12-lead ECG during Tachy 10.30.31 Sinus Rhythm Single His 11.20.02 Induction tachycardia 11.23.23 Tachy 11.25.23 1
I This finding excludes: (a) AVNRT (either typical or atypical) Tachy: Alternating cycle length 12.01.33 (b) (c) excludes atrial tachycardia His-purkinje system is involved II Possibilities include: (a) intrahisian reentry (b) nodo-fascicular tachycardia Vp@CL350 ms: VAV response 12.22.51 Vp at CL 500 ms during adenosine 12mg IV VA Block 11.46.48 2
VPC His refractory, CI 294 ms (1) 11.26.58 These findings shows orthodromic entrainment of H1 - H2 with ventricular pacing (1) No evidence for retrograde conduction over extranodal AP (2)Absence of fusion strongly against ventricular involvement (absent fusion suggests AVNRT or N-F pathway) Adenosine 12 mg IV; Stop Tachy 12.16.32 Termination with adenosine (a) very long H1-H2 suggests nodal rather than intra-hisian delay (b) termination supports nodal involvement of SVT circuit 3
13.36.56 Post ablation AP@CL 470, S2 280 13.38.03 Post ablation Ap@CL 470, S2 200 ms Single His Summary 1. Tachycardia initiated with APC which produced split His potential 2. Dual AV nodal conduction present 3. H1 - H2 drives V1 V2 H2 - V constant H2 - H1 constant 4. Adenosine terminates SVT 5. Ablation of SP cures SVT and only single His potential is inscribed 4
NF 25 year old male with narrow and WCT tachycardia. No past history of cardiac disease LVEF = 60%. S/P attempted left post fascicle ablation, referred because of incessant tachycardia refractory to lidocaine, adenosine, verapamil, metoprolol and amiodarone Initial Intracardiac EGMs; Short H-V interval noted 5
Early VPC terminates tachycardia then resumes after sinus complex Just inferior to LBB potential Entrainment from just below the LBB 6
RAO view of ESI/NavX map of LV with sites ( F ) of presystolic potentials Tachycardia features and diagnosis Site of Successful Ablation Site of 10/12 pacemap Incessant tachycardia was independent of the atrium (adenosine) AV nodal reentry excluded by: 1) lack of critical A-H interval for tachycardia initiation; 2) the short H-V interval in tachycardia; 3) successful site of ablation in LV BBRT is excluded because of short H-V Fascicular tachycardia is present because each QRS is preceded by a fascicle potential which excludes myocardial VT Tachycardia features and diagnosis Left Bundle Branch Anatomy Anterograde nodo-fascicular tachycardia is excluded by absence of response to large doses of adenosine and the 3 different ECG morphologies of tachycardia Concealed nodofascicular tachycardia is excluded due to short H-V interval in tachycardia 7
Anterior & Posterior Fascicles Posterior Fascicle Anterior Fascicle Atrial Flutter: Isthmus Dependent RAO LAO Adapted from Mayo Foundation for Medical Education and Research I II III R L F V1 V2 V3 V4 V5 V6 CCW I II III R L F V1 V2 V3 V4 V5 V6 CW 8
Isthmus Flutter: Electrograms CCW AFL Lateral Right Atrium T9 T8 T10 SVC T7 Septum T6 2 0-pole CS cat heter cathet er T5 HIS T4 RF T3 cathet er T2 CS os T1 IVC Isthmus 6:00 Lateral CTI Medial CTI II avf V1 HIS CS md CS px T1 T2 T3 T4 T5 T6 T7 T8 T9 T10 UC SF PPI- TCL =17 MS FROM MEDIAL CTI PPI- TCL= 45MS FROM LATERAL CTI 9
IIR 132 ms Slow Conduction Within CTI PPI - TCL = 59 ms V1 E1 E2 CS OS PPI - TCL = 92 ms -139 ms MI D V V PPI - TCL = 42 ms PPI - TCL = 25 ms MI P UC SF LAO TA CS OS RF UC SF 10
I avf V1 200ms Simultaneous Pattern Hypothetical IIR Circuit AS CS D SVC AS Activation Patterns CS M CS OS CTI TA2 TA4 TA6 300ms E 1 E 2 340ms 325ms = Medial CTI Pacing CT CS OS ER E 1 E IVC 2 * CTI IVC CS TA Simultaneous CCW CW TA8 UC SF Image from Dr. M. Borggrefe UC SF 11