Background

Although three dimensional (3D) electroanatomic mapping systems allow detailed assessment of anatomy and substrates, ablation still carries substantial risk when close proximity to coronary arteries is suspected. 3D integration of coronary anatomy in mapping systems is still cumbersome, highlighting the need for an option of ad hoc acquirement of coronary artery anatomy. The goal of this case series was to evaluate the feasibility of a wire-based approach to the live visualization of coronary arteries and to assess its diagnostic information regarding procedure guiding.

Methods

For this single center case series, we included procedures in which a close proximity of a possible ablation site to any given epicardial vessel had to be suspected. In these cases, an uninsulated-tip wire (VisionWire, Biotonik) was introduced into the coronary arteries via diagnostic catheters after exclusion of critical stenosis. The wire was then connected to the 3D mapping system (Ensite Precision, Abbott) using a clamp and pin connection. Integrating this setup in the mapping system allows for live visualization of the wire tip, as well as the assessment of the local electrograms within the respective vessel.

Results

We included a total of 9 procedures in this case series, consisting of 4 ventricular tachycardia (VT) ablation procedures and 5 procedures for the ablation of premature ventricular contractions (PVCs). The left coronary arteries were mapped in 8 cases, the right coronary artery in one case. Mostly, the arrhythmogenic substrate was located in the left ventricle (LV, 5/9) or LV summit area and the distal coronary sinus respectively (3/9). In two cases, epicardial mapping was performed combined with visualization of the right or left coronary arteries, respectively. There were no complications attributed to coronary wiring and mapping in this case series.  

In two cases, the diagnostic information from mapping of the coronary arteries could be used to rule out an epicardial origin of arrhythmia. In further cases, the information obtained allowed for a tailored ablation approach, such as insertion of 2 coated coronary wires to protect epicardial vessels during close ablation or choosing an ablation site >5 mm from an epicardial vessel (figure 1). In the majority of cases, coronary visualization was used to ascertain a proper distance between ablation site and vessel.  

Discussion

In this case series, we could demonstrate the feasibility and safety of coronary artery visualization and its integration in a 3D mapping system. The data obtained was used for diagnostic, as well as safety aspects. The electrograms from the VisionWire were used to quickly assess relative timing of arrhythmias, thus allowing for an estimation of possible epicardial origin. The visualization of the coronary arteries added valuable information, without the need for preprocedural planning or the purchase of separate software. 

Conclusion:

Applying the same caveats as for any wiring of coronary arteries, their electroanatomic visualization is achieved in a safe and straightforward manner, with minimal technical requirements. Mapping of the coronary arteries adds critical diagnostic information and their real-time visualization is feasible without exceeding costs or risks.

Figure 1: Local activation time map with PVC focus in the distal coronary sinus (CS). Note the close relationship to the bifurcation of left anterior descending (LAD) and circumflex artery (CX).