Electrophysiology Unit (EPU) Practice Exam

These imaging methods are used to guide catheter-based procedures by providing real-time visualization of the heart. They both help with transseptal puncture by showing the septum and the needle position, and they can detect thrombus in the left atrium or left atrial appendage, which is crucial before left‑sided interventions. They also allow assessment of pulmonary vein anatomy to ensure proper planning and safe ablation or access. What they do not provide is a true 360-degree cross-sectional view around a structure. The ultrasound beam from these transducers is arranged as a sector or a limited-volume render, not a full circumferential, ring-like cross-section in real time. Achieving a true 360° radial cross-section around a lumen is a feature more characteristic of intravascular ultrasound catheters, not standard transesophageal or intracardiac echocardiography.