LF component in systolic arterial pressure in patients with atrial fibrillation: Detection and reliability

Abstract

Atrial fibrillation (AF) is a common arrhythmia characterized by desynchronization of atrial electrical activity causing a consequent irregular ventricular response. Blood pressure fluctuates in a complex mode composed of both short-term and long-term variability. In AF, the beat-to-beat variation of blood pressure is increased because of variations in filling time and in contractility. However, a few studies have analyzed short-term blood pressure variations in AF being the interest mainly addressed to 24-hour variations. We recently observed an harmonic LF component in systolic arterial pressure (SAP) in patients with persistent AF, referred for electrical cardioversion. Aim of the present study was to propose a method to verify the reliability of the LF component found in SAP series, based on the position of the poles of the autoregressive spectral decomposition in the z-plane. 75% of the LF components resulted reliable in the SAP series, whereas only 20% in the RR series. Thus, we concluded that, at variance with RR ones, SAP LF components are likely to represent true physiological oscillations.