Blood pressure variability in patients with atrial fibrillation

The highly irregular ventricular rate during atrial fibrillation (AF) represents a unique and physiological experimental model to eliminate the influence of rhythmical components of RR variability on arterial pressure variability for investigating the origin of low frequency (LF) component in arterial pressure. Surface ECG, blood pressure and respiratory signals were recorded in thirty patients with persistent AF, at rest and during a passive orthostatic stimulus ("tilt test"). Short-term systolic (SAP) and diastolic arterial pressure (DAP) variability was estimated by autoregressive method. In 15 patients (group A), SAP significantly increased during tilt (from 98±16 to 114±18mmHg, p