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FIGURE 2. (A) Example of phase analysis in a nonresponder to CRT. At baseline, no LV dyssynchrony with phase analysis was present in this patient. Nonnormalized (top panel) and normalized (bottom panel) phase distributions are relatively uniform and the corresponding phase histograms are highly peaked, narrow distributions. After 6-mo follow-up, no response to CRT was observed, as reflected by deterioration in NYHA functional class from 3 to 4. In addition, LVEF remained unchanged (baseline [32%] vs. 6-mo follow-up [33%]). (B) Example of phase analysis in a responder to CRT. In this patient, LV dyssynchrony with phase analysis was present at baseline. Nonnormalized (top panel) and normalized (bottom panel) phase distributions show substantial nonuniformity, whereas the corresponding phase histograms are widely spread distributions. After 6-mo follow-up, this patient improved in NYHA functional class from 3 to 2, indicating response to CRT. In addition, LVEF increased from 27% at baseline to 33% at 6-mo follow-up.
