Electrophysiology study (EPS) is an invasive diagnostic procedure performed to evaluate the heart’s electrical system. This procedure is used to determine the source of arrhythmias, perform risk assessment, and plan treatment.
What is an Electrophysiology Study?#
EPS is the recording and stimulation of the heart’s electrical activity through special catheters placed in the heart.
What EPS Evaluates:
- Sinus node function
- AV conduction system
- His-Purkinje system
- Inducibility of arrhythmias
- Presence of accessory pathways
EPS Indications#
Diagnostic Purposes#
Syncope Evaluation:
- Unexplained fainting
- Structural heart disease + syncope
- Family history of sudden death
Arrhythmia Diagnosis:
- Palpitation complaints (not captured on ECG)
- Wide QRS tachycardia (VT vs SVT differentiation)
- Preexcitation syndromes
Risk Assessment:
- Sudden cardiac death risk
- ICD indication evaluation
- Brugada syndrome
Therapeutic Purposes#
- Pre-ablation mapping
- Ablation procedure (in same session)
How is EPS Performed?#
Pre-Procedure Preparation#
- Discontinuation of antiarrhythmic drugs (5 half-lives)
- Fasting (6-8 hours)
- Blood tests
- Groin area shaving
Procedure Steps#
- Anesthesia: Local anesthesia + sedation
- Vascular access: Femoral vein (groin)
- Catheter placement: Under fluoroscopy guidance
- High right atrium
- His bundle
- Coronary sinus
- Right ventricular apex
- Baseline recordings: Measurement of conduction times
- Programmed stimulation: Induction of arrhythmias
- Mapping: Determination of arrhythmia source (if needed)
- Catheter removal: Hemostasis with pressure
Procedure Duration#
- Diagnostic EPS: 1-2 hours
- EPS + Ablation: 2-4 hours
Parameters Measured in EPS#
Conduction Times#
| Parameter | Normal Value |
|---|---|
| PA interval | 25-55 ms |
| AH interval | 55-125 ms |
| HV interval | 35-55 ms |
| SNRT | <1500 ms |
| CSNRT | <550 ms |
| Wenckebach point | >500 ms |
Programmed Stimulation#
- Atrial stimulation (SVT induction)
- Ventricular stimulation (VT induction)
- Burst pacing
- Extra stimulus protocols
EPS Results#
Normal Findings#
- Normal conduction times
- No arrhythmia inducibility
- Normal sinus node function
Abnormal Findings#
- Prolonged conduction times
- Inducible arrhythmias
- Presence of accessory pathway
- Sinus node dysfunction
EPS Risks#
Procedure risks are low:
- Access site complications (bleeding, hematoma)
- Heart perforation (rare)
- AV block (temporary or permanent)
- Thromboembolism
- Arrhythmia induction (in controlled environment)
Post-Procedure Care#
In Hospital:
- 4-6 hours bed rest
- Access site monitoring
- Rhythm monitoring
After Discharge:
- Avoid heavy activity for 24-48 hours
- Follow-up appointment for results evaluation
Frequently Asked Questions#
Is EPS painful?
How long does EPS take?
When can I go home after EPS?
Is it dangerous if arrhythmia is triggered during EPS?
What do EPS results mean?
Appointment and Contact#
If you would like to schedule an appointment for electrophysiology study:
📍 Avrasya Hospital - Beştelsiz Mah. 101. Sokak No:107, Zeytinburnu, Istanbul
📞 Phone: +90 212 665 50 50 (Ext: 4012)
This content has been prepared by Assoc. Prof. Dr. Habib Çil for general informational purposes. Please consult a cardiology specialist for definitive diagnosis and treatment.
Related Arrhythmia Treatments#
Other arrhythmia treatments related to electrophysiology study:
- Ablation - Catheter ablation
- Cardioversion - Electrical cardioversion
- ICD - Implantable cardioverter defibrillator
- Permanent Pacemaker - Bradycardia treatment
- Holter - 24-hour rhythm monitoring