Intracardiac echocardiographic anatomy for the interventional electrophysiologist

The Utility of Intracardiac Echocardiography Following Melody™ Transcatheter Pulmonary Valve Implantation

The aim of this study was to determine the utility of intracardiac echocardiography (ICE) in assessing Melody™ transcatheter pulmonary valve (TPV) function immediately following valve implantation. ICE is used increasingly in percutaneous cardiac interventions. At our center, ICE is routinely utilized to evaluate valve function following Melody TPV implantation, but the utility of this practice remains unclear. A retrospective review of all Melody valves placed in the right ventricular outflow tract from April 2010 to September 2013 was performed. The clinical utility of ICE was described, along with the relationship between ICE data and traditional hemodynamic/angiographic data. ICE was performed in 54 cases and provided excellent Melody TPV visualization with no complications. ICE did not change clinical management but did provide supplemental information in two cases. In one case, angiography showed severe catheter-related Melody insufficiency. Subsequent ICE confirmed no insufficiency and prevented the need for additional angiography. In the second case, ICE allowed characterization of the mechanism of a residual gradient. ICE did not detect any clinically significant paravalvar leaks or valvar insufficiency not seen by angiography. The peak catheterization gradient was more closely approximated by the mean ICE gradient (median difference -7.4 % between measurements) than by the peak ICE gradient (median difference 58.3 %; p < 0.0001). ICE provides excellent and safe visualization following Melody TPV implantation but did not provide new clinical information impacting management in this series. Selective use of ICE in cases with more than expected valve insufficiency or larger than expected residual gradients may streamline use while maintaining optimal clinical outcomes.

Intracardiac echocardiography: clinical utility and application

Intracardiac echocardiography (ICE) broadens the spectrum of available echocardiographic techniques and provides the operator direct visualization of cardiac structures in real time. ICE has clear advantages over fluoroscopy, transthoracic echocardiography, and transesophageal echocardiography as the imaging modality of choice in the cardiac catheterization and electrophysiological laboratories. With the development of steerable phased array catheters with low frequency and Doppler qualities, there is marked improvement in visualization of left-sided structures from the right heart. Appropriate utilization of ICE is likely to maximize safety and efficacy of complex interventional procedures and may improve patient outcomes. Future advances in ICE imaging will further improve the ease of device guidance and, in combination with new imaging modalities, could dramatically improve other applications of echocardiography which may result in improved patient outcomes. This review describes the technical evolution of ICE, the use of ICE in guiding percutaneous interventional procedures and possible future applications of ICE in the ever-growing field of interventional cardiology.

Echocardiographic detection of cardiac ectopy: a possible alternative to electrophysiological mapping?

PURPOSE

Three-dimensional (3-D) visualization of ventricular activation sequence is imperative for the diagnosis and treatment of malignant cardiac arrhythmias. Modern mapping systems that serve as the gold standard for detection and localization of the focus are costly and require an invasive approach into the cavity of the ventricles. The aim of our study was the development of a noninvasive and 3-D mapping system based upon echocardiography.

METHODS

In a porcine model, animals underwent ablation of the atrioventricular node (AV-node). 3-D electrophysiological cardiac mapping was performed using the ENSITE™ electro-anatomical system (St. Jude Medical, Minneapolis, MN, USA). Simultaneously, transesophageal echocardiography (TEE) including pulse wave (Pw) tissue Doppler was performed, and time to peak early diastolic velocity (PEDV) was measured. Both ENSITE-mapping and tissue Pw-Doppler were compared as to their ability to pinpoint the origin of ventricular ectopic focus.

RESULTS

PEDV corresponded well with the results as determined by noncontact mapping with ENSITE.

CONCLUSIONS

Tissue Doppler is a reliable method to deliver information about the topography of first onset of myocardial excitation. Further development of this method with a higher regional resolution and integration of color Doppler as well as 3-D echocardiography may eventually lead to the development of a completely noninvasive and echo-based electromechanical mapping system.

Intracardiac echocardiography in patients with pacing and defibrillating leads: a feasibility study

BACKGROUND

Lead extraction, an important and necessary component of treatment for many common device and lead-related complications, is a procedure that can provoke much anxiety in even the most experienced operators given the potentially serious complications. The principal impediment to lead extraction is the body's response to an intravascular foreign body with matrix intravascular neoformation, which causes the lead to adhere to the endocardium or vascular structure, increasing the risk of vascular or myocardial damage with lead removal. Fluoroscopic visualization, the commonly visualization used tool, has several limits in terms of anatomical structures visualization. The aim of this study was to assess the safety and feasibility of intracardiac echocardiography (ICE) in patients undergoing pacing and defibrillating leads before and during a transvenous device removal, and its potential role in detecting intracardiac leads and areas of fibrous adherence.

METHODS

ICE interrogation was performed in 25 consecutive patients with pacing and defibrillating implantable cardioverter defibrillators (ICD) leads before and during device removal.

RESULTS

A programmed ICE analysis was completed in 23 out of 25 patients with excellent resolution, providing a "qualitative-quantitative" information on anatomical structures, cardiac leads, and related areas of fibrous adherence. No ICE-related complications occurred.

CONCLUSIONS

ICE evaluation is safe and feasible in patients with pacing and defibrillating leads before and during transvenous lead removal, offering an excellent visualization of cardiac leads and related areas of adherence. ICE can assist pacing and ICD lead removal and could improve procedure efficacy and safety.