Table 2.

Effect of breathing on the accuracy of the NEEES

Heart chamber	RA (N = 24)	RV (N = 36)	LV (N = 36)	RA + RV + LV (N = 96)
Spontaneous breathing, mean ± SD (mm)	8.0 ± 1.8	6.3 ± 1.8	6.4 ± 1.5	6.8 ± 1.9 (P < 0.001 vs. inspiration and expiration)
Inspiration breath hold, mean ± SD (mm)	5.9 ± 1.3	4.7 ± 1.3	5.9 ± 1.6	5.5 ± 1.6 (P < 0.001 vs. spontaneous breathing and expiration)
Expiration breath hold, mean ± SD (mm)	9.5 ± 1.9	8.1 ± 1.7	8.5 ± 1.1	8.6 ± 1.6 (P < 0.001 vs. spontaneous breathing and inspiration)

Pacing during spontaneous breathing and during breath hold on inspiration and expiration. Mean distance between reference pacing site and reconstructed pacing site and standard deviation for N pacing events.

RA, right atrium; RV, right ventricle; LV, left ventricle.