Discussion:
Anomalous coronary arteries with a malignant course are associated with an increased risk of arrhythmias and sudden cardiac death,4-6 though ventricular arrhythmias have not been previously localized to the site of an anomalous coronary artery. This is the first report associating a PVC to the site of an anomalous, interarterial, intramural coronary artery.
PVC localization and surgical cryoablation were guided by the use of a novel ECG mapping system. ECG data are imported into the computational mapping system that then localizes and integrates the highest probabilistic location for the PVC focus onto the patient’s CT 3D reconstruction model. This algorithm is based on forward-solution computational simulation libraries of arrhythmias including PVCs originating from sites around the heart with or without scar. The simulation libraries are based on 3D finite element models of monodomain cardiac action potential propagation using the Continuity simulation environment. The models consist of detailed descriptions of cardiac geometry, myofiber orientation, and scar. The simulation library incorporates >1 million simulated arrhythmia cycles.
There are many advantages to this technique. This method is less time consuming than traditional invasive catheter-based mapping and is easy to incorporate into any clinical workflow, including mapping in an outpatient clinic using standard widely-available ECG equipment. It has been shown to be a rapid and accurate technique, with a recent blinded multicenter clinical trial showing segmental accuracy of 100% [96-100%] and spatial accuracy of 11mm [5-22mm] for PVC localization.8
The use of a non-invasive 12-lead ECG based mapping system to successfully guide surgical ablation of ventricular arrhythmias is a novel approach that can expand the indications for concomitant arrhythmia ablation during cardiac surgery for other indications. The familiarity of the 12-lead ECG to all physicians including cardiac surgeons is attractive as it can be easily integrated into any clinical pre-procedural workflow.