 Radial artery applanation tonometry and pulse wave analysis will be used to calculate a central aortic pressure and other parameters using commercially available SphygmoCor system. Central aortic pressures will be obtained immediately following measurement of brachial artery pressures. Patients will be seated for 5 minutes in a quiet room after which time blood pressure will be measured over the brachial artery three times at 5 minute intervals. The mean of the last two measurements will be recorded as representative of the brachial artery pressure. After the last measurement, radial artery pressure waveforms of the same arm will be sampled over 10 seconds with a Millar tonometer and calibrated to the average brachial pressure. Waveforms will be processed with dedicated software SphygmoCor version 7, AtCor. The software will be used to calculate an averaged radial artery waveform and to derive a corresponding central aortic pressure. Aortic pressure waveforms will be subjected to further analysis by the SphygmoCor software to identify the time to the peakshoulder of the first and second pressure wave components T1, T2 during systole. The pressure at the peakshoulder of the first component sill be identified as P1 height outgoing pressure wave and the pressure difference between P1 and the maximal pressure during systole P or augmentation will be identified as the reflected pressure wave occurring during systole. Augmentation index AIx, defined as the ratio of augmentation to central pulse pressure, will be expressed as the percentage: AIx PPP x 100, where P is pressure and PP is pulse pressure. Pulse pressure amplification PPA will be expressed as the ratio of central pulse pressure CPP to peripheral brachial pulse pressure PPP: PPA PPPCPP 