�鶹��վ

Method for creating accurate activation timing maps to diagnose/localize cardiac arrythmia without using a time alignment reference catheter

Background

More than 14 million Americans are currently living with cardiac rhythm disorders. One of the most performed procedures in managing dysrhythmias is catheter ablation of atrial fibrillation (AF). A key step in catheter ablation for various types of complex arrhythmias to pinpoint areas for ablation by cardiac mapping. A key unmet clinical need are novel methods to enable more effective ablation targeting. Sequential mapping is the most commonly used technique by physicians. It analyzes intracardiac electrograms (IEGMs) from catheters sequentially placed in the cardiac chamber, and time alignment references (TAR) to develop isochrone and conduction velocity (CV) maps. A reference IEGM is required as a time reference to align the “temporal phase” of collected IEGMs using a coronary sinus (CS) catheter. CV can be estimated by analyzing IEGMs, and velocity vector (VV) is estimated using the location of the catheter’s electrodes. Time alignment of sequential recordings is typically performed when regular rhythm is present. However, time alignment using IEGMs is not possible during complex arrhythmias like AF. During AF multiple wavefronts excite different parts of the atria and may not hit the CS catheter. Consequently, sequential mapping fails in VV estimation. Therefore, currently available software cannot create a propagation map during complex arrhythmias. 

Technology Overview

Queen’s researchers have developed method for generating a propagation map and a conduction velocity map for complex cardiac arrhythmia. With this technique IEGMs are collected using sequential mapping catheters and a predictive algorithm is used to estimate cardiac propagation without using an independent TAR. In this study the activation time is a weighted summation of several nonlinear nonorthogonal candidate functions (CF) which have been selected from a bank of CFs. Activation time function (ATF) is generated using CFs and the ATF is used to generate propagation and velocity maps of cardiac arrhythmias.