Pulmonary Vein Morphology Research Articles

DECNet: Left Atrial Pulmonary Vein Class Imbalance Classification Network.

In clinical practice, the anatomical classification of pulmonary veins plays a crucial role in the preoperative assessment of atrial fibrillation radiofrequency ablation surgery. Accurate classification of pulmonary vein anatomy assists physicians in selecting appropriate mapping electrodes and avoids causing pulmonary arterial hypertension. Due to the diverse and subtly different anatomical classifications of pulmonary veins, as well as the imbalance in data distribution, deep learning models often exhibit poor expression capability in extracting deep features, leading to misjudgments and affecting classification accuracy. Therefore, in order to solve the problem of unbalanced classification of left atrial pulmonary veins, this paper proposes a network integrating multi-scale feature-enhanced attention and dual-feature extraction classifiers, called DECNet. The multi-scale feature-enhanced attention utilizes multi-scale information to guide the reinforcement of deep features, generating channel weights and spatial weights to enhance the expression capability of deep features. The dual-feature extraction classifier assigns a fixed number of channels to each category, equally evaluating all categories, thus alleviating the learning bias and overfitting caused by data imbalance. By combining the two, the expression capability of deep features is strengthened, achieving accurate classification of left atrial pulmonary vein morphology and providing support for subsequent clinical treatment. The proposed method is evaluated on datasets provided by the People's Hospital of Liaoning Province and the publicly available DermaMNIST dataset, achieving average accuracies of 78.81% and 83.44%, respectively, demonstrating the effectiveness of the proposed approach.

Pulmonary Vein Morphology in Patients Undergoing Catheter Ablation of Atrial Fibrillation.

Variations in the anatomy of pulmonary veins can influence selection of approaches of atrial fibrillation catheter ablation. Therefore, preprocedural evaluation and knowledge of pulmonary veins anatomy is crucial for proper mapping and the successful ablation of atrial fibrillation. The aim of this observational study was to assess CT angiography scans and perform detailed analysis of pulmonary veins morphology in patients scheduled for catheter ablation of atrial fibrillation. CT angiography was performed in 771 individuals (223 females, 548 males, mean age 58.4 ± 10.7years). Pulmonary veins anatomy was evaluated using 3D models. The patterns used for evaluation included typical anatomy with four separate pulmonary veins, a common left ostium, and various types of accessory veins either alone or in combination with common left ostia. An anatomical variant with common left ostium was observed as the most prevalent anatomy (44%). The typical variant was observed in 34.8% of patients. Accessory pulmonary veins were observed predominantly on the right side. The prevalence of anatomical variants did not differ between sexes with the exception of the unclassifiable category U (4.4% vs. 9%, p < 0.05). Our study shows that a considerable number of atypical anatomies is present in patients undergoing AF catheter ablation. This knowledge may influence the choice of instrumentation. The data could be possibly helpful also in development of new ablation techniques.

Abstract 18852: Machine Learning to Predict Atrial Fibrillation Recurrence Using Pulmonary Vein Morphology

Introduction: Predicting risk of recurrence and sites of recurrence after atrial fibrillation (AF) ablation help direct ablation strategies. While the left atrium (LA) has been implicated as a possible site of AF recurrence leading to ablation directed toward LA substrates, reconnection of pulmonary veins (PVs) has been observed as a mechanism of recurrence on repeat ablations. Hypothesis: Regions of statistical shape differences between AF recurrence (AF+) and non-recurrence patients (AF-) within the PV on a CT scan might be associated with sites of recurrence, that features extracted from these regions may be better predictors of AF recurrence. Methods: A Hierarchical Atlas construction method for PV branching shape analysis was developed. Patients with the median volume of LA plus PV in each cohort were selected as the templates. All CT scans in each cohort were registered to the cohort’s template. Then, each branch was individually registered to the branch’s template and resulting control points applied to the LA and other PV branches to maintain connectivity. This process was repeated with 6 iterations to better adjust branching. Two separate atlases of AF+ and AF- were constructed. The areas of significant shape differences on the PV, surfaces of interest (SOIs), between the two groups were obtained via a General Linear Model based t-test on the atlases. Normal and curvature-based features were extracted from SOI regions. A Gradient Boosting classifier was trained based on these features. Cross-validation and atlas construction involved 104 cases. 50 cases served as a holdout set. Results: The classifier trained on SOI features on CT scans achieved AUCs of 0.76 (cross-validation) and 0.74 (holdout set). SOIs include sites within the left superior PV and the right PV carina. Conclusions: This finding appears to suggest that SOI regions on PVs tend to be associated with recurrence and hence may be candidate sites for additional ablation for preventing recurrence of AF.

Pulmonary Veins Morphometric Characteristics and Spatial Orientation Influence on Its Cryoballoon Isolation Results.

The aim of this paper is to evaluate the effect of pulmonary vein (PV) morphometric characteristics and spatial orientation on the results of cryoballoon ablation (CBA). Methods: A randomized, prospective, single-center controlled study was conducted, enrolling 230 patients with drug-refractory atrial fibrillation (AF). We compared procedural and long-term outcomes in patients who underwent their first procedure of pulmonary vein isolation (PVI) for AF with either radiofrequency ablation (RFA) (n = 108) or CBA (n = 122) and assessed their interaction with the different pattern of PV anatomy, morphometric characteristics, and spatial orientation. The primary efficacy endpoint was any documented atrial arrhythmia recurrence (AF, atrial flutter, or atrial tachycardia) lasting over 30 s during a 12-month follow-up after a 90-day blanking period and discontinuation of antiarrhythmic drugs. The procedure’s endpoint was the achievement of PVI. Before the intervention, all patients underwent computed tomography (CT) to assess the PV anatomical variant, maximum and minimum diameters of the PV’s ostia, their cross-sectional area, orifice ovality index, and PV tilt angles. Results: The mean follow-up period was 14 months (12; 24). Long-term efficacy in the cryoablation group was 78.8% and in the RFA group—83.3% (OR = 0.74; 95% CI 0.41–1.3; p = 0.31). The RFA results did not depend on PV anatomy. The «difficult» occlusion of the right inferior PV (RIPV) occurred in 12 patients and was associated with a more horizontal PV position in the frontal plane; the mean tilt angle was −15.2 ± 6.2° versus −26.5 ± 6.3° in the absence of technical difficulties (p = 0.0001). In 11 cases (9%), during ablation of the right superior PV (RSPV), phrenic nerve injury (PNI) occurred and was associated with the maximum and minimum RSPV diameter, 20.0–20.4 mm (OR = 13.2; 95% CI: 4.7–41.9, p < 0.05) and 17.5–20 mm (OR = 12.5; 95% CI 3.4–51, p < 0.05), respectively. Patients with arrhythmia recurrence were characterized by significantly larger diameters and ovality of the left superior PV (LSPV). The spatial orientation of the PV does not affect the long-term results of cryoablation. Conclusion: Preprocedural evaluation of PV morphology and orientation using cardiac CT might help choose the optimal technology for the individual patient.

New Radiomic Markers of Pulmonary Vein Morphology Associated With Post-Ablation Recurrence of Atrial Fibrillation.

Objective: To identify radiomic and clinical features associated with post-ablation recurrence of AF, given that cardiac morphologic changes are associated with persistent atrial fibrillation (AF), and initiating triggers of AF often arise from the pulmonary veins which are targeted in ablation. Methods: Subjects with pre-ablation contrast CT scans prior to first-time catheter ablation for AF between 2014–2016 were retrospectively identified. A training dataset (D1) was constructed from left atrial and pulmonary vein morphometric features extracted from equal numbers of consecutively included subjects with and without AF recurrence determined at 1 year. The top-performing combination of feature selection and classifier methods based on C-statistic was evaluated on a validation dataset (D2), composed of subjects retrospectively identified between 2005–2010. Clinical models (n}{}text{M}_{mathrm {C}}n) were similarly evaluated and compared to radiomic (n}{}text{M}_{mathrm {R}}n) and radiomic-clinical models (n}{}text{M}_{mathrm {RC}}n), each independently validated on D2. Results: Of 150 subjects in D1, 108 received radiofrequency ablation and 42 received cryoballoon. Radiomic features of recurrence included greater right carina angle, reduced anterior-posterior atrial diameter, greater atrial volume normalized to height, and steeper right inferior pulmonary vein angle. Clinical features predicting recurrence included older age, greater BMI, hypertension, and warfarin use; apixaban use was associated with reduced recurrence. AF recurrence was predicted with radio-frequency ablation models on D2 subjects with C-statistics of 0.68, 0.63, and 0.70 for radiomic, clinical, and combined feature models, though these were not prognostic in patients treated with cryoballoon. Conclusions: Pulmonary vein morphology associated with increased likelihood of AF recurrence within 1 year of catheter ablation was identified on cardiac CT. Significance: Radiomic and clinical features-based predictive models may assist in identifying atrial fibrillation ablation candidates with greatest likelihood of successful outcome.

Left atrial, pulmonary vein, and left atrial appendage anatomy in Indigenous individuals: Implications for atrial fibrillation.

BackgroundIndigenous Australians experience a greater burden of AF. Whether this is in-part due to differences in arrhythmogenic structures that appear to contribute to AF differences amongst other ethnicities is not known.MethodsWe studied forty individuals matched for ethnicity and other AF risk factors. Computed tomography imaging was used to characterise left atrial (LA), pulmonary vein (PV), and left atrial appendage (LAA) anatomy.ResultsThere were no significant differences in LA diameters or volumes between Indigenous and non-Indigenous Australians. Similarly, we could not detect any consistent differences in PV number, morphology, diameters, or ostial characteristics according to ethnicity. LAA analyses suggested that Indigenous Australians may have a greater proportion of non chickenwing LAA type, and a tendency for eccentric, oval-shaped LAA ostia; however, there were no other differences seen with regards to LAA volume or depth. Indexed values for LA, PV and LAA anatomy corrected for body size were broadly similar.ConclusionsIn a cohort of individuals matched for AF risk factors, we could find no strong evidence of ethnic differences in LA, PV, and LAA characteristics that may explain a predisposition of Indigenous Australians for atrial arrhythmogenesis. These findings, in conjunction with our previous data showing highly prevalent cardiometabolic risk factors in Indigenous Australians with AF, suggest that it is these conditions that are more likely responsible for the AF substrate in these individuals. Continued efforts should therefore be directed towards risk factor management in an attempt to prevent and minimise the effects of AF in Indigenous Australians.

Interatrial distance predicts the necessity of additional carina ablation to isolate the right-sided pulmonary veins.

BackgroundAblation of the pulmonary vein (PV) carina is occasionally required for PV isolation (PVI). Marshall bundle and epicardial connections between the right-sided PV (RtPV) carina and right atrium (RA) may be one of the mechanisms that necessitates carina ablation.ObjectiveWe sought to clarify anatomical characteristics predictive of the necessity of carina ablation.MethodsForty-five consecutive patients undergoing radiofrequency catheter ablation of atrial fibrillation were prospectively included in this study. Left atrial (LA) and PV size and morphology, and interatrial distance in the posterior aspect, were measured on cardiac computed tomography (CT) images.ResultsFor right-sided PVI, the patients were divided into 2 groups based on the necessity of RtPV carina ablation, Carina-ABL group (n = 21) and Non-Carina-ABL group (n = 24). The distance between the anterior portion of the RtPV carina and RA was shorter in the Carina-ABL group vs in the Non-Carina-ABL group (7.7 ± 1.7 mm/m2 vs 9.5 ± 2.3 mm/m2; P = .005), whereas other anatomical parameters (LA and RA volumes, right inferior PV angle, and ostial diameters of the RtPVs) did not differ between the groups. For left-sided PVI, the ostial diameter and circumference of the left superior PV were smaller in the Carina-ABL group (n = 13) vs the Non-Carina-ABL group (n = 32) (8.6 ± 2.1 mm/m2 vs 7.3 ± 1.5 mm/m2; P = .044, and 34.9 ± 6.0 mm/m2 vs 30.1 ± 5.1 mm/m2; P = .017, respectively).ConclusionsA shorter interatrial distance for right-sided PVI and a smaller PV ostium for left-sided PVI were associated with the necessity of additional carina ablation. The presence and location of the epicardial fibers may be affected by the atrial and PV geometry.

Comparison of Echocardiography and Computed Tomography/Magnetic Resonance Imaging for Assessing of Pulmonary Vein Stenosis in Children

Pulmonary vein (PV) stenosis is a rare disease with high recurrence and mortality rates.&#x0D; Objective. This study was aimed to evaluate the diagnostic accuracy of echocardiography versus cross-sectional modalities.&#x0D; Material and methods. Our study includes 11 consecutive patients who underwent a comprehensive PV anatomy assessment between April 2018 and June 2019 at Ukrainian Children’s Cardiac Center, Kyiv. Echocardiographic studies of each pulmonary vein followed by computed tomography (CT) or magnetic resonance imaging (MRI) were performed in all patients. A total of 27 CT/MRI studies were performed.&#x0D; Results. There were four patients whose echocardiography findings were completely confirmed by CT/MRI method. In some patients significant stenosis was underestimated by echocardiography. Sensitivity and specificity were 86.4 and 88.9 for echo, as well as 100 and 94.4 for CT/MRI, respectively.&#x0D; Conclusion. This study recognizes the limitations of echocardiography as an imaging tool for pulmonary veins morphology assessment. Cross-sectional studies overcome these limitations and provide excellent morphological as well as functional (MRI) evaluation of pulmonary veins.

P1911The impact of pulmonary vein morphology and orientation on the outcomes of cryoballoon ablation in patients with paroxysmal atrial fibrillation

Abstract Background Circumferential contact of cryoballoon and pulmonary vein (PV) ostium is an important factor for pulmonary vein isolation (PVI). PV ostium shape and orientation can make challenges for PV occlusion. Purpose We aimed to assess the impact of pulmonary vein morphology and orientation on cryoablation outcomes in patients with paroxysmal AF. Material and methods The single-center prospective study included 122 patients (males: 46.7% (57), mean age 57 (53; 62) with drug-refractory paroxysmal AF. The mean AF duration was 4 years (2; 4). A multislice cardiac computed tomography (MSCT) was performed prior to CBA in order to evaluate the PV anatomy (maximal and minimal ostium diameters, ovality of PV ostium, angle of PV orientation in the frontal and axial plane (Figure1)). The presence of typical anatomy (4 separate ostia of PVs) was inclusion criteria. Procedures were performed with 28-mm second generation balloon. A procedural endpoint was the achievement of PVI. Outcomes of PVI were defined as freedom from any AF episodes documented by ECG from the end of blanking period to 12 months. Results PVI was achieved in 97.5% of PVs (476/488). Freedom from AF was 78.7%. Difficult occlusion of right inferior PV was observed in 12 patients and associated with a more horizontal PV orientation in the frontal plane: −15.2±6.20 versus −26.5±6.3°, p&lt;0.001. A total of 11 (9%) patients experienced transient phrenic nerve injury (PNI) during ablation of right superior PV (RSPV). PNI was associated with the maximum and minimum diameter of the RSPV 20.0–24.0 mm (OR=13,2; 95% CI: 3.4–51; p&lt;0.05) and 17.5–20.0 mm (OR=12.5; 95% CI: 4.7–41.9; p&lt;0.05), respectively. Patients with AF recurrence had significantly larger maximum and minimum diameters of left superior PV (LSPV): 18.8 versus 17.5 mm, p=0.048, and 13.4 versus 12.5 mm, p=0.05, respectively. Ovality of PV ostium was larger in the recurrence group: 0.36 versus 0.18, p=0.05. Figure 1. Evaluation of PV orientation Conclusions Evaluation of PV morphology and orientation can be used to predict CBA results. AF recurrence was associated with larger diameters and ovality of LSPV ostium. More horizontal RIPV orientation was associated with difficult PV occlusion. RSPV morphology can affect safety of procedure.

Pulmonary vein anatomy addressed by computed tomography and relation to success of second-generation cryoballoon ablation in paroxysmal atrial fibrillation.

BackgroundCryoballoon isolation is considered a safe and effective treatment for atrial fibrillation (AF). However, recurrence of AF after first cryoballoon ablation occurs in ~30% of patients. Pre‐procedurally identifying patients at risk of AF recurrence could be beneficial.HypothesisOur aim was to determine how pulmonary vein (PV) anatomy influences the recurrence of AF using the second‐generation cryoballoon in patients with paroxysmal AF.MethodsWe included 88 consecutive patients with paroxysmal AF undergoing PVI procedure with a second‐generation 28‐mm cryoballoon. All patients were evaluated at 3, 6 and 12 months using a 12‐lead ECG and 24‐hour Holter monitoring. PV anatomy was assessed by creating three‐dimensional models using computed tomography (CT) segmentations of the left atrium.ResultsFifty‐one patients (61%) had left PVs with a shared carina, 35 patients (42%) had a shared right carina. Nine patients (11%) were classified having a right middle PV. In total 17 (20.2%) of patients had a left common PV. At 12 months, 14 patients (17%) had experienced AF recurrence. Neither PV ovality, variant anatomy, the presence of shared carina nor a common left PV was a predictor for AF recurrence.ConclusionsNo specific characteristics of PV dimensions nor morphology were associated with AF recurrence after cryoballoon ablation in patients with paroxysmal AF.

Morphology and morphometry of pulmonary veins and the left atrium in multi-slice computed tomography

PurposePulmonary veins are involved in pathogenesis and treatment of atrial fibrillation and structures at risk during thoracic surgeries. There is lack of data regarding pulmonary vein morphology and morphometry in normal population.MethodsThe study was conducted using 135 chest computed tomography studies with intra-venous iodine contrast injection. The study population contained 86 females and 49 males, mean age was 60. 13 had atrial fibrillation. The studies were analyzed using radiological workstation.ResultsMean dimensions of the left atrium: transverse 52 mm, coronal 49 mm, and sagittal 35 mm. The mean volume of the left atrium was 93 cm3. The mean volume of the left atrium in patients with atrial fibrillation was 176 cm3. The sagittal dimension and the volume of the left atrium were correlated with age, r = 0.43 and r = 0.42, respectively. Surface area of the left inferior pulmonary vein ostium was 136 mm2, significantly less than the surface area of other ostia of pulmonary veins. The mean distance between two pulmonary veins was 5.42 mm on the right and 4.02 mm on the left side. 13 types of pulmonary veins outflow patterns were described on the right side and 5 types on the left side. 66.7% of right pulmonary veins and 82% of the left pulmonary veins emptied into the left atrium with two venous trunks on each side (the typical pattern).ConclusionsMorphological features of pulmonary veins and morphometry of the left atrium and pulmonary veins are important for clinical purposes and are in accordance with previous papers.

The predictive value of cardiac morphology for long-term outcome of patients undergoing catheter ablation for atrial fibrillation

ObjectiveCatheter ablation (CA) is an established therapy for selected patients with atrial fibrillation (AF), but predictors of CA ablation outcome are still not fully elucidated. The aim of the study was to identify structural and morphological parameters from computed tomography (CT) as predictors of successful CA of AF in a single center prospective cohort. MethodsAn analysis of CT scans dedicated to LA evaluation was performed in 99 patients (63 ± 8 years old, 70% males, 59% paroxysmal AF) scheduled for CA of AF. Survival free of atrial fibrillation/flutter/tachycardia at 1- and 3-years was assessed. ResultsIn overall study population, both 1- and 3-year responders had smaller distance to the first division in left superior pulmonary vein (16.3 ± 5.42 mm vs. 19.1 ± 7.0 mm and 14.9 ± 3.6 mm vs. 18.7 ± 7.0 mm; p < 0.05). One-year responders had larger ostium area of left inferior pulmonary vein (median 236 mm2 [IQR = 97] vs. 222 mm2 [IQR = 71]; p = 0.03) and less acute angle between the interatrial septum and the right superior pulmonary vein (102 ± 20° vs. 95 ± 10°; p = 0.03). Three-years' responders had smaller ostium area of the right superior pulmonary vein (248 ± 94 mm2 vs. 364 ± 282 mm2; p = 0.02). Multivariate Cox regression analysis identified different predictors in paroxysmal and non-paroxysmal AF. For patients with paroxysmal AF, the predictors were angle to right superior pulmonary vein and left superior/inferior pulmonary veins carina thickness with hazard ratios of 0.965 (95%CI 0.939 to 0.992, p = 0.010) and 0.747 (95%CI 0.591 to 0.944, p = 0.015). In patients with persistent AF, the predictors were gender and NYHA stage with hazard ratios of 4.9 (95%CI 1.758 to 13.579, p = 0.002) and 0.365 (95%CI 0.148 to 0.899, p = 0.028) respectively. ConclusionsThe anatomy of LA, especially morphology of pulmonary veins, seems to be one of the predictors of clinical outcome after CA for paroxysmal AF. In non-paroxysmal AF LA anatomy is less relevant in prediction of clinical outcome.

Incidence and Factors Associated With the Occurrence of Pulmonary Vein Narrowing After Cryoballoon Ablation.

In contrast with traditional radiofrequency ablation, little is known about the influence of cryoballoon ablation on the morphology of pulmonary veins (PVs). We evaluated the influence of cryoballoon ablation on the PV dimension (PVD) and investigated the factors associated with a reduction of the PVD. Seventy-four patients who underwent cryoballoon ablation for paroxysmal atrial fibrillation were included in the present study. All subjects underwent contrast-enhanced computed tomography both before and at 3 months after the procedure. The PVD (cross-sectional area) was measured using a 3-dimensional electroanatomical mapping system. Each PV was evaluated according to the PVD reduction rate (ΔPVD), which was calculated as follows: (1-post-PVD/pre-PVD)×100 (%). Ninety-two percent of the PVs (271/296) were successfully isolated only by cryoballoon ablation; the remaining 8% of the PVs required touch-up ablation and were excluded from the analysis. Mild (25%-50%), moderate (50%-75%), and severe (≥75%) ΔPVD values were observed in 87, 14, and 3 PVs, respectively, including 1 case with severe left superior PV stenosis (ΔPVD: 94%) in a patient who required PV angioplasty. In multivariable analysis, a larger PV ostium and lower minimum freezing temperature during cryoballoon ablation were independently associated with PV narrowing (odds ratio, 1.773; P=0.01; and odds ratio, 1.137; P<0.001, respectively). A reduction of the PVD was often observed after cryoballoon ablation for atrial fibrillation. A larger PV ostium and lower minimum freezing temperature during cryoballoon ablation were associated with an increased risk of PVD reduction.

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.

Pulmonary vein morphology by free‐breathing whole heart magnetic resonance imaging at 3 tesla versus breathhold multi‐detector computed tomography

To compare pulmonary vein and left atrial anatomy using three-dimensional free-breathing whole-heart magnetic resonance imaging (MR) at 3 Tesla (T) and multi-detector computed tomography (MDCT). Thirty-three subjects (19 male, age 49 ± 12 years) underwent free-breathing 3T MR and contrast-enhanced MDCT during inspiratory breath hold. Pulmonary vein parameters (ostial areas, diameters, angles) were measured. All pulmonary veins and anomalies were identified by 3T MR and by MDCT. The right-sided pulmonary veins were directed more posteriorly, the right superior pulmonary vein more inferiorly, and the right inferior pulmonary vein more superiorly by 3T MR when compared with MDCT. The cross-sectional area, perimeters and minimum diameters of right-sided pulmonary vein ostia were significantly larger by MR, as were the maximum diameters of right and left inferior pulmonary veins. There were no significant differences between techniques in distance to first pulmonary vein branch. Pulmonary vein measurements demonstrated significant differences in angulations and dimensions when 3T MR is compared with MDCT. These differences likely represent hemodynamic and respiratory variation during free-breathing with MR versus breath-holding with MDCT. MR imaging at 3T during free-breathing offers an alternate method to define pulmonary vein and left atrial anatomy without exposure to radiation.

Anatomical basis of minimally invasive epicardial ablation of atrial fibrillation

Minimally invasive atrial fibrillation surgery (MIAFS) has become a well established and increasingly used option for managing patients with stand-alone arrhythmia. Pulmonary veins (PVs) isolation continues to be the cornerstone of ablation strategies. Indeed, in most cases, atrial fibrillation (AF) is triggered in or near the PVs. Nevertheless, ectopic beats initiating AF may occasionally arise from non-PV foci. The knowledge of the anatomy and underlying morphology of PVs and non-PV foci is essential for cardiac surgeons treating AF patients with epicardial minimally invasive procedures. The anatomical structures relevant to the pathogenesis and the epicardial treatment of AF include the PVs, the pericardial space, the pericardial sinuses, the phrenic nerve, the left atrium, the retro-atrial and caval ganglionated plexuses, the ligament of Marshall, the caval veins and the left atrial appendage. In this review, we briefly describe the basic anatomy of these structures and discuss their specific correlations for cardiac surgeons interested in performing MIAFS.

Catheter Ablation of Atrial Fibrillation in Patients With Chronic Lung Disease

Chronic lung disease (CLD) is one of the important underlying diseases of atrial fibrillation (AF). The outcomes after radiofrequency catheter ablation of AF in patients with CLD have not yet been reported. We investigated the electroanatomic alterations in pulmonary veins (PVs) in CLD patients with AF and assessed their effect on the outcomes of radiofrequency catheter ablation of AF. We assessed 15 patients who had CLD and underwent radiofrequency catheter ablation of AF. CLD included chronic obstructive pulmonary disease, a tuberculosis-destroyed lung, and interstitial lung disease. For controls, we selected 60 sex-, age-, and procedure era-matched non-CLD patients who received radiofrequency catheter ablation for AF (4 controls for each CLD patient). Eight patients had chronic obstructive pulmonary disease, 6 had a tuberculosis-destroyed lung, and 1 had interstitial lung disease. PV morphology in the affected lung was altered significantly, ie, obliteration, pulling of the PVs toward the destroyed lung, or compensatory bulging of the PV antrum. These alterations were related to arrhythmogenicity in 6 (40%) of 15 patients with CLD. Non-PV foci were more common in the CLD group (4/15, 26.7%) than in the control group (3/60, 5.0%; P=0.025). All non-PV foci were located in the right atrium. The AF recurrence rate in the CLD group (26.7%, 4/15) was similar to that in the control group (18.3%, 11/60; P=0.45). Significant alteration of PV anatomy was related to arrhythmogenicity, and non-PV foci from the right atrium were commonly observed in the CLD group. Radiofrequency catheter ablation can be performed safely for AF in CLD patients with a comparable success rate to that in patients with normal lungs.

Coexistence of Left-Sided Atrioventricular Accessory Pathways With a Common Inferior Pulmonary Vein Ostium

As the technique for radiofrequency catheter ablation for atrial fibrillation (AF) has progressed, so has our knowledge of both normal and abnormal anatomy of the left atrium and pulmonary veins (PV). We treated several AF patients with accessory conduction pathways (ACP) who were also found to have a common ostium of inferior PVs (CIPV), a relatively rare PV anomaly. No relation between ACP and PV anomalies has ever been reported, and the aim of our study was to study this association. This study included 137 consecutive patients (104 men; mean age, 60±9 years) who underwent AF ablation for paroxysmal and persistent AF at our institution from March 2009 to August 2010. We analyzed coexisting supraventricular tachycardias and left atrium and PV morphology by multidetector row CT. Thirty-eight of 137 patients (27.7%) were found to have some PV anomaly, consisting of 13 with a common trunk of left PV, 19 with right additional PV, 3 with a common trunk of right PV, and 3 with CIPV. Thirty-one patients (22.6%) had supraventricular tachycardias. They were 26 cases of atrial flutter, 4 of Wolff-Parkinson-White syndrome, and 3 of atrioventricular nodal reentrant tachycardia. The prevalence of a coexisting ACP was significantly higher in patients with CIPV than in those without CIPV (3 of 3 [100%] versus 1 in 134 [0.7%]; P<0.0001). All ACPs with CIPV were located in the left side. The other supraventricular tachycardias were not associated with any PV anomalies. There is a possible association between CIPV and left-sided ACP in AF patients. This suggests that there is a likelihood of developmental association between them.

187 Incidental extracardiac findings on cardiac computed tomography performed before radiofrequency ablation of atrial fibrillation

Radiofrequency ablation has became a validated technique to cure symptomatic refractory atrial fibrillation (AF). Cardiac computed tomography (CT) is used to evaluate the left atrial (AT) anatomy in order to improve the ablation technique. The analysis of non-cardiac structures during cardiac CT may identify clinically significant incidental findings (IF). The objective of this study was to determine the prevalence of IF in patients undergoing AF catheter ablation. Between February 2006 and March 2010, patients undergoing a procedure of AF or left atrial tachycardia (LAT) ablation were enrolled and underwent a cardiac CT scan. Extracardiac IF were considered to be present if an abnormality was identified without previous clinical suspicion or known disease. 250 patients (55.2 ± 9.6 years of age, 82.4% men) were enrolled (133 paroxysmal, 43 persistent, 58 permanent AF and 16 LAT). Fifty-eight patients (23.2%) had a total of 76 IF. Patients with IF were significantly older (59.5 ± 8.2 vs 53.8 ± 9.7 years old, p<0.001). No relationship exist between the type of arrhythmia and the existence of IF. The majority of IF were pulmonary (50%). Two lung cancers were discovered. Cardiac CT scan is a useful tool to evaluate LA and pulmonary veins morphology before AF ablation. However, as a considerable prevalence of IF was found in our study, extracardiac structures should be routinely analyzed to detect unknown diseases. Organ Incidental findings n Lungs (n = 38) Emphysema 12 Atelectasis 6 Bronchic syndrome 6 Bronchectasis 5 Fibrosis 2 Pleural effusion 2 Lung cancer 2 Interstitial Pneumonia 1 Pleural calcifications 1 Asbestosis 1 Mediastinum (n = 15) Adenopathy 15 Vasculature (n = 11) Aorta dilation 9 Aorta ulceration 1 Pulmonary arteries anomalies 1 Liver (n = 5) Nodule 3 Cyst 2 Coronary arteries (n = 2) Congenital coronary arteries anomalies 2 Other (n = 5) Hiatal hernia 2 Kidney cyst 1 Pericardial calcifications 1 Thymus relicate 1

Magnetic Resonance Imaging Versus Computed Tomography for Characterization of Pulmonary Vein Morphology Before Radiofrequency Catheter Ablation of Atrial Fibrillation

The accurate assessment of pulmonary vein (PV) anatomy is important in planning radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF). The aim of the present study was to perform a head-to-head comparison of magnetic resonance imaging (MRI) and multislice computed tomography (CT) for the evaluation of PV morphology before RFCA of AF. Contrast-enhanced MRI (on a 1.5-T system) and multislice CT (on a dual-source system) were performed for the evaluation of the PVs in 44 consecutive patients (31 men, mean age 56 +/- 10 years) admitted for RFCA of drug-refractory AF. Data on PV anatomy, ostial branching pattern, and ostial dimensions were compared between MRI and multislice CT. Variant PV anatomy was observed in 21 patients (48%) with the 2 imaging approaches. The incidence of PV ostial branching, as assessed with MRI and multislice CT, was higher on the right and more common in the inferior than superior vein. Agreement between the 2 imaging modalities for the evaluation of variant PV anatomy (kappa = 0.87, 95% confidence interval 0.77 to 0.97) and ostial branching pattern (kappa = 0.84, 95% confidence interval 0.75 to 0.93) was nearly perfect. Assessment of PV ostial cross-sectional area as well as maximal and minimal ostial diameters resulted in strong agreement and correlation (r(2) = 0.75 to 0.99, p <0.001 for all) between the 2 imaging approaches. In conclusion, MRI and multislice CT of the PVs appear to provide similar and detailed anatomic and quantitative information before RFCA of AF.