Contrast-Based 3D/2D Registration of the Left Atrium: Fast versus Consistent.

For augmented fluoroscopy during cardiac ablation, a preoperatively acquired 3D model of a patient's left atrium (LA) can be registered to X-ray images recorded during a contrast agent (CA) injection. An automatic registration method that works also for small amounts of CA is desired. We propose two similarity measures: The first focuses on edges of the patient anatomy.

Electrophysiology Catheter Detection and Reconstruction From Two Views in Fluoroscopic Images.

Electrophysiology (EP) studies and catheter ablation have become important treatment options for several types of cardiac arrhythmias. We present a novel image-based approach for automatic detection and 3-D reconstruction of EP catheters where the physician marks the catheter to be reconstructed by a single click in each image. The result can be used to provide 3-D information for enhanced navigation throughout EP procedures.

Accuracy assessment of catheter guidance technology in electrophysiology procedures: a comparison of a new 3D-based fluoroscopy navigation system to current electroanatomic mapping systems.

Background: With increasing complexity in electrophysiology (EP) procedures, the use of electroanatomic mapping systems (EAMS) as a supplement to fluoroscopy has become common practice. This is the first study that evaluates spatial and point localization accuracy for 2 current EAMS, CARTO3(®) (Biosense Webster, Diamond Bar, CA, USA) and EnSite Velocity(®) (St. Jude Medical Inc.

Semi-automatic catheter reconstruction from two views.

We propose novel methods for (a) detection of a catheter in fluoroscopic images and (b) reconstruction of this catheter from two views. The novelty of (a) is a reduced user interaction and a higher accuracy. It requires only a single seed point on the catheter in the fluoroscopic image.

Pulmonary vein isolation supported by MRI-derived 3D-augmented biplane fluoroscopy: a feasibility study and a quantitative analysis of the accuracy of the technique.

Background: Despite the advancement of technology in electroanatomic mapping systems (EAMS), fluoroscopy remains a necessary, basic imaging modality for electrophysiology procedures. We present a feasibility study of new software that enables 3D-augmented fluoroscopy in biplane catheterization laboratories for planning and guidance of pulmonary vein isolation (PVI). The computer-assisted overlay registration accuracy was assessed in a clinical setting using an automatic calculation of overlay projection geometry that was derived from hardware sensors in C-arms, detectors, and patient table.

Constrained registration for motion compensation in atrial fibrillation ablation procedures.

Fluoroscopic overlay images rendered from preoperative volumetric data can provide additional anatomical details to guide physicians during catheter ablation procedures for treatment of atrial fibrillation (AFib). As these overlay images are often compromised by cardiac and respiratory motion, motion compensation methods are needed to keep the overlay images in sync with the fluoroscopic images. So far, these approaches have either required simultaneous biplane imaging for 3-D motion compensation, or in case of monoplane X-ray imaging, provided only a limited 2-D functionality.

Circumferential pulmonary vein isolation with the cryoballoon technique results from a prospective 3-center study.

Objectives: The purpose of this study was to investigate the efficacy safety of the novel cryoballoon device (Arctic Front, Cryocath, Quebec, Canada).

Background: Antral pulmonary vein (PV) ablation with radiofrequency energy is widely used as a strategy for catheter ablation of paroxysmal atrial fibrillation (PAF). A novel double lumen cryoballoon catheter was designed for circumferential pulmonary vein isolation (PVI) with the cryoablation technique.

Asymptomatic recurrences of atrial fibrillation after pulmonary vein isolation.

Aims: The purpose of this study was to determine the occurrence of asymptomatic episodes of atrial fibrillation (AF) and wrong AF perception after pulmonary vein isolation (PVI). We evaluated the success of ablation by using the following measurements: (i) clinical symptoms and duration of symptoms noticed by patients and (ii) synchronous event recording (ER).

Methods And Results: Eighty patients with paroxysmal AF underwent PVI and were provided repeatedly with a portable ER upon discharge and every 3 months for a year.

Acute success and persistence of bidirectional conduction block in the cavotricuspid isthmus one month post cryocatheter ablation of common atrial flutter.

Introduction: Cryoablation is successful in the treatment of common atrial flutter. Long-term clinical success is mainly dependent on persistence of bidirectional conduction block (BCB) in the inferior cavotricuspid isthmus (CTI). Only few data on persistence of BCB post cryoablation with the reported technique are available.

Usefulness of atrial fibrillation burden as a predictor for success of pulmonary vein isolation.

Background: The definition of symptomatic improvement after pulmonary vein isolation (PVI) is controversial. We assessed primarily the usefulness and predictive accuracy (PA) of AF (atrial fibrillation) burden (AFB) within the first 3 months after the procedure as an early predictor for curative success as well as reduction of symptoms.

Methods: We studied 100 pts (62 men, mean age: 54 +/- 9 years, LVEF: 57 +/- 9%, paroxysmal AF, 85, persistent AF, 15) who underwent PVI.

Percutaneous pulmonary vein stenting for the treatment of severe stenosis after pulmonary vein isolation.

Introduction: Pulmonary vein stenosis (PVS) is a potential complication of pulmonary vein isolation (PVI) using radiofrequency energy. The aim of our study was the evaluation of the severity and long-term outcome of primary angioplasty and angioplasty with pulmonary vein stenting for PVS.

Methods And Results: Twelve patients with 15 PVS (greater than 70% stenosis) were prospectively evaluated.

Invasive optimization of cardiac resynchronization therapy: role of sequential biventricular and left ventricular pacing.

Background: Aim of this invasive study was to characterize and quantify changes in left ventricular (LV) systolic function due to sequential biventricular pacing (BV) as compared to right atrial triggered simultaneous BV (BV(0)), LV, and right ventricular (RV) pacing in patients with congestive heart failure (CHF).

Methods: In 22 CHF patients, all in sinus rhythm, temporary multisite pacing was performed prior to implantation of a permanent system. LV systolic function was evaluated invasively by the maximum rate of LV pressure increase (dP/dt(max)).

Cryocatheter ablation of right ventricular outflow tract tachycardia.

Introduction: Cryocatheter techniques have been successfully applied to treat supraventricular tachycardia but there are no reports on their value in treating ventricular tachycardia (VT). We present our initial experience with cryocatheter ablation of right ventricular outflow tract (RVOT) tachycardia.

Methods And Results: Cryocatheter ablation was attempted in 14 patients (13 females, age 45.

A decrease in pulmonary vein diameter after radiofrequency ablation predicts the development of severe stenosis.

A decrease in ostial pulmonary vein (PV) diameter was observed in patients on the day after radiofrequency ablation of atrial fibrillation (AF). This study examined whether a relative reduction in PV diameter on day 1 (RRPVD1) after the procedure predicts the late development of severe PV stenosis (PVS). The study included 104 consecutive patients (mean age = 55 years, range 46-61, 34 women) with drug refractory AF.