
==== Front
BMC Cardiovasc Disord
BMC Cardiovasc Disord
BMC Cardiovascular Disorders
1471-2261
BioMed Central London

4187
10.1186/s12872-024-04187-1
Research
The value of computed tomography angiography for evaluation of left atrial enlargement in patients with persistent atrial fibrillation
Lin Fang-fang 12
Chen Qian 1
Wu Qiu-yan 1
Li Shi-jie 1
Zhu Yao-bin 5
Tang Yi 1
Xue Yun-jing 4
Luo Jie-wei docluo0421@aliyun.com

1
Li Zuo-an 61395776@qq.com

13
Chen Hong-yi chenhongyi@fjmu.edu.cn

13
1 grid.415108.9 0000 0004 1757 9178 Department of Radiology, Shengli Clinical Medical College of Fujian Medical University, Fujian Provincial Hospital, Fuzhou, 350001 China
2 https://ror.org/045wzwx52 grid.415108.9 0000 0004 1757 9178 Department of Radiology, Fujian Provincial Hospital, Fuzhou, 350001 China
3 Fujian Provincial Key Laboratory of Emergency Medicine, Fujian Provincial Institute of Emergency Medicine, Fujian Emergency Medical Center, Fuzhou, 350001 China
4 https://ror.org/055gkcy74 grid.411176.4 0000 0004 1758 0478 Department of Radiology, Fujian Medical University Union Hospital, Fuzhou, 350001 China
5 grid.256112.3 0000 0004 1797 9307 Department of Traditional Chinese Medicine, the First Affiliated Hospital, Fujian Medical University, Fuzhou, 350005 China
19 9 2024
19 9 2024
2024
24 50218 6 2024
12 9 2024
© The Author(s) 2024
2024
https://creativecommons.org/licenses/by-nc-nd/4.0/ Open Access This article is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License, which permits any non-commercial use, sharing, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if you modified the licensed material. You do not have permission under this licence to share adapted material derived from this article or parts of it. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by-nc-nd/4.0/.
Background

The post-processing technology of CTA offers significant advantages in evaluating left atrial enlargement (LAE) in patients with persistent atrial fibrillation (PAF). This study aims to identify parameters for rapidly and accurately diagnosing LAE in patients with PAF using CT cross-sections.

Methods

Left atrial pulmonary venous (PV) CT was performed to 300 PAF patients with dual-source CT, and left atrial volume (LAV), left atrial anteroposterior diameter (LAD1), left atrial transverse diameter (LAD2), and left atrial area (LAA) were measured in the ventricular end systolic (ES) and middle diastolic (MD). LA index (LAI) = LA parameter/body surface area (BSA). Left atrial volume index (LAVIES) > 77.7 ml/m2 was used as the reference standard for the LAE diagnosis.

Results

227 patients were enrolled in the group, 101 (44.5%) of whom had LAE. LAVES and LAVMD (r = 0.983), LAVIES and LAVIMD (r = 0.984), LAAES and LAVIES (r = 0.817), LAAMD and LAVIES (r = 0.814) had strong positive correlations. The area under curve (AUC) showed that all measured parameters were suitable for diagnosing LAE, and the diagnostic efficacy was compared as follows: LAA/LAAI> LAD> the relative value index of LAD, LAD2> LAD1. LAA and LAAI demonstrated comparable diagnostic efficacy, with LAA being more readily available than LAAI.

Conclusions

The axial LAA measured by CTA can be served as a parameter for the rapid and accurate diagnosis of LAE in patients with PAF.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-024-04187-1.

Keywords

Left atrial enlargement
Atrial fibrillation
Left atrial area
Computed tomography angiography
http://dx.doi.org/10.13039/501100003392 Natural Science Foundation of Fujian Province 2021J01704, 2022J01996, 2021J02053 http://dx.doi.org/10.13039/100017954 Fujian Provincial Finance Department 2022-840# National famous and old Chinese medicine experts (Zhang Xuemei, Yan Xiaohua) inheritance studio construction project2022-75 issue-copyright-statement© BioMed Central Ltd., part of Springer Nature 2024
==== Body
pmcIntroduction

Left atrial enlargement (LAE) is closely associated with atrial fibrillation (AF) and its complications [1]. The rapid impulses generated by the atria and ectopic excitation foci in the muscle sleeves of distal pulmonary veins (PV) lead to the development of AF, causing changes such as electrical, structural, and functional remodeling of the left atrium (LA) [2]. Correspondingly, the electrical, structural, and functional remodeling of the left atrium assumes a crucial role in the pathogenesis of AF [3]. This process involves a series of interstitial alterations, amplified myofibroblast activity, collagen deposition, fibrofatty deposits, changes in ion channel expression, and inflammatory infiltration [3]. Particularly, atrial fibrosis has been recognized as a significant pathophysiological factor linked with the complications, drug resistance, and recurrence of AF [4, 5]. LAE can also exacerbate AF [6]. The size of LA is also the most reliable preoperative predictor of recurrence following AF ablation, and it stands as a highly independent risk factor for various cardiovascular events [7–12]. Catheter ablation procedures for AF create scar tissue and achieve pulmonary vein isolation (PVI) [13]. The recurrence rate of AF after catheter ablation is approximately 10% ~ 30%, while the success rate of PVI ranges from 50–80% [14]. The left atrial appendage is a potential source for the spontaneous onset of AF, while the LA represents another possible origin for AF recurrence [15]. Hence, it is critical to precisely ascertain the size of LA [16].

Computed tomography angiography (CTA) using Siemens third-generation dual-source CT offers the advantages of lower radiation dose, convenience, high temporal and spatial resolution, robust post-processing technology, and high precision. ECG gating technology or FLASH scanning mode can be utilized to minimize artifacts resulting from breathing and heartbeat. CT is increasingly employed for evaluating the structure and function of LA without necessitating additional scan time, radiation exposure, and the administration of contrast agents. ECG-gated CT imaging can be combined with three-dimensional (3D) reconstruction software to directly measure cardiac chamber volumes without making geometric assumptions. And the Left Atrial Volume (LAV) measured by CTA correlated closely with magnetic resonance imaging (MRI) [17, 18]. The measurement of LA volume on CT is feasible, robust, and highly reproducible [19].

The left atrial volume index (LAVI) is currently a superior index for evaluating LA size, but measuring LA volume on CT is cumbersome. This study aims to focus on the LA by utilizing easily obtained axial image data from PV-CTA, measuring the left atrial diameter (LAD) and the left atrial area (LAA), and indexing them with body surface area (BSA) and vertebral parameters. The goal is to identify parameters for the rapid and accurate diagnosis of LAE in PAF patients using CT cross-sections.

Methods

Study subjects

300 patients with PAF who underwent pulmonary vein CTA at X Hospital from December 2020 to August 2021 were collected in the study. Height, weight, body mass Index (BMI), heart rate, and past medical history were documented. The formula for calculating body surface area (BSA) is BSA(m2)=0.0061 × Height(cm) + 0.0128 × weight (kg)-0.1529. Patients diagnosed with PAF who underwent pulmonary vein CTA were included in the study. Patients with contraindications to contrast-enhanced CT, a history of surgeries affecting normal LAV measurements, conditions affecting endocardial delineation, and those unable to cooperate with the examination were excluded.

Inspection method and scanning parameters

A Siemens dual-source CT scanner (SOMATOM Force, Siemens Healthineers, Forchhemi, Germany) and Siemens Syngo.Via workstation were utilized. The excitation level was positioned at the descending aorta at the level of the LA, with the threshold set at 100 Hounsfield unit (HU). This threshold was automatically activated upon reaching the set value, with a delay time of 6 s. Subsequently, 50 ml of 0.9% saline was administered at the same rate immediately after the bolus injection of the contrast agent. The Cardiac window and Bv40 convolution kernel algorithm were adopted. A reconstruction with a layer thickness of 0.75 mm and an increment of 0.5 mm was performed. The advanced modeled iterative reconstruction (ADMIRE) technique was employed with the iterative intensity set to ADMIRE = 4.

Image post-processing

The cardiac indexes of all patients were analyzed by the first author and an experienced radiologist with a decade of clinical practice, both of whom were blinded to the patients’ details. The image analysis was performed using a post-processing workstation (Syngo.Via, VB20AHF91, Siemens Healthcare). The axial image sequences were reconstructed at 40% and 75% of the R-R interval, with 40% of the R-R interval defined as end-systolic (ES) and 75% as mid-diastolic (MD).

Measurement of LAV

LAV was measured using semi-automatic CT measurement software on the post-processing workstation. The region growth function in MM Reading was used. LAV was measured through automatic tracking of the endocardial contour and VRT editing correction (Fig. 1a–b). LAV: LAVES, LAVMD were recorded in the ES and MD phases, respectively. The ratio of LAV to BSA is defined as the left atrial volume index (LAVI): LAVIES, LAVIMD.

Fig. 1 The image post-processing workstation software automatically calculated LAV. LAV included LAA, but not PV, which was manually cut and removed at the opening, and the LA posterior view of before editing (a) and after editing (b); (c) for the determination of levels measured for LA parameters: at the opening of the right inferior PV, with the largest LAA; (d) For the determination of the measured vertebral body, the reference line was positioned to the vertebral body at the same level as (c) the LA parameter was measured and corresponded to the vertebral body in the sagittal plane; (e) the reference line was rotated and positioned at the center of the upper and lower ½ of the vertebral body; (f) the cross section corresponding to the red reference line (e) was selected as the measurement level for vertebral parameters

Measurement of LA and thoracic vertebra parameter

The anteroposterior diameter, transverse diameter, and area of LA, as well as the thoracic vertebra parameter, were measured in the ES and MD phases, respectively. The parameters of the LA were measured at the level of the largest LAA at the ostium of the right inferior PV (Fig. 1c). These parameters included the followings: left atrial anteroposterior diameter LAD1 (LAD1ES and LAD1MD) (Fig. 2a), left atrial transverse diameter LAD2 (LAD2ES and LAD2MD) (Fig. 2b), and LAA (LAAES and LAAMD) (Fig. 2c). The thoracic vertebra closest to the LA measurement level was selected (Fig. 1d), and the center of the selected vertebral body (Fig. 1e) was determined as the level for measuring the vertebral parameter (Fig. 1f). The items included the following: vertebral body diameter (VD), which comprised the anteroposterior vertebral body diameter (VD1) (Fig. 2d) and transverse vertebral body diameter (VD2) (Fig. 2e), as well as the vertebral body area (VA) (Fig. 2f).

Fig. 2 Measurement of LA parameters. (a) Parallel to the sagittal plane of the human body, the largest LA anteroposterior diameter (LAD1) was measured along the endocardial border; (b) parallel to the coronal plane of the human body, the largest LA transverse diameter (LAD2) was measured along the endocardial border; (c) LAA* was measured along the endocardial border, excluding the pulmonary vein confluence. Measurement of vertebral parameters. (d) Parallel to the sagittal plane of the human body, the maximum anteroposterior diameter (VD1) of the vertebral body was measured along the endomembrane boundary; (e) parallel to the coronal plane of the human body, the maximum transverse diameter (VD2) of the vertebral body was measured along the endomembrane boundary; (f) the vertebral area (VA) was measured along the endomembrane boundary, excluding osteophytes

Calculation of the left atrio-vertebral ratio (LAVR) involved the left atrio-vertebral diameter ratio (LAVD), which included the left atrio-vertebral anteroposterior ratio LAVD1 (LAVD1ES and LAVD1MD), the left atrio-vertebral transverse ratio LAVD2 (LAVD2ES and LAVD2MD), and the left atrio-vertebral area ratio (LAVA) (LAVAES and LAVAMD). Left atrial diameter index (LADI) and left atrial area index (LAAI) were computed. The formula was as follows: LADI1ES = LAD1ES/BSA; LADI2ES = LAD2ES/BSA; LAAIES=LAAES/BSA; LADI1MD = LAD1MD/BSA; LADI2MD = LAD2MD/BSA; LAAIMD=LAAMD/BSA.

Consistency of intra- and inter-observer measurements

50 patients were randomly chosen for repeated measurements after a two-week interval. The data for these 50 patients were measured by the primary author of this journal and another radiologist with 10 years of experience, both of whom were blinded to the data of all the patients. The consistency of measurement results between different measurers was assessed.

Statistical analysis

Statistical analysis was performed using SPSS 22.0 and Medcalc software. The comparison between two groups that followed a normal distribution was conducted using a T-test, while the comparison between two groups that did not follow a normal distribution was performed using the Mann-Whitney U test. The χ2 test was used to analyze the counting data. ROC curves were utilized to compare the diagnostic effectiveness of each CT measurement parameter, and the DeLong method was employed to compare the disparities in the area under the curves (AUC). Bland-Altman diagram analysis or intraclass correlation coefficient (ICC) was employed to assess the consistency of intra-observer and inter-observer parameters. The correlation of parameters was analyzed using Pearson ‘s method. A significance level of P < 0.05 was considered.

Results

Clinical data of patients

In this study, 300 PAF patients were initially collected. After excluding 73 patients, a total of 227 patients were ultimately enrolled. Based on reference(23), patients were categorized into two groups: those with LAVIES > 77.7 ml/m2, comprising 126 patients in the normal group and 101 patients in the LAE group. There were no statistically significant differences in age, gender, heart rate, height, weight, BSA, BMI, hypertension, diabetes, and hyperlipidemia between the two groups (P > 0.05) (Table 1).

Table 1 Clinical data of rolled patients in this study

	All patients (n = 227)		Normal LA (n = 126)	LAE(n = 101)	t -value /χ2-value	P-value*	
Male	140(61.7)		74(32.6)	66(29.1)	1.038	0.308#	
Female	87(38.3)		52(22.9)	35(15.4)	
Age (year)	61.09 ± 9.98		60.15 ± 10.08	62.27 ± 9.76	-1.594	0.112	
Heart rate	74.99 ± 13.75		75.48 ± 14.46	74.38 ± 12.84	0.603	0.547	
Height (cm)	166.09 ± 7.41		166.56 ± 7.46	165.50 ± 7.34	1.080	0.281	
Weight (kg)	66.77 ± 10.92		66.36 ± 10.81	67.28 ± 11.08	-0.633	0.527	
BMI (kg/m2)	24.12 ± 3.10		23.82 ± 2.89	24.50 ± 3.32	-1.640	0.102	
BSA (m2)	1.71 ± 0.17		1.71 ± 0.17	1.72 ± 0.17	-0.231	0.818	
Hypertension disease	92		47	45	1.224#	0.269	
Diabetes	41		21	20	0.372#	0.542	
Hyperlipidemia	67		43	24	2.895#	0.089	
#, χ2 test was used, and t-test was used for the rest. *, Comparison of measurement parameters between normal LA group and LAE group

Measurements of all parameters

Among the enrolled patients, significant differences were observed in parameters other than VD and VA between the two groups (P < 0.001) (Table 2).

Table 2 Comparison of LA related parameters measured by CT

Measured parameters	All patients (n = 227)	Normal LA (n = 126)	LAE(n = 101)	t-value /U-value	P-value	
LAD1ES (cm)	4.42 ± 0.75	4.07 ± 0.61	4.87 ± 0.65	-9.487	< 0.001	
LAVD1ES	1.69 ± 0.31	1.56 ± 0.27	1.85 ± 0.29	-7.697	< 0.001	
LADI1ES	2.59 ± 0.45	2.38 ± 0.36	2.85 ± 0.41	-9.106	< 0.001	
LAD2ES (cm)	7.69 ± 0.88	7.20 ± 0.58	8.31 ± 0.81	1509.500#	< 0.001	
LAVD2ES	2.65 ± 0.35	2.51 ± 0.28	2.83 ± 0.35	-7.714	< 0.001	
LADI2ES	4.53 ± 0.65	4.24 ± 0.49	4.88 ± 0.65	2714.000#	< 0.001	
LAAES (cm2)	28.67 ± 6.63	24.68 ± 4.24	33.64 ± 5.64	-13.668	< 0.001	
LAVAES	4.00 ± 1.05	3.49 ± 0.71	4.64 ± 1.07	2253.000#	< 0.001	
LAAIES	16.79 ± 3.90	14.47 ± 2.46	19.70 ± 3.38	-13.468	< 0.001	
LAD1MD (cm)	4.02 ± 0.76	3.70 ± 0.62	4.34 ± 0.72	-8.294	< 0.001	
LAVD1MD	1.54 ± 0.30	1.42 ± 0.26	1.68 ± 0.28	3129.000#	< 0.001	
LADI1MD	2.36 ± 0.46	2.17 ± 0.38	2.60 ± 0.44	2784.000#	< 0.001	
LAD2MD (cm)	7.18 ± 0.96	6.68 ± 0.68	7.81 ± 0.89	1785.000#	< 0.001	
LAVD2MD	2.47 ± 0.36	2.32 ± 0.28	2.66 ± 0.37	-7.891	< 0.001	
LADI2MD	4.23 ± 0.69	3.93 ± 0.51	4.59 ± 0.71	-8.124	< 0.001	
LAAMD (cm2)	25.35 ± 6.82	21.22 ± 4.18	30.50 ± 5.92	-13.820	< 0.001	
LAVAMD	3.53 ± 1.03	3.00 ± 0.65	4.20 ± 1.04	-10.622	< 0.001	
LAAIMD	14.87 ± 4.13	12.45 ± 2.50	17.89 ± 3.75	-13.053	< 0.001	
VD1 (cm)	2.64 ± 0.26	2.62 ± 0.25	2.65 ± 0.27	-0.852	0.395	
VD2 (cm)	2.92 ± 0.28	2.90 ± 0.29	2.96 ± 0.27	-1.567	0.119	
VA (cm)	7.30 ± 1.19	7.20 ± 1.18	7.43 ± 1.21	-1.412	0.159	
# Mann–Whitney U test was used, and t-test was used for the rest. *, Comparison of measurement parameters between normal LA group and LAE group

Analysis of arameter correlation

Strong positive correlations were found between LAVES and LAVMD (r = 0.983, P < 0.001), as well as between LAVIES and LAVIMD (r = 0.984, P < 0.001) (Fig. 3a and b). Good positive correlations were observed between LAAES and LAVES (r = 0.885, P < 0.001), LAAES and LAVIES (r = 0.817, P < 0.001), LAAMD and LAVES (r = 0.852, P < 0.001), as well as LAAMD and LAVIES (r = 0.814, P < 0.001) (Supplement Table 1).

Fig. 3 (a), (b) Scatter plots of left atrial volume (LAV) and volume index (LAVI) at ES and MD phases, respectively, showed a positive linear relationship between LAVES and LAVMD, LAVIES and LAVIMD. (c), (d) Bland-Altman plots of intra observer agreement for LAVES or LAVMD measurements. Results 98% (49/50) of LAVES and 98% (49/50) of LAVMD measured values were distributed within the 95% limit of agreement, indicating that the measured values were in good agreement within the observer. (e), (f) Bland-Altman plots of agreement between observers for measuring LAVES and LAVMD. 96% (48/50) of LAVES and 96% (48/50) of LAVMD measurements were distributed within the 95% limits of agreement, and both LAVES and LAVMD measurements had good interobserver agreement

Consistency analysis between measured parameters

The LAVES and LAVMD measurements were evaluated for intra-observer and inter-observer reliability using the Bland-Altman method, demonstrating good consistency for both measurements (Fig. 3c and f). Both intra-observer and inter-observer assessments for each parameter were evaluated using the intraclass correlation coefficient, which demonstrated robust consistency across all measurements (Supplement Table 2).

Diagnostic efficiency

Using LAVIES > 77.7 ml/m2 as the reference standard, ROC curve analysis indicated that all parameters (LAD1, LAVD1, LADI1, LAD2, LAVD2, LADI2, LAA, LAVA, LAAI) in ES and MD were effective for diagnosing LAE. The LAA /area index exhibited the highest diagnostic efficacy in both ES and MD (Fig. 4a and b).

Fig. 4 (a) ROC curve of parameters measured during ES phase for LAE diagnosis, and each parameter was feasible. The diagnostic efficacy was as follows: LAA/ LAAI > LAD2 > LAVA > other LAD -related parameters. (b) ROC curve of parameters measured during MD phase for LAE diagnosis, and each parameter was feasible. The diagnostic efficacy was as follows: LAA/LAAI > LAVA/LAD2 > other LAD -related parameters

Differences in the AUC of ROC curves for different measurement parameters were compared using the DeLong method within the Medcalc software (Table 3):

Table 3 Accuracy analysis of all measured parameters in LAE diagnosis

Measured parameters	AUC (95%CI)	Threshold value	Se	Sp	PV	LR	Coincidence rate	
PPV	NPV	LR+	LR-	
LAD1ES (cm)	0.810 (0.753–0.859)	4.53	71.3	78.6	72.7	77.3	3.33	0.37	75.4	
LAVD1ES	0.766 (0.705–0.819)	1.81	56.4	84.1	74.0	70.7	3.56	0.52	71.8	
LADI1ES	0.811 (0.754–0.860)	2.59	71.3	79.4	73.5	77.5	3.45	0.36	75.8	
LAD2ES(cm)	0.881 (0.832–0.920)	7.85	71.3	88.1	82.8	79.3	5.99	0.33	80.6	
LAVD2ES	0.766 (0.705–0.819)	2.63	74.3	66.7	64.1	76.4	2.23	0.39	70.1	
LADI2ES	0.787 (0.728–0.838)	4.44	76.2	65.9	64.2	77.5	2.23	0.36	70.5	
LAAES (cm2)	0.917 (0.873–0.949)	28.63	84.2	88.9	85.9	87.5	7.57	0.18	86.8	
LAVAES	0.823 (0.767–0.870)	3.81	80.2	70.6	68.6	81.6	2.73	0.28	74.9	
LAAIES	0.926 (0.883–0.956)	16.14	90.1	82.5	80.5	91.2	5.16	0.12	85.9	
LAD1MD (cm)	0.795 (0.736–0.845)	4.12	72.3	80.2	74.5	78.3	3.64	0.35	76.7	
LAVD1MD	0.754 (0.693–0.809)	1.52	72.3	67.5	64.1	75.2	2.22	0.41	69.6	
LADI1MD	0.781 (0.722–0.833)	2.27	79.2	68.3	66.7	80.4	2.50	0.30	73.1	
LAD2MD (cm)	0.860 (0.808–0.902)	7.17	77.2	80.2	75.8	81.4	3.89	0.28	78.9	
LAVD2MD	0.777 (0.717–0.829)	2.55	64.4	80.2	72.3	73.8	3.24	0.44	73.2	
LADI2MD	0.794 (0.736–0.845)	4.21	72.3	76.2	70.9	77.4	3.04	0.36	74.5	
LAAMD (cm2)	0.913 (0.869–0.946)	25.58	79.2	88.1	84.1	84.1	6.65	0.24	84.1	
LAVAMD	0.850 (0.797–0.894)	3.39	83.2	74.6	84.7	84.7	3.27	0.23	78.4	
LAAIMD	0.911 (0.866–0.945)	14.20	88.1	81.7	89.5	89.5	4.83	0.15	84.2	

(1) The comparison of AUC for LAD1-related parameters was as follows: ①LAD1ES (0.810) > LAVD1ES (0.766) (P = 0.0149); LAD1MD (0.795) > LAVD1MD (0.754) (P = 0.0385). ② LAD1ESvs. LADI1ES (P = 0.9426), LAD1MDvs. LADI1MD (P = 0.4693). ③LADI1ES (0.811) > LAVD1ES (0.766)(P = 0.0350);LADI1MD > LAVD1MD(P = 0.2266). These results indicate that the diagnostic efficiency of LAD1 was the highest when using LAD1-related parameters to evaluate LAE. Measurements of LAD1 and LADI1 are more convenient, so it is recommended to use LAD1 or LADI1 for evaluating LAE.

(2) The comparison of AUC for LAD2-related parameters was as follows: ①LAD2ES (0.881) > LAVD2ES (0.766)(P = 0.0001);LAD2ES (0.881) > LADI2ES (0.787) (P = 0.0006); LAD2MD (0.860) > LAVD2MD (0.777) (P = 0.0016); LAD2MD (0.860) > LADI2MD (0.794) (P = 0.0044). ②LAVD2ESvs. LADI2ES (P = 0.5014), LAVD2MDvs. LADI2MD (P = 0.5328). These results indicate that the diagnostic efficiency of LAD2 was the highest when using LAD2-related parameters to evaluate LAE.

(3) The comparison of AUC for LAA-related parameters was as follows: ①LAAES(0.917) > LAVAES(0.823) (P = 0.0001); LAAIES (0.926) > LAVAES (0.823) (P < 0.0001); LAAMD(0.913) > LAVAMD (0.850) (P = 0.0022); LAAIMD(0.911) > LAVAMD(0.850) (P = 0.0027);②LAAESvs. LAAIES(P = 0.4603);LAAMDvs. LAAIMD (P = 0.8407). It was indicated that LAA and LAAI exhibited the highest diagnostic efficacy for LAE when utilizing LAA-related parameters, with LAAI being easier to obtain.

(4) The comparison of AUC among LAD2, LAD1, and LAVA was as follows: ① (LAD2ES (0.881) > LAD1ES (0.810)(P = 0.0187);LAD2MD (0.860) > LAD1MD (0.795)(P = 0.0459);②LAD2ES(0.881) > LAVAES (0.823)(P = 0.0450); LAD2MD (0.860) vs. LAVAMD (0.850) (P = 0.7462). It was indicated that the diagnostic efficiency of LAD2 was the highest, and it was easier to obtain. Therefore, LAD2 is recommended for the diagnosis of LAE.

(5) The comparison of AUC between LAA and LAD2 was as follows: LAAES (0.917) > LAD2ES (0.881) (P = 0.0336); LAAMD (0.913) > LAD2MD (0.860) (P = 0.0042). Therefore, the diagnostic efficiency of LAA is higher than that of LAD2.

In summary, it is evident that the diagnostic efficacy of LAA in evaluating LAE is optimal. As shown in Table 3, when the LAAES threshold was 28.63cm2 or the LAAMD threshold was 25.58cm2, the sensitivity and specificity for diagnosing LAE are high.

Discussion

By employing a range of post-reconstruction techniques, including curved planar reformation (CPR), multiple planar reformation (MPR), maximum intensity projection (MIP), and volume rendering (VR), CTA can acquire 3D datasets of the entire heart and adjacent structures, enabling reconstruction in arbitrary orientations.

The 3D visualization data can visually display the ostium and quantity of the PV, ascertain the size of the PV’s ostium and its distance from the first branch, as well as the location of the esophagus and vagal structures. These data assist in ECG anatomical mapping, offer guidance for radiofrequency catheter ablation, and identify anatomical variation of the PV. CTA can also be utilized to exclude the presence of left atrial appendage thrombosis. Delayed imaging cardiac CTA has an accuracy of 99% in the diagnosis of thrombus in LAA [20]. The dimensions of the LA can be evaluated using CTA. For each incremental increase in LAV/LAVI, the probability of AF recurrence rises by 3% [21]. For every 1 mm increase in LA diameter, the likelihood of AF recurrence increased by 2% [22]. LAE is an independent risk factor for AF recurrence in elderly patients with AF following pacemaker surgery [23].

The latest version of the ASE guidelines recommends the use of LAVI to measure the size of LA. The reason we selected the threshold of 77.7 mL/m2 proposed by Lin et al. for diagnosing LAE on CT is based on the following reasons(23): Individuals who were relatively healthy and free from various cardiovascular diseases were included in their study; their results are similar to those obtained by Gulati et al. using cardiovascular magnetic resonance imaging (CMR) (72mL/m2) [24], and CMR serves as the reference standard for evaluating LAVI [25]; measurements performed by Lin included the volume of the left atrial appendage. The development and prognosis of AF are associated with the size and morphology of the left atrial appendage [26–29]. However, the volume of the left atrial appendage was not included in other studies [30–32], which is clearly inappropriate.

The CT measurement of the LAA is relatively simple and convenient. There was a moderate positive correlation between the LAD1 and LAV (r = 0.67, P < 0.001) [33], which is consistent with our findings. Stolzmann et al. suggested that LAD1 > 4.5 cm in male or LAD1 > 4.4 cm in female could diagnose LAE [34], while Eifer et al. proposed that LAD1 ≥ 4.5 cm in male or ≥ 4.4 cm in female [35]. Cohort studies of patients with AF have found that LAE could be specifically diagnosed when LAD1 > 4.5 cm or > 4.3 cm [36, 37]. Sohrabi ‘s study concluded that LAE could be accurately detected when LAD2 > 7.3 cm [37]. The diagnostic efficacy of LAD2 (AUC = 0.89) was superior to that of LAD1 (AUC = 0.81), and an increase of 1 cm in LAD2 increased the likelihood of LAE by approximately 15 times. The aforementioned research findings align with the results of this study. When affected by the condition, the expansion of LA was asymmetric in all dimensions, primarily in the left-right and supero-inferior diameters, while the antero-posterior diameter was limited due to the constraints of the sternum and spine. Therefore, When assessing LAE using parameters of LAD, the diagnostic efficiency of LAD2 was found to be higher than that of LAD1.

Currie et al. proposed that the optimal specific thresholds for identifying pulmonary artery wedge pressure exceeding 15 mmHg and 18 mmHg were LAA values of 26.8 cm2 and 30.0 cm2, respectively [38]. In our study, a significant correlation was observed between the measured LAA and LAV. Mahabadi also discovered a strong correlation between LAA and LAV (r = 0.88 P < 0.001), suggesting that the correlation of LAA with LAV is superior to its correlation with LAD1 [33]. The diagnostic thresholds for LAA proposed by us exhibited high sensitivity and specificity: LAAES > 28.63 cm2 or LAAMD > 25.58 cm2. LAA measurements can be directly obtained from CT cross-sectional data without the need for additional contrast agent application, radiation exposure, or 3D reconstruction.

The relative LA diameter parameters were anticipated to be superior in assessing LAE. However, in this study, the diagnostic efficacy of LAD parameters such as LAD1ES, LAD2ES, LAD1MD, and LAD2MD was found to be higher than that of the LA diameter relative value parameters. Eifer suggested that absolute value indexes were more effective than relative value indexes when assessing LAE using LAD [35]. Nevertheless, it is feasible to assess LAE using relative value parameters of LA. For instance, Baque-Juston suggested that LA/vertebral transverse diameter > 2.1 (at the ostium of the left inferior PV) was closely related to cardiogenic pulmonary edema, indirectly indicating LAE [39]. In this study, LAVD2ES > 2.63 or LAVD2MD > 2.55 (at the ostium of the right inferior PV) indicated the presence of LAE. The measurement results could be affected by the selection of enrolled patients and the anatomical reference frame. Montillet proposed that a mid-diastolic LA/vertebral area ratio > 3 was highly specific for diagnosing LAE (compared to > 3.39 in our study) [40]. The slight difference may be attributed to the fact that they measured LAA at the base of the right lower PV opening, whereas we selected the layer near the right lower PV opening with the largest visually observed LAA. They measured the vertebral body in the pedicle plane of the vertebral body at the same level as the LA measurement, whereas we measured the central slice at the center level of half of the vertebral body closest to the left atrial measurement level.

The right inferior PV ostium, which serve as a relatively fixed frame of reference, was selected in the transverse plane without the need for additional 3D reconstructions. The LAV at the end of systole is the largest, which can best reflect the maximum dimension of LA. Mid-diastole (MD) is the optimal quiescent phase of the heart, occupying 75% of the R-R interval of the cardiac cycle, and there was a strong correlation between LAVES and LAVMD [32]. Hence, we opted to measure the relevant parameters in MD. Furthermore, the radiation exposure from high-frequency and high-spiral-acquisition “flash” scans, triggered by prospective axial scans and prospective electrocardiogram, only occurred during MD, resulting in an 80% reduction in dose compared with retrospective scans.

Limitations of this study should be noticed. Firstly, the LAV threshold of 77.7 ml/m2, pertinent to the European population, was employed in this study. However, the recent research has found LA indices are generally lower in the East Asian population compared to the European population [41], which may have led to the misclassification of the LAE group as normal. Secondly, CMR imaging, which provides superior isotropic visualization of the heart, is widely acknowledged as the reference standard for evaluating LA indices [42, 43]. Ideally, the LA indices should be assessed using both CMR and CTA. However, a limitation of this study is the exclusive use of CTA. Finally, the LA indices of all patients were evaluated by two radiologists, potentially introducing bias in the measurements. Nevertheless, an assessment of inter-observer consistency for each parameter was conducted, revealing robust consistency across all measurements.

Conclusion

The axial left atrial area on CTA could be served as a rapid and accurate diagnostic parameter for identifying LAE in PAF patients. The diagnosis of LAE in PAF patients demonstrates high sensitivity and specificity when LAAES is greater than 28.63 cm2 or LAAMD is greater than 25.58 cm2 at the end of systole.

Electronic supplementary material

Below is the link to the electronic supplementary material.

Supplementary Material 1

Acknowledgements

Not applicable.

Author contributions

FFL, QYW, QC, SJL, YT, YBZ and YJX drafted the manuscript, performed the acquisition, analysis, and interpretation of the data; HYC, ZAL and JWL provided critical revision of the manuscript, designed and supervised the study. All authors read and approved the final manuscript.

Funding

This work was supported in part by grants from Fujian Province Natural Science Fund Project (2021J01704, 2022J01996, 2021J02053), the Special Research Foundation of Fujian Provincial Department of Finance (2022 − 840#), National famous and old Chinese medicine experts (Zhang Xuemei, Yan Xiaohua) inheritance studio construction project (2022-75).

Data availability

The datasets used and/or analyzed during the present study are available from the corresponding author upon reasonable request.

Declarations

Ethics approval and consent to participate

All procedures were performed in accordance to the tenets of the Declaration of Helsinki and the study was approved by the Ethics Committee of Fujian Provincial Hospital, Fuzhou, China. All participants and legal guardians of the minors involved in the present study provided written informed consent.

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.

Abbreviations

ADMIRE Advanced modeled iterative reconstruction

AUC Area under the curves

BMI Body mass index

BSA Body surface area

CMR Cardiovascular magnetic resonance imaging

CPR Curved planar reformation

CR Coincidence rate

CT Computed tomography

CTA Computed tomography angiography

ES End systolic

ESC European society of cardiology

FBP Filtered back projection

HU Hounsfield unit

LA Left atrium

LAA Left atrial area

LAAI Left atrial area index

LAD Left atrial diameter

LAD1 Left atrial anteroposterior diameter

LAD2 Left atrial transverse diameter

LADI Left atrial diameter index

LADI1 Left atrial anteroposterior diameter index

LADI2 Left atrial transverse diameter index

LAE Left atrial enlargement

LAI Left atrial index

LAV Left atrial volume

LAVA Left atrio-vertebral area ratio

LAVD Left atrio-vertebral diameter ratio

LAVI Left atrial volume index

LAVR Left atrio-vertebral ratio

MD Mid diastolic

MIP Maximum intensity projection

MPR Multiple planar reformation

MRI Magnetic resonance imaging

NPV Negative predictive value

PAF Persistent atrial fibrillation

PPV Positive predictive value

PV Pulmonary vein

PVI Pulmonary vein isolation

RFCA Radio frequency catheter ablation

ROC Receiver operating characteristic curve

Se Sensitivity

Sp Specificity

TEE Transesophageal echocardiography

TTE Transthoracic echocardiography

VA Vertebral body area

VD Vertebral body diameter

VR Volume rendering

Publisher’s note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Fang-fang Lin, Qian Chen and Qiu-yan Wu contributed equally to this work.
==== Refs
References

1. Corrigendum to 2020 ESC guidelines for the diagnosis and management of atrial fibrillation developed in collaboration with the European Association of Cardio-Thoracic Surgery (EACTS) Eur Heart J 2021 42 5 546 7 10.1093/eurheartj/ehaa945 33242070
Corrigendum to. 2020 ESC guidelines for the diagnosis and management of atrial fibrillation developed in collaboration with the European Association of Cardio-Thoracic Surgery (EACTS). Eur Heart J. 2021;42(5):546–7. 10.1093/eurheartj/ehaa945.33242070
2. Iwasaki YK Nishida K Kato T Nattel S Atrial fibrillation pathophysiology: implications for management Circulation 2011 124 20 2264 74 10.1161/CIRCULATIONAHA.111.019893 22083148
Iwasaki YK, Nishida K, Kato T, Nattel S. Atrial fibrillation pathophysiology: implications for management. Circulation. 2011;124(20):2264–74. 10.1161/CIRCULATIONAHA.111.019893.22083148
3. Writing Committee M Joglar JA Chung MK Armbruster AL Benjamin EJ Chyou JY 2023 ACC/AHA/ACCP/HRS Guideline for the diagnosis and management of Atrial Fibrillation: a report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice guidelines J Am Coll Cardiol 2024 83 1 109 279 10.1016/j.jacc.2023.08.017 38043043
Writing Committee M, Joglar JA, Chung MK, Armbruster AL, Benjamin EJ, Chyou JY, et al. 2023 ACC/AHA/ACCP/HRS Guideline for the diagnosis and management of Atrial Fibrillation: a report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice guidelines. J Am Coll Cardiol. 2024;83(1):109–279. 10.1016/j.jacc.2023.08.017.38043043
4. Arabia G Bellicini MG Cersosimo A Memo M Mazzarotto F Inciardi RM Ion channel dysfunction and fibrosis in atrial fibrillation: two sides of the same coin Pacing Clin Electrophysiol 2024 47 3 417 28 10.1111/pace.14944 38375940
Arabia G, Bellicini MG, Cersosimo A, Memo M, Mazzarotto F, Inciardi RM, et al. Ion channel dysfunction and fibrosis in atrial fibrillation: two sides of the same coin. Pacing Clin Electrophysiol. 2024;47(3):417–28. 10.1111/pace.14944.38375940
5. Morin DP, Bernard ML, Madias C, Rogers PA, Thihalolipavan S, Estes NA 3. rd. The State of the Art: Atrial Fibrillation Epidemiology, Prevention, and Treatment. Mayo Clin Proc. 2016; 91(12): 1778–1810. 10.1016/j.mayocp.2016.08.022
6. Krishnamoorthy S Khoo CW Lim HS Lip GY Predictive value of atrial high-rate episodes for arterial stiffness and endothelial dysfunction in dual-chamber pacemaker patients Eur J Clin Invest 2014 44 1 13 21 10.1111/eci.12182 24111528
Krishnamoorthy S, Khoo CW, Lim HS, Lip GY. Predictive value of atrial high-rate episodes for arterial stiffness and endothelial dysfunction in dual-chamber pacemaker patients. Eur J Clin Invest. 2014;44(1):13–21. 10.1111/eci.12182.24111528
7. Ersboll M Andersen MJ Valeur N Mogensen UM Waziri H Moller JE The prognostic value of left atrial peak reservoir strain in acute myocardial infarction is dependent on left ventricular longitudinal function and left atrial size Circ Cardiovasc Imaging 2013 6 1 26 33 10.1161/CIRCIMAGING.112.978296 23192848
Ersboll M, Andersen MJ, Valeur N, Mogensen UM, Waziri H, Moller JE, et al. The prognostic value of left atrial peak reservoir strain in acute myocardial infarction is dependent on left ventricular longitudinal function and left atrial size. Circ Cardiovasc Imaging. 2013;6(1):26–33. 10.1161/CIRCIMAGING.112.978296.23192848
8. Holtstrand Hjalm H Fu M Hansson PO Zhong Y Caidahl K Mandalenakis Z Association between left atrial enlargement and obstructive sleep apnea in a general population of 71-year-old men J Sleep Res 2018 27 2 252 8 10.1111/jsr.12585 28836321
Holtstrand Hjalm H, Fu M, Hansson PO, Zhong Y, Caidahl K, Mandalenakis Z, et al. Association between left atrial enlargement and obstructive sleep apnea in a general population of 71-year-old men. J Sleep Res. 2018;27(2):252–8. 10.1111/jsr.12585.28836321
9. Katsiki N Mikhailidis DP Papanas N Left atrial volume: an independent predictor of cardiovascular outcomes Int J Cardiol 2018 265 234 5 10.1016/j.ijcard.2018.04.121 29885689
Katsiki N, Mikhailidis DP, Papanas N. Left atrial volume: an independent predictor of cardiovascular outcomes. Int J Cardiol. 2018;265:234–5. 10.1016/j.ijcard.2018.04.121.29885689
10. Mosquera VX Bouzas-Mosquera A Gonzalez-Barbeito M Bautista-Hernandez V Muniz J Alvarez-Garcia N Indexed left atrial size predicts all-cause and cardiovascular mortality in patients undergoing aortic valve surgery J Thorac Cardiovasc Surg 2017 153 6 1275 e12841277 10.1016/j.jtcvs.2017.01.054 28291607
Mosquera VX, Bouzas-Mosquera A, Gonzalez-Barbeito M, Bautista-Hernandez V, Muniz J, Alvarez-Garcia N, et al. Indexed left atrial size predicts all-cause and cardiovascular mortality in patients undergoing aortic valve surgery. J Thorac Cardiovasc Surg. 2017;153(6):1275–e12841277. 10.1016/j.jtcvs.2017.01.054.28291607
11. Stojanovska J Cronin P Patel S Gross BH Oral H Chughtai K Reference normal absolute and indexed values from ECG-gated MDCT: left atrial volume, function, and diameter AJR Am J Roentgenol 2011 197 3 631 7 10.2214/AJR.10.5955 21862805
Stojanovska J, Cronin P, Patel S, Gross BH, Oral H, Chughtai K, et al. Reference normal absolute and indexed values from ECG-gated MDCT: left atrial volume, function, and diameter. AJR Am J Roentgenol. 2011;197(3):631–7. 10.2214/AJR.10.5955.21862805
12. Yaghi S Moon YP Mora-McLaughlin C Willey JZ Cheung K Di Tullio MR Left atrial enlargement and stroke recurrence: the Northern Manhattan Stroke Study Stroke 2015 46 6 1488 93 10.1161/STROKEAHA.115.008711 25908460
Yaghi S, Moon YP, Mora-McLaughlin C, Willey JZ, Cheung K, Di Tullio MR, et al. Left atrial enlargement and stroke recurrence: the Northern Manhattan Stroke Study. Stroke. 2015;46(6):1488–93. 10.1161/STROKEAHA.115.008711.25908460
13. Li L Wu F Yang G Xu L Wong T Mohiaddin R Atrial scar quantification via multi-scale CNN in the graph-cuts framework Med Image Anal 2020 60 101595 10.1016/j.media.2019.101595 31811981
Li L, Wu F, Yang G, Xu L, Wong T, Mohiaddin R, et al. Atrial scar quantification via multi-scale CNN in the graph-cuts framework. Med Image Anal. 2020;60:101595. 10.1016/j.media.2019.101595.31811981
14. Calkins H Kuck KH Cappato R Brugada J Camm AJ Chen SA 2012 HRS/EHRA/ECAS expert consensus statement on catheter and surgical ablation of atrial fibrillation: recommendations for patient selection, procedural techniques, patient management and follow-up, definitions, endpoints, and research trial design J Interv Card Electrophysiol 2012 33 2 171 257 10.1007/s10840-012-9672-7 22382715
Calkins H, Kuck KH, Cappato R, Brugada J, Camm AJ, Chen SA, et al. 2012 HRS/EHRA/ECAS expert consensus statement on catheter and surgical ablation of atrial fibrillation: recommendations for patient selection, procedural techniques, patient management and follow-up, definitions, endpoints, and research trial design. J Interv Card Electrophysiol. 2012;33(2):171–257. 10.1007/s10840-012-9672-7.22382715
15. Di Biase L Burkhardt JD Mohanty P Sanchez J Mohanty S Horton R Left atrial appendage: an underrecognized trigger site of atrial fibrillation Circulation 2010 122 2 109 18 10.1161/CIRCULATIONAHA.109.928903 20606120
Di Biase L, Burkhardt JD, Mohanty P, Sanchez J, Mohanty S, Horton R, et al. Left atrial appendage: an underrecognized trigger site of atrial fibrillation. Circulation. 2010;122(2):109–18. 10.1161/CIRCULATIONAHA.109.928903.20606120
16. Lancellotti P Donal E Magne J Moonen M O’Connor K Daubert JC Risk stratification in asymptomatic moderate to severe aortic stenosis: the importance of the valvular, arterial and ventricular interplay Heart 2010 96 17 1364 71 10.1136/hrt.2009.190942 20483891
Lancellotti P, Donal E, Magne J, Moonen M, O’Connor K, Daubert JC, et al. Risk stratification in asymptomatic moderate to severe aortic stenosis: the importance of the valvular, arterial and ventricular interplay. Heart. 2010;96(17):1364–71. 10.1136/hrt.2009.190942.20483891
17. Fredgart MH Carter-Storch R Moller JE Ovrehus KA Pecini R Dahl JS Measurement of left atrial volume by 2D and 3D non-contrast computed tomography compared with cardiac magnetic resonance imaging J Cardiovasc Comput Tomogr 2018 12 4 316 9 10.1016/j.jcct.2018.04.001 29666031
Fredgart MH, Carter-Storch R, Moller JE, Ovrehus KA, Pecini R, Dahl JS, et al. Measurement of left atrial volume by 2D and 3D non-contrast computed tomography compared with cardiac magnetic resonance imaging. J Cardiovasc Comput Tomogr. 2018;12(4):316–9. 10.1016/j.jcct.2018.04.001.29666031
18. Fuchs A Kuhl JT Lonborg J Engstrom T Vejlstrup N Kober L Automated assessment of heart chamber volumes and function in patients with previous myocardial infarction using multidetector computed tomography J Cardiovasc Comput Tomogr 2012 6 5 325 34 10.1016/j.jcct.2012.01.006 23040538
Fuchs A, Kuhl JT, Lonborg J, Engstrom T, Vejlstrup N, Kober L, et al. Automated assessment of heart chamber volumes and function in patients with previous myocardial infarction using multidetector computed tomography. J Cardiovasc Comput Tomogr. 2012;6(5):325–34. 10.1016/j.jcct.2012.01.006.23040538
19. Agner BF Kuhl JT Linde JJ Kofoed KF Akeson P Rasmussen BV Assessment of left atrial volume and function in patients with permanent atrial fibrillation: comparison of cardiac magnetic resonance imaging, 320-slice multi-detector computed tomography, and transthoracic echocardiography Eur Heart J Cardiovasc Imaging 2014 15 5 532 40 10.1093/ehjci/jet239 24247925
Agner BF, Kuhl JT, Linde JJ, Kofoed KF, Akeson P, Rasmussen BV, et al. Assessment of left atrial volume and function in patients with permanent atrial fibrillation: comparison of cardiac magnetic resonance imaging, 320-slice multi-detector computed tomography, and transthoracic echocardiography. Eur Heart J Cardiovasc Imaging. 2014;15(5):532–40. 10.1093/ehjci/jet239.24247925
20. Romero J Husain SA Kelesidis I Sanz J Medina HM Garcia MJ Detection of left atrial appendage thrombus by cardiac computed tomography in patients with atrial fibrillation: a meta-analysis Circ Cardiovasc Imaging 2013 6 2 185 94 10.1161/CIRCIMAGING.112.000153 23406625
Romero J, Husain SA, Kelesidis I, Sanz J, Medina HM, Garcia MJ. Detection of left atrial appendage thrombus by cardiac computed tomography in patients with atrial fibrillation: a meta-analysis. Circ Cardiovasc Imaging. 2013;6(2):185–94. 10.1161/CIRCIMAGING.112.000153.23406625
21. Njoku A Kannabhiran M Arora R Reddy P Gopinathannair R Lakkireddy D Left atrial volume predicts atrial fibrillation recurrence after radiofrequency ablation: a meta-analysis Europace 2018 20 1 33 42 10.1093/europace/eux013 28444307
Njoku A, Kannabhiran M, Arora R, Reddy P, Gopinathannair R, Lakkireddy D, et al. Left atrial volume predicts atrial fibrillation recurrence after radiofrequency ablation: a meta-analysis. Europace. 2018;20(1):33–42. 10.1093/europace/eux013.28444307
22. Miyazaki S Kuwahara T Kobori A Takahashi Y Takei A Sato A Preprocedural predictors of atrial fibrillation recurrence following pulmonary vein antrum isolation in patients with paroxysmal atrial fibrillation: long-term follow-up results J Cardiovasc Electrophysiol 2011 22 6 621 5 10.1111/j.1540-8167.2010.01984.x 21235666
Miyazaki S, Kuwahara T, Kobori A, Takahashi Y, Takei A, Sato A, et al. Preprocedural predictors of atrial fibrillation recurrence following pulmonary vein antrum isolation in patients with paroxysmal atrial fibrillation: long-term follow-up results. J Cardiovasc Electrophysiol. 2011;22(6):621–5. 10.1111/j.1540-8167.2010.01984.x.21235666
23. Park J Yang PS Kim TH Uhm JS Kim JY Joung B Low left atrial compliance contributes to the clinical recurrence of Atrial Fibrillation after catheter ablation in patients with structurally and functionally normal heart PLoS ONE 2015 10 12 e0143853 10.1371/journal.pone.0143853 26624617
Park J, Yang PS, Kim TH, Uhm JS, Kim JY, Joung B, et al. Low left atrial compliance contributes to the clinical recurrence of Atrial Fibrillation after catheter ablation in patients with structurally and functionally normal heart. PLoS ONE. 2015;10(12):e0143853. 10.1371/journal.pone.0143853.26624617
24. Gulati A Ismail TF Jabbour A Ismail NA Morarji K Ali A Clinical utility and prognostic value of left atrial volume assessment by cardiovascular magnetic resonance in non-ischaemic dilated cardiomyopathy Eur J Heart Fail 2013 15 6 660 70 10.1093/eurjhf/hft019 23475781
Gulati A, Ismail TF, Jabbour A, Ismail NA, Morarji K, Ali A, et al. Clinical utility and prognostic value of left atrial volume assessment by cardiovascular magnetic resonance in non-ischaemic dilated cardiomyopathy. Eur J Heart Fail. 2013;15(6):660–70. 10.1093/eurjhf/hft019.23475781
25. Wijesurendra RS, Rider OJ, Neubauer S. Left atrial volumes in Health and Disease measured using Cardiac magnetic resonance. Circ Cardiovasc Imaging. 2017;10(2). 10.1161/CIRCIMAGING.117.006124.
26. Adukauskaite A Barbieri F Senoner T Plank F Beyer C Knoflach M Left atrial appendage morphology is Associated with Cryptogenic Stroke: a CTA study JACC Cardiovasc Imaging 2019 12 10 2079 81 10.1016/j.jcmg.2019.04.015 31202750
Adukauskaite A, Barbieri F, Senoner T, Plank F, Beyer C, Knoflach M, et al. Left atrial appendage morphology is Associated with Cryptogenic Stroke: a CTA study. JACC Cardiovasc Imaging. 2019;12(10):2079–81. 10.1016/j.jcmg.2019.04.015.31202750
27. Di Biase L Santangeli P Anselmino M Mohanty P Salvetti I Gili S Does the left atrial appendage morphology correlate with the risk of stroke in patients with atrial fibrillation? Results from a multicenter study J Am Coll Cardiol 2012 60 6 531 8 10.1016/j.jacc.2012.04.032 22858289
Di Biase L, Santangeli P, Anselmino M, Mohanty P, Salvetti I, Gili S, et al. Does the left atrial appendage morphology correlate with the risk of stroke in patients with atrial fibrillation? Results from a multicenter study. J Am Coll Cardiol. 2012;60(6):531–8. 10.1016/j.jacc.2012.04.032.22858289
28. Saver JL CLINICAL PRACTICE. Cryptogenic Stroke N Engl J Med 2016 374 21 2065 74 10.1056/NEJMcp1503946 27223148
Saver JL. CLINICAL PRACTICE. Cryptogenic Stroke. N Engl J Med. 2016;374(21):2065–74. 10.1056/NEJMcp1503946.27223148
29. Tian X Zhang XJ Yuan YF Li CY Zhou LX Gao BL Morphological and functional parameters of left atrial appendage play a greater role in atrial fibrillation relapse after radiofrequency ablation Sci Rep 2020 10 1 8072 10.1038/s41598-020-65056-3 32415245
Tian X, Zhang XJ, Yuan YF, Li CY, Zhou LX, Gao BL. Morphological and functional parameters of left atrial appendage play a greater role in atrial fibrillation relapse after radiofrequency ablation. Sci Rep. 2020;10(1):8072. 10.1038/s41598-020-65056-3.32415245
30. Fayad E Boucebci S Vesselle G Zourdani H Herpe G Hamya I Left atrial volume assessed by ECG-gated computed tomography: variations according to age, gender and time during the cardiac cycle Diagn Interv Imaging 2018 99 2 105 9 10.1016/j.diii.2017.10.011 29289529
Fayad E, Boucebci S, Vesselle G, Zourdani H, Herpe G, Hamya I, et al. Left atrial volume assessed by ECG-gated computed tomography: variations according to age, gender and time during the cardiac cycle. Diagn Interv Imaging. 2018;99(2):105–9. 10.1016/j.diii.2017.10.011.29289529
31. Mahabadi AA Bamberg F Toepker M Schlett CL Rogers IS Nagurney JT Association of aortic valve calcification to the presence, extent, and composition of coronary artery plaque burden: from the rule out myocardial infarction using computer assisted Tomography (ROMICAT) trial Am Heart J 2009 158 4 562 8 10.1016/j.ahj.2009.07.027 19781415
Mahabadi AA, Bamberg F, Toepker M, Schlett CL, Rogers IS, Nagurney JT, et al. Association of aortic valve calcification to the presence, extent, and composition of coronary artery plaque burden: from the rule out myocardial infarction using computer assisted Tomography (ROMICAT) trial. Am Heart J. 2009;158(4):562–8. 10.1016/j.ahj.2009.07.027.19781415
32. Walker JR Abadi S Solomonica A Mutlak D Aronson D Agmon Y Left-sided cardiac chamber evaluation using single-phase mid-diastolic coronary computed tomography angiography: derivation of normal values and comparison with conventional end-diastolic and end-systolic phases Eur Radiol 2016 26 10 3626 34 10.1007/s00330-016-4211-z 26809292
Walker JR, Abadi S, Solomonica A, Mutlak D, Aronson D, Agmon Y, et al. Left-sided cardiac chamber evaluation using single-phase mid-diastolic coronary computed tomography angiography: derivation of normal values and comparison with conventional end-diastolic and end-systolic phases. Eur Radiol. 2016;26(10):3626–34. 10.1007/s00330-016-4211-z.26809292
33. Mahabadi AA Truong QA Schlett CL Samy B O’Donnell CJ Fox CS Axial area and anteroposterior diameter as estimates of left atrial size using computed tomography of the chest: comparison with 3-dimensional volume J Cardiovasc Comput Tomogr 2010 4 1 49 54 10.1016/j.jcct.2009.10.013 20159629
Mahabadi AA, Truong QA, Schlett CL, Samy B, O’Donnell CJ, Fox CS, et al. Axial area and anteroposterior diameter as estimates of left atrial size using computed tomography of the chest: comparison with 3-dimensional volume. J Cardiovasc Comput Tomogr. 2010;4(1):49–54. 10.1016/j.jcct.2009.10.013.20159629
34. Stolzmann P Scheffel H Leschka S Schertler T Frauenfelder T Kaufmann PA Reference values for quantitative left ventricular and left atrial measurements in cardiac computed tomography Eur Radiol 2008 18 8 1625 34 10.1007/s00330-008-0939-4 18446346
Stolzmann P, Scheffel H, Leschka S, Schertler T, Frauenfelder T, Kaufmann PA, et al. Reference values for quantitative left ventricular and left atrial measurements in cardiac computed tomography. Eur Radiol. 2008;18(8):1625–34. 10.1007/s00330-008-0939-4.18446346
35. Eifer DA Nguyen ET Thavendiranathan P Hanneman K Diagnostic accuracy of sex-specific chest CT measurements compared with Cardiac MRI findings in the Assessment of Cardiac Chamber Enlargement AJR Am J Roentgenol 2018 211 5 993 9 10.2214/AJR.18.19805 30240288
Eifer DA, Nguyen ET, Thavendiranathan P, Hanneman K. Diagnostic accuracy of sex-specific chest CT measurements compared with Cardiac MRI findings in the Assessment of Cardiac Chamber Enlargement. AJR Am J Roentgenol. 2018;211(5):993–9. 10.2214/AJR.18.19805.30240288
36. Huckleberry J Haltom S Issac T Gabaldon J Ketai L Accuracy of non-ECG-gated computed tomography angiography of the chest in assessment of left-sided cardiac chamber enlargement J Thorac Imaging 2012 27 6 354 8 10.1097/RTI.0b013e31822bddbb 22071674
Huckleberry J, Haltom S, Issac T, Gabaldon J, Ketai L. Accuracy of non-ECG-gated computed tomography angiography of the chest in assessment of left-sided cardiac chamber enlargement. J Thorac Imaging. 2012;27(6):354–8. 10.1097/RTI.0b013e31822bddbb.22071674
37. Sohrabi S Hope M Saloner D Keedy A Naeger D Lorca MC Left atrial transverse diameter on computed tomography angiography can accurately diagnose left atrial enlargement in patients with atrial fibrillation J Thorac Imaging 2015 30 3 214 7 10.1097/RTI.0000000000000132 25629578
Sohrabi S, Hope M, Saloner D, Keedy A, Naeger D, Lorca MC, et al. Left atrial transverse diameter on computed tomography angiography can accurately diagnose left atrial enlargement in patients with atrial fibrillation. J Thorac Imaging. 2015;30(3):214–7. 10.1097/RTI.0000000000000132.25629578
38. Currie BJ Johns C Chin M Charalampopolous T Elliot CA Garg P CT derived left atrial size identifies left heart disease in suspected pulmonary hypertension: derivation and validation of predictive thresholds Int J Cardiol 2018 260 172 7 10.1016/j.ijcard.2018.02.114 29530618
Currie BJ, Johns C, Chin M, Charalampopolous T, Elliot CA, Garg P, et al. CT derived left atrial size identifies left heart disease in suspected pulmonary hypertension: derivation and validation of predictive thresholds. Int J Cardiol. 2018;260:172–7. 10.1016/j.ijcard.2018.02.114.29530618
39. Baque-Juston M Volondat M Fontas E Roger C Brunner P Padovani B Left atrio-vertebral ratio: a new computed-tomography measurement to identify left atrial dilation Eur J Radiol 2016 85 1 255 60 10.1016/j.ejrad.2015.11.016 26724674
Baque-Juston M, Volondat M, Fontas E, Roger C, Brunner P, Padovani B, et al. Left atrio-vertebral ratio: a new computed-tomography measurement to identify left atrial dilation. Eur J Radiol. 2016;85(1):255–60. 10.1016/j.ejrad.2015.11.016.26724674
40. Montillet M Baque-Juston M Tasu JP Bertrand S Berthier F Zarqane N The left atrio-vertebral ratio: a new simple means for assessing left atrial enlargement on computed tomography Eur Radiol 2018 28 3 1310 7 10.1007/s00330-017-5041-3 28956130
Montillet M, Baque-Juston M, Tasu JP, Bertrand S, Berthier F, Zarqane N, et al. The left atrio-vertebral ratio: a new simple means for assessing left atrial enlargement on computed tomography. Eur Radiol. 2018;28(3):1310–7. 10.1007/s00330-017-5041-3.28956130
41. Echocardiographic Normal Ranges Meta-Analysis of the Left Heart C Ethnic-specific normative reference values for Echocardiographic LA and LV size, LV Mass, and systolic function: the EchoNoRMAL Study JACC Cardiovasc Imaging 2015 8 6 656 65 10.1016/j.jcmg.2015.02.014 25981507
Echocardiographic Normal Ranges Meta-Analysis of the Left Heart C. Ethnic-specific normative reference values for Echocardiographic LA and LV size, LV Mass, and systolic function: the EchoNoRMAL Study. JACC Cardiovasc Imaging. 2015;8(6):656–65. 10.1016/j.jcmg.2015.02.014.25981507
42. Csecs I Garcia MJ Reference CMR values of atrial size and function: are they similar in the east and the west? Int J Cardiol 2022 358 134 5 10.1016/j.ijcard.2022.02.036 35483479
Csecs I, Garcia MJ. Reference CMR values of atrial size and function: are they similar in the east and the west? Int J Cardiol. 2022;358:134–5. 10.1016/j.ijcard.2022.02.036.35483479
43. Gao Y Zhang Z Zhou S Li G Lou M Zhao Z Reference values of left and right atrial volumes and phasic function based on a large sample of healthy Chinese adults: a cardiovascular magnetic resonance study Int J Cardiol 2022 352 180 7 10.1016/j.ijcard.2022.01.071 35124105
Gao Y, Zhang Z, Zhou S, Li G, Lou M, Zhao Z, et al. Reference values of left and right atrial volumes and phasic function based on a large sample of healthy Chinese adults: a cardiovascular magnetic resonance study. Int J Cardiol. 2022;352:180–7. 10.1016/j.ijcard.2022.01.071.35124105
