Non-invasive beat-to-beat determination of changes in the small artery compliance after smoking

We investigated the response of the small arterial compliance on smoking in 5 occasional smokers before, during and after inhaling the first cigarette in the day. For this purpose we used a non-invasive method based on interpretation of the oscillometric signal from the finger cuff coupled to the signal from photoplethysmograph. This system enables on-line determination of the finger artery compliance as function of transmural pressure (p(tm)) between 0 and 120 mm Hg, where each heart beat is presented by a set of compliance values in the range of the pulse pressure reduced by the cuff pressure. This procedure allowed construction of time course of the arterial compliance. When comparing the compliance value at ptm of 40 mm Hg, we found its fluctuations around the steady value during the rest and immediate lowering of the compliance after smoking, accompanied by the increase of blood pressure and heart rate.