Many cardiac arrhythmias are caused by conduction defects that interfere with the propagation of normal electrical signals within the heart. The method adopted to treat arrhythmia is dependent on the nature and position of the underling conduction defect. Thus, electrophysiological mapping plays an important role in measuring the electrical activity of the heart. These techniques often require specialized equipment to locate the position of catheters in physical space and reconstructing the shape of the chamber from multiple site recordings. It would be desirable to provide 3D mapping without such equipment.
State of the Art 3D mapping systems use magnetic fields, electrical fields or ultrasound to localize catheters. The main disadvantage of these systems is the prohibitive cost involved with the equipment and the need for both a conventional EP recording system and a separate 3D mapping/localization system. While manual positioning is not as accurate as current technologies, it is significantly more cost effective than conventional EP mapping systems and can be performed more rapidly.
It remains necessary to locate a target (active) site if an arrhythmia is to be terminated. A number of catheter locating systems are known in the art, but each introduces components and complexity to EP procedures. EP operators, however, are usually quite capable of piloting an EP catheter to a desired site within a patient's vasculature, particularly with fluoroscopic assistance. A difficulty remains, even if the location of the catheter is estimated based on fluorscopic guidance, in matching indwelling EP electrodes to sites on a cardiac model. This problem is all the more difficult when the model is rendered in 3D.
In part, the operator has data captured by a variety of systems. For example, electrogram channels monitor signals from indwelling electrodes, such as intracardiac electrodes and reference electrodes, and that information has to be coordinated with an anatomical (e.g., cardiac) model. Fluoroscopic images of the anatomy generally have no connection to other systems in the EP lab, and so piloting a catheter that lacks a locating system is done as a parallel, distinct part of the EP procedure. Cardiac mapping, therefore, has required great effort at a time when the operator's attention needs to focus on the patient or in labs where cost is an impediment and a highly trained technician is not available to operate a complex 3D mapping system.
The present invention addresses one or more of these problems.