electrophysiology study

Think of an electrician tracing a building’s wiring to find where a fault hides, deliberately probing circuits to see how they behave. An electrophysiology study (EP study) maps the heart’s electrical system from the inside, recording and gently testing its wiring to understand an abnormal rhythm.

Thin catheters with electrodes are threaded through veins into the heart, where they record electrical signals directly from inside the chambers. The cardiologist can deliver small, controlled pacing impulses to provoke or trace abnormal rhythms, measure how quickly signals travel, and pinpoint the exact origin or circuit of an arrhythmia. This detailed map guides treatment.

EP studies are used to diagnose unexplained fast or slow rhythms, locate the source of a tachycardia, assess risk of dangerous arrhythmias, and plan catheter ablation — which is frequently performed in the same session once the target is found. It is an invasive procedure done in a specialized lab, and findings depend on whether the arrhythmia can be reproduced during the test.