Beta blockers for blood pressure: A second opinion
Medicine is a dynamic science; if there is anything constant about the profession, it's that things change.
One of the most important areas of change has come in our understanding of blood pressure and our management of hypertension (high blood pressure). Dr. Scipione Riva-Rocci developed the sphygmomanometer (blood pressure cuff) in 1896, and Dr. Nikolai Korotkoff learned how to team it with a stethoscope to get reliable measurements in 1905. In the early days, the readings were just numbers, but doctors gradually learned that high numbers predict an increased risk of stroke, heart attack, kidney failure, cognitive impairment, and premature death. At first, they believed that only the diastolic blood pressure (the lower reading, measured while the heart is relaxing and refilling with blood between beats) was important. But scientists have learned that both numbers count, and that the systolic blood pressure (the higher number, measured while the heart is pumping blood) is actually more important.
The definition of a hypertensive pressure has also changed. First, it fell from 160/90 mm Hg to 140/90. Then, in 2003, the Joint National Committee on Prevention, Detection, and Treatment of High Blood Pressure issued its Seventh Report (JNC7), which turned the world of hypertension upside down. Based on a wealth of new data, JNC7 explained that 120/80 is the highest reading that qualifies as normal. The report also established a new diagnostic category of prehypertension for readings between 120/80 and 140/90, and it confirmed 140/90 as the standard for full-blown hypertension.