Challenges and Pitfalls of Entrainment Mapping of Ventricular Tachycardia

Although entrainment mapping is a time-honored, powerful electrophysiological technique that provides insight into arrhythmia mechanisms and circuit characterization, many limitations are inherent because of the perturbations that occur when the natural state of arrhythmia is probed (Heisenberg uncertainty principle). These recording variables, such as pacing current strength, electrode size/spacing, filtering, gain, and noise, introduce additional factors that challenge the practice of entrainment mapping. Importantly, an improved understanding of the conceptual factors that are associated with exceptions to the rule may be useful to avoid interpretative errors. Cognitive adjustments during the clinical practice of entrainment mapping are likely to improve our ability to find gold (isthmus), when the gold standard seemingly leads us astray.