LAUSR

Owing to the combination of highly accurate ultrasound-guided imaging and high-resolution mapping, the Acutus noncontact mapping system (Acutus Medical, Carlsbad, CA) can be particularly beneficial for detailed characterization of atrial tachyarrhythmias and choice of tailored ablation strategies. Introduction Identification of atrial tachycardia mechanisms on the basis of 12-lead electrocardiogram can be misleading, particularly in patients with previous atrial ablation or congenital cardiac anomalies. Even in cases of electrocardiogram appearance of typical cavotricuspid isthmus (CTI)–dependent atrial flutter, it is important to keep an openmind about other possiblemechanisms. The AcQMap combined imaging and electrophysiological mapping system (Acutus Medical, Carlsbad, CA) is an emerging noncontact charge density mapping system. Its dedicated AcQMap mapping catheter (Acutus Medical) has a deployable spheroid shape formed by 6 splines, each one containing 8 electrodes and 8 ultrasound transducers. The Acutus system reconstructs 3-dimensional endocardial anatomy from reflection points marked by the ultrasound transducers and inversely derives charge density data from unipolar cavitary electrograms recorded by the noncontact electrodes. A key concept in biophysics, namely the relationship between voltage and charge, is then exploited to facilitate the visualization of high-resolution maps of arrhythmia propagation.