Intravascular pulmonary venous ultrasound imaging for catheter ablation of atrial fibrillation

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

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.

Intracardiac ultrasound to detect aneurysm in arrhythmogenic right ventricular dysplasia/cardiomyopathy

Arrhythmogenic right ventricular dysplasia/cardiomyopathy is a genetic disorder characterized by fibrofattty replacement of the right ventricular myocardium. In the revised 2010 Task Force Criteria, a major criteria for ARVD/C is the presence of RV aneurysm by 2D echo. Our report demonstrates that intracardiac ultrasound can detect RV aneurysms and also focal absence of trabeculations which brings additional value to the diagnosis of ARVD/C. A 26-year-old male patient suffering from multiple sustained episodes of ventricular tachycardia was implanted with an internal cardiac defibrillator after confirmation of the disease by cardiac magnetic resonance imaging. Intracardiac ultrasound was performed using a 6F, 9 MHz catheter and the iLAB intravascular system (Boston Scientific). Images of right ventricular inflow tract, outflow tract, apex and pulmonary artery were taken and saved on videotape. ICE revealed loss of trabecular structure at the right ventricular outflow tract with an antero-septal aneurysm at this level. Intravascular ultrasound provides useful information on the presence of aneurysms and of tissue characterization.

Direct ICE imaging from inside the left atrial appendage during ablation of persistent atrial fibrillation

We present the case of a 59-year-old patient with persistent atrial fibrillation, referred for atrial fibrillation ablation. The procedure was performed with the help of NAVX 3D mapping system (Saint Jude Medical) and iLAB Ultra ICE Plus ultrasound imaging catheter (Boston Scientific). The catheter permits cross-sectional images perpendicular to catheter's long axis. From inside left atrial appendage (LAA) looks trabeculated, due to pectinate muscles running parallel to each other. The presence of a thrombus was excluded from the appendage. The contractility of LAA was also assessed using multiple frames recorded on videotape. Our case demonstrates that LAA's morphology and function can be directly assessed by intracardiac ultrasound with the probe inserted inside the appendage.