The Flexibility of Delayed Fluoroscopic Left Ventricular Angiography in Peri-procedural Real-time Visualization of the Lead Tip in Left Bundle Branch Pacing

Figures

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  Figure 1. Overview of the study design. ECG = electrocardiography; EGM = electrogram; LBB = left bundle branch; LBBP = left bundle branch pacing; LVSP = left ventricular septal pacing.

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  Figure 2. Illustration of the lead tip–to–LV/RV septal border distance in LBBP cases. Panels A–D show an 87-year-old female with 2:1 AV block undergoing LBBP. A: Early contrast phase in the RV showed approximately one-third of the insertion of the anode into the septum. B: Late contrast phase showed the lead tip near the LV septal border. C: Final ECG. D: Fascicular potential and V6 LVAT of 64 ms. Lead tip–to–LV septal border distances were 1.1 mm (end-diastole) and 0.9 mm (end-systole); lead tip–to–RV border distances were 14.0 mm and 14.1 mm, respectively. Panels E–H show a 90-year-old female with complete AV block undergoing LBBP. Both fascicular potential and LBBP ECG capture criteria are evident, with a V6 LVAT of 74 ms from pacing stimulus and 28 ms from QRS onset; QRS duration was 96 ms, closely matching the native beat, fulfilling physiological criteria. The lead insertion depth was 13.5 mm, with a 0.9 mm tip-to-LV septal border distance at end-diastole. AV = atrioventricular; BPM = beats/min; COI = current of injury; ECG = electrocardiography; EGM = electrogram; LBB = left bundle branch; LBBP = left bundle branch pacing; LV = left ventricle; LVAT = left ventricular activation…

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  Figure 3. The illustrative cases of LV angiography and local EGMs in patients of LBBP and LVSP. A–D: A 54-year-old woman with advanced AV block undergoing LBBP. ECG showed an M-beat in lead V1; EGM revealed a fascicular potential (arrow), confirming left bundle branch capture. Inserted lead length = 14.2 mm; tip-to-LV septal border = 0.8 mm (end-diastole). E–H: A 76-year-old woman with complete AV block received LVSP. No fascicular potential or morphology transition on EGM. V1 showed right bundle branch delay; V6 had a small R wave; LVAT = 40 ms. Lead tip–to–RV and tip–to–LV septal border distances were 13.7 mm and 2.9 mm, respectively. AV = atrioventricular; BPM = beats/min; COI = current of injury; ECG = electrocardiography; EGM = electrogram; LBBP = left bundle branch pacing; LV = left ventricle; LVAT = left ventricular activation time; LVSP = left ventricular septal pacing; RV = right ventricle.

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  Figure 4. Angiography-guided lead advancement to achieve LBB capture. Panels A–D illustrate the case of a 79-year-old female with sick sinus syndrome and impaired AV nodal function undergoing angiography-guided LBBP. A: Initial delayed LV angiography showed a tip–to–LV septal border distance of 3.8 mm. C: The corresponding EGM, revealing a tiny fascicular potential, V6 LVAT of 88 ms. B: After angiography-guided advancement, tip-to-LV distance decreased to 0.5 mm, with a clearer fascicular potential and shortened V6 LVAT (74 ms) at low-output pacing (D). Panels E–H show a 74-year-old man with complete AV block undergoing angiography-guided LBBP. After a sequence similar to panels A to D, panels E and F showed tip-to-LV distance decreased from 1.5 to 0.5 mm after further advancement, accompanied by a more prominent fascicular potential and >10 ms shortening of V6 LVAT (G and H). AV = atrioventricular; BPM = beats/min; COI = current of injury; EGM = electrogram; LBB = left bundle branch; LBBP = left bundle branch pacing; LV = left ventricle; LVAT = left ventricular activation time.

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  Figure 5. AUROC analysis of lead tip–to–LV/RV septal border distances for confirming LBB capture. Receiver operating characteristic analysis showed that the AUROC for the lead tip–to–LV septal border distance in predicting confirmed LBB capture was 0.924. The AUROC for the lead tip–to–RV septal border distance was 0.287. AUROC = area under the receiver operating characteristic curve; LBB = left bundle branch; LV = left ventricle; RV = right ventricle.