The Electrophysiology study also known as EPS is performed in the electrophysiologic laboratory on patients in a pre-absorptive state.
Electrode catheters are inserted percutaneously and positioned at multiple cardiac sites. Standard quadripolar electrode catheters with 1 cm interelectrode distance will be used for stimulation and recording from specific sites. Surface electrocardiographic leads at least one limb lead and V1 and V2 at the 3rd ICS should be displayed simultaneously with the intracardiac signals.
Cardiac stimulation is performed with a programmable constant-current stimulator that delivered rectangular pulses of 2 msec duration at twice the diastolic threshold.
Intracardiac electrograms are filtered at 30 to 300 Hz.
VT/VF is induced by programmed electrical stimulation (PES) with the premature right ventricular stimulation up to triple stimuli is used during ventricular pacing or sinus rhythm up to 3 cycle lengths.