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Spatial Resolution of Defibrillator Electrograms to Detect Distinct Exit Sites of Scar‐Related Ventricular Tachycardia
Author(s) -
SANTANGELI PASQUALE,
ALCALDE OSCAR,
ZADO ERICA S.,
CALLANS DAVID J.,
MARCHLINSKI FRANCIS E.
Publication year - 2014
Publication title -
pacing and clinical electrophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.686
H-Index - 101
eISSN - 1540-8159
pISSN - 0147-8389
DOI - 10.1111/pace.12444
Subject(s) - medicine , ventricular tachycardia , cardiology , ablation , implantable cardioverter defibrillator
Background Analysis of implantable cardioverter‐defibrillator electrograms (IEGMs) with pacing along the scar edge is often used to approximate distinct exit sites of scar‐related ventricular tachycardia (VT). We evaluated the spatial resolution of IEGMs in identifying distinct exit sites of scar‐related VT. Methods and Results Seventeen patients with scar‐related VT were included. Threshold pacing (500‐ms cycle length) was performed at sites spaced 10 mm apart along the scar border, as defined by high‐density bipolar voltage mapping. Twelve‐lead electrocardiogram and near‐field and far‐field IEGMs were recorded at each pacing site and assessed for morphology. The average scar size was 60 ± 30 cm 2 and the scar border perimeter measured 28 ± 9 cm. A median of 18 pacing sites per patient were collected, spaced 14 ± 11 mm apart. The mean spatial resolution for the near‐field, far‐field, and combination of both was 82.7 ± 76 mm, 62.7 ± 53.6 mm, and 56.7 ± 50 mm (P for trend < 0.001). In all cases, IEGM analysis failed to identify distinct VT exit sites spaced <2 cm apart. Conclusions Analysis of IEGM morphology with pacing around the edge of the scar is unable to distinguish distinct VT exit sites spaced <2 cm apart, with an average spatial resolution of 5 cm. Given the wide range of values observed, detailed pace mapping over a perimeter of 10–15 cm along the scar edge appears crucial to define the boundaries of a linear ablation strategy to target the VT exit site based on IEGM pace match alone.