Predicting Left Atrial Low-Voltage Areas During Sinus Rhythm on the Basis of Low Voltage During Atrial Fibrillation

Abstract

Background: As we have found a significant correlation between left atrial (LA) voltage during sinus rhythm (SR) and that during atrial fibrillation (AF), we hypothesized that the existence of low-voltage zones (LVZs) during AF can be used to identify LVZs during SR. Therefore, we conducted a study to test this hypothesis. Methods: In 8 patients, high-density bipolar voltage mapping (> 300 points) of the left atrium was performed with a 20-pole circular catheter with 4-4-4-mm interelectrode spacing. The left atrium was divided into 7 segments, and the mean LA bipolar voltages recorded over 5 seconds during SR and AF were determined by measurement of the peak-to-peak amplitudes. Results: LVZs identified at each segment were compared between SR and AF. LA bipolar voltages obtained during SR and AF correlated positively (r = 0.74, p < 0.0001). With the low voltage during SR defined as < 0.5 mV, the low voltage of < 0.2 mV during AF approximately matched the low LVZs mapped during SR. Conclusions: These findings indicate that LVZs of < 0.5 mV during SR could be predicted from LVZs identified during AF by designating a threshold AF voltage of 0.2 mV.