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Background/Introduction Amiodarone is a widely used class III anti-arrhythmic drug that is highly effective in the treatment and suppression of ventricular tachycardia (VT). Amiodarone non-competitively blocks both alpha- and beta-adrenergic receptors and increases action potential duration prolonging repolarisation and refractoriness. Amiodarone pre-VT ablation has been shown to temporarily mask local abnormal ventricular activities and late potentials, resulting in less extensive mapping and ablation times in amiodarone-treated compared to amiodarone-naïve patients. It has more recently been demonstrated that chronic amiodarone therapy effects the identification of wavelet-transform high frequency substrate within critical components of the VT circuit. However, data regarding the effect of amiodarone on overall scar burden and myocardial voltages are limited.Purpose/Aims This study aims to define whether significant differences occur in myocardial voltages and overall scar burden in patients who receive chronic amiodarone therapy compared to those who are amiodarone naïve.Methods All patients underwent VT ablation using the EnSite™ X mapping system with the HDGrid mapping catheter utilising the OTNF signal wavelet algorithm. Only cases with high density sinus rhythm substrate maps were included. An offline retrospective analysis was subsequently conducted to determine whether significant differences occurred in overall scar burden (<1.5mv) and myocardial voltages in those who receive chronic amiodarone therapy compared to amiodarone naïve patients.Results A total of 57 ablation cases were reviewed and following exclusion, 30 patients were included in the final analysis. The mean age was 64±15years with an average ejection fraction of 34% and a total of 20 patients received chronic amiodarone therapy. On comparison of those on chronic amiodarone therapy to amiodarone naïve patients, there was no significant difference in total map omnipolar voltage [0.78 (±0.31) vs. 0.65 (±0.38), P = 0.24] or low voltage area [145.9 (±58.55) vs. 154.1 (±59.83), P = 0.68] between the two groups.Conclusion Despite its pronounced effect on the cardiac action potential, chronic amiodarone therapy does not appear to significantly affect overall scar burden or myocardial voltages during VT substrate mapping. Larger population-based studies and further relationship testing with advanced imaging modalities are required.