Influence of systemic arterial blood pressure and nonhemodynamic factors on the brachial artery pulsatility index in mild to moderate essential hypertension

There is a general consensus that casual and clinic blood pressure (BP) measurements are predictive of subsequent cardiovascular damage.^1,2 There is evidence that ambulatory BP values are more predictive for organ damage, especially left ventricular hypertrophy.^3,4 In addition to the ambulatory BP parameters, nonhemodynamic factors such as the renin-angiotensin-aldosterone system and 1-84 parathyroid hormone are important determinants of left ventricular mass, as well.⁵ Since the introduction of real-time spectral analysis in Doppler ultrasound examination, the most frequently used wave-form has been the maximal frequency envelope of the spectrum. In 1974, Gosling and King⁶ introduced the term "pulsatility index" (PI), defined as the peak-to-peak swing of the velocity waveform (i.e., the difference between the peak systolic and minimal diastolic values) divided by the average value over 1 cardiac cycle. It remains uncertain in arterial hypertension whether the changes in arterial elastic behavior are a secondary consequence of long-term BP increases or are due to an influence of nonhemodynamic factors on the large arteries. Therefore, the aim of this study was to examine the relation between ambulatory BP, humoral factors and PI.