Cardiac aliasing in atrial rate variation response to fixed-rate ventricular pacing

It is found that the frequency components of atrial rate variation (ARV) of AV-block patient with fixed-rate ventricular pacing vary irregularly with the pacing rates. We attempt to learn about the relationship between the oscillation frequency of ARV and the blood pressure (BP) pattern in this study. The beat-to-beat ARVs extracted from esophageal ECG and noninvasive BP waveforms of seven AV-block patients were recorded. Each patient was paced under 60, 90, 120 beats/min of three ventricular rates. Results reveal that the oscillation frequency of ARV does not correlate to the variation frequency of systolic or diastolic BP or respiration frequency. Instead, it may be an aliasing phenomenon of BP pulse frequency exactly equal to ventricular rate when the mean atrial rate is considered as the sample rate of ARV signal. This study suggests that the BP pulse dominate the ARV in AV asynchronous situation.