Cardiac imaging to assist complex ablation procedures

Abstract

The introduction of three-dimensional (3D) electroanatomical mapping into the clinical electrophysiology realm has led to the ability to properly diagnose and treat a wide variety of complex arrhythmias such as ventricular tachycardia and atrial fibrillation. 3D mapping allows for reconstruction of heart models providing detailed anatomical information linked to voltage and activation data from local electrograms to help define regions of abnormal tissue, representing arrhythmic substrates which are amenable to ablation therapy. Unfortunately, the accuracy of these reconstructed images can be affected by intravascular volume changes, respiratory motion, patient movement, and electrical interference from surrounding equipment which can lead to inaccurate representation of the true cardiac anatomy and misguide adequate therapy. The use of linear image acquisition techniques such as computed tomography (CT), magnetic resonance imaging (MRI), and positron-emission tomography (PET) provides high-resolution cardiac image datasets which can be integrated with the 3D maps in a process called image integration or image fusion. Thus, the combination of pre-procedural linear imaging technology with intra-procedural imaging techniques such as 3D electroanatomical mapping and intracardiac ultrasound (ICE) allows real-time, accurate high-resolution anatomical reconstruction of cardiac structures. This chapter describes the process of image integration between pre-procedural imaging incorporated into 3D maps and intracardiac ultrasound and its clinical applicability to a wide variety of atrial and ventricular arrhythmias to safely and effectively guide complex ablation procedures.