Pulmonary Vein Ostial Diameters Research Articles

Presence of a left common pulmonary vein and pulmonary vein anatomical characteristics as predictors of outcome following cryoballoon ablation for paroxysmal atrial fibrillation.

Pulmonary vein (PV) isolation using cryoballoon ablation (CBA) is a common therapy for patients with drug-refractory paroxysmal atrial fibrillation (PAF). However, initial CBA is successful in only 70-80% of patients. The role of an atypical left common PV (LCPV) and PV anatomical indices on CBA outcomes remains unclear. We followed 80 patients (age 60.7 ± 9.7, 31 % women) with PAF undergoing CBA for 1-year post-procedure for the development of recurrent atrial arrhythmias (AA). Recurrence was assessed by documented AA on EKG or any form of long-term cardiac rhythm monitoring. The presence of an LCPV and individual PV diameters were evaluated using cardiac CT. Based on the maximum and minimum PV ostial diameters, the eccentricity index (EI), ovality index (OI), and PV ostial area (PVA) were calculated for all the veins. A multivariable Cox-proportional hazard model assessed whether the presence of an LCPV or PV anatomic indices (EI, OI, and PVA) predicted recurrence of AA following CBA. After 1-year follow-up, 19 (23.7%) participants developed recurrence of AA. On multivariable regression, the presence of an LCPV did not predict the recurrence of AA (p = 0.38). Among the PV anatomical indices, on univariate analysis, only the area of the left inferior PV showed a trend towards predicting recurrence, though this result was not significant on multivariate analysis (p = 0.09). In patients with PAF, neither the presence of an LCPV nor individual PV anatomical indices predicted recurrence of AA following CBA.

Ostial dimensional changes after pulmonary vein isolation: Pulsed field ablation vs radiofrequency ablation

Pulmonary vein (PV) stenosis is an important potential complication of PV isolation using thermal modalities such as radiofrequency ablation (RFA). Pulsed field ablation (PFA) is an alternative energy that causes nonthermal myocardial cell death. The purpose of this study was to compare the effect of PFA vs RFA on the incidence and severity of PV narrowing or stenosis. Data were analyzed from 4 paroxysmal atrial fibrillation ablation trials using either PFA or RFA; because of absent CT scans or poor computed tomography scan quality, 73 of 153 patients (47.7%) were excluded. Baseline and 3-month cardiac computed tomography scans were reconstructed into 3-dimensional images, and the long and short axes of the PV ostia were quantitatively and qualitatively assessed in a randomized blinded manner by 2 physicians. A total of 299 PVs from 80 patients after either PFA (n = 37) or RFA (n = 43) were enrolled. PV ostial diameters decreased significantly less with PFA than with RFA (% change; long axis: 0.9% ± 8.5% vs -11.9% ± 16.3%; P < .001 and short axis: 3.4% ± 12.7% vs -12.9% ± 18.5%; P < .001). After a combined quantitative/qualitative analysis, mild (30%-49%), moderate (50%-69%), or severe (70%-100%) PV narrowing was observed, respectively, in 9.0% (15 of 166), 1.8% (3 of 166), and 1.2% (2 of 166) of PVs in the RFA cohort but in none of the PVs after PFA (P < .001). Overall, PV narrowing/stenosis was present in 0% and 0% vs 12.0% and 32.5% of PVs and patients who underwent PFA and RFA, respectively. This study indicates that unlike after RFA, the incidence and severity of PV narrowing/stenosis after PV isolation is virtually eliminated with PFA.

310 Computed Tomography Pulmonary Venogram Characteristics of Patients Undergoing Hybrid Atrial Fibrillation Ablation

Computed tomography pulmonary venogram can provide anatomic information of the left atrium, left atrial appendage and pulmonary veins that assist in planning radiofrequency catheter ablation for atrial fibrillation. 26 patients underwent computed tomography pulmonary venograms prior to their hybrid atrial fibrillation ablation. Left atrial abnormalities, lack of left atrial appendage opacification, pulmonary vein ostial diameters and variant anatomy were recorded. The mean pulmonary vein cross-sectional diameters were as follows:•Right superior pulmonary vein were 20.2±4.8mm x 17.8±4.3mm;•Right inferior pulmonary vein 19.6±3.9mm;•Left superior pulmonary vein 19.4±3.3mm x 16.1±2.9mm; and•Left inferior pulmonary veins 20.3±6.4mm x 16.4±3.5mm. There were 7 pulmonary vein variants. 3 patients had a common left pulmonary vein with a mean cross-sectional diameter of 33±2.6mm x 25.3±4 mm. 4 patients had right middle pulmonary veins with a mean cross-sectional diameter of 9±1.4mm x 8.5±1mm. There were no left atrial abnormalities. The left atrial appendages were well opacified. The pulmonary vein characteristics and variant anatomy were obtained. 29% of patients had variant anatomy, which is similar to the documented rates in the literature, with the most common variant being the right middle pulmonary vein.

Pulmonary venous abnormalities encountered on pre-radiofrequency ablation mapping multidetector computed tomography

Multidetector computed tomography (MDCT) elegantly renders pulmonary venous anatomy. With increasing numbers of radiofrequency ablation procedures being performed, there is now a greater emphasis on pre-procedure imaging to delineate this anatomy. Pulmonary venous mapping studies can be performed with or without ECG-gating. However, ECG-gating improves both the quality of 3D images and the accuracy of pulmonary vein (PV) ostial diameter measurements. Including the superior thorax, and not just the left atrium and central PVs, allows visualization of aberrant pulmonary venous drainage to the brachiocephalic veins or superior vena cava. Normally, there are two superior PVs, one right and one left, and two inferior PVs, one right and one left. The right superior vein usually drains the right upper and middle lobe. The left superior vein drains the left upper lobe including the lingula. The inferior veins drain their respective lower lobe. PV anatomy is more variable than pulmonary arterial anatomy, and developmental anomalies are common. This article describes, illustrates and reviews the common anomalies of the PVs in our experience performing over 1000-pre-radiofrequency ablation cardiac MDCT studies. The commonest anomalies are supernumerary or accessory veins (on the right) and a (left) common trunk. More rarely, partial anomalous pulmonary venous return and Cor triatriatum are seen, and rarest of all is total anomalous pulmonary venous return, PV varix and single or multiple vein stenosis or atresia.

Evaluation of pulmonary vein anatomy using 256-slice computed tomography

Background/aim: This study aimed to evaluate pulmonary vein (PV) anatomy using 256-slice computed tomography (CT), which may be necessary for electrophysiologists to know before radiofrequency catheter ablation (RFCA) therapy.Materials and methods: A total of 102 patients with paroxysmal and persistent atrial fibrillation underwent 256-slice cardiac CT angiography prior to catheter ablation. PV morphology, ostial diameter, ostial orientation, and distance from ostium to first bifurcation were evaluated using three-dimensional volume-rendering and multiplanar-reformatting technology. Results: We found that 72.5% of patients had four conventional PVs. On the right, 22.5% of patients had one accessory PV, 4.9% had 2 accessory PVs, 1% had one common PV, and 1% had one top vein. On the left, 27.5% of patients had one common PV. Additionally, 9.8% of patients had bilateral PV variation. Ostial size was larger for superior PVs than inferior PVs and larger for right PVs than left PVs. PV ostia on the right tended to be more circular. There was a rather wide variation of projective angle and distance from ostium to first bifurcation. Early branching occurred more often in the right inferior PV. Conclusion: 256-Slice CT can depict PV anatomy and afford substantial data, which will help electrophysiologists conduct the RFCA procedure safely and efficiently.

Measurements of the left atrium and pulmonary veins for analysis of reverse structural remodeling following cardiac ablation therapy

Rationale and objectivesGeometric analysis of the left atrium and pulmonary veins is important for assessing reverse structural remodeling following cardiac ablation therapy. Most volumetric analysis techniques, however, require laborious manual tracing of image cross-sections. Pulmonary vein diameters are typically measured at the junction between the left atrium and pulmonary veins, called the pulmonary vein ostia, with manually drawn lines on volume renderings or in image slices. In this work, we describe a technique for making semi-automatic measurements of left atrial volume and pulmonary vein diameters from high resolution CT scans and demonstrate its use for analyzing reverse structural remodeling following cardiac ablation therapy. MethodsThe left atrium and pulmonary veins are segmented from high-resolution computed tomography (CT) volumes using a 3D volumetric approach and cut planes are interactively positioned to separate the pulmonary veins from the body of the left atrium. Left atrial volume and pulmonary vein ostial diameters are then automatically computed from the segmented structures. Validation experiments are conducted to evaluate accuracy and repeatability of the measurements. Accuracy is assessed by comparing left atrial volumes computed with the proposed methodology to a manual slice-by-slice tracing approach. Repeatability is assessed by making repeated volume and diameter measurements on duplicated and randomized datasets. The proposed techniques were then utilized in a study of 21 patients from the Catheter Ablation versus Antiarrhythmic Drug Therapy for Atrial Fibrillation Trial (CABANA) pilot study who were scanned both before and approximately 3 months following ablation therapy. ResultsIn the high resolution CT scans the left atrial volume measurements show high accuracy with a mean absolute difference of 2.3±1.9cm3 between volumes computed with the proposed methodology and a manual slice-by-slice tracing approach. In the intra-rater repeatability study, the mean absolute difference in left atrial volume was 4.7±2.5cm3 and 4.4±3.4cm3 for the two raters. Intra-rater repeatability for pulmonary vein diameters ranged from 0.9 to 2.3mm. The inter-rater repeatability for left atrial volume was 5.8±5.1cm3 and inter-rater repeatability for pulmonary vein diameter measurements ranged from 1.4 to 2.3mm. In the patient study, significant (p<.05) decreases in left atrial volume and all four pulmonary vein diameters were observed. The absolute change in LA volume was 20.0cm3, 95%CI [12.6, 27.5]. The left inferior pulmonary vein diameter decreased 2.1mm, 95%CI [0.4, 3.7], the left superior pulmonary vein diameter decreased 3.2mm, 95%CI [1.0, 5.4], the right inferior pulmonary vein diameter decreased 1.5mm, 95%CI [0.3, 2.7], and the right superior pulmonary vein diameter decreased 2.8mm, 95%CI [1.4, 4.3]. ConclusionsUsing the proposed techniques, we demonstrate high accuracy of left atrial volume measurements as well as high repeatability for left atrial volume and pulmonary vein diameter measurements. Following cardiac ablation therapy, a significant decrease was observed for left atrial volume as well as all four pulmonary vein diameters.

Pulmonary Vein Stenosis After Catheter Ablation

Background— Radiofrequency ablation inside pulmonary vein (PV) ostia can cause PV stenosis. A novel alternative method of ablation is irreversible electroporation, but the long-term response of PVs to electroporation ablation is unknown. Methods and Results— In ten 6-month-old pigs (60–75 kg), the response of PVs to circular electroporation and radiofrequency ablation was compared. Ten consecutive, nonarcing, electroporation applications of 200 J were delivered 5 to 10 mm inside 1 of the 2 main PVs, using a custom-deflectable, 18-mm circular decapolar catheter. Inside the other PV, circular radiofrequency ablation was performed using 30 W radiofrequency applications via an irrigated 4-mm ablation catheter. PV angiograms were made before ablation, immediately after ablation, and after 3-month survival. PV diameters and heart size were measured. With electroporation ablation, PV ostial diameter decreased 11±10% directly after ablation, but had increased 19±11% after 3 months. With radiofrequency ablation, PV ostial diameter decreased 23±15% directly after ablation and remained 7±17% smaller after 3 months compared with preablation diameter despite a 21±7% increase in heart size during aging from 6 to 9 months. Conclusions— In this porcine model, multiple circumferential 200-J electroporation applications inside the PV ostia do not affect PV diameter at 3-month follow-up. Radiofrequency ablation inside PV ostia causes considerable PV stenosis directly after ablation, which persists after 3 months.

Characterization of Pulmonary Vein Dimensions Using High-Definition 64-Slice Computed Tomography prior to Radiofrequency Catheter Ablation for Atrial Fibrillation.

Background. Contrast-enhanced computed tomography is commonly acquired before radiofrequency catheter ablation (RFCA) for atrial fibrillation (AFib) to guide the procedure. We analyzed pulmonary vein (PV) ostial diameter and volumes on a high-definition 64-slice CT (HDCT) scanner in patients with AFib prior to RFCA. Methods and Results. This retrospective study included 50 patients (mean age 60.2 ± 11.4 years, 30 males) undergoing cardiac HDCT scanning before RFCA for drug refractory AFib and 50 age-, BMI-, and sex-matched controls with normal sinus rhythm undergoing HDCT. PV ostial diameter and volume were measured and calculated using a semiautomatic calliper tool. Total ostial PV volume was significantly increased in patients with AFib as compared to controls (P < 0.005). Similarly, total ostial PV diameter was significantly increased in AFib compared to controls (P < 0.001). In AFib, the largest PV volume and diameters were measured in right superior PV (P < 0.05 versus controls). The difference in PV volume between patients and controls was most pronounced in right superior PVs (P = 0.015). Right middle PVs were found more often in patients with AFib (16/50; 32%) than in normal subjects (7/50; 14%). Conclusion. Enlargement of PV ostial area and enlargement of volume are frequent findings in patients with drug refractory AFib. These parameters may add to the risk stratification for AFib recurrence following RFCA.

The utility of three-dimensional rotational angiography during catheter ablation for atrial fibrillation; comparison with conventional electroanatomical mapping system

Background: Rotational angiography of the left atrium with 3-dimensional reconstruction (3DATG) is a new imaging tool to guide atrial fibrillation (AF) ablation. The purpose of this study was to compare the procedural outcome and radiation exposure of patients with AF treated by catheter ablation using either conventional electroanatomical mapping system (CARTO) or 3DATG. Methods: One hundred twenty-eight consecutive patients with AF treated by Catheter Ablation using either 3D-ATG (75 patients) or CARTO (53 patients) were included. 3DATG was performed by using the Philips Allura Xper FD 10 system operated at a low-frame pulsed fluoroscopy (7.5 frames per second). Intraoperative 3DATG was performed with contrast medium injection directly into the bilateral upper pulmonary veins, during rapid ventricular pacing. Contrast-enhanced computed tomography-fluoroscopy overlay system (CCT) was also performed preoperatively for all patients. We evaluated vertical ostial pulmonary vein (PV) diameters and left atrial (LA) diameter, time needed to perform PV isolation, and radiation exposure for each imaging method. Results: Time required for PV isolation using 3DATG was significantly shorter than that using CARTO (104±31min. vs. 124±41min.; p<0.05). Mean fluoroscopy durations for AF ablation with 3DATG were 63±21 minutes in the anteroposterior (AP) and 51±25 minutes in the left anterior oblique (LAO) projection. The mean radiation exposure measured with air kerma was 356±177 mGy in the AP and 410±358 mGy in the LAO projection. Surface radiation dosage using 3DATG was significantly reduced compared with CCT (0.040±0.021 mGy vs. 1.017±0.205 mGy; p<0.001). The effective dose from CCT was 15.2±4.0 mSv. The vertical PV ostial diameters and the LA diameter in 3DATG almost accorded with those in CCT (left upper PV: 20.3±2.7mm vs. 21.8±4.1mm. r=0.72; p<0.001, right upper PV: 19.5±3.0mm vs. 20.4±3.6mm. r=0.60; p<0.01, LA longitudinal diameter: 66.4±5.2mm vs. 66.8±6.2mm. r=0.79; p<0.001). Conclusion: 3DATG-guided AF ablation has similar radiation exposure and procedural and outcome characteristics compared with CARTO-guided ablation. 3DATG is a reasonable alternative to conventional 3D electroanatomical mapping systems.

Rapid ventricular pacing to optimize rotational angiography in atrial fibrillation ablation

Conventional pulmonary vein (PV) angiography cannot precisely delineate the left atrium (LA)-PV anatomy, which is essential for the ablation of atrial fibrillation (AF). The aim of the study was to test the feasibility of a novel method of rotational angiography for the AF ablation. Forty-one patients were enrolled in this study. CT scanning was performed in all patients before the procedure. Rotational angiography (rotating from right anterior oblique 55 degrees to left anterior oblique 55 degrees ) was performed before AF ablation. Rapid ventricular pacing (RVP, 300 ms) was carried out to reduce cardiac output while contrast medium was injected into the LA via a pigtail catheter. RVP was successfully performed in 36 (87.8%) patients. The ostia of all PVs and the LA appendage were visible in all these 36 cases. There was a good correlation in the PV ostial diameters as assessed by rotational angiography via RVP as compared to CT imaging (r (2) > 0.85). Rotational angiography by RVP is able to delineate the LA-PV anatomy. There is a good correlation in the PV ostial diameters as assessed by rotational angiography via RVP and CT imaging. Rotational angiography by RVP is feasible during AF ablation.

Measurements of pulmonary vein ostial diameter and distance to first bifurcation: A comparison of different measurement methods

The purpose of this study was to evaluate the agreement between axial, multiplanar reformatted (MPR) and semi-automated software measurements of pulmonary vein ostial diameters and distance to the first bifurcation. CT examinations of the thorax were retrospectively reviewed in 150 consecutive patients. The pulmonary vein ostial diameter and distance to the first bifurcation of the four main pulmonary veins were independently measured. The three measurement methods were compared using a Bland–Altman test. There was no significant variation between pulmonary vein ostial diameter measurements for the superior pulmonary veins across the three measurement methods. There was significant variation between the semi-automated program and both the axial ( p = 0.001) and MPR ( p < 0.001) measured diameters for the right inferior pulmonary vein ostial diameter and between the MPR and semi-automated program measurements ( p = 0.02) for the left inferior pulmonary vein ostial diameter. There was no significant variation between the pulmonary vein distance to first bifurcation measurements for any pulmonary vein across the three measurement methods. However, from a clinical perspective, differences were negligible; therefore, the clinician may confidently use any of the three measurement methods presented.

Reliability of MDCT measurements of pulmonary vein ostial diameter and distance to first bifurcation: an interobserver study comparing radiologists with a semiautomated software

The purpose of this study was to evaluate agreement between radiologists and semiautomated software measurements of pulmonary vein ostial diameters and distance to the first bifurcation. Computed tomography (CT) examinations of the thorax were retrospectively reviewed in 50 consecutive patients. The pulmonary vein ostial diameter and distance to the first bifurcation of the four major, and the middle lobe pulmonary veins, were measured independently by two experienced cardiothoracic radiologists, and using CardEP semiautomated software. The two measurement methods were compared. Analyses were performed using a Bland-Altman test. There is no significant variation between readers or between readers and the software in pulmonary vein ostial diameter measurements for the four major pulmonary veins. There is significant variation between the first reader (P = 0.03) and between the second reader and the software (P = 0.01) in vein diameter measurements for the middle lobe vein. And, also between the second reader and the first reader for the right inferior (P = 0.02) and left inferior (P = 0.02) pulmonary vein distance to first bifurcation, and between the second reader and the software for the right inferior (P = 0.01) and left inferior vein (P = 0.02) distance to first bifurcation. There is good interobserver agreement when measuring the major pulmonary vein diameters. Measurements of distances to first bifurcation were less reliable across readers and the readers and the semiautomated software.

Reliability of MDCT in Characterizing Pulmonary Venous Drainage, Diameter and Distance to First Bifurcation: An Interobserver Study

To evaluate the interobserver agreement of readers in evaluating pulmonary venous anatomy and in measuring pulmonary vein ostial diameters and distance to first bifurcation. This study was approved by our institutional review board. Thin-section contrast material-enhanced multidetector computed tomography examinations of the thorax were retrospectively reviewed in 200 consecutive patients (38 females and 162 males), age 24-79 years (mean, 52.8) referred for imaging before radiofrequency ablation therapy for atrial fibrillation. For each patient, pulmonary venous anatomy and drainage patterns including the number of venous ostia was assessed independently by experienced cardiothoracic radiologists. Pulmonary vein ostial diameter and distance to the first bifurcation of the four major pulmonary veins (right inferior and superior, left inferior and superior), the middle lobe pulmonary vein, and any anomalous pulmonary veins (common trunks and accessory veins) were measured independently at a workstation. Interreader assessment of pulmonary venous anatomy was evaluated using the Kappa statistic. Interreader variation in measurements of venous diameter and distant to first bifurcation were estimated by Bland-Altman plots and Pitman's test of difference in variance. Very good to excellent interreader agreement in detection of anomalous pulmonary venous anatomy, middle lobe pulmonary venous drainage, and other thoracic venous anomalies. No significant variation between readers in pulmonary vein ostial diameter measurements for the four major and middle lobe pulmonary veins, or the anomalous pulmonary veins. Significant interreader variability was noted in measurements of the pulmonary vein distance to first bifurcation for the right inferior (P = .017), middle lobe (P = .005), and left inferior (P = .015) pulmonary veins. There is excellent interobserver agreement when evaluating normal and anomalous pulmonary venous drainage patterns, and when measuring normal or anomalous pulmonary vein diameters. However, measurements of distances to first bifurcation were less reliable across readers.

Normative Analysis of Pulmonary Vein Drainage Patterns on Multidetector CT With Measurements of Pulmonary Vein Ostial Diameter and Distance to First Bifurcation

To document the frequency of normal and anomalous drainage patterns of the pulmonary veins, and to establish normal values for pulmonary vein ostial diameters, and distance to first bifurcation using multidetector computed tomography, as pertinent to ablation procedures for atrial fibrillation. Two cardiothoracic radiologists retrospectively reviewed thin-section contrast material-enhanced multidetector computed tomography examinations of the thorax in 200 consecutive patients (38 females and 162 males), age 24-79 years (mean 52.8) referred for imaging before radiofrequency ablation therapy for atrial fibrillation. Pulmonary vein anatomy was based on both the number of venous ostia and the drainage patterns of pulmonary veins. Pulmonary vein ostial diameters and distance to first bifurcation of the four major pulmonary veins (right inferior and superior, left inferior and superior) and any additional pulmonary veins were measured at a workstation using both axial images and multiplanar reconstructions by two experienced cardiothoracic radiologists; the mean pulmonary vein diameter and the shortest distance to first bifurcation of the two measurements are reported. The majority of patients, 82% (164 patients) had four pulmonary veins, with a superior and inferior ostium on the right and a superior and inferior ostium on the left. Of the remainder, 9% (18 patients) had five veins, 4.5% (9 patients) had three veins, 3% (6 patients) had two anomalies each, and 0.5% (1 patient) had three anomalies. The middle lobe pulmonary vein drained into the right superior pulmonary vein in 83.5% of patients, directly into the left atrium in 11% of patients, and into the right inferior pulmonary vein in 5.5% of patients; 6.5% of patients had a single left pulmonary vein ostium. Mean pulmonary vein diameters with 95% confidence intervals at the ostia were as follows: right superior 17.6 (13.64-15.36) mm; left superior 16.6 (16.03-17.08) mm; right inferior 17.1 (16.58-17.55) mm; left inferior 14.8 (14.25-15.27) mm, and independent middle lobe 8.6 (8.27-8.86) mm. Mean distance to first bifurcation with 95% confidence intervals were: right superior 14.5 (17.02-18.23) mm; left superior 17.6 (16.63-18.53) mm; right inferior 7.0 (6.49-7.46) mm; left inferior 13.5 (12.83-14.16) mm, and independent middle lobe 8.4 (7.7-9.17) mm. Thin-section thoracic computed tomography demonstrates a greater variability of pulmonary venous drainage than previously described. There is greater variability of the right lung venous drainage compared to the left lung. Eighty-two percent of people have four standard pulmonary veins. There is significant variability in pulmonary vein diameter and distance to first bifurcation.

Atrial Volume Reduction Following Catheter Ablation of Atrial Fibrillation and Relation to Reduction in Pulmonary Vein Size: An Evaluation Using Magnetic Resonance Angiography

Catheter ablation to achieve pulmonary vein (PV) isolation has become an increasingly used treatment strategy for patients with atrial fibrillation (AF). The purpose of this study was to evaluate the impact of segmental isolation of PVs on volume of left atrium and its relation to the decrease in the size of the pulmonary veins. Gadolinium enhanced Magnetic Resonance Angiography (MRA) was performed in 51 AF patients before and 6 approximately 8 weeks post PV isolation, using cooled radio-frequency (RF) energy. Three-dimensional reconstruction with maximum intensity projections and multiplanar reformations was performed. Oblique coronal projections were used to measure the ostial size of PVs. Three orthogonal dimensions of LA chamber were measured and computed to assess the volume of the left atrium. The mean LA volume decreased by 15.7% after ablation (p<0.001). The mean PV ostial diameter decreased by 11%, from 18.3+/-0.8 mm to 16.7+/-1.0 mm (p=0.005). Moderate PV stenosis was noted in two veins out of the 192 veins analyzed. There was a significant correlation between changes in the size of PV ostium to that of the LA. Catheter ablation of AF using a segmental PV isolation approach results in a significant reverse remodeling in the left atrium. Significant stenosis of PVs appears to be rare after the segmental isolation procedure.

Comparison of pulmonary vein ostial diameters by computed tomography and phased array intracardiac echocardiography during radiofrequency ablation of atrial fibrillation

Background: Pulmonary vein (PV) ostial diameters are measured to assist with decisions regarding optimal equipment during ablation of atrial fibrillation and to assess for post ablation stenosis. Knowing the diameter may assist choice of the multipolar loop catheter diameter for ideal mapping and ablation of the arrythmogenic foci at the perimeter of the PV ostia. Fluoroscopic venography relies on projections that may result in inaccurate estimation of PV diameters. Better methods may exist for making these important determinations including helical computerized tomography with 3 dimensional reconstruction (CT) and phased array intracardiac echocardiography (ICE).

Pulmonary Vein Imaging: Comparison of 3D Magnetic Resonance Angiography with 2D Cine MRI for Characterizing Anatomy and Size

Pulmonary vein imaging is integral for planning atrial fibrillation ablation procedures. We tested the feasibility of quantifying pulmonary vein ostial diameter using two-dimensional cine cardiac magnetic resonance (2D cine CMR) and three-dimensional magnetic resonance angiography (3D MRA). Nine patients with a history of atrial fibrillation and 20 normal volunteers underwent 2D cine CMR and contrast-enhanced 3D MRA of pulmonary veins on a 1.5 T scanner. Pulmonary vein ostial diameters were measured and pulmonary vein vessel border sharpness was graded qualitatively. Both techniques provided excellent pulmonary vein imaging; however, 3D MRA was faster to perform. The average difference between the systolic and diastolic pulmonary vein diameter was 2.5 mm (23.2%, p < 0.0001) in normal volunteers and 2.2 mm (16.9%, p < 0.0001) in atrial fibrillation patients. The ostial diameter measurements by 3D MRA were significantly larger than on 2D cine CMR. Additionally, the pulmonary vein borders appeared sharper with 2D cine CMR compared to 3D MRA. In conclusion, the 2D images can resolve differences in diameter across the cardiac cycle, while the 3D images provide high quality anatomical depiction but blur borders due to pulsatile motion. We suggest a protocol combining 2D cine CMR and 3D MRA for comprehensive evaluation of pulmonary veins.

Transvenous Catheter Cryoablation for Treatment of Atrial Fibrillation:

Pulmonary vein (PV) isolation using radiofrequency (RF) ablation can induce PV stenosis. Cryoablation may offer a safer alternative energy source for PV isolation. PV isolation with cryoablation was attempted in 31 patients with paroxysmal atrial fibrillation (AF). Event monitors were used to measure the AF episode burden. Serial spiral CT scans were obtained to monitor PV stenosis pre- and postcryoablation. Cryoablation was immediately successful for PV isolation in 29 of 31 patients (94%), with 5.9 +/- 1.2 months of follow-up. Additional RF ablation was performed for AF recurrences in seven patients. The remaining 22 patients with a single cryoablation procedure demonstrated a time-dependent, long-term reduction in the frequency of AF episodes. At 6 months of follow-up, 18 of 22 of cryo-treated only patients (82%) were free of symptomatic AF episodes, and antiarrhythmic drugs were discontinued in 12 of 22 patients. Serial spiral CT scans demonstrated no change in the cryo-treated PV ostial diameter. PV cryoablation was effective to control paroxysmal AF in most patients. Early recurrences of AF postcryoablation were common, though tended to resolve within 6 months postablation, consistent with a process of reverse atrial remodeling. Cryoablation of the PVs did not cause PV stenosis or other serious adverse events.

Anatomical observations of the pulmonary veins with intracardiac echocardiography and hemodynamic consequences of narrowing of pulmonary vein ostial diameters after radiofrequency catheter ablation of atrial fibrillation

Intracardiac echocardiography was used to explore pulmonary venous (PV) anatomy and to monitor PV stenosis in 31 patients referred for radiofrequency catheter ablation at PV ostia. Interindividual variations in PV anatomy and insertion in the left atrium were observed. Narrowing of PV ostia after radiofrequency catheter ablation did not produce significant hemodynamic changes.

A comparison of pulmonary vein ostial anatomy by computerized tomography, echocardiography, and venography in patients with atrial fibrillation having radiofrequency catheter ablation

Accurate assessment of pulmonary vein anatomy is important to procedures that isolate these structures in patients with atrial fibrillation. Various modalities of pulmonary vein (PV) imaging are employed in clinical practice; however, the consistency of findings among the different modalities is unknown. The purpose of this study is to compare PV ostial anatomy by 4 common imaging techniques. Twenty-four patients undergoing catheter-based PV isolation procedures for atrial fibrillation had their PV ostial anatomy determined by cardiac computerized tomography (CT) and transesophageal echocardiography (TEE) before ablation and by intracardiac echocardiography (ICE) and venography during the ablation procedure. The number and maximal dimension of the PV ostia were determined by each imaging modality. In the 24 patients, 98 PV ostia were visualized by CT, 93 by ICE, 81 by TEE, and 71 by venography. The average ostial diameters were similar between CT (1.45 ± 0.29 cm) and ICE (1.51 ± 0.22 cm, p = 0.066). Compared with CT or ICE, the ostial diameters were larger with venography (1.67 ± 0.32 cm) and smaller with TEE (1.16 ± 0.28 cm, all p <0.001). PV ostial diameters as determined by ICE were significantly correlated with CT measurements (r = 0.57, p <0.001) and venography (r = 0.52, p <0.001). Venography measures of PV diameter were correlated with measures by CT (r = 0.33, p = 0.03). TEE measures were not correlated with any other modality (all p ≥0.43). CT identifies the greatest number of PV ostia followed by ICE. Venography overestimates and TEE underestimates ostial diameters compared with CT or ICE. The PV ostial dimensions obtained by ICE, CT, and venography are all significantly correlated.