Quantitative analyses of the distal bipolar electrogram for focal premature ventricular contraction ablation.

BACKGROUND

Accurate interpretation of the distal bipolar electrogram (bi-EGM) is essential for successful ablation of idiopathic focal PVC. Sharp, early, and fractionated bi-EGM is often considered to be near-field and targeted, but in an empiric fashion rather than by quantitative criteria.

OBJECTIVES

To quantify the distal bi-EGM with five parameters to elucidate quantitative criteria distinguishing near-field from far-field bi-EGM.

METHODS

The distal bi-EGM was quantified and analyzed using: half time of activation ( ), slope factor (, derived by fitting the Boltzmann equation), linear slope (), time from onset of bi-EGM to surface ECG ( ) and number of deflections (#).

RESULTS

Among 41 patients, 26 were ablated successfully and 15 unsuccessfully. and , defining the sharpness of the activation process, were significantly different between the two groups (3.2 ± 0.3 vs. 5.9 ± 0.6 ms,  < 0.001 and 0.8 ± 0.1 vs. 4.8 ± 2.0,  = 0.01). was earlier in the successful group (35.6 ± 1.3 vs. 25.8 ± 1.6 ms,  0.01). and were not statistically different (0.2 ± 0.04 vs. 0.1 ± 0.02 mV/ms,  = 0.06; and 2.7 ± 0.2 vs. 2.3 ± 0.3,  = 0.22). The 5 parameters showed indifference across anatomic locations. AUCs of ROC curve are >0.8 ( 0.85, 0.85 and 0.87).

CONCLUSION

, and are precise in quantifying the sharpness and earliness of distal bi-EGM; therefore, discriminating the near-field from far-field bi-EGM for guiding successful ablation.