TEE vs. CT in the Evaluation of the Left Atrium
In conversation with Ryan Daly, MD, FACC; Bruno Lima, MD, PhD, FACC; & Parin Patel, MD, FACC
Quick recap
Dr. Bruno Lima discussed the advantages and limitations of cardiac CT and transesophageal echocardiogram in evaluating the left atrial appendage, highlighting CT’s non-invasive nature and TEE’s superior accuracy for detecting thrombi. He explored the use of cardiac imaging techniques in cardiology, including their applications for pulmonary vein mapping and ablation procedures, while emphasizing the importance of coordination between radiology and cardiology departments. The discussion concluded with insights on the growing use of cardiac CT scans across medical centers, including its efficiency, safety, and reimbursement, as well as the need to update older cardiologists on evolving technologies.
Dr. Bruno Lima, an associate professor of radiology at Vanderbilt University, discussed the advantages and limitations of cardiac CT and transesophageal echocardiogram (TEE) in evaluating the left atrial appendage. He highlighted that while CT offers the advantage of not requiring sedation and being a simple test to perform, it is inferior to TEE in terms of accuracy for detecting thrombi, as shown in meta-analyses and systematic reviews. However, when performed correctly, CT can be a safe alternative to TEE for ruling out thrombi before cardioversion.
Cardiac CT for LAA Measurement
Bruno discussed the advantages of cardiac CT over TEE for measuring left atrial appendage size, highlighting its non-invasive nature, higher 3D spatial resolution, and ability to provide precise measurements in various planes. He emphasized the importance of delay imaging, between 30 to 60 seconds, to differentiate between pseudo-filling defects and actual clots, especially in patients with atrial fibrillation.
Cardiac Imaging for Cardioversion Protocols
Bruno discussed the use of cardiac imaging techniques in cardiology, noting that cardiac CT and MRI are commonly used for pulmonary vein mapping before ablation, while transesophageal echocardiogram is more prevalent for outpatient cardioversion at Vanderbilt. He highlighted logistical challenges with obtaining same-day imaging and cardioversion, particularly for outpatients, and emphasized the importance of a strong relationship between cardiology and radiology departments to streamline protocols. When asked about the validity period of a cardiac CTA before cardioversion, Bruno did not specify a duration but mentioned that it depends on various factors, including anticoagulation status.
Cardiac CT for Clot Detection
The discussion focused on the use of cardiac CT for clot detection before cardioversion, where Bruno and Parin agreed that if patients are adequately anticoagulated, CCTA can be used similarly to no imaging at all, though they noted limited data on this specific application. Bruno explained that CCTA is a quick and straightforward test, requiring only 20 minutes total (5 minutes for acquisition and 10-15 minutes for reporting), making it more efficient than a transesophageal echocardiogram. Parin inquired about the growing use of CCTA across different medical centers, to which Bruno responded that its usage depends on the specific practice, noting that academic centers like Vanderbilt use it extensively.
Cardiac CT Trends
Bruno discussed the growing use of cardiac CT scans in Tennessee, particularly for coronary CTAs and pulmonary vein mapping, highlighting the need for coordination between radiology and cardiology services. He noted that while patient-specific challenges such as contrast exposure exist, the procedure is generally safe and well-reimbursed by insurance companies, including Medicare and Medicaid. Bruno also emphasized the importance of updating who trained some time ago on evolving technologies and mentioned his role as co-chair of the Advanced Imaging Section on ACC.org, where resources are provided to help cardiologists stay informed about new imaging technologies.
