Author Block M Matangi
BACKGROUND: Rounding up and rounding down of blood pressure measurements taken using a mercury sphygmomanometer is a well recognized phenomenon. The purpose of this investigation was to see if this phenomenon also occurs during exercise stress testing where blood pressure is measured by highly skilled nurses.
METHODS: 32,208 patients underwent exercise stress testing between May 1999 and December 2011 who had both resting and peak BP recorded using a mercury sphygmomanometer. All data are entered into our cardiology database. The 32,208 resting and peak BPs were retrieved and placed into an EXCEL file. The last digit was retrieved for both sets of data and entered into a pie chart.
RESULTS: See image below.
CONCLUSION: It is of interest that although there is rounding up or down to “0” during the resting BP measurement, this phenomenon disappears with the peak exercise BP measurement. It is possible that there is some complacency with the performing of the resting BP which is not present during the recording of the peak BP.