Feasibility and safety of a three-dimensional anatomic map-guided transseptal puncture for left-sided catheter ablation procedures.

Aims: Transseptal puncture (TP) for left-sided catheter ablation procedures is routinely performed under fluoroscopic or echocardiographic guidance [transoesophageal echocardiography (TEE) or intracardiac echocardiography (ICE)], although three-dimensional (3D) mapping systems are readily available in most electrophysiology laboratories. Here, we sought to assess the feasibility and safety of a right atrial (RA) 3D map-guided TP.

Methods And Results: In 104 patients, 3D RA mapping was performed to identify the fossa ovalis (FO) using the protrusion technique.

3D mapping of phrenic nerve course for radiofrequency pulmonary vein isolation.

Introduction: Phrenic nerve (PN) injury is a rare but severe complication of radiofrequency (RF) pulmonary vein isolation (PVI). The objective of this study was to characterize the typical intracardiac course of the PN with a three-dimensional electroanatomic mapping system, to quantify the need for modification of the ablation trajectory to avoid delivering an ablation lesion on sites with PN capture, and to identify very circumscribed areas of common PNC on the routine ablation trajectory of a RF-PVI, allowing fast and effective PN screening for everyday usage.

Methods: We enrolled 137 consecutive patients (63 ± 9 years, 64% men) undergoing PVI.

Characterization of circumferential antral pulmonary vein isolation areas resulting from pulsed-field catheter ablation.

Aims: The cornerstone of pulmonary vein (PV) isolation (PVI) is a wide-area circumferential ablation (WACA) resulting in an antral PVI area. Pulsed-field ablation (PFA) is a new nonthermal 'single-shot' PVI technique resulting in well-characterized posterior isolation areas. However, information on circumferential PVI area is lacking.

Non-invasive body surface electrocardiographic imaging for diagnosis of atrial cardiomyopathy.

Aims: Atrial cardiomyopathy (ACM) is associated with new-onset atrial fibrillation, arrhythmia recurrence after pulmonary vein isolation (PVI) and increased risk for stroke. At present, diagnosis of ACM is feasible by endocardial contact mapping of left atrial (LA) low-voltage substrate (LVS) or late gadolinium-enhanced magnetic resonance imaging, but their complexity limits a widespread use. The aim of this study was to assess non-invasive body surface electrocardiographic imaging (ECGI) as a novel clinical tool for diagnosis of ACM compared with endocardial mapping.

3D mapping for the identification of the fossa ovalis in left atrial ablation procedures: a pilot study of a first step towards an electroanatomic-guided transseptal puncture.

Aims: Transseptal puncture (TP) for left atrial (LA) catheter ablation procedures is routinely performed under fluoroscopic guidance. To decrease radiation exposure and increase safety alternative techniques are desirable. The aim of this study was to assess whether right atrial (RA) electroanatomic 3D mapping can reliably identify the fossa ovalis (FO) in preparation of TP.

Amplified sinus-P-wave reveals localization and extent of left atrial low-voltage substrate: implications for arrhythmia freedom following pulmonary vein isolation.

Aims: Presence of arrhythmogenic left atrial (LA) low-voltage substrate (LVS) is associated with reduced arthythmia freedom rates following pulmonary vein isolation (PVI) in persistent atrial fibrillation (AF). We hypothesized that LA-LVS modifies amplified sinus-P-wave (APW) characteristics, enabling identification of patients at risk for arrhythmia recurrences following PVI.

Methods And Results: Ninety-five patients with persistent AF underwent high-density (>1200 sites) voltage mapping in sinus rhythm.

The Duration of the Amplified Sinus-P-Wave Identifies Presence of Left Atrial Low Voltage Substrate and Predicts Outcome After Pulmonary Vein Isolation in Patients With Persistent Atrial Fibrillation.

Objectives: Left atrial (LA) low-voltage substrate (LVS) potentially slows intra-atrial conduction, which might identify patients at risk for arrhythmia recurrence following pulmonary vein isolation (PVI).

Background: Up to 50% of patients with persistent atrial fibrillation (AF) have arrhythmia recurrence following PVI, mostly due to arrhythmogenic LA LVS.

Methods: Seventy-two patients with persistent AF underwent electrocardioversion to sinus rhythm and high-density voltage mapping of the left atrium.

Novel Electrocardiographic Criteria for Real-Time Assessment of Anterior Mitral Line Block: "V Jump" and "V Delay".

Objectives: This study hypothesized that P-wave morphology and timing under left atrial appendage (LAA) pacing change characteristically immediately upon anterior mitral line (AML) block.

Background: Perimitral flutter commonly occurs following ablation of atrial fibrillation and can be cured by an AML. However, confirmation of bidirectional block can be challenging, especially in severely fibrotic atria.

Important reduction of the radiation dose for pulmonary vein isolation using a multimodal approach.

Aims: The number of pulmonary vein isolation (PVI) ablation procedures is steadily increasing worldwide resulting in a substantial radiation exposure to patients and operators. The aim of our study was to reduce radiation exposure during these procedures to a critical amount without compromising patient safety.

Methods And Results: First, we assessed radiation exposure for primary PVI procedures over time (2005-2015) at the University Heart Center Freiburg-Bad Krozingen.

Ablation of Persistent Atrial Fibrillation Targeting Low-Voltage Areas With Selective Activation Characteristics.

Background: Complex-fractionated atrial electrograms and atrial fibrosis are associated with maintenance of persistent atrial fibrillation (AF). We hypothesized that pulmonary vein isolation (PVI) plus ablation of selective atrial low-voltage sites may be more successful than PVI only.

Methods And Results: A total of 85 consecutive patients with persistent AF underwent high-density atrial voltage mapping, PVI, and ablation at low-voltage areas (LVA < 0.

Relationship between MDCT-imaged myocardial fat and ventricular tachycardia substrate in arrhythmogenic right ventricular cardiomyopathy.

Background: Myocardial fibrofatty infiltration is a milieu for ventricular tachycardia (VT) in arrhythmogenic right ventricular cardiomyopathy (ARVC) and can be depicted as myocardial hypodensity on contrast-enhanced multidetector computed tomography (MDCT) with high spatial and temporal resolution. This study aimed to assess the relationship between MDCT-imaged myocardial fat and VT substrate in ARVC.

Methods And Results: We studied 16 patients with ARVC who underwent ablation and preprocedural MDCT.

Mechanisms of pulmonary vein reconnection after radiofrequency ablation of atrial fibrillation: the deterministic role of contact force and interlesion distance.

Introduction: Pulmonary vein reconnection (PVR) is an important cause of AF recurrence after ablation. With the advent of force sensing catheters, catheter-tissue contact can be determined quantitatively. Since contact force (CF) plays a major role in determining the characteristics of RF lesion, we prospectively assessed the mechanisms of PVR with regard to catheter-contact and lesion distances in patients undergoing AF ablation.

Transseptal access for left atrial ablation: the catheter-probing techniques are not without risk.

Background: Transseptal puncture (TP) is a prerequisite for LA ablations. LA access can be gained by catheter probing in case of PFO (trans-PFO method) or puncture of the interatrial septum (IAS) using a transseptal needle. A 2nd access can again be gained via PFO, a 2nd TP or catheter probing of the previous puncture site (probe-TS method).

Do atrial differences in endothelial damage, leukocyte and platelet activation, or tissue factor activity contribute to chamber-specific thrombogenic status in patients with atrial fibrillation?

Background: Thrombi form mainly in the left rather than the right atria of patients with atrial fibrillation (AF), the reason of this predilection being unknown.

Objective: The purpose of this study was to investigate whether atrial-specific differences in endothelial damage, leukocyte activation, platelet stimulation, and tissue factor activity occur in patients with AF.

Methods: Twenty-two patients (16 men, 6 women; age 56 ± 8 years; 16 paroxysmal AF, 6 persistent AF) with AF undergoing pulmonary vein isolation were investigated.

Enhanced efficiency of a novel porous tip irrigated RF ablation catheter for pulmonary vein isolation.

Introduction: Irrigated tip radiofrequency (RF) catheter ablation is the most frequently used technology for pulmonary vein isolation (PVI). The purpose of this study was to compare the efficiency and the safety of 2 different open irrigated tip RF ablation catheters.

Methods And Results: A total of 160 patients with symptomatic AF (29% persistent, 68% male, 61 ± 10 years) were randomized to circumferential PVI using 2 different irrigated tip catheters: (1) the novel Thermocool SF(®) with a porous tip (56 holes) or (2) the Thermocool(®) catheter with 6 irrigation holes at the distal tip in both power- and temperature-controlled modes.

Sinus node disease in subjects with type 1 ECG pattern of Brugada syndrome.

Background: The spectrum of phenotypes related to mutations of the SCN5A gene include Brugada syndrome (BS), long QT syndrome, progressive cardiac conduction defect, and sinus node disease (SND). The present study investigated the incidence of SND in subjects with type 1 electrocardiogram (ECG) pattern of BS.

Methods And Results: The study population consisted of 68 individuals (55 males, mean age 44.

"Dormant transisthmus conduction" revealed by adenosine after cavotricuspid isthmus ablation.

Background: Linear radiofrequency ablation at the cavotricuspid isthmus (CTI) is the treatment of choice for typical flutter. Despite a high acute success rate, reconduction through the CTI may occur in approximately 15% of patients and eventually lead to flutter recurrence.

Objective: The purpose of this study was to test the hypothesis that injection of adenosine may reveal transient CTI reconduction and predict early relapse of permanent CTI conduction.

Why the structure but not the activity of the immunoproteasome subunit low molecular mass polypeptide 2 rescues antigen presentation.

The proteasome is responsible for the generation of most epitopes presented on MHC class I molecules. Treatment of cells with IFN-γ leads to the replacement of the constitutive catalytic subunits β1, β2, and β5 by the inducible subunits low molecular mass polypeptide (LMP) 2 (β1i), multicatalytic endopeptidase complex-like-1 (β2i), and LMP7 (β5i), respectively. The incorporation of these subunits is required for the production of numerous MHC class I-restricted T cell epitopes.

Cellular damage, platelet activation, and inflammatory response after pulmonary vein isolation: a randomized study comparing radiofrequency ablation with cryoablation.

Background: Experimental data suggest that use of cryoablation in pulmonary vein isolation (PVI) is associated with less cell damage and less thrombus formation compared to radiofrequency (RF) energy.

Objective: The purpose of this study was to test the hypothesis that cryoablation significantly reduces markers of cell damage, platelet activation, and inflammation in patients undergoing PVI for treatment of atrial fibrillation (AF).

Methods: Sixty patients with symptomatic drug-resistant AF (age 56 ± 9 years, 48 males, 38 with paroxysmal AF) were randomly assigned to undergo PVI using either an open irrigated-tip RF catheter or a cryoballoon.

The impact of body mass index on the efficacy and safety of catheter ablation of atrial fibrillation.

Background: Obesity is a well established risk factor for atrial fibrillation (AF) development. Our purpose was to determine the impact of body mass index (BMI) on the safety and efficacy of radiofrequency catheter ablation of AF.

Methods: Two hundred and twenty-six consecutive patients with symptomatic, drug-refractory paroxysmal (59.