1. Basic electrophysiology Dr Mohamad Abdelshafy Assistant lecturer Suez Canal University

2. Objectives General objectives of EP-study: General objectives of EP-study: - Induce tachycardia & study its mechanism - Induce tachycardia & study its mechanism - Assess the integrity or function of conductive system - Assess the integrity or function of conductive system Sinus node function AVN function

3. EPS procedure Vascular access (Venous – arterial) Vascular access (Venous – arterial) Electrode catheter (contact mapping – pacing) Electrode catheter (contact mapping – pacing) Catheter position Catheter position Multichannel recording system + programmable stimulator Multichannel recording system + programmable stimulator

4. Electrode catheter Bipolar intracardiac recording (localized leectrical activity- depolarization of tissue) Connecting port 1 4 3 2 1 Dist. Prox.

5. Ablation catheter RF-current applic.

6. Catheter position SVT VT SVT VT HRA SAN HRA HRA SAN HRA His AV cond His His AV cond His RVA RVA +/- LVA RVA RVA +/- LVA CS SCV puncture CS SCV puncture Recording from all major 4 chambers & His position

7. Catheter position RAOLAO CS His RV

8. Intracardiac electrogram Bipolar recording of cardiac elecrical activity (localized area) Bipolar recording of cardiac elecrical activity (localized area) High frequency, high amplitude signal (tissue depolar.) in contact with recording electrode High frequency, high amplitude signal (tissue depolar.) in contact with recording electrode Nomenclature ……. Nomenclature ……. Sequence of activation Sequence of activation

9. Nomenclature & Measurement of baseline cond. intervals Cycle length = 60.000/ HR length of time bet. Heart beats V A V SCL P His electrogram (3 components) low RA- His-upper RV-no AVN

10. baseline cond. intervals SCL= interval bet. 2 successive A waves SCL= interval bet. 2 successive A waves AH interval ( 50—120 msec) AVN AH interval ( 50—120 msec) AVN HV interval (35 – 55 msec) His- purk HV interval (35 – 55 msec) His- purk His deflection (cond. Via His bundle) His deflection (cond. Via His bundle) IACT (not basic) = interval bet SAN & His IACT (not basic) = interval bet SAN & His

11. Sequence of activation-catheter setup

12. SAN function Pacing (site- type- differentiation) Pacing (site- type- differentiation) Tests of SAN function: Tests of SAN function: -SNRT (assess SAN automaticity) (up to 1500 msec) - variable with HR -SNRT (assess SAN automaticity) (up to 1500 msec) - variable with HR -cSNRT (SNRT-BSL) up to 525 msec -cSNRT (SNRT-BSL) up to 525 msec - SACT (50-125 msec) assess cond. of impulse from SAN to adjacent atrial tiss - SACT (50-125 msec) assess cond. of impulse from SAN to adjacent atrial tiss

13. SAN function S1 A 550 SCL= 450 msec SNRT= 550 msec CSNRT= 150 msec 400 Time = 30 sec HRA Recovery interval

14. SAN function S1 A Idea: reset the SAN – Narula method 580 Recovery interval= time of paced beat penetrates & resets SAN+SCL+time for spont. Beat to exit SAN = SCL+ 2 SACT 8 paced beats

15. Assessment of AVN function Pacing: Pacing: site site type (burst –ramp) type (burst –ramp) Extrastimulation (site – number- coupling intervals) Differentiation (atrial- ventricular)

16. Atrial pacing A V S1 Pacing interval

17. V pacing A VV A

18. Tests of AVN function Antegrade 1:1 AV conduction Antegrade 1:1 AV conduction Antegrade WCL Antegrade WCL Retrograde 1:1 VA conduction Retrograde 1:1 VA conduction Retrograde WCL Retrograde WCL AVN/ERP AVN/ERP

19. 1:1 AV cond. A V

20. AVN/ERP 400/350 S1S2

21. 1:1 VA cond. PCL= 300 msec V A Retrograde sequence of activation

22. VA dissociation PCL=260 msec AA VV V

23. V. extrastim S1SS2