Estimation of the Cardiac Field in the Esophagus Using a Multipolar Esophageal Catheter

Abstract

The rapid progress of invasive therapeutic options for cardiac arrhythmias increases the need for accurate diagnostics. The surface electrocardiogram (ECG) is still the standard of noninvasive diagnostics but lacks atrial signal resolution. By contrast, esophageal electrocardiography (EECG) yields atrial signals of high amplitude and with a high signal-to-noise ratio. Esophageal electrocardiography has become fast and safe, but the mechanical constraints of esophageal measuring catheters and the "random" motion of the catheter inside the subject's esophagus limit the spatial resolution of EECG signals. In this paper, we propose a method to estimate the electrical field projected onto the esophagus with an increased spatial resolution, using commonly available esophageal catheters. In a first step, we estimate the time-varying catheter position, and in a second step, we estimate the projected electrical field with enhanced spatial resolution. The proposed algorithm comprises several consecutive optimization steps, where each intermediate step produces not just a single point estimate, but a cost function over multiple solutions, which reduces the information loss at each processing step. We conclude with examples from a clinical trial, where the fields of cardiac arrhythmias are presented as two-dimensional contour plots.

Toward a novel semi‐invasive activation mapping tool for the diagnosis of supraventricular arrhythmias from the esophagus

“…To reconstruct the cardiac electric field from the eECGs, a novel algorithm was implemented as detailed in a technical article (Wildhaber et al, 2018). In summary, the algorithm utilizes the constant slight cranio-caudal movement of the esophageal electrodes in relation to the heart (due to breathing, esophageal peristalsis, swallowing, heart movements, aortic pulsations) to calculate the cardiac electric activity projected into the esophagus with a much higher (i.e., subelectrode) resolution.…”