Significant Pulmonary Vein Stenosis Research Articles

Pulmonary Artery Wedge Pressure Can Underestimate Direct Pulmonary Vein Pressure in Pediatric Pulmonary Vein Stenosis

BackgroundPulmonary artery wedge pressure (PAWP) can underestimate directly measured pulmonary vein pressure (PVP) as demonstrated in animal studies and human case reports. This concept has not been validated in a larger cohort of pediatric patients with pulmonary vein stenosis (PVS). MethodsPediatric patients who underwent cardiac catheterization for PVS at a single center from January 1, 2018, to March 31, 2023, were retrospectively reviewed. Mismatch between the PAWP and directly measured PVP or LA pressure was defined as >3 mm Hg. Preintervention angiography was reviewed and percent stenosis calculated. ResultsTwenty-six patients met inclusion criteria; 51 lower pulmonary veins (34 left, 17 right) from 42 catheterizations were evaluated. Significant PVS (≥30% stenosis) was seen in 38/51 (75%) veins, and 9/51 (18%) veins had no angiographic narrowing (0% stenosis). PAWP-PVP mismatch occurred in 37/51 (73%) veins with a median difference of 8 mm Hg (IQR, 6-12). Of these, PAWP was equal to LA pressure in 26 instances, all of which had significant PVS (median % stenosis 54 [IQR, 45-60]). Six of the cases with PAWP-PVP mismatch, PVS (range, 41%-70% stenosis), and no PAWP-LA mismatch reported both a proximal and distal segmental PAWP. In all 6 instances, there was no distal PAWP-PVP mismatch (median difference 1 mm Hg [range, 0-3]). ConclusionsIn this single-center study of pediatric patients with PVS, PAWP significantly underestimated directly measured PVP in lower pulmonary veins. Balloon wedge or end hole catheter position in a distal lobar segment may more accurately estimate the PVP.

EP080: A rare case of mosaic trisomy 15 with chylothorax

eP080: A rare case of mosaic trisomy 15 with chylothorax

B-PO02-109 SAFE AND EFFECTIVE DELIVERY OF HIGH-POWER, SHORT-DURATION RADIOFREQUENCY ABLATION LESIONS WITH A NOVEL, FLEXIBLE-TIP RADIOFREQUENCY ABLATION CATHETER

High-power, short-duration (HPSD) radiofrequency (RF) ablation may reduce ablation time. Concerns that a catheter mounted thermocouple (TC) can underestimate tissue temperature and increase risk of steam pop formation limit widespread adoption of HPSD ablation. This study compared the safety and efficacy of HPSD and standard RF during pulmonary vein isolation (PVI). A novel irrigated ablation catheter with a contact force (CF) sensor and a TC in a flexible tip electrode was used to perform PVIs in 12 dogs. Two ablation protocols were performed: Standard: 30 W for up to 60 s and HPSD: 50 W for 10 s with the same irrigation rate (13 ml/m) and CF (5-20 g) for all lesions. RF delivery ended if the TC reached 45 C. PVI was assessed at 30 min and 28 ± 3 days post ablation. Baseline and follow up CT scans were performed to assess pulmonary vein stenosis (PVS). Lesions were evaluated with histopathology. All animals survived the follow up period. A total of 545 ablations were delivered: 252 with standard (0 steam pops) and 293 with HPSD RF (2 steam pops, p = 0.501). HPSD led to significantly shorter time to PVI. All 24 PVs were isolated 30 min after ablation with 12/12 standard and 11/12 HPSD remaining isolated at follow up. Histopathology showed all HPSD and standard ablations were transmural. Neither standard nor HPSD ablations produced significant PVS (LIPV narrowing 36.1 ± 11.2% (standard) vs 30.9 ± 22.8% (HPSD); LSPV narrowing 22.2 ± 5.9% (standard) vs 24.8 ± 7.8%(HPSD)). A novel ablation catheter safely and effectively delivered HPSD RF ablation lesions. Ablation time required to achieve PVI with HPSD was more than 3-fold shorter than with standard RF.

Low Risk of Pulmonary Vein Stenosis After Contemporary Atrial Fibrillation Ablation - Lessons From Repeat Procedures After Radiofrequency Current, Cryoballoon, and Laser Balloon.

The incidence of pulmonary vein stenosis (PVS) after AF ablation following contemporary procedures remains unclear. We compared the incidence of PVS/narrowing (PVS/N) after PV isolation (PVI) for (1) 3-D mapping-guided wide-area encircling irrigated radiofrequency current (RFC) ablation; (2) first-third-generation big cryoballoon (CB1-3) ablation; and (3) laser balloon (LB) ablation.Methods and Results:All patients undergoing a second procedure between January 2012 and November 2016 were subgrouped according to index ablation (PVI): RFC; CB; or LB. PVS/N was classified using PV diameter ratio (second/index procedure) on selective PV angiogram performed before ablation: mild, 25-49%; moderate, 50-74%; or severe, ≥75%. A total of 344 patients (1,362 PV) were analyzed (RFC, n=211; 840 PV; CB1, n=21; 82 PV; CB2,3, n=64; 250 PV; LB, n=48; 190 PV). In the LB group, 45 patients (94%) were treated with dose ≥8.5 W. Second procedures were performed on average 14.9±14.1 months after the index procedure. Mild PVS/N was observed in 18.4%, 9.5% and 3.6% of PV in the LB, RFC and CB groups, respectively (P<0.01). Moderate PVS was recognized in 2 PV (0.1%; RFC, LB). Severe PVS was never observed, and no PV intervention/surgery was required. The risk for significant PVS is low after RFC/CB. The incidence of mild PVS/N was highest after standard-dose LB ablation and lowest after high-dose CB ablation.

Characteristics of Phrenic Nerve Injury During Pulmonary Vein Isolation Using a 28-mm Second-Generation Cryoballoon and Short Freeze Strategy.

BackgroundThe reported incidence of phrenic nerve injury (PNI) varies owing to different definitions, balloon generations, balloon size, freezing regimen, and protective maneuvers. We evaluated the incidence, predictors, and outcome of PNI during cryoballoon pulmonary vein isolation in a large population.Methods and ResultsFive hundred fifty atrial fibrillation patients underwent pulmonary vein isolation using one 28‐mm second‐generation cryoballoon and single 3‐minute freeze strategy under diaphragmatic compound motor action potential (CMAP) monitoring. A total of 34 (6.2%) patients experienced PNI during the right superior and inferior pulmonary vein ablation in 30 and 4 patients, respectively. Applications were interrupted using double‐stop techniques after 136 [104–158] second applications, and a pulmonary vein isolation was already achieved in all but one case. The baseline CMAP amplitude and timing of deflation (CMAP def) were 0.75±0.30 and 0.17±0.17 mV, respectively. Persistent atrial fibrillation, larger right superior pulmonary vein ostia, and deeper balloon positions were associated with higher incidences of PNI. The CMAP def predicted a PNI recovery delay, and the best cutoff value for predicting PNI recovery by the next day was 0.20 mV (sensitivity 57.1%, specificity 100%). Among 6 patients undergoing second procedures 8.5 (6.7–15.0) months later, the right superior pulmonary vein was durable in 3 with >120 second applications. Despite active balloon deflation, no significant pulmonary vein stenosis was observed in 15 right superior pulmonary veins evaluated 6 (5–9) months later. No patients had symptoms, and the PNI recovered 1 day and 1 month postprocedure in 21 and 4 patients, respectively.Conclusions PNI resulting from cryoballoon ablation was reversible. The double‐stop technique is safe, and immediate active deflation following a CMAP decrease appears to be essential for faster PNI recovery.

Controlled Atrial Fibrillation after Pulmonary Vein Stenting.

When there is no pulmonary vein reconnection after catheter ablation for atrial fibrillation, patients can experience recurrence of atrial fibrillation without clear evidence of non-pulmonary vein foci. We describe a patient with significant pulmonary vein stenosis and recurrent atrial fibrillation after four ablation procedures. After successful pulmonary vein stenting, the symptoms were resolved, and sinus rhythm was maintained for 2 years without treatment with antiarrhythmic medication. We believe pulmonary vein stenting potentially controlled atrial fibrillation by providing pulmonary vein pressure relief or by compressing the epicardial triggers occurring at the pulmonary vein ostium.

Pre-procedural evaluation of the left atrial anatomy in patients referred for catheter ablation of atrial fibrillation

BackgroundCardiac computed tomography (CT) provides accurate imaging of the pulmonary vein (PV) and left atrial (LA) anatomy. This study aimed to evaluate the prevalence and morphological characteristics of anatomical variants that could influence atrial fibrillation (AF) ablation procedures. Methods and resultsOne thousand forty consecutive patients (62±10 years, 243 female, 644 paroxysmal AF) undergoing pre-procedural imaging with a 320-row CT and their first AF ablation procedure were analyzed. A total of 194 (18.7%) patients had anatomical variants. Left, right, and inferior common PVs were observed in 118, 5, and 6 patients, respectively. Three right and left PVs were observed in 44 and 4 patients, respectively. Three patients had remnants of PVs after lobectomies, and significant PV stenosis was observed in one. Supernumerary PVs that drained into the LA and diverticula were observed in eight patients. One patient had a string-like structure connecting the LA septum and posterior LA, and the others had membranous structures incompletely compartmentalizing the LA. Three patients had persistent left superior vena cavae, two strong deviations of the LA and PVs, and one dexiocardia. All patients underwent successful PV isolation during the index procedure. ConclusionsPatients referred for AF ablation often have anatomical variants, which could influence the procedure. This information might aid in planning procedural strategies, and reducing unexpected procedural complications in AF ablation.

Abstract 14782: Incidence and Characteristics of Pulmonary Vein Stenosis Following Catheter Ablation of Atrial Fibrillation: Insights From the Contemporary Multicenter ADVICE Trial

Introduction: Pulmonary vein (PV) stenosis is a well-described complication of atrial fibrillation (AF) ablation. Available data regarding the incidence of pulmonary vein (PV) stenosis associated with radiofrequency catheter ablation of AF are limited to surveys, single-center studies, and small trials. We prospectively assessed the incidence of PV stenosis after catheter ablation of AF in the context of a large randomized multicenter international study (ADVICE). Methods: Patients undergoing a first PV isolation procedure for the treatment of symptomatic paroxysmal AF were enrolled from 13 centers. PV isolation was performed by encircling all PVs using an irrigated-tip radiofrequency ablation catheter guided by a circular mapping catheter with the endpoint of electrical PV isolation. Systematic imaging of the left atrium and PVs using computed tomography-scan (CT-Scan) or magnetic resonance (MRI) was performed at 90 days post ablation to assess the incidence of PV stenosis. Significant PV stenosis was defined by a narrowing of PV luminal diameter greater than 70% as per Heart Rhythm Society guidelines. The incidence of moderate PV stenosis defined by a narrowing between 50% and 70% was also analyzed. Predictors of PV stenosis were explored by logistic regression analyses. Results: A total of 197 patients (mean age 59±9 yrs, 71% male) were included in this study. Electrical PV isolation was achieved in all patients. On the post ablation imaging study (performed at a mean of 103±33 days post ablation), a significant PV stenosis was observed in 1.52% [95% confidence interval (0.00%-3.23%)] of patients. In addition, a moderate PV stenosis was seen in 3.55% [95% confidence interval (0.97%-6.14%)] of patients. The affected PVs included 8 left inferior PVs, 1 right inferior and 1 right middle PV. None of the patients were symptomatic or required an intervention related to the PV stenosis. The presence of PV stenosis could not be predicted by clinical, hemodynamic, or procedural parameters. Conclusions: Our systematic evaluation of the incidence of PV stenosis in the context of a prospective multinational trial confirms previously reported low rates of significant PV stenosis following radiofrequency catheter ablation of AF.

Pulmonary Vein Isolation Using a Visually Guided Laser Balloon Catheter

Background— Because of the technical difficulty with achieving pulmonary vein (PV) isolation in the treatment of patients with paroxysmal atrial fibrillation, novel catheter designs to facilitate the procedure are in development. A visually guided laser ablation (VGLA) catheter was designed to allow the operator to directly visualize target tissue for ablation and then deliver laser energy to perform point-to-point circumferential ablation. Single-center studies have demonstrated favorable safety and efficacy. We sought to determine the multicenter feasibility, efficacy, and safety of performing PV isolation using the VGLA catheter. Methods and Results— This study includes the first 200 paroxysmal atrial fibrillation patients treated with the VGLA catheter (33 operators, 15 centers). After transseptal puncture, the VGLA catheter was used to perform PV isolation. Electric isolation was assessed using a circular mapping catheter. Using the VGLA catheter, 98.8% (95% confidence interval, 97.8%–99.5%) of targeted PVs were isolated using a mean of 1.07 catheters per patient. Fluoroscopy and procedure times were 31±21 (mean±SD) and 200±54 minutes, respectively, and improved with operator experience. There were no instances of stroke, transient ischemic attack, atrioesophageal fistulas, or significant PV stenosis. There was a 2% incidence of cardiac tamponade and a 2.5% incidence of phrenic nerve palsy. At 12 months, the drug-free rate of freedom from atrial arrhythmias after 1 or 2 procedures was 60.2% (95% confidence interval, 52.7%–67.4%). Conclusions— In this multicenter experience of the first 200 patients treated with the VGLA catheter, PV isolation can be achieved in virtually all patients using a single VGLA catheter with an efficacy similar to radiofrequency ablation.

The Anatomic Impact of Sequential, Additional, Ostial Radiofrequency Ablation Following Pulmonary Vein Cryo‐Isolation

Although pulmonary vein (PV) stenosis is a serious complication of radiofrequency PV isolation, the anatomical impact of a combination of two energy sources on PV diameter has not been evaluated. The aim of this study was to evaluate the impact of supplementary point-by-point radiofrequency applications (following PV cryoablation) on the PV orifice diameter. Forty-nine patients having undergone PV isolation for drug-refractory atrial fibrillation were included. All had undergone cardiac computed tomography before ablation and again at least 3 months afterwards. When isolation with the cryoballoon was not complete, a conventional irrigated-tip radiofrequency catheter was used for point-by-point applications. Of the 189 target PVs, 117 were isolated with cryotherapy alone (cryo PVs) and 72 required additional radiofrequency (hybrid PVs). The second scan (performed an average of 11.4 ± 5.4 months after) showed a decrease in diameter for all the hybrid PVs (17.2 ± 2.6 to 16.3 ± 3.4 mm; P = 0.037) but no change for the cryo PVs. This change was associated with a decrease in left superior pulmonary vein (LSPV) diameter (19.2 ± 3.0 to 17.8 ± 4.9 mm, P = 0.014). There were no changes in other veins. A subgroup analysis for the LSPV revealed a decrease for the hybrid PVs (18.8 ± 3.6 to 15.9 ± 7.1 mm, P = 0.046) but not for the cryo PVs. Significant PV stenosis was observed in three hybrid PVs (two severe stenosis of the LSPV and one moderate stenosis of the right inferior pulmonary vein) but not in cryo PVs (4.1% vs 0%, respectively; P = 0.023). Cryoballoon ablation of the PV with adjunct, focal, irrigated ostial RF applications may be associated with a higher risk of PV stenosis.

Safety of the Open‐Irrigated Ablation Catheter for Radiofrequency Ablation: Safety Analysis from Six Clinical Studies

The open-irrigated catheter is used most frequently for atrial and ventricular radiofrequency ablation (RFA), and is often considered as the standard by which new ablation systems are compared. But few data have been published concerning its safety. This report provides a comprehensive safety analysis of the use of an open-irrigated catheter for RFA of atrial flutter, ventricular tachycardia, and atrial fibrillation in 1,275 patients in six rigorously monitored, prospective, multicenter studies. This analysis is of data from six studies conducted as part of both Food and Drug Administration-mandated investigational device exemption studies and postapproval studies. The six studies span a period of more than 10 years. All serious RFA complications and vascular access complications that occurred within seven days postprocedure were included. The number of patients who experienced any acute serious RFA complication in these studies combined was 4.9% (63/1,275). The two earliest studies were conducted when the open-irrigated catheter was first introduced, and accounted for 55.6% of the complications. In the first atrial flutter ablation study, RFA complications decreased by 60% (15.4%-6.2%) after a proctoring program was initiated during the study. For all studies, vascular access complications ranged between from 0.5%-4.7%, and no stroke or transient ischemic attack was reported within 7 days postprocedure. No significant pulmonary vein stenosis was reported from the atrial fibrillation studies. A proctoring program, careful fluid management, and absence of char and coagulum contributed to the safe use of the open-irrigated RFA catheter.

065 Atrial fibrillation ablation in a district general hospital: 3 years experience

IntroductionThe practice of atrial fibrillation (AF) ablation is increasing exponentially. At present, these procedures are performed in a small number of surgical tertiary centres. In order to meet the growing...

Pulmonary vein stenosis detection by early cardiac magnetic resonance imaging post-atrial fibrillation ablation

Summary Identification of early post-atrial ablation MRI characteristics can help predict the development of significant chronic pulmonary stenosis. Background Pulmonary vein stenosis (PVS) is a rare complication of atrial fibrillation (AF) ablation with a rate of significant stenosis, defined as >50%, of 1.3% in a recent multicenter study. As significant morbidity is associated with PVS, detection and surveillance with non-invasive imaging is routine. In this study, we hypothesized that prediction of PVS can be determined with early MRI to identify patients at risk for this complication. Methods A single-center, retrospective, 1:1 cohort to control matched study including patients with (23) and without (23) significant PVS 3 months post-ablation (3moPA) was performed. Study groups were selected from 925 patients who underwent AF ablation and serial MRI scanning. Inclusion criteria for both groups required a full set of three MRI scans: pre-ablation (pre), 24 hours post-ablation (24hrPA), and 3moPA. MRI scanning was performed on a 1.5T or 3T Siemens magnet. Of the 925 patients, 28 were found with significant stenosis on MRA 3moPA. The final PVS study cohort included 23/ 28 patients as 5 were excluded secondary to incomplete MRI scan sets. The control group was comprised of 23 age and sex-matched patients without significant stenosis 3moPA. PV cross-sectional areas were measured at the ostial/proximal portion of the vessels by 3D MRA (Figure 1). In patients with multiple stenotic PV’s, the most stenotic vein was selected for analysis. Results Out of 925 patients, we found 3% (28/925) incidence of significant PVS 3moPA. Of the 23/28 patients in the PVS study cohort, early PV narrowings of >20% on the 24hrPA scan were found in all (23/23, 100%) compared with significantly fewer in the control group (9/23, 39%) (p 20%) on the 24hrPA MRI scan. In addition, small PV caliber on baseline imaging appears to predispose to PVS with the LIPV involved disproportionately. Overall, MRI image characteristics are useful for predicting PVS and may help determine which patients will benefit from surveillance imaging.

Should Catheter Ablation of Atrial Fibrillation Be a First-Line Therapy in the Young?

During the past decade, catheter ablation of atrial fibrillation (AF) has emerged as an important treatment option for patients with symptomatic AF. It is now widely accepted that catheter ablation of AF is indicated for treatment of symptomatic AF refractory to at least one class 1 or 3 antiarrhythmic drug.1 The body of literature that has defined the safety and effectiveness of AF ablation comprises single-center experiences, registry data, metaanalyses, and a number of prospective multicenter randomized clinical trials. The patients enrolled in these clinical trials were predominantly white, otherwise healthy men aged 50 to 65 years with paroxysmal AF. Much remains to be learned about the long-term effectiveness of AF ablation and the safety and effectiveness of AF ablation in those populations of patients who were not well represented in these prior clinical trials. Article see p 452 In this issue of Circulation: Arrhythmia and Electrophysiology , Leong-Sit et al2 contribute to the discussion by asking whether younger patients may benefit more than older patients from AF ablation. The authors report outcomes from 2038 AF ablation procedures in 1548 consecutive patients performed over an 8-year period. This single-center observational experience compares effectiveness and complication rates among the following groups of patients stratified by age: group 1, 65 years (n=308). The primary outcome measure of “AF control” includes patients with “rare AF,” which is defined as 6 or fewer AF episodes over the prior 12 months on or off antiarrhythmic medications after 1 or more ablation procedures. Major complications are defined as stroke or transient ischemic attack, significant pulmonary vein stenosis, pericardial tamponade, atrioesophageal fistula, death, phrenic nerve injury, retroperitoneal bleeding, or severe anaphylaxis. Other complications were large …

Emerging therapies for atrial fibrillation: is the paradigm shifting?

In 1962, Thomas Kuhn popularized the term “paradigmshift” to describe a fundamental change in scientificassumptions in his book entitled “The Structure ofScientific Revolutions” [1]. While some would argue thatthe term has been overused, most would agree thatrevolutionary moments that fundamentally alter our under-standing of a condition merit this designation. Someconsider such a “paradigm shift” to have occurred inthe field of cardiac electrophysiology in 1998 withHaissaguerre’s publication in The New England Journal ofMedicine on “Spontaneous Initiation of Atrial Fibrillationby Ectopic Beats Originating in the Pulmonary Veins” [2].Over a decade later, the medical community has embracedthis mechanistic insight that the triggers of atrial fibrillation(AF) are often found in the pulmonary veins. As a result,we have added AF ablation procedures to our therapeuticarmamentarium in an effort to cure this arrhythmia. Due tothe heterogeneous nature of AF, involving multiple triggersand substrates which range from structurally normal heartsto complex congenital and acquired abnormalities, ourmechanistic knowledge remains rudimentary. While weremain in the infancy of our understanding of thisextraordinary common, yet challenging, arrhythmia, weare on the threshold of innovative ablation techniques,multiple novel antiarrhythmic agents, and alternatives tovitamin K antagonists with the emergence of directthrombin and factor Xa inhibitors [3–5]. Each has thepotential to fundamentally alter the clinical strategiestraditionally employed for restoration of normal sinusrhythm and prevention of thromboembolic events. In thisrespect, it is appropriate to evaluate these emergingtherapies and their potential impact on therapeutic strategiesfor AF over the next several years.While most of the clinical experience with AF ablationhas been with thermal lesions from radiofrequency energy,new energy sources are emerging that have the potential toimprove outcomes in AF patients. The emergence of coldas a therapeutic modality can be traced to James Arnott, awell known British physician (1797–1883). Only in recentyears, however, with the development of an over-the-wire,deflectable, balloon-based catheter design has the potentialfor the delivery of cryoenergy in the treatment of AFbecome a reality. The novelty lays not only in the energysource, cryothermal energy, rather than conventionalradiofrequency energy, but also in the approach to lesionssets, single and circumferential, as opposed to traditionalpoint-by-point ablation. A balloon-based delivery platformmay provide a more efficient means of achieving pulmo-nary vein isolation, particularly suited for patients withparoxysmal AF in whom the goal is to abolish triggers.Thus far, several European centers have demonstratedprocedure safety and short-term efficacy, achieving sinusrhythm in 74% of patients with paroxysmal AF without theuse of antiarrhythmic drug therapy [3]. The major compli-cation appears to be phrenic nerve palsy with ablation ofthe right-sided veins, whereas no significant pulmonaryvein stenosis has been noted [3, 6]. Further advances indevice configurations will likely address the issues ofvariable anatomy, and hybrid approaches will be necessaryto ablate the substrate in patients with persistent AF.Direct clinical comparisons between radiofrequency andcryoablation will expectedly follow.

Pulmonary Vein Isolation using a High Density Mesh Ablator Catheter: Incorporation of three-Dimensional Navigation and Mappin.

Background: We evaluated the use of a novel High Density Mesh Ablator (HDMA) catheter in combination with three-dimensional navigation for the treatment of paroxysmal atrial fibrillation. Methods: The HDMA catheter was used to carry out pulmonary vein isolation in a consecutive series of patients. Three-dimensional geometry of the left atrial-pulmonary vein (LA-PV) junctions were first created with the HDMA catheter. Ostial, proximal and distal sites within the pulmonary veins were tagged with catheter shadows on the created geometry to allow for re-interrogation of these exact sites after ablation. Results: The HDMA catheter was successfully used to create three dimensional geometry of the LA-PV junction in a total of 20 pulmonary veins which involved 5 patients. In all cases, ostial ablation alone was sufficient to achieve electrical isolation. No significant pulmonary vein stenosis was seen acutely after ablation. Conclusion: We describe the successful use of the novel HDMA catheter to create three-dimensional geometry of the LA-PV junction to assist with pulmonary vein isolation.

Simultaneous angiographic imaging of ipsilateral pulmonary veins for catheter ablation of atrial fibrillation

Various imaging techniques are nowadays in clinical use to obtain important information about pulmonary vein (PV) anatomy in patients undergoing catheter ablation of atrial fibrillation (AF). Although some controversy exists about the optimal approach for catheter ablation of AF in recent times, knowledge of the individual left atrial-PV anatomy remains a basic feature of the different ablational techniques. Angiographic delineation of PV ostia has become an integral part of the PV isolation procedure, mainly in order to avoid potentially harmful PV stenosis. Selective venography with angiocatheters is well documented and widely available but has its own limitations, particularly with respect to visualization of the atriovenous junctions. The present report summarizes the usefulness, safety and feasibility of a new angiographic technique for simultaneous imaging of ipsilateral PVs applicable during catheter ablation of AF. Electrophysiologically guided segmental PV isolation was accomplished in 31 patients mostly with paroxysmal atrial fibrillation, who experienced significant clinical improvement during a followup of 17 +/- 15 months. The angiographic technique was effective for assessment of the individual anatomy including common ostia and supernumerary veins which can be easily missed by selective venography. Variant PV ostia were identified in about 20% of patients; particularly the presence of a left common trunk was challenging for the segmental ablation strategy. Angiographic detection of variant PV anatomy was comparable to visualization with computer tomography performed at 4-months follow-up. Finally, this type of angiographic imaging performed at the time of catheter ablation may help to reduce the risk of significant PV stenosis.

Transesophageal echocardiography: A screening method for pulmonary vein stenosis after catheter ablation of atrial fibrillation

Pulmonary vein (PV) stenosis has been described as a complication after catheter ablation of atrial fibrillation. The aim of the study was to investigate the diagnostic role of transesophageal echocardiography (TEE) in the assessment of PV stenosis. Ninety-one patients (71 men, mean age 57+/-16years), initially treated by catheter ablation of atrial fibrillation, underwent re-ablation because of arrhythmia recurrences. PV angiograms and TEE were performed before the first and second ablation. PVs were analysed in an intraindividual comparison by measurements of mean and peak flow velocity and of velocity time integrals and diameters. PV angiograms served as standard for assessment of PV stenosis. Sixteen of 91 patients developed PV stenoses as a consequence of the first ablation (13 mild PV stenoses, 4 moderate PV stenoses). All patients with PV stenosis were asymptomatic. In moderate PV stenosis (50-70%) a significant increase of blood flow parameters, reduction of vessel diameter, inhomogeneous blood flow and aliasing were demonstrated by TEE. Using quantitative TEE criteria moderate PV stenosis could be identified with a sensitivity of 84% and specificity of 98%. Detection of mild PV stenosis (30-50%) is challenging (sensitivity of 48% and specificity of 75%). TEE identifies significant PV stenosis by assessment of flow characteristics and vessel diameter and can thereby be used as a follow-up tool after catheter ablation of atrial fibrillation.

MR evaluation of pulmonary vein diameter reduction after radiofrequency catheter ablation of atrial fibrillation

Fifty consecutive patients aged 52+/-12 years suffering from drug refractory atrial fibrillation (AF) underwent baseline and post-ablation MR angiography (MRA) at a mean follow-up of 4+/-3.5 months. Pulmonary vein (PV) disconnection was performed with a maximum energy delivery of 30 W. MRA allowed a two-plane measurement of each PV ostium. After ablation, no significant stenosis was observed, and only 1/194 (0.5%) and 3/194 (2%) PVs had a diameter reduction of 31-40% in the coronal and axial planes, respectively. There was a significant overall post-procedural PV narrowing of 4.9% in the coronal plane and 6.5% in the axial plane (P=ns between both planes). MRA is an efficient technique that can be used in pre- and postoperative evaluation of AF patients. Using a maximal power delivery limited to 30 W, no significant PV stenosis was observed at mid-term follow-up. Late PV anatomical assessment is needed to confirm these results on long-term follow-up.

Pulmonary Hemodynamics at Rest and During Exercise in Patients With Significant Pulmonary Vein Stenosis After Radiofrequency Catheter Ablation for Drug-Resistant Atrial Fibrillation

Pulmonary Hemodynamics at Rest and During Exercise in Patients With Significant Pulmonary Vein Stenosis After Radiofrequency Catheter Ablation for Drug-Resistant Atrial Fibrillation