The role of imaging to support catheter ablation of atrial fibrillation

Three-dimensional transesophageal echocardiographic evaluation of pulmonary vein anatomy prior to cryoablation: validation with cardiac CT scan

BACKGROUND

Anatomical characteristics of the left atrium and the pulmonary veins (PVs) may be relevant to the success rate of cryoballoon (CB)-ablation for atrial fibrillation (AF). Cardiac computed tomography (CCT) is considered as the gold standard for preablation imaging. Recently, three-dimensional transesophageal echocardiography (3DTOE) has been proposed for preprocedural assessment of cardiac structures relevant to CB-ablation. The accuracy of 3DTOE has not been validated by other imaging modalities.

OBJECTIVE

We prospectively evaluated the feasibility and the accuracy of 3DTOE imaging for the assessment of left atrial and PV structures prior to pulmonary vein isolation (PVI). In addition, CCT was used to validate the measurements obtained with 3DTOE.

METHODS

PV anatomy of 67 patients (59.7% men, mean age 58.5 ± 10.5 years) was assessed using both 3DTOE and CCT scan prior to PVI with the Arctic Front CB. The following parameters were measured bilaterally: PV ostium area (OA), the major and minor axis diameters of the ostium (a > b) and the width of the carina between the superior and the inferior PVs. In addition, the width of the left lateral ridge (LLR) between the left atrial appendage and the left superior PV. Evaluation of inter-technique agreement was based on linear regression with Pearson correlation coefficient (PCC) and Bland-Altman analysis of biases and limits of agreement.

RESULTS

Moderate positive correlation (PCC 0.5-0.7) was demonstrated between the two imaging methods for the right superior PV's OA and both axis diameters, the width of the LLR and left superior PV (LSPV) minor axis diameter (b) with limits of agreement ˂50% and no significant biases. Low positive or negligible correlation (PCC < 0.5) was found for both inferior PV parameters.

CONCLUSIONS

Detailed assessment of the right superior PV parameters, LLR and LSPV b is feasible with 3DTOE prior to AF ablation. This 3DTOE measurements demonstrated a clinically acceptable inter-technique agreement with those obtained with CCT.

Novel Solutions Applied in Transseptal Puncture: A Systematic Review

Access to the left atrium is required for several minimally invasive cardiac interventions in the left heart. For this purpose, transseptal puncture (TSP) technique is often performed, perforating the atrial septum under fluoroscopic or/and ultrasound imaging guidance. Although this approach has been used for many years, complications/failures are not uncommon mainly in patients with abnormal atrial anatomy and repeated TSP. Thus, this study presents an overview of methods and techniques that have been proposed to increase the safety and feasibility of the TSP. A systematic review of literature was conducted through the analysis of the articles published between 2008 and 2015. The search was performed in PubMed, Scopus, and ISI Web of Knowledge using the expression “transseptal puncture.” A total of 354 articles were retrieved from the databases, and 64 articles were selected for this review. Moreover, these 64 articles were divided into four categories, namely: (1) incidence studies, (2) intraprocedural guidance techniques, (3) preprocedural planning methods, and (4) surgical instruments. A total of 36 articles focused on incidence studies, 24 articles suggested novel intraprocedural guidance techniques, 5 works focused on preprocedural planning strategies, and 21 works proposed surgical instruments. The novel 3D guidance techniques, radio-frequency surgical instruments, and pre-interventional planning approaches showed potential to overcome the main procedural limitations/complications, through the reduction of the intervention time, radiation, number of failures, and complications.