Invasive electrophysiological study (EPS)	Class	References
EPS is indicated in patients with syncope and previous myocardial infarction, or other scar-related conditions when syncope remains unexplained after non-invasive evaluation.		69
EPS may be considered in patients with syncope and asymptomatic sinus bradycardia, in a few instances when non-invasive tests (e.g. ECG monitoring) have failed to show a correlation between syncope and bradycardia		70–72
EPS may be considered in patients with EF ≤ 40%, without a primary prophylactic ICD indication, and non-sustained VT in ICM (MUSTT criteria) to ascertain the presence of sustained VT events.		73
EPS may be helpful in patients with syncope and presence of a cardiac scar, including those with a previous myocardial infarction, or other scar-related conditions, when the mechanism of syncope remains unexplained after non-invasive evaluation.		66 , 70 , 71 , 73
EPS may be considered in patients with syncope and bifascicular block, when the mechanism of syncope remains unexplained after non-invasive evaluation.		67 , 70 , 71 , 74
EPS may be considered for risk stratification of SCD in patients with tetralogy of Fallot who have one or more risk factors among LV dysfunction, non-sustained VT and QRS duration exceeding 180 ms.		67 , 70 , 71 , 74
EPS may be considered in patients with congenital heart disease and non-sustained VT to determine the risk of sustained VT or identify SVT that could be ablate.		67 , 70 , 71 , 74
EPS may be considered in asymptomatic patients with spontaneous type 1 Brugada ECG pattern, or drug-induced type 1 ECG pattern and additional risk factors.		75–77
EPS is not recommended for additional risk stratification in patients with either long or short QT, catecholaminergic VT or early repolarization.		70 , 71
EPS is not recommended for risk stratification in patients with ischaemic or non-ischaemic DCM who meet criteria for ICD implantation.		70 , 71