Robotics in EP
Robotics in EP Section Editors
Case report: Mapping and Ablation of patient with PVC’s using Robotic Navigation and Pre-operative Imaging
J. Peter Weiss MD, MSc - Banner University of Arizona Medical Center, Phoenix
Introduction
With improvement in mapping, pre-procedural imaging, and catheter navigation premature ventricular contractions (PVC’s) can increasingly be successfully treated using catheter ablation. In this case, we coupled robotic catheter navigation through Stereotaxis and pre-procedural imaging with ADAS 3D with standard electro-anatomic (EA) mapping to plan and complete a successful ablation in a patient with frequent symptomatic PVC’s and suspected mid-myocardial substrate.
Case Report
Figure 1. ADAS 3D reconstructive imaging, paired with EA intracardiac map
A 42 year-old patient was referred with a history of nonischemic cardiomyopathy and frequent symptomatic PVC’s. With suspicion of mid-myocardial fibrosis, we also scheduled the patient for an MRI, which was later segmented and analyzed using ADAS 3D. The results showed delayed enhancement in the inferior to mid basal septum (Figure 1). The anatomic reconstruction of the patient’s LV anatomy was uploaded into the Stereotaxis system.
The patient presented with frequent PVC’s in the lab, consistent with those observed in clinic. By visual 12-lead analysis, the site of origin for the clinical PVC was determined to be the infero-basal septum ‘LV crux’ (Figure 2).
Figure 2. 12-lead of the clinical PVC
This location was consistent with the mid-myocardial substrate identified on MRI and analyzed with ADAS 3D.
A transeptal approach was chosen to access the target site, using a Mullens sheath. Mapping was conducted with the Navistar RMT Thermocool catheter, using Carto 3v6. Robotic magnetic navigation was chosen due to its ability to precisely map ventricular arrythmias and provide safe and effective ablation. Additionally, the stability of the RMT catheter was thought to provide additional safety as we could be mapping close to the patient’s conduction system.
Figure 3. EA mapping of clinical PVC and endocardial voltage map
EA mapping of the clinical PVC showed a target area in the low basal septum, with timing -28ms and favorable unipolar recordings although endocardial voltage mapping was normal (Figure 3). Application of RF terminated the patient’s PVC’s, which did not recur during a waiting period of 30 minutes and upon follow-up in clinic.
Discussion
This case report highlights the utility of combining advanced pre-procedural imaging with in-procedure robotic navigation. The presence of mid-myocardial delayed enhancement on MRI correlated well with the clinical PVC and was helpful in planning the procedure as well as targeting the origin of the arrhythmia when endocardial voltage mapping was normal and thus unhelpful. The characteristics of magnetic navigation including reach, precision, and continuous focal contact then allowed a safe and effective procedure targeting an arrhythmia arising from a traditionally difficult anatomical region.
