iPhone App Compared to Standard RR-measurement During Stress Testing

The iPARR DELTA BP Study is designed to evaluate whether a new smartphone app using the photoplethysmography signal of the inbuilt camera can measure blood pressure (BP) fluctuations with sufficient correlation compared to the goldstandard oscillometric BP measurements. Investigators will recruit patients who are scheduled for a routine treadmill stress test and assess their blood pressure before and right after the test with the smartphone app and the standard BP measurements on the opposite upper extremity. Pronounced BP fluctuations are encountered during vigorous activities. The primary endpoint of the iPARR DELTA BP Study is the correlation of the absolute difference of subsequent measurements between both techniques. If the relative chances of BP fluctuations are sufficiently assessed with this new device, BP fluctuations could be monitored continuously after calibration.