ICE Catheter as Transesophageal Probe in Children With Congenital Heart Disease Undergoing an Electrophysiology Study

Abstract

Background

Intracardiac echocardiography (ICE) is conventionally used as an endovascular imaging modality during electrophysiology procedures. Reports of transesophageal ICE are limited and have not included pediatric electrophysiology procedures.

Case Summary

We report the first case series of transesophageal ICE (NuVision NAV) in 6 infants and young children with congenital heart disease undergoing electrophysiology studies and catheter ablation. Indications included preoperative conduction mapping and clinical arrhythmias.

Discussion

Transesophageal placement preserves the imaging advantages of ICE while avoiding large-bore venous access in small children without compromising image quality. The technique facilitates electroanatomic mapping by providing accurate delineation of the atrioventricular annulus in patients with complex congenital heart disease.

Take-Home Message

Transesophageal ICE with four-dimensional multiplanar imaging provides high-quality real-time anatomical guidance for electrophysiology procedures in infants and young children with complex congenital heart disease and may offer a practical alternative to intravascular ICE when large-bore venous access is undesirable.

Visual Summary

NuVision NAV is a novel model of intracardiac echocardiography (ICE) catheter compatible with CARTO 3 electroanatomic mapping system (Biosense Webster) and received Food and Drug Administration clearance in 2021. Compared with the more typical SOUNDSTAR ICE catheter (Biosense Webster) ultrasound catheter, it provides four-dimensional (4D) multiplanar visualization, allowing simultaneous imaging of multiple cross sections of the heart, and can provide color and spectral Doppler. Here, we present a case series of 6 infants and young children with complex congenital heart disease who had the NuVision NAV catheter positioned in the esophagus as a surrogate for transesophageal echocardiography (TEE) to enable a three-dimensional (3D) anatomical shell before an electrophysiology study (EPS). We propose this approach to improve delineation of complex cardiac anatomy and facilitate rapid intracardiac mapping while avoiding the need for a large 10.5-F sheath, which carries increased vascular risk in small pediatric patients.

Use of TEE has been described and even recommended for guidance during some cases of radiofrequency ablation in pediatric patients.¹ However, very few cases of using an ICE catheter as a substitute for a TEE probe have been reported in the literature. The available reports—mostly from adult cardiology—describe the off-label use of an esophageal ICE catheter to obtain intracardiac imaging during left atrial appendage closure.2, 3, 4 In pediatrics, only a few cases have described the use of ICE catheters in infants with small or abnormal oropharyngeal anatomy, during congenital heart surgery, particularly in patients weighing <5 kg.5, 6, 7 Currently, no imaging society has endorsed an official indication for this technique.

Methods

This is a single-center retrospective case series and was approved for exemption by our institutional review board. The included patients underwent procedures between July 1, 2025, and February 28, 2026. We included children (<21 years old) with congenital heart disease who had the ICE NuVision NAV catheter used in the esophagus during an EPS. A total of 6 consecutive patients were included in the series. Reported data included demographic characteristics, congenital heart disease diagnosis, prior surgeries and procedures. EPS-related data included clinical indication, catheters used, CARTO 3 images, electrophysiological diagnosis, interventions, outcomes, complications, and follow-up. Continuous data were reported as medians.

Patients’ Characteristics and Past Medical History

Six patients between the ages of 6 months and 9 years (median age 3.6 years) were included. Their weight ranged from 6.9 kg to 25.6 kg (median weight 14.0 kg). These patients had diverse congenital heart diseases (Table 1). Indications for EPS varied. Three patients underwent conduction system mapping before biventricular repair (Patients 3, 4, and 6). One patient underwent EPS for suspected pre-excitation before the Fontan procedure (Patient 2). The remaining patients underwent EPS for clinical arrhythmias and/or pre-excitation (Patients 1 and 5). They both underwent redo procedures following recurrence of arrhythmias, as both had multiple substrates.

Table 1.

Patients Demographic and Procedural Characteristics

	Weight at EPS (kg)	Exact Age at EPS (y)	Cardiac Anatomy	Past Cardiac Surgeries	Indication for EPS	Utility of Esophageal Use of NuVision NAV	Diagnosis Post-EPS	Intervention	Complications
Patient 1	24.30	8.90	ccTGA with Ebstenoid Tricuspid valve	None	WPW	Previsualization of AV annuluses before procedure	Two left-sided atrioventricular accessory pathways	RF ablation of both pathways	None
Patient 1 (redo)	25.60	9.26	ccTGA with Ebstenoid Tricuspid valve	None	Recurrence of WPW	Previsualization of AV annuluses before procedure	Recurrence of left infero septal accessory pathway	RF ablation of pathway	None
Patient 2	13.30	3.03	DILV, D-TGA and hypoplastic aortic arch	BTT shunt, DKS surgery, cavopulmonary bidirectional anastomosis Left pulmonary artery stent placement	Suspicion of pre-excitation, pre-Fontan	Previsualization of complex anatomy and AV annuluses before procedure	Nodoventricular pathway No atrioventricular accessory pathway	None	None
Patient 3	10.20	1.05	Right atrial isomerism with intracardiac TAPVR, balanced CAVC, DORV with D-malposition of the great vessels and RVOT obstruction	Three RVOT stents installed	Conduction system mapping pre biventricular repair	Previsualization of complex anatomy and AV annulus before procedure	Single infero septal AVN with bidirectional conduction and dual AVN physiology	None	None
Patient 4	6.90	0.51	Right atrial isomerism with supracardiac TAPVR, CAVC unbalanced, unbalanced DORV with D-malposed great vessels and aortic arch hypoplasia	TAPVR repair Pulmonary artery banding Aortic arch repair	Conduction system mapping pre biventricular repair	Previsualization of complex anatomy and AV annulus before procedure	Single infero septal AVN with bidirectional conduction and dual AVN physiology	None	None
Patient 5	14.70	4.21	PAPVR	Warden repair	Atrial tachycardia	Previsualization of anatomy and annulus before procedure	Typical atrial flutter	RF ablation of CTI	None
Patient 5 (redo)	15.10	4.43	PAPVR	Warden repair	Recurrence of atrial tachycardia	Visualization of left appendage to exclude presence of thrombus Previsualization of anatomy and annulus before procedure	IART using a scar on the right lateral wall of the RA	RF ablation of slow isthmus between 2 RA scars	None
Patient 6	8.50	0.76	Right atrial isomerism with dextrocardia, supracardiac TAPVR, unbalanced CAVC, L-looping of the ventricles, DORV with L-malposition of the great vessels and pulmonary atresia	Two RVOT stents installed	Conduction system mapping pre biventricular repair	Previsualization of complex anatomy and AV annulus before procedure	Single mid-infero septal AVN (retrograde conduction not tested)	None	None

AVN = atrioventricular node; BTT = Blalock-Taussig-Thomas; CAVC = complete atrioventricular canal; ccTGA = congenitally corrected transposition of the great vessels; CTI = cavotricuspid isthums; DILV = double inlet left ventricle; DKS = Damus-Kaye-Stansel; DORV = double outlet right ventricle; D-TGA = dextro transposition of the great arteries; IART = intra-atrial reentrant tachycardia; PAPVR = partial anomalous pulmonary venous return; RF = radiofrequency; RVOT = right vetricular outflow tract; TAPVR = total abnormal pulmonary venous return; WPW = Wolf Parkinson White.

Management (Interventions)

All patients were brought to the electrophysiology lab and placed under general anesthesia. The typical case flow was to start with the ICE catheter, which was introduced transesophageally to generate a detailed 3D anatomical shell of the heart. Particular attention was given to defining the atrioventricular (AV) annuli because of the complex anatomy in these patients. The AV valves were clearly visualized using both single-plane and multiplanar imaging and were integrated into the anatomical shell. This is well illustrated in patient 3 (Video 1) and patient 4 (Figures 1A and 1B), where the common AV valve of the complete AV canal was well delineated. We were also able to clearly define the left-sided AV annulus in patients with 2 AV annuli, as shown with patient 5 (redo) (Figure 2A). This was particularly useful in patient 1 with congenitally corrected transposition of the great arteries and atypical AV annular anatomy. The ICE catheter was also used to visualize and confirm the absence of thrombus in the left atrial appendage before the procedure (Figure 2B) with patient 5 (redo), as the patient had been in incessant atrial tachycardia for a few weeks.

Figure 1.

Transesophageal Intracardiac Echocardiography for Conduction System Mapping (Patient 4)

The NuVision NAV catheter positioned in the esophagus enabled detailed delineation of atrioventricular valve anatomy and integration with computed tomography imaging in a child undergoing preoperative conduction system mapping. (A and B) Demonstrate biplane and triplane transesophageal intracardiac echocardiography (ICE) imaging of the common atrioventricular valve (violet). (C) Shows close correlation between ICE-derived annular reconstruction and catheter-derived reconstruction (white), with the His bundle shown in yellow. (D) Shows computed tomography-integrated three-dimensional reconstruction demonstrating the relationship between the atrioventricular annulus, ventricular septal defect, and His bundle (yellow). AO = aorta; AP = anteroposterior; CL = cycle length; INF =inferior; INNOM = innominate vein; LAO = left anterior oblique view; LAT = local activation time; LL = left lateral; PA = posteroanterior; PA (anatomic structure/tab on the ultrasound panel) = pulmonary artery; RA = right atrium; RAO: right anterior oblique; RL = right lateral ; SUP = superior; ULS = ultrasound.

Figure 2.

Transesophageal Intracardiac Echocardiography for Arrhythmia Mapping and Ablation (Patient 5: Redo)

Transesophageal NuVision NAV imaging facilitated anatomical reconstruction and arrhythmia mapping during electrophysiology study for recurrent atrial tachycardia (AT). (A) Demonstrates delineation of the Tricuspid (blue) and Mitral (pink) annuli and (B) the exclusion of left atrial appendage thrombus. (C) Shows strong correlation between intracardiac echocardiography (ICE)-derived (right) and catheter-derived anatomical shells (left) with the His bundle (yellow). (D) Demonstrates activation and voltage mapping of a macro-re-entrant right AT circuit. This highlights the utility of transesophageal ICE in complex congenital heart disease. AP = anteroposterior; CTI = cavotricuspid isthmus; CL = cycle length; INF = inferior; INNOM = innominate vein; IVC = inferior vena cava; LAO = left anterior oblique; LAAP = left atrial appendange; LAT = left anterior oblique; LL = left lateral; MVA = mitral valve annulus; PA ( anatomic structure/tab on the ultrasound panel) = pulmonary artery; PATCH = (ventricular septal defect) patch; PULM = pulmonary; RA = right atrium; RAAP = right atrial appendange; RAO = right anterior oblique; RL = right lateral; PA = posteroanterior; SEPTU = septum; SUP = superior; TVA = tricuspid valve annulus; ULS = ultrasound.

After the initial anatomical shell of the heart was created with the ICE catheter, the image was merged with a recent cardiothoracic computed tomography (CT) scan for 2 patients (patients 4 and 6). A mapping catheter was then introduced to complete the anatomical shell and map the annulus, which closely correlated with ICE-derived anatomy (Figures 1C and 2C). This facilitated mapping of the AV annuli, conduction system and accessory pathways, with ablation performed when indicated. In patient 5 (redo), the initial shell and tricuspid annulus facilitated right atrial activation and voltage mapping of the macro-reentrant circuit (Figure 2D).

For patient 4, who had conduction system mapping required, we generated a complete CT-based 3D reconstruction by merging the anatomical shell of the heart obtained during the study with the ICE and the CT scan images, allowing visualization of the His bundle within the heart and, most importantly, in relation to the ventricular septal defect (Figure 1D).

Outcome and Follow-Up

None of these patients had complications during the procedure related to the use of the ICE, intracardiac catheters, or vascular access. Patient 1 had recurrence of one of the 2 previously ablated left-sided accessory pathways and underwent successful repeat ablation. Patient 5 developed a second macro-re-entrant atrial tachycardia involving lateral right atrial scar tissue, which was successfully ablated during a redo procedure.

Two of the 3 patients who underwent prebiventricular conduction system mapping had their biventricular repair with intact postoperative AV conduction (patients 3 and 6). The third patient (patient 4) underwent bidirectional cavopulmonary anastomosis (Glenn) palliation, with the possibility of eventual biventricular repair depending on left ventricular development.

Discussion

Electrophysiology procedures in pediatric patients with complex congenital heart disease are challenging and carry increased risk. Most mapping and ablation catheters are designed for older and larger patients. Therefore, mapping the AV annulus and the conduction system, and performing ablations, can be particularly complex and time-consuming in these patients. In older patients with congenital heart disease, placement of an ICE catheter in the standard endovascular position is frequently helpful for understanding these complex cardiac anatomies before mapping and ablation.

The NuVision NAV catheter is Food and Drug Administration-approved for intravascular use during electrophysiology procedures. In the small and young patients included in this series, we elected to position the catheter in the esophagus because of the vascular risks associated with introducing the large-bore sheath required for intravascular placement. Despite this alternative positioning, the catheter enabled accurate 3D reconstruction of cardiac anatomy and clear delineation of the AV annuli. The availability of 4D and multiplanar imaging allowed comprehensive visualization of the annulus without the need for extensive manipulation of the catheter within the esophagus. Remote control of sector angle and tilt from the CARTO workstation allowed comprehensive visualization through a 90 × 90 field of view. This flexibility improved the efficiency of mapping the AV valve annuli from multiple angles. Performing this imaging before the procedure greatly facilitated quick intracardiac mapping, a significant advantage in infants and young children, for whom prolonged general anesthesia carries higher risk. Visualization of the left atrial appendage is also possible to exclude an intracardiac thrombus before a procedure for patients at risk.

The NuVision NAV catheter, when used in conjunction with CT image integration, offers a powerful complementary approach in patients with complex cardiac anatomy. CT merging provided a clear spatial framework of cardiac structures, reducing the need to search for anatomical landmarks with ICE alone, whereas NuVision NAV offered real-time visualization and precise documentation of structures not achievable with static images alone. This approach also facilitated the creation of a 3D heart reconstruction by merging the anatomical shell obtained during the study with CT images, enabling identification of the position of the conduction system relative to cardiac structures for surgical planning (Figure 1D).

Compared with intravascular use of the NuVision NAV, which requires an 11-F sheath, the transesophageal approach may represent a safer alternative in this study group by reducing vascular risk. Furthermore, the catheter tip (approximately 3.0 mm) is smaller than standard neonatal TEE probes, such as the Philips MicroTEE (tip dimensions 7.5 mm × 5.5 mm),⁸ while providing comparable image quality.

It is important to recognize that the standard imaging views obtained with the ICE catheter positioned in the esophagus differ from those acquired using a conventional intracardiac ICE catheter. Nevertheless, the resulting images closely resemble standard TEE imaging planes, still allowing reliable visualization of cardiac structures. Catheter manipulation is minimal, with imaging performed primarily through the CARTO console. Combined with real-time visualization of the probe imaging plane orientation on CARTO, this facilitates image acquisition and is associated with a short learning curve.

One other limitation is the lower image resolution observed during biplane imaging when using purely orthogonal (90°) imaging planes. To overcome this, we routinely adjust the biplane angle away from 90°, which increases the number of active piezoelectric crystals and improves image quality. Using this approach, high-quality biplane images can be consistently obtained (Video 1).

A known complication with transesophageal probes is the risk of thermal injury. The NuVision NAV system has integrated temperature monitoring via a thermistor located at the tip of the probe. The temperature is displayed in real time on the mapping console. If the temperature exceeds 43 °C, the system automatically reduces the delivered energy or shuts down to mitigate the risk of thermal injury. To prevent exceeding this threshold, particularly because 3D/4D imaging modes generate more heat and accelerate temperature rise, the probe temperature was continuously monitored. When the temperature approached 40 °C, imaging was intermittently paused for a few seconds to allow cooling and prevent automatic system shutdown.

Conclusions

Transesophageal placement of the NuVision NAV catheter at the start of an EPS facilitated accurate delineation of the AV annulus and subsequent mapping in patients with complex cardiac anatomy in this case series of 6 patients. This approach could result in reduced procedure time, an important advantage in infants and young children for whom prolonged general anesthesia carries increased risk. Although no official indication currently exists for this technique, transesophageal ICE may represent a useful surrogate for conventional intravascular ICE in situations where large-bore venous access poses significant risk, while preserving the benefits of intracardiac echocardiographic imaging. Integration of CT scan imaging, as performed in the first patient, can further enhance anatomical delineation but is not always feasible and may result in increased radiation exposure in young patients.

Visual Summary.

Patient With Congenitally Corrected Transposition of the Great Arteries, Ebsteinoid Tricuspid Valve and Atrial Septal Defect, Referred for an Electrophysiological Study for Wolf-Parkinson-White Syndrome (Patient 1)

This illustration depicts the workflow of ICE integration into electroanatomic mapping in a patient with congenitally corrected transposition of the great arteries, an Ebsteinoid systemic atrioventricular valve, atrial septal defect, and Wolf-Parkinson-White syndrome. Annular landmarks identified on ICE images are annotated and imported into the mapping system to reconstruct the atrioventricular annuli. The reconstructed annuli are then integrated into the three-dimensional cardiac shell, providing an anatomical roadmap for catheter navigation and annular mapping. ICE = intracardiac echocardiography.

Funding Support and Author Disclosures

The authors have reported that they have no relationships relevant to the contents of this paper to disclose.

Take-Home Messages

• •Transesophageal use of an intracardiac echocardiography catheter with four-dimensional multiplanar capacities can provide high-quality real-time three-dimensional anatomical imaging to facilitate electrophysiology procedures in infants and young children with complex congenital heart disease.
• •This approach may offer a practical alternative to intravascular intracardiac echocardiography when large-bore venous access is undesirable.

Appendix

Video 1

Biplane Imaging for Atrioventricular Valve Annular Delineation Using the NuVision Catheter

Biplane echocardiographic cine acquired with the NuVision catheter positioned in the esophagus, demonstrating the common atrioventricular valve in 2 imaging planes in a patient with complex congenital heart disease (Patient 3). The atrioventricular valve hinge points are clearly visualized and were used to acquire annular mapping points for three-dimensional reconstruction (displayed in blue on the right side of the video).