Cited 24 times since 2018 (5.9 per year) source: EuropePMC European heart journal, Volume 39, Issue 31, 1 1 2018, Pages 2867-2875 Whole human heart histology to validate electroanatomical voltage mapping in patients with non-ischaemic cardiomyopathy and ventricular tachycardia. Glashan CA, Androulakis AFA, Tao Q, Glashan RN, Wisse LJ, Ebert M, de Ruiter MC, van Meer BJ, Brouwer C, Dekkers OM, Pijnappels DA, de Bakker JMT, de Riva M, Piers SRD, Zeppenfeld K

Aims

Electroanatomical voltage mapping (EAVM) is an important diagnostic tool for fibrosis identification and risk stratification in non-ischaemic cardiomyopathy (NICM); currently, distinct cut-offs are applied. We aimed to evaluate the performance of EAVM to detect fibrosis by integration with whole heart histology and to identify the fibrosis pattern in NICM patients with ventricular tachycardias (VTs).

Methods and results

Eight patients with NICM and VT underwent EAVM prior to death or heart transplantation. EAVM data was projected onto slices of the entire heart. Pattern, architecture, and amount of fibrosis were assessed in transmural biopsies corresponding to EAVM sites. Fibrosis pattern in NICM biopsies (n = 507) was highly variable and not limited to mid-wall/sub-epicardium. Fibrosis architecture was rarely compact, but typically patchy and/or diffuse. In NICM, biopsies without abnormal fibrosis unipolar voltage (UV) and bipolar voltage (BV) showed a linear association with wall thickness (WT). The amount of viable myocardium showed a linear association with both UV and BV. Accordingly, any cut-off to delineate fibrosis performed poorly. An equation was generated calculating the amount of fibrosis at any location, given WT and UV or BV.

Conclusion

Considering the linear relationships between WT, amount of fibrosis and both UV and BV, the search for any distinct voltage cut-off to identify fibrosis in NICM is futile. The amount of fibrosis can be calculated, if WT and voltages are known. Fibrosis pattern and architecture are different from ischaemic cardiomyopathy and findings on ischaemic substrates may not be applicable to NICM.

Eur Heart J. 2018 8;39(31):2867-2875