Comparison of blood pressure and rate-pressure product responses in maximal dynamic and isometric exercise

The relationship between hemodynamic responses to maximal dynamic and isometric exercise have not been clearly established. We monitored heart rate (HR), systolic and diastolic blood pressure (SBP, DBP), electrocardiogram (ECG), as well as symptoms and signs, during both maximal treadmill test (GXT) and one-minute maximal handgrip dynamometry (HG) in the same individuals. Subjects were 164 adult male office patients, ages 20-79 years, who were not on medication. There was a wide range of responses in HR, SBP, DBP, and heart rate-systolic blood pressure product (MTTI), but with significant differences in mean values between GXT and HG as follows. SBP absolute value and percent increase over resting level were higher on GXT than on HG, DBP was higher on HG than GXT. HR was greater on GXT than on HG, MTTI was greater on GXT than on HG, both for mean absolute value and percent increase over resting level. Normal GXT related to lower SBP response on HG, abnormal GXT to higher. Normal vs abnormal GXT did not correlate significantly with MTTI. SBP on maximal HG was greater than it was for low levels of GXT, less than for high levels of GXT. DBP increase was greater for maximal HG than for any level of GXT. BP response is critical in monitoring HG, as HR is for GXT. Both GXT and HG are useful tests, without undue risk if contra-indications are observed and patients are properly monitored. There are notable HR, BP and MTTI differences in the two tests, which can only be determined by monitoring each individual.