Dundee step test: a simple method of measuring the blood pressure response to exercise

The exercise systolic blood pressure (BP) response provides prognostic information over and above that of resting clinic BP in both normotensive and hypertensive individuals. We have developed a 3-min step test as a method of measuring the exercise systolic BP. Healthy volunteers and patients referred for assessment of hypertension took part in validating this exercise test. We assessed the reproducibility of the exercise systolic BP response, and this was compared with that obtained using the cycle ergometry at an equivalent workload. We also compared the baseline characteristics, BP profiles and exercise systolic BP responses in different subject groups. The intra-observer coefficient of variation assessed in 25 subjects was 5.9% with a mean difference of 1.8 mm Hg, The values for between observer were 8.3% and 2.5 mm Hg respectively. Exercise systolic BP measured with the step test correlated with that of cycle ergometer (n = 37, r = 0.93, P < 0.01). Exercise systolic BP data from healthy volunteers (n = 107) showed a normal distribution. An exercise systolic BP of greater than or equal to 180 mm Hg was greater than 2 standard deviations from the mean and was taken as an abnormally high BP during exercise. There was a positive correlation between exercise BP and increasing age in healthy volunteers (r = 0.57, P < 0.01). This was also present in hypertensive subjects (n = 46, r = 0.48, P = 0.001), however the slope of this relationship was twice as steep as in the normal subjects. Hypertensive subjects with high exercise systolic BP had significantly higher clinic BP, ABPM and a greater BP rise during exercise. The Dundee step test is quick, reproducible and may be prognostically useful.