Computer analysis of cardiovascular activity in conscious unrestrained hypertensive rats of the Lyon strain

A new computerized technique was developed for the continuous analysis of intra arterially recorded blood pressure (BP) curve in freely moving rats during long periods of time. For each cardiac cycle 5 parameters were calculated on-line and stored. Off-line processing allowed graphical display and statistical analysis. This technique demonstrated that 21 week-old genetically hypertensive rats from the Lyon strain (LH) exhibited higher and more variable BP and dp/dt max. with a lower heart rate than normotensive (LN) and low blood pressure (LL) controls. LL rats differed from LN by a slightly higher systolic and a lower diastolic BP.