Clinical Spectrum of Nodoventricular Accessory Pathways

Figures

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  Figure 1. Clinical Tachycardia, Electrograms, and Successful Ablation Site of Case 1 (A) Twelve-lead-ECG showing narrow complex tachycardia and sinus rhythm without ventricular pre-excitation. (B) PVC occurring during His activation was able to terminate tachycardia with retrograde AV block. (C) Ventricular entrainment pacing during tachycardia showing a short postpacing interval of 34 ms indicated that the ventricle was part of the tachycardia circuit. (D) Spontaneous PVC occurring during tachycardia was able to advance the A signal with H-H interval remaining the same, confirming that the accessory pathway was part of the re-entrant circuit. (E) Extrastimulus (S2) from the coronary sinus catheter during tachycardia showed that the A signal was dissociated from the V signal while the VV interval remained the same, indicating that the atrium was not part of the circuit. (F) Catheter position at the successful ablation site at the right infero-paraseptal area with ablation signal during tachycardia and sinus rhythm showed a sharp earliest A potential associated with a small discrete potential between the A and V signal. ABL = ablation catheter; CS = coronary sinus; d = distal, ECG =…

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  Figure 2. Clinical Tachycardia, Electrograms, and Successful Ablation Site of Case 2 (A) Twelve-lead-ECG shows complete RBBB without pre-excitation and the other 2 types of wide complex tachycardia. (B) Ventricular overdrive pacing during tachycardia showed a short PPI-TCL (<110 ms). (C) Spontaneous PVC with fusion complex occurring during tachycardia was able to advance the A signal and reset the tachycardia. (D) V-pacing during tachycardia showed a progressive fusion until the tachycardia terminated. (E) Tachycardia was spontaneously terminated and showed paradoxical AH response. (F) Catheter position at the successful ablation site at the right infero-paraseptal area. Ablation signal during tachycardia showed a sharp earliest A potential with a small potential within which was thought to be the accessory pathway potential. Abl = ablation catheter; ECG = electrocardiogram; H = His; HRA = high right atrium; LRA = low right atrium; PPI-TCL = postpacing interval–tachycardia cycle length; PVC = premature ventricular complex; RBBB = right bundle branch block; RV = right ventricle.

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  Figure 3. Clinical Tachycardia, Electrograms, and Successful Ablation Site of Case 3 (A) Twelve-lead-ECG in sinus rhythm and during wide complex tachycardia and LBBB morphology. (B) V-extra-stimulus at different interval show retrograde conduction property with echo-beats. (C) RV pacing during narrow QRS with progressive fusion with progressively longer ventriculoatrial conduction with same H-H intervals. (D) His refractory PVC was able to advance the A activation and reset the tachycardia (blue arrow). Also noted that there is a prolongation of the ventriculoatrial time (red arrow) when narrow QRS complexes (first QRS) was changed to wide complexes with LBBB (from second QRS) with. (E) Atrial overdrive pacing at 350 ms showed no ventricular reset, and the tachycardia cycle length remain the same (370 ms). (F) Fluoroscopic view of the catheter position and signal at the successful ablation site at left infero-paraseptal area. A = atrium; Abl = ablation catheter; AP = accessory pathway; CS = coronary sinus; d = distal; ECG = electrocardiogram; H = His; HRA = high right atrium; LBBB = left bundle branch block; p = proximal; RV = right ventricle; V = ventricle.

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  Figure 4. Clinical Tachycardia, Electrograms, and Successful Ablation Site of Case 4 (A) Twelve-lead-ECG in sinus rhythm with minimal pre-excitation, during narrow complex tachycardia, and in sinus rhythm after ablation. (B) With pacing from the right atrium 600 ms and 420 ms, AH prolongation and became negative and hiding inside the V signal together with delta augmentation and Stim-to-delta delay. (C) Ventriculoatrial decremental conduction was seen during ventricular extrastimulus. (D) PVC during His refractory was able to advance the atrial signal and reset the tachycardia cycle length. (E) Atrial overdrive pacing from the high right atrium was able to capture and entrain the right atrium without altering the cycle length of the tachycardia as seen in the VV cycle length. (F) Ventricular overdrive pacing during narrow complex tachycardia showed progressive fusion. (G) Fluoroscopic view of the catheter position and signal at the successful ablation site at the right infero-paraseptal area. A = atrium; Abl = ablation catheter; AP = accessory pathway; CS = coronary sinus; d = distal; ECG = electrocardiogram; H = His; HRA = high right atrium; LAO = left anterior oblique; p = proximal; PVC…

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  Figure 5. Clinical Tachycardia and Electrograms of Case 5 (A) 12-lead ECG in sinus rhythm and tachycardia showing positive P waves in leads II and III with negative P in V1 (red arrows), consistent with an inferior-posterior axis and suggestive of a high supero-paraseptal origin. (B) Ventriculoatrial (VA) conduction demonstrated identical atrial activation with S1 and S2 and VA conduction prolongation during S2, confirming decremental properties of the retrograde pathway. (C) Sinus rate increase with longer PR (blue arrow) initiated tachycardia without AH jump. (D) A His-refractory PVC advanced the atrial signal and reset tachycardia, confirming the accessory pathway as the retrograde limb of the re-entry circuit. VA conduction during tachycardia was shorter than Stim-A during S2 from the RV, further supporting decremental properties of the retrograde pathway. (E) Early S2 from the RA resulted in RA dissociation without changes in CS and RV electrograms, ruling out atrioventricular re-entrant tachycardia or permanent junctional reciprocating tachycardia. CS = coronary sinus; ECG = electrocardiogram; RA = right atrium; RV = right ventricle.

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  Figure 6. Mapping Electrograms and Successful Ablation Site of Case 5 (A and B) During right ventricular pacing, signals from the distal ablation catheter at the right and left infero-paraseptal area were not earlier than His activation; also, a far-field His signal was noted at the right supero-paraseptal area. (C) Retrograde mapping from the noncoronary aortic sinus revealed a small fragmented early potential, earlier and without far-field His signal. Ablation at this site produced ventriculoatrial dissociation and rendered the tachycardia noninducible. CS = coronary sinus; RA = right atrium; RV = right ventricle.