Topographic variability of the left atrium and pulmonary veins assessed by 3D-CT predicts the recurrence of atrial fibrillation after catheter ablation

The association between the recurrence of atrial fibrillation and the shape of left atrial lateral ridge

To investigate the role of the geometry of the left atrial lateral ridge (LLR) in the atrial fibrillation (AF) recurrence after radiofrequency ablation (RFA). A total of 225 patients with AF who underwent RFA for the first time were retrospectively enrolled and divided into the recurrence (n = 53) and non-recurrence (n = 172) groups. The clinical data and the volume of left atrium (LAV) and the LLR geometry were analyzed. The LAV in the recurrence group was greater than that in the non-recurrence group (P < 0.001). There were more rectangular LLR in the recurrence group than the non-recurrence group (43% vs. 77%, P < 0.001). The anteroposterior diameter of the LLR orifice in the recurrence group was smaller than that in the non-recurrence group (P = 0.001), while the length of the LLR in the recurrence group was longer (P = 0.012). Multivariate analysis revealed the shape of the LLR was significant independent predictor of recurrence AF. The shape of the LLR is an independent predictor of recurrence after RFA.

Relationship between anatomical characteristics of pulmonary veins and atrial fibrillation recurrence after radiofrequency catheter ablation: a systematic review and meta-analysis

Background

The aim of the current study was to investigate the potential relationship between anatomical characteristics of pulmonary veins (PVs) and atrial fibrillation recurrence (AFR) following radiofrequency catheter ablation (RFCA), specifically focusing on PV diameter and cross-sectional orifices index (CSOA). The analysis was based on a comprehensive review of currently available literature, providing valuable insights for the prevention and treatment of AFR.

Methods

Data was collected from five databases, including PubMed, MEDLINE, EMBASE, and Cochrane, spanning the period from 2004 to October 2022. The search strategy utilized Medical Subject Headings (MeSH) terms related to PV diameter, PV size, PV anatomy, and AFR. Indicators of PV diameter and CSOA from the included studies were collected and analyzed, with Weight mean difference (WMD) and 95% confidence intervals (CIs) representing continuous variables.

Results

The meta-analysis included six studies. The results revealed that patients with AFR had a significant larger mean PV diameter compared to those without AFR (MD 0.33; 95% CI: 0.01, 0.66; P = 0.04; I2 = 33.80%). In a meta-analysis of two studies involving a total of 715 participants, we compared the diameters of the left superior pulmonary vein (LSPV), left inferior pulmonary vein (LIPV), right superior pulmonary vein (RSPV), right inferior pulmonary vein (RIPV) between patients with AFR and patients without AFR. The results showed that there were no statistically significant differences between the two groups in any of the four data items (all P > 0.05). Additionally, the pooled estimate revealed that LSPV-CSOA, LIPV-COSA, RSPV-COSA, and RIPV-CSOA were greater in the AFR group compared to the non-AFR group, but the differences were not statistically significant (all P > 0.05).

Conclusion

We found evidence supporting the notion that the PV diameter of patients who experienced AFR after RFCA was significantly larger than that of patients without AFR. The findings suggested that the PV diameter could serve as a potential predictor of the risk of AFR following RFCA.

Correlation of the peak oxygen consumption and ventilatory aerobic threshold by cardiopulmonary exercise testing with atrial fibrillation recurrences after ablation in patients with paroxysmal atrial fibrillation

Background

The cardiopulmonary function is hypothesized to be associated with atrial fibrillation/atrial tachyarrhythmia (AF/AT) recurrence after AF ablation.

Purpose

To clarify the relationship between the cardiopulmonary function after successful ablation and AF/AT recurrence.

Methods

We examined 31 patients with paroxysmal AF who underwent AF ablation. Cardiopulmonary exercise testing (CPET) was performed at 1month after the ablation. A continuously increasing loading method on a bicycle ergometer was employed for the CPET.

Results

No adverse events, including AF/AT recurrence, occurred during the CPET. Among 31 patients, AT/AF recurrence was observed in seven (23%). The ventilatory anaerobic threshold (VAT) and peak oxygen consumption (VO2) were significantly higher in patients without AF/AT recurrence than in those with AT/AF recurrences (peak VO2 23.6 ± 5.7 vs 17.2 ± 4.1 mL/kg/min; VAT, 16.7 ± 2.8 vs 13.8 ± 2.7 mL/min/kg). The areas under the receiver operating characteristic curve for the peak VO2 and VAT were 0.786 (P < .01) and 0.789(P < .01), respectively. Both indices had a sensitivity of 70%–80% and specificity of 70%–80% for predicting AT/AF recurrence. Similar results were obtained for the percent values of the predicted peak VO2 and VAT.

Conclusions

The present pilot study found that CPET can be performed safely at approximately 1 month after AF ablation. The peak VO2 and VAT were significantly associated with AT/AF recurrence. The peak VO2 and VAT were thought to provide helpful information regarding AT/AF recurrence.

Can an increase in the pulmonary vein volume measured by three dimensional computed tomography predict the presence of atrial fibrillation?

BACKGROUND

Left atrial (LA) dilation is associated with morbidity of atrial fibrillation (AF). However, little is known about pulmonary vein (PV) dilation.

PURPOSE

We investigated the PV volume in the patients with AF.

METHODS AND RESULTS

We performed 3dimensional computed tomography (3DCT) in 155 patients and divided them into three groups: 19 patients without AF (non-AF group, mean age 66 ± 12 years), 50 with paroxysmal AF (PAF group, mean age 67 ± 8 years) and 24 with persistent AF (PeAF group, mean age 64 ± 10 years). The absence of AF was diagnosed in patients with a cardiac implantable electronic device for at least 1 year (mean: 59 ± 37 months). We determined the PV volume as the total volume from the orifice to the first branch of each PV. According to the echocardiographic data, the LA dimension (LAD) and LA volume index (LAVI) were largest in the PeAF group followed by the PAF and non-AF group. According to the morphometric data obtained on 3D-CT, the PV volume was similar in PeAF and PAF groups but significantly smaller in the non-AF group (median value: 24 vs 21 vs 14 mL, respectively). According to the receiver operating characteristic curve analysis, the area under the curve for the PV volume in the presence of AF was 0.80, and the optimum cut-off value was 17 mL (sensitivity 74%, specificity 80%).

CONCLUSION

The PV volume might be useful for predicting the presence of AF before increases in the LAD and LAVI on echocardiography.

Anatomical dilatation of the superior vena cava associated with an arrhythmogenic response induced by SVC scan pacing after atrial fibrillation ablation

Background

The relationship between pulmonary vein (PV) arrhythmogenicity and its anatomy has been reported. However, that of the superior vena cava (SVC) has not been well discussed. Arrhythmogenic response induced by pacing stimulation at SVC might help with identifying SVC arrhythmogenicity. The purpose of this study was to investigate the relationship between the anatomical dilatation of SVC and the arrhythmogenic response induced by pacing at SVC.

Methods

Forty-three patients who underwent atrial fibrillation (AF) ablation were enrolled in this study. After PV isolation, scan pacing (up to triple extra stimulation following intrinsic sinus beats) was performed at SVC. The arrhythmogenic response was defined as following: (1) repetitive atrial responses, (2) non-sustained, and (3) sustained AF/ atrial tachycardia. To assess the dilatation of SVC, we measured the cross-sectional area of the SVC (SVC-area) using multi-planar reconstruction CT imaging.

Results

Arrhythmogenic responses were documented in 24 patients (Group 1). No arrhythmogenic responses were documented in the remaining 19 patients (Group 2). The SVC-area was significantly larger in Group 1 than Group 2 (3.1±0.9 vs. 2.2±0.8 cm², P=0.004). A multivariate analysis revealed only SVC-area was associated with arrhythmogenic responses (odds ratio=2.87, CI 1.05–7.82, P=0.04). Furthermore, AF recurrence rate was significantly higher in patients with SVC-area>2.56 cm² than those with SVC-area <2.56 cm² (9 [42.9%] of 21 vs. 3 [13.6%] of 22, P=0.026).

Conclusion

Dilatation of SVC was associated with an arrhythmogenic response, and the AF recurrence rate was significantly higher in patients with large SVC-area. Adjunctive catheter intervention for the SVC might be indicated in patients with a dilated SVC and an arrhythmogenic response.

Multimodality Cardiac Imaging for the Assessment of Left Atrial Function and the Association With Atrial Arrhythmias

Several cardiac imaging modalities are able to visualize the left atrium (LA) and, therefore, allow for quantification of both structural and functional properties of this cardiac chamber. In echocardiography, only the maximal LA volume is included in the assessment of diastolic function at the current moment. Numerous studies, however, have shown that functional measures may be superior to the maximal LA volume in several aspects and to possess clinical value even in the absence of structural abnormalities. Such functional measures could prove particularly useful in the setting of predicting atrial fibrillation, which will be a point of focus in this review. Pivotal cardiac magnetic resonance imaging studies have revealed high correlation between LA fibrosis and risk of atrial fibrillation recurrence after catheter ablation, and subsequent multimodality imaging studies have uncovered an inverse relationship between LA reservoir function and degree of LA fibrosis. This has sparked an increased interest into the application of advanced imaging modalities, including both speckle tracking echocardiography and tissue tracking by cardiac magnetic resonance imaging. Even though increasing evidence has supported the use of functional measures and proven its superiority to the maximal LA volume, they have still not been adopted in clinical guidelines. The reason for this discrepancy may rely on the fact that there is little to no agreement on how to technically perform deformation analysis of the LA. Such technical considerations, limitations, and alternate imaging prospects will be addressed in this review.

Plasma oxidative stress and inflammatory biomarkers are associated with the sizes of the left atrium and pulmonary vein in atrial fibrillation patients

BACKGROUND

Oxidative stress and inflammatory processes are responsible for the pathogenesis of AF, but their relationship with the sizes of the LA and PVs in AF patients remains unclear.

HYPOTHESIS

Oxidative stress and inflammatory processes are associated with the sizes of the LA and PVs in AF patients.

METHODS

82 AF patients were compared to 30 control patients by using a case-control study design. Oxidative stress, inflammatory biomarkers and the sizes of the LA and PVs were detected.

RESULTS

(1) Hs-CRP, IL-6, IL-8, TNF-α, MDA and ox-LDL were higher, and SOD was lower in AF patients than in control patients. Hs-CRP, MDA and ox-LDL were higher in permanent AF patients than in paroxysmal and persistent AF patients. (2) CsA of LSPV, RSPV, RIPV, LAA and LAV were statistically higher in AF patients than in control patients. CsA of RSPV, LSPV, LIPV and LAV were higher in permanent AF patients than in paroxysmal and persistent AF patients. (3) In the AF group, hs-CRP and TNF-α were positively correlated with LAV; MDA was positively correlated with CsA of LAA, LSPV and LAV; SOD was passively correlated with CsA of LAA and LAV; ox-LDL was positively correlated with CsA of LAA and LAV. Multivariate logistic regression analysis showed hs-CRP, ox-LDL, RSPV CsA, LIPV CsA and LAV were associated with AF.

CONCLUSIONS

Oxidative stress, inflammatory biomarkers and the sizes of the LA and PVs were significantly increased in AF patients. Hs-CRP, ox-LDL, RSPV CsA, LIPV CsA and LAV were associated with AF persistence.

Characteristics of Residual Atrial Posterior Wall and Roof-Dependent Atrial Tachycardias after Pulmonary Vein Isolation

BACKGROUND

Roof-dependent atrial tachycardia (roof AT) sometimes occurs after pulmonary vein isolation (PVI) of atrial fibrillation (AF). This study aimed to investigate the relationship between the anatomy of the residual left atrial posterior wall and occurrence of roof AT.

METHODS

A total of 265 patients with AF who underwent PVI were enrolled. After the PVI, induced or recurrent roof AT was confirmed by an entrainment maneuver or activation mapping using a three-dimensional (3D) mapping system. To identify the predictors of roof AT, the minimum distance between both PVI lines (d-PVI) was measured by a 3D mapping system and the anatomical parameters, including the left atrial (LA) diameter, left atrial volume index (LAVi), and shape of the left atrial roof, were analyzed by 3D computed tomography.

RESULTS

Roof AT was documented in 11 (4.2%) of 265 patients. A multivariable analysis demonstrated that the d-PVI, Deep V shape of the LA roof, and LAVi were associated with roof AT occurrences (d-PVI: odds ratio: 0.72, confidence interval [CI]: 0.61-0.86, P < 0.001; Deep V shape: odds ratio: 0.19, CI: 0.04-0.82, P = 0.03; LAVi: odds ratio: 1.05, CI: 1.02-1.07, P = 0.001). A receiver-operating characteristic curve analysis yielded an optimal cut-off value of 15.5 mm and 55.7 mL/m² for the d-PVI and LAVi, respectively.

CONCLUSION

The shorter d-PVI at the LA roof, greater LAVi, and Deep V shape were associated with the occurrence of a roof AT.

Anatomical Evaluation of the Pulmonary Veins and the Left Atrium Using Computed Tomography Before Catheter Ablation: Reproducibility of Measurements

Background

Atrial fibrillation (AF) is a common supraventricular arrhythmia. ECG-gated MDCT seems to be currently a method of choice for pre-ablation anatomical mapping due to an excellent resolution and truly isotropic three-dimensional nature. The aim of this study was to establish the between-subject variability and inter-observer reproducibility of anatomical evaluation of the pulmonary veins (PV) and the left atrium (LA) using computed tomography.

Material/Methods

A retrospective analysis included 42 patients with AF, who were scheduled for a cardiac CT for ablation planning. Images were assessed by two independent radiologists using a semi-automatic software tool. The left atrium anatomy (volume, AP diameter), anatomy of the pulmonary veins (number, ostia diameters and surface area) were evaluated. The relative between-subject variability and the inter-observer variability of measurements were calculated.

Results

The heart rate during scanning ranged from 50 to 133/min. (mean 79.1/min.) and all examinations were of adequate image quality. Accessory pulmonary veins were found in 24% of patients. Between-subject variability of the PV ostial cross-sectional area ranged from 33% to 48%. The variability of the left atrium size was 21% for the diameter and 35% for the volume. The inter-observer agreement for the detection of accessory pulmonary veins was good (κ=0.73; 95% CI, 0.54–0.93).

Conclusions

Between-subject variability of the pulmonary vein ostial cross-sectional area and the left artial volume is substantial. The anatomical assessment of the pulmonary vein ostia and the left atrium size in computed tomography presents a good inter-observer reproducibility.