Intra-cardiac echocardiography guided cardioversion to help interventional procedures (ICE-CHIP) study: study design and methods

A standardized protocol to reliably visualize the left atrial appendage with intracardiac echocardiography: Importance of multiple imaging sites

BACKGROUND

Currently, there is no accepted protocol for left atrial appendage (LAA) imaging with intracardiac echocardiography (ICE).

OBJECTIVE

This study aimed to assess the utility of ICE to reliably visualize the entire cavity of the LAA and propose a specific procedural protocol to achieve the above objective.

METHODS

We created a three-dimensional reconstruction of the LAA, using two-dimensional ICE sections obtained from three different location (the right atrium [RA], right ventricle inflow [RVI], and right ventricular outflow [RVOT]). We then compared the three-dimensional LAA reconstruction by ICE with one obtained by cardiac computed tomography angiography (CCTA) for morphological and volume differences.

RESULTS

Three-dimensional reconstruction with ICE could reliably reproduce the LAA as visualized with CCTA but only when ICE sampling was performed from at least two catheter positions. There was no statistically significant difference between LAA volumes obtained with ICE and CCTA (P = 0.33). The contribution of each anatomical location to the total volume was 17% ± 16.6%, 74% ± 13.3%, and 33% ± 26% for RA, RVI, and RVOT, respectively.

CONCLUSION

In comparison with CCTA, the LAA can be reliably visualized in its entity by ICE, but only if multiple imaging positions (RA, RV inflow, and RVOT) are used.

Intracardiac Echocardiography for Structural Heart and Electrophysiological Interventions

PURPOSE OF REVIEW

With an increasing number of interventional procedures performed for structural heart disease and cardiac arrhythmias each year, echocardiographic guidance is necessary for safe and efficient results. The purpose of this review article is to overview the principles of intracardiac echocardiography (ICE) and describes the peri-interventional role of ICE in a variety of structural heart disease and electrophysiological interventions.

RECENT FINDINGS

Both transthoracic (TTE) and transesophageal echocardiography have limitations. ICE provides the advantage of imaging from within the heart, providing shorter image distances and higher resolution. ICE may be performed without sedation and avoids esophageal intubation as with transesophageal echocardiography (TEE). Limitations of ICE include the need for additional venous access with possibility of vascular complications, potentially higher costs, and a learning curve for new operators. Data supports the use of ICE in guiding device closure of interatrial shunts, transseptal puncture, and electrophysiologic procedures. This paper reviews the more recent reports that ICE may be used for primary guidance or as a supplement to TEE in patients undergoing left atrial appendage (LAA) closure, interatrial shunt closure, transaortic valve implantation (TAVI), percutaneous mitral valve repair (PMVR), paravalvular leak (PVL) closure, aortic interventions, transcatheter pulmonary valve replacement (tPVR), ventricular septal defect (VSD), and patent ductus arteriosus (PDA) closure. ICE imaging technology will continue to expand and help improve structural heart and electrophysiology interventions.

A Prospective Comparison of Cardiac Imaging Using Intracardiac Echocardiography With Transesophageal Echocardiography in Patients With Atrial Fibrillation

Background—

The Intracardiac Echocardiography Guided Cardioversion Helps Interventional Procedures study evaluated the concordance of intracardiac echocardiography (ICE) with transesophageal echocardiography (TEE) in patients with atrial fibrillation (AF).

Methods and Results—

Patients with AF undergoing right heart catheterization underwent left atrium (LA) and interatrial septal (IAS) imaging by TEE and ICE. A blinded comparison of the 2 modalities was performed at a core laboratory. Ninety-five patients aged 58±12 years completed the study. The LA was profiled in all patients with both techniques, and concordance for image quality was 96%. LA appendage (LAA) imaging was achieved in 85% with ICE and 96% with TEE. There was no difference in the presence of spontaneous echo contrast between ICE and TEE during LA imaging, but there was a trend toward a greater incidence in the LAA with TEE ( P =0.109). Intracardiac thrombus was uncommonly seen (TEE, 6.9%; ICE, 5.2%). The concordance for the presence or absence of thrombus was 97% in the LA and 92% in the LAA, but the latter was detected more frequently with TEE. IAS imaging was achieved in 91% with ICE and in 97% with TEE ( P =0.177). Concordance for patent foramen ovale and atrial septal aneurysms was 100% and 96%, respectively. A negative ICE examination was associated with absence of dense echo contrast or thrombus on TEE in 86%.

Conclusions—

This study provides validation for the use of ICE for LA and IAS imaging. ICE imaging was less sensitive compared to TEE for LAA thrombus identification.

Clinical Trial Registration—

URL: http://www.clinicaltrials.gov . Unique identifier: NCT00281073.

Imaging studies in patients with heart failure: current and evolving technologies

Technological advances continue to expand the clinical role of echocardiography in the intensive care unit, particularly in patients with heart failure. It has many advantages over tomographic techniques such as echo cardiac magnetic resonance imaging and cardiac computed tomography, can provide rapid bedside cardiac assessment, and facilitate emergent decision-making for critically ill patients. Image quality problems in the intensive care setting have largely been overcome by the use of harmonic imaging, contrast opacification, and when indicated, transesophageal echocardiography. Newer techniques promise to advance the scope and prognostic power of echocardiography, and to expand the portability and availability of this tool.