent reduction as cardiac hypertrophy develops. Finally, the possible consequences of preservation of reflex control of circulation in hypertension are discussed. It is speculated that this phenomenon may be in part responsible for the similar percentage of blood pressure oscillations that can be observed in normotensive and borderline, moderate, and severe hypertensive subjects.