An analysis of blood pressure recordings made over several years in a population suggests that hypertension may be a discrete condition of rather abrupt onset.
In this series at least, hypertension is associated with an unstable blood pressure rather than a narrow fixation at an elevated level, Richard E. Tracy, MD, reported to the multidiscipline research forum.
Those selected for study were 107 autopsied hospital patients for whom records were available of blood pressures taken over a period of at least three to six years.
In 91 of these patients, blood pressure had remained level; only 16 patients showed a rising blood pressure over the years. Moreover, there was a distinct division between those with normal blood pressure and hypertensives.
There also was an almost perfect association between high blood pressure and the presence of hyalinized arterioles in the kidneys.
The lack of patients with intermediate blood pressure and the