Left bundle area pacing: Guiding implant depth by ring measurements.

BACKGROUND: Criteria for successful left bundle area pacing (LBAP) are in flux and currently guided by lead tip measurements. Lead ring measurements during LBAP have not been well studied. OBJECTIVE: The purpose of this study was to investigate dynamics in pacing parameters during successful and unsuccessful lead implant attempts. METHODS: SelectSecure 3830 pacing leads (Medtronic, Inc) guided by C315 sheaths for LBAP were placed for standard pacing indications in 73 patients. Retrospective review of procedural, echocardiographic, and standard pacing data were performed. Depth and lead-septal angle of implanted electrodes were determined from fluoroscopy with septal contrast delineation. Depth was graded in 4 categories according to the degree of ring penetration into the septum. Successful implant was defined by the ability to advance the lead deep into the septum and achieve LBAP criteria (ventricular activation time, QRS width/shape). RESULTS: Ring impedance increased stepwise during successful attempts as opposed to unsuccessful attempts (P = .039). A wider lead-septal angle at implant position correlated with higher ring impedance (P = .036), whereas no association was found with tip impedance. Unipolar ring threshold correlated with depth of lead implant (P = .029). Tip impedance measurements at implant position were less predictive of lead depth and did not correlate with septal thickness. CONCLUSION: Ring pacing parameters are more predictive of lead progress than tip measurements. Lead depth and lead-septal angle can be determined from ring impedance measurements. These measurements may provide determination of lead depth and could obviate the need for contrast injection.

First experience of 3D rotational angiography fusion with NavX electroanatomical mapping to guide catheter ablation of atrial fibrillation.

BACKGROUND: Rotational angiography of the left atrium with 3-dimensional reconstruction (3DATG) is a new imaging tool to guide atrial fibrillation (AF) ablation. Its role as part of a complex imaging strategy with NavX has not yet been evaluated. OBJECTIVE: To determine the feasibility of using 3DATG fusion with NavX in guiding AF ablation. METHODS: 3DATG was performed in 24 consecutive patients undergoing AF ablation by using the Philips Allura Xper FD 10 system. The 3DATG anatomical shell was fused with NavX data (fusion group). Procedural characteristics of the fusion group were compared to 12 patients (control group) who underwent AF ablation guided by NavX only during the preceding 6 months. RESULTS: 3DATG/NavX fusion was successful in all patients and required 12 ± 2 fiducial points. Total radiation dose, fluoroscopy, and procedural times were significantly lower in the fusion group despite additional time and radiation exposure from 3DATG (total radiation dose of 20.4 mSv in the fusion group vs 34.0 mSv in the control group; P = .04; fluoroscopy time 50.5 minutes vs 69.7 minutes; procedural time 4.3 hours vs 5.1 hours). Ablation was successful acutely in 35 of 36 patients. At follow-up, 14 of 24 (58.3%) patients in the fusion group and 6 of 12 (50%) patients in the control group were in sinus rhythm. There was 1 complication in each group. CONCLUSIONS: AF ablation guided by 3DATG/NavX fusion is associated with reduced procedural time and radiation exposure and similar clinical outcomes when compared with NavX mapping only. 3DATG/NavX fusion may provide a lower radiation alternative to NavX only or preprocedural cardiac computed tomography as part of complex imaging strategies.

First experience with rotational angiography of the right ventricle to guide ventricular tachycardia ablation.

BACKGROUND: Rotational angiography with three-dimensional reconstruction (3DRA) is a new imaging tool recently introduced to guide mapping and ablation of the left atrium. OBJECTIVE: The purpose of this study was to determine the utility of 3DRA for imaging the ventricles and guiding ventricular tachycardia (VT) ablation. METHODS: Using the Philips Allura Xper FD10 system, 3DRA was performed in eight patients referred for right ventricular outflow tract (RVOT) VT ablation. The imaging protocol for right ventricular (RV) injection is described. IV contrast was injected at the RA/IVC junction over 4 sec and 3DRA was obtained immediately. Images were segmented manually on the EP Navigator workstation and registered on live fluoroscopy. Intracardiac electrograms were superimposed on 3DRA creating a true electroanatomic map (ElectroNav). CARTO mapping and echocardiograms were performed on all patients, cardiac computed tomography (CT) in 4, and magnetic resonance imaging (MRI) in 1. RESULTS: Three-dimensional rotational angiography was successful in 7 of 8 patients. Image interpretation was unsuccessful in one patient due to poor isocentering. RV imaging was performed with 82 ± 18 mL of contrast. RV image segmentation required 19 ± 5 minutes. CARTO maps of the RVOT required 43 ± 12 minutes and additional fluoroscopy. Three-dimensional rotational angiography was used to guide VT ablation by providing realistic anatomic images of the pulmonary valve plane, endo-views of the ventricle, and ablation point tagging. Anatomic detail provided by 3DRA was qualitatively superior to CARTO. VT ablation was acutely successful in all patients. Close concordance between echocardiographic, CT/MRI, and 3DRA measurements of the RVOT was observed (r = 0.9, P <.01). CONCLUSION: Three-dimensional rotational angiography of the RV and RVOT is a feasible imaging technique that utilizes a protocol of timed angiography, manual segmentation, image registration, and superimposition of intracardiac electrograms to create an angiogram-based electroanatomic model of these structures.