Epicardial Connections After a Conventional Pulmonary Vein Antrum Isolation in Patients With Atrial Fibrillation

Abstract

wave front propagation, especially in low voltage zones. By performing HDM mapping inside the PVAI lines after conventional encirclement lesions, we hoped to identify any RPs associated with ECs inside our PVAI lines. Thus, the purpose of this study was to determine the prevalence and number of ECs inside the PVAI lines after a conventional PVAI, and the effect of an EC ablation on the outcomes in patients with non-valvular paroxysmal (pAF), persistent (persAF), and long-lasting AF (LLAF). Methods Baseline Clinical Characteristics of the Patient GroupsThe present study was approved by the institutional review committee and ethics review board of our hospital, the Ethical Review Board of Steel Memorial Yawata Hospital. The procedures were followed in accordance with the Declaration of Helsinki and the ethical standards of the responsible committee on human experimentation. Moreover, we enrolled this study in an international registry of P ulmonary vein (PV) antrum isolation (PVAI) with radiofrequency catheter ablation (RFCA) has proven to be a useful strategy for atrial fibrillation patients (AF) worldwide. 1 To prevent initiating and maintaining AF, a complete PVAI should be a target of the AF treatment. 1 However, in spite of establishing complete PVAI lines, we rarely experience and encounter remaining potentials (RPs) inside our PVAI lines detected by high-density mapping (HDM). Then, when we perform pacing from the ablation catheter on the RPs inside our PVAI lines, we confirm that the pacing can capture RPs and conduct to the atrium. This finding indicates the existence of epicardial connection(s) (ECs) from inside the PVAI lines to the atrium after establishing complete conventional PVAI lines. The recent Intellamap Orion 2 (Boston Scientific Corporation, Marlborough, MA, USA) and Advisor TM HD Grid 3 (Abbott, Plymouth, MN, USA) advanced catheter technologies, which are directional HDM catheters, can not only identify low voltages and small local electrical signals, but also more importantly can capture the direction of the

Epicardial connection(s) inside the pulmonary vein antrum isolation lines contribute to subsequent atrial fibrillation: a case report

“…Although we could not confirm whether the ECs were conducted from the PVs due to continuation of AF, recent studies have led us to hypothesize that they might have been conducted from the LSPV to the coronary sinus (CS) or Marshall bundle 6 and from the RSPV to the right atrium. 4 , 5 Moreover, we could not confirm the EC directionality. A previous report demonstrated that unidirectional entrance block with SA in the PVs conducted to atrium may prove an incomplete PVAI, while bidirectional block can decrease acute PV reconnections and AF recurrence in patients undergoing PVAI for AF.…”

“…Due to a suspicion of EC presence, 4–6 all PVs were mapped in detail using EnSite™ with the CMC, and a voltage map was drawn. Isolated RPs were detected at sites 27 and 30 mm distal to the PVAI line at the left superior PV (LSPV) ( Figures 2B and 4A, B ) and right superior PV (RSPV) ( Figures 2C and 4C, D ), respectively.…”

“… 1–3 Moreover, complete PVAI is essential to prevent AF initiation and recurrence. 1 However, recent reports have demonstrated epicardial connections (ECs) within the PVAI lines in ∼10% of patients with AF, 4 which could be a possible mechanism for failure to achieve complete PVAI, thus contributing to AF recurrence. 4–7 …”

A case report of an important role of epicardial connections in producing spontaneous pulmonary vein activity and initiating and maintaining atrial fibrillation

“…However, sinus rhythm still could not be maintained. Because we suspected the presence of ECs, 5 , 6 the LA and PVs were reconstructed in detail by the EnSite system using a steerable high-density mapping catheter (Advisor HD Grid catheter; Abbott, Plymouth, MN) and demonstrated a remaining potential at a 35-mm-distal site from the PVAI line in the left superior pulmonary vein (LSPV; white arrows in Figure 1 D and 1 E). We also confirmed there were no concealed low-voltage signals (CLVSs) 9 along the PVAI lines, indicating the completion of the PVAI lines.…”

“… 1 However, even if using contemporary advanced techniques such as a 3-dimensional mapping system and contact force monitoring, a first-pass isolation is sometimes difficult to perform and additional ablation inside the veins is commonly necessary and effective in achieving these objectives. 4 Recent studies have demonstrated that the presence of epicardial connections (ECs) 5 involving the pulmonary veins (PVs) is one of the mechanisms for failure in achieving a complete PVAI. 6 , 7 , 8 …”