Comparison of Intracardiac Echocardiography and Transesophageal Echocardiography

Transesophageal echocardiography (TEE) is the clinical standard for diagnosis of left atrial appendage (LAA) and right atrial appendage (RAA) thrombi before cardioversion or instrumentation of the left atrium during ablation proce- dures.1-5 Occasionally, TEE cannot be performed because of anatomic limitations requiring an alternative imaging strategy to exclude LAA thrombi. Phased-array intracardiac echocardiography (ICE) is routinely used during atrial fibrillation (AF) ablation procedures to guide transseptal puncture and detect complications. The standard position of the transducer is in the right atrium (RA). This allows adequate visualization of the interatrial septum and body of the left atrium (LA) but not of the LAA because of significant physical distance from the transducer. Imaging of the LAA from closer anatomic structures such as the right ventricular outflow tract (RVOT) and pulmonary artery (PA) can improve visualization of the LAA. If ICE provided imaging of the LAA comparable to TEE with a good safety profile, it could potentially serve as an alternative to TEE in patients undergoing catheter ablation. Such an approach could reduce risk, cost, and patient discomfort associated with TEE combined with ICE. In this prospective blinded study, we sought to directly compare the sensitivity and specificity of TEE with ICE for detection of LAA and RAA anatomy and thrombus in patients with atrial tachyarrhythmias undergoing catheter ablation.