Three-Dimensional Echocardiographic Method for the Visualization and Assessment of Specific Parameters of the Pulmonary Veins

Summary

The dimensions of the pulmonary veins (PV) are important parameters when planning pulmonary vein isolation. 2D transoesophageal echocardiography can only provide limited data about the PVs; however, 3D echocardiography can evaluate relevant diameters and areas of the PVs, as well as their spatial relationship to surrounding structures.

Abstract

The dimensions of the pulmonary veins are important parameters when planning pulmonary vein isolation (PVI), especially with the cryoballoon ablation technique. Acknowledging the dimensions and anatomical variations of the pulmonary veins (PVs) may improve the outcome of the intervention. Conventional 2D transoesophageal echocardiography can only provide limited data about the dimensions of the PVs; however, 3D echocardiography can further evaluate relevant diameters and areas of the PVs, as well as their spatial relationship to surrounding structures. In previous literature data, parameters influencing the success rate of PVI have already been identified. These are the left lateral ridge, the intervenous ridge, the ostial area of the PVs and the ovality index of the ostium. Proper imaging of the PVs by 3D echocardiography is a technically challenging method. One crucial step is the collection of images. Three individual transducer positions are necessary to visualize the important structures; these are the left lateral ridge, the ostium of the PVs and the intervenous ridge of the left and right PVs. Next, 3D images are acquired and saved as digital loops. These datasets are cropped, which result in the en face views displaying spatial relationships. This step can also be employed to determine the anatomical variations of the PVs. Finally, multiplanar reconstructions are created to measure each individual parameter of the PVs.

Optimal quality and orientation of the acquired images are paramount for the appropriate assessment of PV anatomy. In the present work, we examined the 3D visibility of the PVs and the suitability of the above method in 80 patients. The aim was to provide a detailed outline of the essential steps and potential pitfalls of PV visualization and assessment with 3D echocardiography.

Introduction

The drainage pattern of the pulmonary veins (PV) is highly variable with 56.5% variation in the average population¹. Evaluation of the PV drainage pattern is crucial when planning PV isolation (PVI), which is the most common interventional treatment of atrial fibrillation nowadays^2,3,4. Although radiofrequency catheter ablation has been the standard technology for achieving PVI, the cryoballoon (CB)-based ablation technology (CA) is an alternative method requiring less procedural time. The technique is less complicated compared with radiofrequency abla....

Protocol

All the patients signed informed consent before examination according to approval of the local ethical committee (OGYÉI/12743/2018).

1. Preparation

1. Start the examination with patient preparation: ensuring at least a 4-hour fasting status, questionnaire about problems with swallowing and known upper gastrointestinal diseases.
2. Ensure that written informed consent is read and signed.
3. Prepare an intravenous line before the examination.
4. Position the patient in a left lateral decubitus position.
5. Administer mild sedation using intravenous midazolam (2.5-5 mg).
6. Monitor ECG and oxyge....

Results

Using the above-described image acquisition protocol, the first step is to visualize the left atrial appendage (LAA) using 2D acquisition (Figure 1). The probe is in the upper (or mid) transoesophageal position at 20-45°. The image shows the LAA. The left lateral ridge and the left upper PV is displayed at 60-80° (Figure 2), and then the 3D dataset is acquired and confirmed by cropping the dataset in order to visualize the LAA and the left lateral ridge with the.......

Discussion

Here, we demonstrate a step-by-step methodology to study the PVs, their surrounding structures and anatomical characteristics with 3D echocardiography. The above described method for 3D imaging of the PVs is an easily standardizable method, which provides high quality 3D images in most patients suitable for precise measurements. Optimal quality and orientation of the acquired images are paramount for the appropriate assessment of PV anatomy. The 3D reconstructed images enhance the visualization of the PV drainage pattern.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
4D Cardio-view 3 software	Tomtec Imaging Systems GmbH
Epiq 7G scanner	Philips
Q-Lab Software	Philips
X5-1 transducer	Philips
Vivid E95 Scanner	GE
4Vc-D transducer	GE