Influence of different types of stressors on the waveform of the peripheral arterial pulse in humans

BACKGROUND: To characterize further the different reflected waves visible at the peripheral arterial pressure waveform, we recorded changes in the pulse wave contour during different stressful interventions. METHODS: Ten young healthy volunteers underwent two protocols. At the first occasion, the digital arterial pressure waveform was continuously recorded with the Portapres device during 5 min of rest, a mental arithmetic stress test (MAT) and during the cold pressor test (COP). At a second occasion, the pulse waveform was recorded at rest and during bicycle exercise. RESULTS: The reflected pressure peak seen during systole arrived earlier and was increased in amplitude during both MAT and COP compared to rest (p < 0.05). The first reflected pressure peak during diastole arrived earlier and was reduced in amplitude compared to the systolic peak during MAT (p < 0.01), while COP induced smaller effects. Bicycle exercise at 100 and 140 heartbeats/min caused the reflected peak in systole to be undetectable in most subjects and induced a marked reduction in the amplitude of the first diastolic reflected peak (p < 0.01), and time to its appearance was markedly reduced at 140 beats/min. CONCLUSION: Several stressors accounted in daily life, such as mental stress, pain and exercise-induced rapid changes in the arterial pulse waveform. In terms of timing and amplitude, the reflected systolic pressure peak and the first diastolic pressure peak did not always change in the same direction during the interventions, implying different origins of these two reflected waves. Combining the stressors used with pulse wave analysis is a simple method for studying vascular reactivity non-invasively.