Rate Pressure Product During Upper and Lower Body Ergometer Exercise

Abstract

PURPOSE: Rate Pressure Product (RPP) [the product of heart rate (HR) and systolic blood pressure (SBP)] is strongly correlated with and used as a marker of myocardial oxygen demands (MVO2), with specific utility during exercise in patients with angina pectoris. Subsequently, RPP is monitored during exercise to assure that patients do not exceed their ischemic threshold. Upper and lower body ergometry have different cardiovascular responses, which may alter the RPP response to exercise. Therefore, the purpose of this investigation was to measure HR, SBP and RPP during at similar workrates during upper body and lower body ergometer exercise. METHODS: Fifteen apparently healthy men (age: 22 ± 1.5 yrs) performed incremental (25 Watts every two minutes) arm and leg ergometry on an electronically braked ergometer to volitional fatigue. HR and SBP were measured at the end of each two-minute work stage. RPP was calculated as the product of HR and SBP. A two-way repeated measures ANOVA was used to determine differences between arm and leg ergometry across work stages. RESULTS: HR was significantly greater during arm ergometry when compared to leg ergometry at higher workrates (75 and 100 W) (p<0.001). SBP increased with increasing workrates (p<0.001) but did not differ between arm and leg ergometry. RPP was greater (p=0.003) during arm ergometry at higher workloads when compared to leg ergometry. CONCLUSIONS: HR increased to a greater magnitude during arm ergometry when compared to leg ergometry, particularly during higher workrates. There was a subsequent greater increase in RPP during arm ergometry at higher workrates. Therefore, caution should be practiced when using HR to assure the desired exercise intensity across exercise modalities for patients with ischemic heart disease. Although appropriate for leg ergometry, the prescribed training heart rate may exceed the patient’s ischemic threshold during arm ergometry.