Intracardiac echocardiography: a new guiding tool for transcatheter aortic valve replacement

Comparison of Intracardiac Echocardiography Versus Transesophageal Echocardiography for Guidance During Transcatheter Aortic Valve Replacement

BACKGROUND AND OBJECTIVES

Evidence regarding the efficacy and safety of intracardiac echocardiography (ICE) for guidance during transcatheter aortic valve replacement (TAVR) is limited. This study aimed to compare the clinical efficacy and safety of ICE versus transesophageal echocardiography (TEE) for guiding TAVR.

METHODS

This prospective cohort study included patients who underwent TAVR from August 18, 2015, to June 31, 2021. Eligible patients were stratified by echocardiographic modality (ICE or TEE) and anesthesia mode (monitored anesthesia care [MAC] or general anesthesia [GA]). Primary outcome was the 1-year composite of all-cause mortality, rehospitalization for cardiovascular cause, or stroke, according to the Valve Academic Research Consortium-3 (VARC-3) definition. Propensity score matching was performed, and study outcomes were analyzed for the matched cohorts.

RESULTS

Of the 359 eligible patients, 120 patients were matched for the ICE-MAC and TEE-GA groups, respectively. The incidence of primary outcome was similar between matched groups (18.3% vs. 20.0%; adjusted hazard ratio, 0.94; 95% confidence interval [CI], 0.53-1.68; p=0.843). ICE-MAC and TEE-GA also had similar incidences of moderate-to-severe paravalvular regurgitation (PVR) (4.2% vs. 5.0%; adjusted odds ratio, 0.83; 95% CI, 0.23-2.82; p=0.758), new permanent pacemaker implantation, and VARC-3 types 2-4 bleeding.

CONCLUSIONS

ICE was comparable to TEE for guidance during TAVR for the composite clinical efficacy outcome, with similar incidences of moderate-to-severe PVR, new permanent pacemaker implantation, and major bleeding. These results suggest that ICE could be a safe and effective alternative echocardiographic modality to TEE for guiding TAVR.

Echocardiographic Imaging in Transcatheter Structural Intervention: An AAE Review Paper

Transcatheter structural heart intervention (TSHI) has gained popularity over the past decade as a means of cardiac intervention in patients with prohibitive surgical risks. Following the exponential rise in cases and devices developed over the period, there has been increased focus on developing the role of "structural imagers" amongst cardiologists. This review, as part of a growing initiative to develop the field of interventional echocardiography, aims to highlight the role of echocardiography in myriad TSHIs available within Asia. We first discuss the various echocardiography-based imaging modalities, including 3-dimensional echocardiography, fusion imaging, and intracardiac echocardiography. We then highlight a selected list of structural interventions available in the region-a combination of established interventions alongside novel approaches-describing key anatomic and pathologic characteristics related to the relevant structural heart diseases, before delving into various aspects of echocardiography imaging for each TSHI.

Intracardiac echocardiography Chinese expert consensus

In recent years, percutaneous catheter interventions have continuously evolved, becoming an essential strategy for interventional diagnosis and treatment of many structural heart diseases and arrhythmias. Along with the increasing complexity of cardiac interventions comes ever more complex demands for intraoperative imaging. Intracardiac echocardiography (ICE) is well-suited for these requirements with real-time imaging, real-time monitoring for intraoperative complications, and a well-tolerated procedure. As a result, ICE is increasingly used many types of cardiac interventions. Given the lack of relevant guidelines at home and abroad and to promote and standardize the clinical applications of ICE, the members of this panel extensively evaluated relevant research findings, and they developed this consensus document after discussions and correlation with front-line clinical work experience, aiming to provide guidance for clinicians and to further improve interventional cardiovascular diagnosis and treatment procedures.

Baseline intracardiac echocardiography predicts haemodynamic changes and Doppler velocity patterns during follow-up after percutaneous pulmonary valve implantation

BACKGROUND

Intracardiac echocardiography Doppler-derived gradients have previously been shown to correlate with post-procedure echocardiographic evaluations when compared with invasive gradients measured during percutaneous pulmonary valve implantation, suggesting that intracardiac echocardiography could offer an accurate and predictable starting point to estimate valve function after percutaneous pulmonary valve implantation.

METHODS

We performed a retrospective chart review of 51 patients who underwent percutaneous pulmonary valve implantation between September 2018 and December 2019 in whom intracardiac echocardiography was performed immediately after valve implantation. We evaluated the correlation between intracardiac echocardiography gradients and post-procedural Doppler-derived gradients. Among the parameters assessed, those which demonstrated the strongest correlation were used to create a predictive model of expected echo-derived gradients after percutaneous pulmonary valve implantation. The equation was validated on the same sample data along with a subsequent cohort of 25 consecutive patients collected between January 2020 and July 2020.

RESULTS

All the assessed correlation models between intracardiac echocardiography evaluation and post-procedure transthoracic echocardiographic assessments were statistically significant, presenting moderate to strong correlations. The strongest relationship was found between intracardiac echocardiography mean gradients and post-procedural transthoracic echocardiographic mean gradients. Therefore, an equation was created based on the intracardiac echocardiography-derived mean gradient, to allow prediction of the post-procedural and follow-up transthoracic echocardiographic-derived mean gradients within a range of ±5 mmHg from the observed value in more than 80% of cases.

CONCLUSIONS

There is a strong correlation between intracardiac echocardiography and post-procedure transthoracic echocardiographic. This allowed us to derive a predictive equation that defines the expected transthoracic echocardiographic Doppler-derived gradient following the procedure and at out-patient follow-up after percutaneous pulmonary valve implantation.

Echocardiographic guidance of interventions in adults with congenital heart defects

Cardiac catheterization procedures have revolutionized the treatment of adults with congenital heart disease over the past six decades. Patients who previously would have required open heart surgery for various conditions can now undergo percutaneous cardiac catheter-based procedures to close intracardiac shunts, relieve obstructive valvular lesions, stent stenotic vessels, or even replace and repair dysfunctional valves. As the complexity of percutaneous cardiac catheterization procedures has increased, so has the use of echocardiography for interventional guidance in adults with congenital heart disease. Transthoracic, transesophageal, intracardiac, and three-dimensional echocardiography have all become part and parcel of the catheterization laboratory experience. In this review, we aim to describe the different echocardiographic techniques and their role in various cardiac catheterization interventions specific to adults with congenital heart disease.

Use of Intracardiac Echocardiography in Interventional Cardiology: Working With the Anatomy Rather Than Fighting It

The indications for catheter-based structural and electrophysiological procedures have recently expanded to more complex scenarios, in which an accurate definition of the variable individual cardiac anatomy is key to obtain optimal results. Intracardiac echocardiography (ICE) is a unique imaging modality able to provide high-resolution real-time visualization of cardiac structures, continuous monitoring of catheter location within the heart, and early recognition of procedural complications, such as pericardial effusion or thrombus formation. Additional benefits are excellent patient tolerance, reduction of fluoroscopy time, and lack of need for general anesthesia or a second operator. For these reasons, ICE has largely replaced transesophageal echocardiography as ideal imaging modality for guiding certain procedures, such as atrial septal defect closure and catheter ablation of cardiac arrhythmias, and has an emerging role in others, including mitral valvuloplasty, transcatheter aortic valve replacement, and left atrial appendage closure. In electrophysiology procedures, ICE allows integration of real-time images with electroanatomic maps; it has a role in assessment of arrhythmogenic substrate, and it is particularly useful for mapping structures that are not visualized by fluoroscopy, such as the interatrial or interventricular septum, papillary muscles, and intracavitary muscular ridges. Most recently, a three-dimensional (3D) volumetric ICE system has also been developed, with potential for greater anatomic information and a promising role in structural interventions. In this state-of-the-art review, we provide guidance on how to conduct a comprehensive ICE survey and summarize the main applications of ICE in a variety of structural and electrophysiology procedures.

Intracardiac echography for left atrial appendage closure: A step-by-step tutorial

OBJECTIVES

We sought to provide a practical educational tool for the utilization of intracardiac echography (ICE) in the left atrium for the percutaneous closure of the left atrial appendage (LAA).

BACKGROUND

Although transesophageal echocardiography (TEE) is the gold-standard imaging technique for LAA closure, ICE is stepping in to support noncoronary cardiology interventions by improving workflow and case turnover and may be more adequate for frail patients with significant and multiple comorbidities.

METHODS

This article discusses the utility of ICE for LAA closure, its advantages compared to TEE, contraindications to TEE use and offers an extensive illustration of the main steps of the procedure.

CONCLUSIONS

The use of ICE in the left atrium allows a feasible guidance of all steps of the percutaneous closure of LAA.

Transcatheter aortic valve replacement with intracardiac echocardiography from the right internal jugular vein

Transesophageal echocardiography (TEE) is a useful imaging modality to guide transcatheter aortic valve replacement (TAVR). The limitations of TEE include the need for general anesthesia (GA) and endotracheal intubation. In Europe, TAVR under local anesthesia (LA) is usually performed without TEE. An intracardiac echocardiography (ICE) catheter may be used as an alternative to TEE, but the catheter is usually inserted from the femoral vein (FV-ICE). There are some reports of TAVR with FV-ICE; however, there are no reports of ICE inserted from the right internal jugular vein (JV-ICE). In the first case of its kind, we successfully performed TAVR under LA with JV-ICE. JV-ICE allows for the evaluation of perioperative hemodynamics, measurement of the aortic valve complex, and assessment of major complications during the procedure without interference from the operator or fluoroscopes; these represent a distinct advantage over TEE, transthoracic echocardiography, and FV-ICE. Moreover, there is no need for the echocardiologist to use maximal barrier precautions; the catheter can be operated in the standing position, like TEE; and operability is higher than that with FV-ICE. TAVR with JV-ICE is a promising alternative to TAVR under GA with TEE and TAVR under LA with FV-ICE.

Large-field intravascular ultrasound for annular sizing and predicting paravalvular regurgitation during TAVR: comparisons with multidetector computed tomography and transoesophageal echocardiography

Aims

The use of contrast media with multidetector computed tomography (MDCT) may induce acute kidney injury in patients with renal failure undergoing transcatheter aortic valve replacement (TAVR). We investigated the role of large-field intravascular ultrasound (IVUS) vs. MDCT and two-dimensional transoesophageal echocardiography (2D-TEE) for annular sizing and predicting paravalvular regurgitation (PVR) during TAVR.

Methods and Results

The aortic annulus was measured by large-field IVUS and 2D-TEE, and compared with MDCT in 50 patients undergoing TAVR. The IVUS and MDCT annular areas and diameters were not significantly different (446 ± 87 mm2 and 23.8 ± 84 mm vs. 466 ± 84 mm2 and 24 ± 2.1 mm, respectively; P > 0.05). IVUS and MDCT mean annular diameters were significantly greater than TEE diameter (23.8 ± 2.4 and 24 ± 2.1 vs. 22 ± 0.65 mm, respectively; P < 0.01). PVR ≥ Mild occurred in 13 patients (26%); 5 patients required post-dilation and 2 patients a second valve. Receiver operating characteristic analyses showed that transcatheter heart valve (THV) area - IVUS or MDCT areas equally predicted of ≥ mild PVR (areas under the curve [AUC] 0.79 and 0.81, respectively; P < 0.001), and were greater than THV diameter-TEE diameter (AUC 0.79 and 0.81 vs. 0.56, respectively; P < 0.05).

Conclusions

The aortic annular measurements and predicting PVR by large field IVUS were not significantly different from those of MDCT, but were greater than those of TEE. Large filed IVUS can be reliably used in lieu of MDCT for annular sizing in patients with aortic stenosis and renal failure or suboptimal MDCT images.

Echocardiographic imaging options in ovine research subjects

OBJECTIVES

To determine the feasibility of acquiring quality transesophageal (TEE), epicardial (EE), and intracardiac (ICE) echocardiographic images in ovine subjects and to discuss the merits of each technique with a focus on ICE image acquisition.

ANIMALS

Eleven male castrated Dorset adult sheep.

METHODS

Transesophageal echocardiography was performed under general anesthesia. Epicardial echocardiography was performed as part of an open chest (thoracotomy or sternotomy) experiment. Subjects were recovered with permanent jugular vein indwelling catheter and ICE from this approach was described. Feasibility of each technique was qualitatively assessed based on subjective image quality from three images for each image plane in each sheep.

RESULTS

Transesophageal echocardiography was technically challenging and did not provide adequate image quality for consistent interpretation. Epicardial echocardiography and ICE had more favorable results with ICE demonstrating unique benefits for post-operative serial monitoring.

CONCLUSIONS

Epicardial echocardiography and ICE were effective imaging techniques. Epicardial echocardiography required the least specialized training but was considered to have limited feasibility due to its requirement for an open chest procedure. Even with the necessity for permanent indwelling jugular cannulation, ICE was the least invasive of the three imaging techniques and potentially the most practical approach for chronic studies by minimizing post-operative stress. Transesophageal echocardiography was not a feasible technique in this study.

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.

Intracardiac versus transesophageal echocardiography to guide transcatheter closure of interatrial communications: Nationwide trend and comparative analysis

OBJECTIVES

This study aimed to assess current temporal trends in utilization of ICE versus TEE guided closure of interatrial communications, and to compare periprocedural complications and resource utilization between the two imaging modalities.

BACKGROUND

While transesophageal echocardiography (TEE) has historically been used to guide percutaneous structural heart interventions, intracardiac echocardiography (ICE) is being increasingly utilized to guide many of these procedures such as closure of interatrial communications.

METHODS

Using the Nationwide Inpatient Sample, all patients aged >18 years, who underwent ASD or PFO closure with either ICE or TEE guidance between 2003 and 2014 were included. Comparative analysis of outcomes and resource utilization was performed using a propensity score-matching model.

RESULTS

ICE guidance for interatrial communication closure increased from 9.7% in 2003 to 50.6% in 2014. In the matched model, the primary endpoint of major adverse cardiovascular events occurred less frequently in the ICE group versus the TEE group (11.1% vs 14.3%, respectively, P = 0.008), mainly driven by less vascular complications in the ICE group (0.5% vs 1.3%, P = 0.045). Length of stay was shorter in the ICE group (3 ± 4 vs 4 ± 4 days, P < 0.0001). Cost was similar in the two groups 18 454 ± 17 035$ in the TEE group vs 18 278 ± 15 780$ in the ICE group (P = 0.75).

CONCLUSIONS

Intracardiac echocardiogram utilization to guide closure of interatrial communications has plateaued after a rapid rise throughout the 2000s. When utilized to guide interatrial communication closure procedure, ICE is as safe as TEE and does not increase cost or prolonged hospitalizations.

Electrifying catheters with light

Smart minimally invasive devices face a connectivity challenge. An example is found in intracardiac echocardiography where the signal transmission and supply of power at the distal end require many thin and fragile wires in order to keep the catheter slim and flexible. We have built a fully functional bench-top prototype to demonstrate that electrical wires may be replaced by optical fibers. The prototype is immediately scalable to catheter dimensions. The absence of conductors will provide intrinsic galvanic isolation as well as radio frequency (RF) and magnetic resonance imaging (MRI) compatibility. Using optical fibers, we show signal transfer of synthetic aperture ultrasound images as well as photo-voltaic conversion to supply all electronics. The simple design utilizes only off the shelf components and holds a promise of cost effectiveness which may be pivotal for translation of these advanced devices into the clinic.

4-D ICE: A 2-D Array Transducer With Integrated ASIC in a 10-Fr Catheter for Real-Time 3-D Intracardiac Echocardiography

We developed a 2.5 ×6.6 mm ² 2 -D array transducer with integrated transmit/receive application-specific integrated circuit (ASIC) for real-time 3-D intracardiac echocardiography (4-D ICE) applications. The ASIC and transducer design were optimized so that the high-voltage transmit, low-voltage time-gain control and preamp, subaperture beamformer, and digital control circuits for each transducer element all fit within the 0.019-mm ² area of the element. The transducer assembly was deployed in a 10-Fr (3.3-mm diameter) catheter, integrated with a GE Vivid E9 ultrasound imaging system, and evaluated in three preclinical studies. The 2-D image quality and imaging modes were comparable to commercial 2-D ICE catheters. The 4-D field of view was at least 90 ^° ×60 ^° ×8 cm and could be imaged at 30 vol/s, sufficient to visualize cardiac anatomy and other diagnostic and therapy catheters. 4-D ICE should significantly reduce X-ray fluoroscopy use and dose during electrophysiology ablation procedures. 4-D ICE may be able to replace transesophageal echocardiography (TEE), and the associated risks and costs of general anesthesia, for guidance of some structural heart procedures.

Transpulmonary echocardiography to guide stent implantation into coarctation of the aorta

Although stent implantation into aortic coarctation has been performed solely under fluoroscopy, we successfully applied intracardiac echocardiography (ICE) to guide this procedure in a 13-year-old patient. Placing an intracardiac echocardiographic catheter in the left pulmonary artery facing upward, we readily visualized the precise anatomy of coarctation, measured the pressure gradient, and monitored the stent inflation process. This report suggests a new application of ICE for intervention with structural and vascular diseases other than interatrial septum.

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 for guidance of transcatheter aortic valve implantation under monitored sedation: a solution to a dilemma?

Transcatheter aortic valve implantation (TAVI) has been established as a valuable alternative to surgical aortic valve replacement in patients deemed to have high or prohibitive perioperative risk. However, there are several technical constraints and procedural risks inherent to TAVI. These risks include annulus rupture, ventricular perforation, aortic dissection, coronary occlusion, and dislodgement or migration of the valve prosthesis to the aorta or the left ventricle (LV). Other complications may be related to inappropriate valve deployment and subsequent paravalvular leak. Most complications cannot be detected at an early stage without echocardiographic guidance. Although not addressed by current guidelines, some European centres have advocated a 'minimalist' approach with exclusively fluoroscopic and angiographic guidance. Transoesophageal echocardiography (TEE), including real-time three-dimensional (RT-3D) imaging, has been established as a standard approach for peri-interventional guidance of TAVI. However, TEE monitoring almost always necessitates general anaesthesia and endotracheal intubation. A potential alternative to TEE is intracardiac echocardiography (ICE) that may provide a solution to a common dilemma: the most important advantage of ICE being the compatibility with monitored anaesthesia care without endotracheal intubation. Other advantages of ICE include uninterrupted monitoring, no fluoroscopic interference, and precise Doppler-based assessment of pulmonary artery pressures. Limitations of ICE include the need for additional venous access, the learning curve associated with a new device, and potentially increased cost.

Intracardiac Doppler Echocardiography for Monitoring of Pulmonary Artery Pressures in High-Risk Patients Undergoing Transcatheter Aortic Valve Replacement

BACKGROUND

Uncontrolled pulmonary hypertension may cause worse outcomes after transcatheter aortic valve replacement (TAVR), while hemodynamic monitoring is desirable for risk control. Pulmonary artery pressure (PAP) readings obtained by intracardiac Doppler echocardiography were evaluated.

METHODS

In 114 patients with symptomatic aortic stenosis and median Society of Thoracic Surgeons scores of 10.5% (interquartile range, 7.7%-15.0%), transfemoral and transapical TAVR was guided by intracardiac Doppler echocardiography. The continuous-wave Doppler beam interrogated the jet of tricuspid regurgitation from the "home view" position. Systolic PAP (PAPs) was estimated as the sum of the pressure gradient derived from the maximum transtricuspid regurgitation jet velocity and the central venous pressure. Mean PAP (PAPm) was calculated by the mean gradient method (1) and the Chemla formula (2). Measurements were obtained immediately before and after TAVR.

RESULTS

Pre- and postinterventional readings showed marginal pressure underestimation in comparison with measurements derived from right-heart catheterization: PAPs, -2.7 (95% CI, -3.3 to 2.1) and -1.4 (95% CI, -1.9 to -0.9); PAPm by the mean gradient method, -1.9 (95% CI, -2.2 to -1.6) and -0.1 (95% CI, -0.4 to 0.2). Agreement (95% limits) for PAPs was -8.6 to 3.2 and -6.8 to 4.0; agreement for PAPm by the mean gradient method was -5.4 to 1.6 and -3.4 to 3.2. The repeatability coefficient (95% limits of agreement) for PAPs was excellent: 3.4 (-4.2 to 2.5) and 5.5 (-5.3 to 5.8); repeatability for PAPm was higher by the mean gradient method than by the Chemla method. In ≥ 85% of patients with pulmonary hypertension, PAPm improved after valve deployment.

CONCLUSIONS

Intracardiac Doppler echocardiography-derived monitoring of PAP by the mean gradient method is accurate and well applicable to high-risk TAVR candidates for intraprocedural risk control.

Practical update on imaging and transcatheter aortic valve implantation

After very rapid advances in the development of the technique and devices, transcatheter aortic valve implantation (named TAVI or TAVR), is today a reality that is here to stay. It has become the minimally-invasive treatment option for high-risk and non-surgical patients with severe symptomatic aortic stenosis. Requiring the participation of a multidisciplinary team for its implementation, cardiac imaging plays an important role. From pre-assessment to determine the suitability of the patient, the access site, the type of device, to the guidance during the procedure, and ultimately the long term monitoring of the patient. Correct selection of the patient and device, correct placement of the stent-valve and early detection of complications are of paramount importance for procedural success and for patient outcome. Each technique has advantages and disadvantages, being the cardiologist who will determine the best approach according to the type of patient and the expertise of the center in each one of them. This article summarizes the last contributions of the most common used imaging techniques, in each step of the procedure.

Trans-pulmonary echocardiography as a guide for device closure of patent ductus arteriosus

OBJECTIVES

The aim of this study was to develop trans-pulmonary echocardiography (TPE) to guide device closure of patent ductus arteriosus (DC-PDA).

BACKGROUND

Aortography requires a large amount of contrast yet may give us an inadequate image to evaluate anatomy or residual shunt in patients with large PDA or dilated vessels and is precluded in patients with renal dysfunction. Practically, there is no imaging modality to monitor the entire procedure except for trans-esophageal echocardiography that requires general anesthesia.

METHODS

Subjects were seven patients with ages ranged from 6- to 77-years old and body weight > 15 kg. The size of the PDA ranged from 1.8 to 6.3 mm with pulmonary to systemic flow ratios from 1.2 to 2.2. During DC-PDA using Ampaltzer Duct Occluder or coil, an intra-cardiac echocardiographic (ICE) catheter was advanced into pulmonary arteries and standard views were developed to guide DC-PDA.

RESULTS

We have developed two standard views; the main pulmonary artery view (MPA view) and the left pulmonary artery view (LPA view). The MPA view provided aortic short axis view equivalent to that seen by trans-thoracic echocardiography in children. The LPA view, obtained by the echo probe in the LPA and turned it up upside down, provided long axis view of the PDA allowing more precise anatomical evaluation. TPE allowed us to monitor the entire procedure and determine residual shunts.

CONCLUSIONS

TPE in the MPA and LPA view can be an effective guide for DC-PDA. This report leads to new application of this imaging device.

The Role of Preoperative and Intraoperative Imaging in Guiding Transcatheter Aortic Valve Replacement

Optimal intraprocedural imaging is central to transcatheter aortic valve replacement (TAVR). Familiarity with commonly used modalities is necessary. Real-time, intraprocedural imaging is provided by fluoroscopy and echocardiography to ensure proper valve position and deployment, and to assess for postdeployment complications. By providing anatomic information to real-time fluoroscopy, fusion imaging has the potential to positively affect TAVR. As newer generation valves are introduced and as TAVR is potentially offered to lower risk patient populations, it will be important to ensure that improvements in intraprocedural imaging lead to better outcomes.

Transcatheter aortic valve implantation

With the improvement in the overall life expectancy, the incidence of aortic stenosis has been increasing. Although aortic valve replacement is a standard therapy, many patients do not undergo surgery for various reasons, including advanced age or the presence of multiple comorbidities. Transcatheter aortic valve implantation (TAVI) has been proposed as a less invasive and equally effective treatment for inoperable or high-risk symptomatic aortic stenosis. Numerous rigorous global clinical trials, as well as a pivotal clinical trial in Japan, have been conducted. In this review, we provide data on the development of TAVI worldwide and discuss the prospects for TAVI in Japan.

The Evolving Utility Of Intracardiac Echocardiography In Cardiac Procedures

Intracardiac echocardiography (ICE) has gained increasing use in electrophysiology due to the need to visualize key anatomic structures. Precise guidance for transseptal puncture and visualization of the pulmonary veins are common essential uses for ICE, but many operators adept at ICE imaging have developed additional and specific uses. With heavy use of ICE guidance, electrophysiologists demonstrated feasibility of left atrial ablation with minimal use of fluoroscopy. With the advent of 3D mapping-integrated ICE, rendering of contours for the left atrium, aortic cusps, and left ventricular structures such as the papillary muscles have become possible. Improved understanding of the anatomy of these areas can facilitate mapping and ablation of these structurally complex sites. Additional uses of scar-visualization and integration into voltage maps have been explored. Left atrial appendage imaging has been an area of interest in the ICE community, although technological improvements are likely needed to make this more reliably complete. A new real-time 3D ICE catheter has also been developed, and work is in progress to delineate potential uses for this new frontier. Increasingly routine use of ICE has led to improved real-time guidance of all percutaneous cardiac procedures.

Intracardiac echocardiography: evolving use in interventional cardiology

Intracardiac echocardiography (ICE) uses a catheter-based steerable ultrasound probe that is passed into the right heart chambers to image intracardiac structures. The transducer can be variably positioned for optimal imaging: in the inferior vena cava to visualize the abdominal aorta; in the right atrium for the interatrial septum, aortic, mitral, and tricuspid valves, and pulmonary veins; or in the right ventricle for the left ventricular function, outflow tract, or pulmonary artery. Intracardiac echocardiography is primarily used for imaging during an invasive cardiac procedure using conscious sedation, when transthoracic image quality would likely be inadequate, and transesophageal imaging would require general anesthesia. Intracardiac echocardiography is generally well tolerated and provides adequate images and sufficient information for the procedure performed. In the cardiac catheterization laboratory, ICE is routinely used for patent foramen ovale, atrial septal defect, and ventricular septal defect closures, allowing adequate percutaneous placement of septal occluders. It is now being considered in the current era of transcatheter aortic valve implantation necessitating improved imaging approaches for accurate placement. It is also routinely used for trans-septal punctures during mitral valvuloplasty and, more recently, with the advent of left atrial appendage closure devices. This article provides a comprehensive review of the current technology for ICE and its growing applications in the realm of interventional cardiology.

Imaging of cardiac valves by computed tomography

This paper describes "how to" examine cardiac valves with computed tomography, the normal, diseased valves, and prosthetic valves. A review of current scientific literature is provided. Firstly, technical basics, "how to" perform and optimize a multislice CT scan and "how to" interpret valves on CT images are outlined. Then, diagnostic imaging of the entire spectrum of specific valvular disease by CT, including prosthetic heart valves, is highlighted. The last part gives a guide "how to" use CT for planning of transcatheter aortic valve implantation (TAVI), an emerging effective treatment option for patients with severe aortic stenosis. A special focus is placed on clinical applications of cardiac CT in the context of valvular disease.

Why is intracardiac echocardiography helpful? Benefits, costs, and how to learn

Current interventional procedures in structural heart disease and cardiac arrhythmias require peri-interventional echocardiographic monitoring and guidance to become as safe, expedient, and well-tolerated for patients as possible. Intracardiac echocardiography (ICE) complements and has in part replaced transoesophageal echocardiography (TEE), including real-time three-dimensional (RT-3D) imaging. The latter is still widely accepted as a method to prepare for and to guide interventional treatments. In contrast to TEE, ICE represents a purely intraprocedural guiding and imaging tool unsuitable for diagnostic purposes. Patients tolerate ICE much better, and the method does not require general anaesthesia. Accurate imaging of the particular pathology, its anatomic features, and spatial relation to the surrounding structures is critical for catheter and wire positioning, device deployment, evaluation of the result, and for ruling out complications. This review describes the peri-interventional role of ICE, outlines current limitations, and points out future implications. Two-dimensional ICE has become a suitable guiding tool for a variety of percutaneous treatments in patients who are conscious or under monitored anaesthesia care, whereas RT-3DICE is still undergoing clinical testing. Continuous TEE monitoring under general anaesthesia remains a widely accepted alternative.

Prediction of paravalvular regurgitation after transcatheter aortic valve implantation by computed tomography: value of aortic valve and annular calcification

BACKGROUND

The purpose of this study was to quantify and characterize aortic valve leaflet and aortic annular calcification with computed tomography angiography (CTA) and to define whether they predict paravalvular regurgitation (PAR) after transcatheter aortic valve implantation.

METHODS

In all, 94 patients (aged 83.6 years) with severe aortic stenosis underwent CTA. Annular calcification was measured in two planes and defined as "protruding" (depth greater than length), "round," or "adherent" (length less than depth) for the right, left, and noncoronary annulus. Leaflet calcification severity and asymmetry were scored. Transthoracic echocardiography graduation of PAR severity was performed after the procedure (0.5 scale).

RESULTS

Thirty-two percent of patients had no or trivial PAR (grade less than 1) and 68% had mild to severe PAR (≥ 1 [mild 45.7%, moderate 20.2%, moderate to severe 2.1%]). The size of annular calcium was higher in patients with moderate to severe PAR greater than 1 (p = 0.015, p = 0.007, and p = 0.004) and predictive (c = 0.67, 0.71, and 0.711) for noncoronary, left, and total annular calcium size, respectively. Increasing PAR severity was correlated with increasing total calcium size (r = 0.422, p < 0.001). Protruding annular calcification greater than 4 mm (p = 0.02) was more frequently found in moderate to severe PAR greater than 1, and predictive (c = 0.7). Adherent calcium greater than 4 mm did not predict PAR greater than 1 and PAR of 1 or less. There was no association of leaflet calcium severity and asymmetry with PAR severity.

CONCLUSIONS

Protruding annular calcium greater than 4 mm predicts moderate to severe PAR after transcatheter aortic valve implantation. Increasing annular calcium size is another predictor, whereas adherent calcium has a "sealing" effect.

Echocardiography in the era of multimodality cardiovascular imaging

Echocardiography remains the most frequently performed cardiac imaging investigation and is an invaluable tool for detailed and accurate evaluation of cardiac structure and function. Echocardiography, nuclear cardiology, cardiac magnetic resonance imaging, and cardiovascular-computed tomography comprise the subspeciality of cardiovascular imaging, and these techniques are often used together for a multimodality, comprehensive assessment of a number of cardiac diseases. This paper provides the general cardiologist and physician with an overview of state-of-the-art modern echocardiography, summarising established indications as well as highlighting advances in stress echocardiography, three-dimensional echocardiography, deformation imaging, and contrast echocardiography. Strengths and limitations of echocardiography are discussed as well as the growing role of real-time three-dimensional echocardiography in the guidance of structural heart interventions in the cardiac catheter laboratory.

Multimodality imaging throughout transcatheter aortic valve implantation

Transcatheter aortic valve implantation (TAVI) is a novel, less-invasive technique used to treat selected patients with severe aortic valve stenosis with a high surgical risk. Noninvasive imaging before, during and after the procedure is of the utmost importance in this minimally invasive procedure. Screening of the patient and sizing of the aortic root by echocardiography and multislice computed tomography is of great importance to ensure success of the TAVI procedure. Echocardiography and fluoroscopy are essential during the procedure. During follow-up of the patients, echocardiography is important to evaluate the prosthesis function, durability and integrity. Additionally, multislice computed tomography and MRI might be helpful in the follow-up of selected cases. This article outlines the evolving role of multimodality imaging throughout TAVI in patients with severe aortic valve stenosis. It describes, in a stepwise approach, how multimodality imaging by echocardiography, angiography, multislice computed tomography and MRI enhances the TAVI procedure.