OBJECTIVES This study sought to determine new reference cutoffs for normal unipolar voltage (UV) and bipolar voltage (BV) that would be adjusted for the LV remodeling.BACKGROUND The definition of ... Show moreOBJECTIVES This study sought to determine new reference cutoffs for normal unipolar voltage (UV) and bipolar voltage (BV) that would be adjusted for the LV remodeling.BACKGROUND The definition of "normal" left ventricular (LV) endocardial voltage in patients with post-infarct scar is still lacking. The reference voltage of the noninfarcted myocardium (NIM) may differ between patients depending on LV structural remodeling and the ensuing interstitial fibrosis.METHODS Electroanatomic voltage mapping was integrated with isotropic late gadolinium-enhanced cardiac magnetic resonance in 15 patients with nonremodeted LV and 12 patients with remodeled LV (end-systolic volume index >50 ml/m(2) with ejection fraction <47% assessed by cardiac magnetic resonance). Reference voltages (fifth percentile values) were determined from pooled NIM segments without late gadolinium enhancement.RESULTS The cutoffs for normal BV and UV were >= 3.0 and >= 6.7 mV for nonremodeled LV and >= 2.1 and >= 6.4 mV for remodeled LV. Endocardial low-voltage area (LVA) defined by the adjusted cutoffs corresponded better to late gadolinium enhancement-detected scar than did LVA defined by uniform cutoffs. In 15 patients who underwent successful ablation of ventricular tachycardia, the LVA contained >97% of targeted evoked delayed potentials. Insights from whole-heart T1 mapping revealed more fibrotic NIM in patients with remodeled LV compared with nonremodeled LV.CONCLUSIONS This study found substantial differences in endocardial voltage of NIM in post-infarct patients with remodeled versus nonremodeled LV. The new adjusted cutoffs for "normal" BV and UV enable a patient-tailored approach to etectroanatomic voltage mapping of LV. (C) 2019 by the American College of Cardiology Foundation. Show less
