Transesophageal and intracardiac ultrasound in arrhythmogenic right ventricular dysplasia/cardiomyopathy: Two case reports

Abstract

Rationale: Two-dimensional echocardiography (2D echo) is a major tool for the diagnosis of Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C). However 2D echo can skip regional localized anomalies of the right ventricular wall. We aimed to determine whether transesophageal and intracardiac ultrasound can provide additional information, on the right ventricular abnormalities compared to 2D echo.

Patient concerns: Case 1 is a 30-year-old patient that presented in the Emergency Department with multiple episodes of fast monomorphic ventricular tachycardia (VT) manifested by palpitations and diziness. Case 2 is a 65-year-old patient that also presented with episodes of ventircular tachycardia associated with low blood pressure.

Diagnosis: Both patients had a clear diagnosis of arrhythmogenic right ventricular dysplasia/cardiomyopathy confirmed by cardiac magnetic resonance imaging.

Intervention: In both patients transesophageal and intracardiac ultrasound was performed, which brought more information on the diagnosis of ARVD/C compared to transthoracic echocardiograpy.

Outcomes: The first patient was implanted with an internal cardiac defibrillator and treated with Sotalol for VT recurrences. He presented episodes of VT during follow-up, treated with antitachycardia pacing. The second patient was implanted with an internal cardiac defibrillator and treated with Sotalol without any VT recurrence at 18 month-follow-up.

Lessons: Transesophageal echocardiography and intracardiac echocardiography can provide additional information on small, focal structural abnormalities in patients with ARVD/C: bulges, saculations, aneurysms with or without associated thrombus, partial or complete loss of trabeculations and hypertrophy of the moderator band. These changes are particularly important in cases with "concealed" form of the disease in which no morphological abnormalities are evident in transthoracic echocardiograpy.

Figure 1

Transesophageal echography using a multiplanar probe. (A) Midesophageal view 4°: in the upper part of the image the left atrium can be seen- this is the closest anatomical structure to the esophagus. Separated by the interatrial septum, in the inferior part of the image lies the right atrium. The interatrial septum is convex towards the left atrium as the pressure inside the right atrium is high, given by the dilation of the right ventricle, tricuspid ring with subsequent tricuspid regurgitation. (B) Artwork with the structures seen in TEE. (C) Midesophageal view 36°: at the level of the right ventricle the moderator band (MB) can be visualized passing the ventricular cavity from the interventricular septum to the lateral wall where the anterior papillary muscle can be found. (D) Artwork with the moderator band as seen in TEE. TEE = transesophageal echocardiography.

Figure 2

Intracardiac echography using a rotational probe. (A) The ViewFlex probe is inserted near the apex of the right ventricle. Please note the normal trabeculations which are present at the level of the lateral wall (yellow arrow). (B) The ViewFlex probe is inserted between the tricuspid valve and the apex of right ventricle. Please note the absence of normal trabeculations at the level of the lateral wall (yellow arrow). The regional absence of the trabeculations at the level of the “triangle of dysplasia” could not be seen with 2D echo and transesophageal echocardiography. 2D = 2-dimensional.

Figure 3

Intracardiac echocardiography using a sectorial probe. (A) Chest X-ray: the ICE probe is inserted in the middle of the right atrium. (B) The RA (44 mm), RV (52 mm), and RVOT (48 mm) are dilated. (C) As the tricuspid ring is dilated, a moderate tricuspid regurgitation is present. (D) Chest X-ray: Intracardiac echography with the probe inserted inside the right ventricle. (E) Near the apex of the right ventricle the moderator band can be visualized (yellow arrow). (F) Chest X-ray: Intracardiac echography with the probe inserted inside the right ventricle. (G) The patient is implanted with an ICD (red arrow) for the secondary prevention of sudden cardiac death as he presented many episodes of ventricular tachycardia. At the apex of the right ventricle a localized aneurysm can be seen with a pediculated thrombus (yellow arrow). ICD = internal cardiac defibrillator, ICE = intracardiac echocardiography, RV = right ventricle, RVOT = right ventricular outflow tract.