1.Paradoxical Response of Giant Left Atrial Appendage Aneurysm after Catheter Ablation of Atrial Fibrillation.
Jee Won CHUNG ; Jaemin SHIM ; Wan Joo SHIM ; Young Hoon KIM ; Sung Ho HWANG
Investigative Magnetic Resonance Imaging 2016;20(2):132-135
We report the case of a 43-year-old male with both giant left atrial appendage (LAA) aneurysm and drug-refractory atrial fibrillation (AF). The patient was treated with percutaneous electrical isolation of cardiac arrhythmogenic substrate, and has been free of AF symptom over one year. Although the surgical resection of giant LAA aneurysm is mostly used to prevent systemic thromboembolism, we have performed follow-up of the giant LAA aneurysm using cardiac magnetic resonance (CMR) imaging and transesophageal echocardiography (TEE) after the successful catheter ablation of refractory AF. At one-year follow-up CMR, the giant LAA aneurysm showed remarkable enlargement as well as decreased contractility. Additionally, one-year follow-up TEE showed spontaneous echo contrast as an indicator of blood stasis in the giant LAA aneurysm. Those findings of giant LAA aneurysm suggest that the risk of thromboembolism may be high despite termination of AF.
Adult
;
Aneurysm*
;
Atrial Appendage*
;
Atrial Fibrillation*
;
Catheter Ablation*
;
Catheters*
;
Echocardiography
;
Echocardiography, Transesophageal
;
Follow-Up Studies
;
Humans
;
Magnetic Resonance Imaging
;
Male
;
Thromboembolism
2.Male Pseudohermaphroditism Presented with Sudden Cardiac Arrest.
Jaemin SHIM ; Hye Jin HWANG ; Hui Nam PAK ; Moon Hyoung LEE ; Boyoung JOUNG
Yonsei Medical Journal 2012;53(3):658-661
Torsades de Pointes is a life-threatening arrhythmia associated with a number of causes, but is very rare among endocrinologic disorders. We report a case of male pseudohermaphroditism with hyperaldosteronism due to a 17alpha-hydroxylase deficiency presented with sudden cardiac arrest.
46, XY Disorders of Sex Development/*diagnosis/drug therapy
;
Adult
;
Death, Sudden, Cardiac/*etiology/*pathology
;
Female
;
Humans
3.Atrial Tachycardia Originating from the Aortomitral Junction.
Seung Hyun LEE ; Jaemin SHIM ; Hui Nam PAK ; Moon Hyoung LEE ; Boyoung JOUNG
Yonsei Medical Journal 2014;55(2):530-534
Atrial tachycardia (AT) originating from the aortomitral junction is a very rare and challenging disease. Its arrhythmic characteristics have not been described in detail compared with the descriptions of the arrhythmic characteristics of AT originating from the other locations. Only a few case reports have documented successful ablation of this type of AT using transaortic or transseptal approaches. We describe a case with AT that was resistant to right-sided ablation near the His bundle failed and transaortic ablation at the aortomitral junction successfully eliminated.
Bundle of His
;
Catheter Ablation
;
Tachycardia*
4.4q25 and ZFHX3 Single Nucleotide Polymorphisms are Associated with Electroanatomical Characteristics of Left Atrium and Clinical Outcomes of Radiofrequency Catheter Ablation in Patients with Atrial Fibrillation.
Jaemin SHIM ; Jae Sun UHM ; Boyoung JOUNG ; Moon Hyoung LEE ; Hui Nam PAK
International Journal of Arrhythmia 2016;17(3):118-134
BACKGROUND AND OBJECTIVES: Previous studies have demonstrated an association between several single nucleotide polymorphisms and atrial fibrillation (AF). We hypothesized that the phenotypes of AF patients were associated with common AF susceptibility alleles. SUBJECTS AND METHODS: A total of 659 patients (57±9 years, 76% male) with AF who underwent catheter ablation and 659 age, and sex-matched controls were genotyped for the common AF susceptibility alleles rs2200733 and rs6843082 at 4q25, rs2106261 at ZFHX3, and rs13376333 at KCNN3. The phenotypes of AF patients, including electroanatomical characteristics of the left atrium and recurrence after ablation, were compared. RESULTS: The rs2200733 variant allele carriers have larger left atrium volume (128.5±40.7 vs. 113.5±29.2 mL, p=0.020), longer PR interval (185.9±32.6 vs. 174.8±21.9 ms, p=0.018), and higher amplitude of negative P-wave terminal force in Lead V₁ (0.07±0.04 vs. 0.05±0.04 mV, p=0.015) on electrocardiography than those without the variant allele. When the patients were assigned to three groups according to the number of variant alleles (Group A: no variant, n=15; Group B: 1 variant, n=158; Group C: 2 variants, n=439), incremental prognostic value, according to the number of variant alleles, was demonstrated (Log Rank p=0.015). Multivariate Cox regression analysis showed that persistent AF (OR 1.677, 95% CI 1.176-2.381, p=0.004) and the number of variants (OR 1.552, 95% CI 1.099-2.222, p=0.015) were independent predictors for recurrence of AF. CONCLUSION: This study showed the common AF susceptibility alleles at 4q25 and ZFHX3 are associated with electroanatomical characteristics of the left atrium and the clinical outcomes of catheter ablation in Korean patients with AF.
Alleles
;
Atrial Fibrillation*
;
Catheter Ablation*
;
Electrocardiography
;
Heart Atria*
;
Humans
;
Phenotype
;
Polymorphism, Single Nucleotide*
;
Recurrence
5.Optimal Cardiac Magnetic Resonance Contrast-Enhanced Timing Robust Angiography (CMR-CENTRA) for the Three-Dimensional Reconstruction of the Bilateral Atria in the Electroanatomic Mapping (EAM) of Atrial Fibrillation.
Jun Seong KIM ; Yu Whan OH ; Jaemin SHIM ; Young Hoon KIM ; Sung Ho HWANG
Investigative Magnetic Resonance Imaging 2017;21(3):131-138
PURPOSE: To optimize the timing of scans using cardiac magnetic resonance contrast-enhanced timing robust angiography (CMR-CENTRA) for electroanatomic mapping (EAM) of the right atrium (RA) and left atrium (LA) in patients with atrial fibrillation (AF). MATERIALS AND METHODS: Fifty patients with AF (38 men; mean age, 59.6 ± 9.3 years) underwent CMR-CENTRA in preparation for EAM. The CMR-CENTRA data were acquired at five different scan times: 0 seconds, 5 seconds, 10 seconds, 15 seconds, and 20 seconds after an intravenous injection of contrast media. To evaluate the degree of contrast enhancement, right atrial relative contrast (RA-RC) and left atrial relative contrast (LA-RC) on the CMR-CENTRA scans were assessed at each time point. The three-dimensional (3D) reconstruction of the RA and LA for the EAM system was performed using the CMR-CENTRA data. RESULTS: A CMR-CENTRA at a scan time of 10 seconds showed significantly greater LA-RC (P < 0.05) compared with all other scan times. A CMR-CENTRA at a scan time of 15 seconds showed significantly greater RA-RC (P < 0.05) compared with all other scan times. In the 3D reconstruction of the RA, the success rates of CMR-CENTRA at scan times of 10 seconds and 15 seconds were 18% and 100%, respectively. In the 3D reconstruction of the LA, the success rates of CMR-CENTRA at 10- and 15-second scan times were 100%. CONCLUSION: The CMR-CENTRA data acquired at 15 seconds after the injection of contrast media is appropriate for the preparation of an EAM system that is focused on the RA and LA in patients with AF.
Angiography*
;
Atrial Fibrillation*
;
Contrast Media
;
Heart Atria
;
Hemodynamics
;
Humans
;
Injections, Intravenous
;
Magnetic Resonance Imaging
;
Male
6.Evaluation of Left Atrial Appendage Isolation Using Cardiac MRI after Catheter Ablation of Atrial Fibrillation: Paradox of Appendage Reservoir
Hyungjoon CHO ; Yongwon CHO ; Jaemin SHIM ; Jong-il CHOI ; Young-Hoon KIM ; Yu-Whan OH ; Sung Ho HWANG
Korean Journal of Radiology 2021;22(4):525-534
Objective:
To assess the effect of left atrial appendage (LAA) isolation on LAA emptying and left atrial (LA) function using cardiac MRI in patients who underwent successful catheter ablation of atrial fibrillation (AF).
Materials and Methods:
This retrospective study included 84 patients (mean age, 59 ± 10 years; 67 males) who underwent cardiac MRI after successful catheter ablation of AF. According to the electrical activity of LAA after catheter ablation, patients showed either LAA isolation or LAA normal activity. The LAA emptying phase (LAA-EP, in the systolic phase [SP] or diastolic phase), LAA emptying flux (LAA-EF, mL/s), and LA ejection fraction (LAEF, %) were evaluated by cardiac MRI.
Results:
Of the 84 patients, 61 (73%) and 23 (27%) patients showed LAA normal activity and LAA isolation, respectively.Incidence of LAA emptying in SP was significantly higher in LAA isolation (91% vs. 0%, p < 0.001) than in LAA normal activation. LAA-EF was significantly lower in LAA isolation (40.1 ± 16.2 mL/s vs. 80.2 ± 25.1 mL/s, pp < 0.001) than in LAA normal activity. Furthermore, LAEF was significantly lower in LAA isolation (23.7% ± 11.2% vs. 31.1% ± 16.6%, p = 0.04) than in LAA normal activity. Multivariate analysis demonstrated that the LAA-EP was independent from LAEF (p = 0.01).
Conclusion
LAA emptying in SP may be a critical characteristic of LAA isolation, and it may adversely affect the LAEF after catheter ablation of AF.
7.Relationship between Epicardial Fat Accumulation and Left Atrial Reverse Remodeling after Catheter Ablation of Atrial Fibrillation
Jeong Yoon LEE ; Yu Whan OH ; Young Hoon KIM ; Jaemin SHIM ; Sung Ho HWANG
Journal of the Korean Radiological Society 2019;80(5):930-941
PURPOSE:
To demonstrate the relationship between epicardial fat accumulation and left atrial reverse remodeling by cardiac multi-detector CT (MDCT) after catheter ablation of atrial fibrillation (AF).
MATERIALS AND METHODS:
Seventy-six patients underwent cardiac MDCT before and after catheter ablation of AF. Left atrial volume (LAV) and epicardial fat volume (EFV) were measured. LAV and EFV before and after catheter ablation of AF were respectively compared and the change percentages (CPs) were evaluated.
RESULTS:
The LAV after catheter ablation of AF was significantly less than the baseline LAV (107.5 ± 50.2 mL vs. 144.9 ± 62.6 mL, p < 0.001). The EFV after catheter ablation of AF was significantly greater than the baseline EFV (105.0 ± 35.6 mL vs. 90.1 ± 31.9 mL, p < 0.001). Mean CPs of LAV and EFV were −23.3% ± 20.8% and 15.9% ± 20.9%, respectively. There was a significantly negative relationship between the CPs of LAV and EFV (R = −0.53, p < 0.001).
CONCLUSION
Catheter ablation of AF may result in a reduction in LAV and an increase in EFV. Left atrial reverse remodeling with a reduction in LAV may be associated with epicardial fat accumulation in patients who undergo catheter ablation of AF.
8.Efficient Segmentation for Left Atrium With Convolution Neural Network Based on Active Learning in Late Gadolinium Enhancement Magnetic Resonance Imaging
Yongwon CHO ; Hyungjoon CHO ; Jaemin SHIM ; Jong-Il CHOI ; Young-Hoon KIM ; Namkug KIM ; Yu-Whan OH ; Sung Ho HWANG
Journal of Korean Medical Science 2022;37(36):e271-
Background:
To propose fully automatic segmentation of left atrium using active learning with limited dataset in late gadolinium enhancement in cardiac magnetic resonance imaging (LGE-CMRI).
Methods:
An active learning framework was developed to segment the left atrium in cardiac LGE-CMRI. Patients (n = 98) with atrial fibrillation from the Korea University Anam Hospital were enrolled. First, 20 cases were delineated for ground truths by two experts and used for training a draft model. Second, the 20 cases from the first step and 50 new cases, corrected in a human-in-the-loop manner after predicting using the draft model, were used to train the next model; all 98 cases (70 cases from the second step and 28 new cases) were trained. An additional 20 LGE-CMRI were evaluated in each step.
Results:
The Dice coefficients for the three steps were 0.85 ± 0.06, 0.89 ± 0.02, and 0.90 ± 0.02, respectively. The biases (95% confidence interval) in the Bland-Altman plots of each step were 6.36% (−14.90–27.61), 6.21% (−9.62–22.03), and 2.68% (−8.57–13.93). Deep active learning-based annotation times were 218 ± 31 seconds, 36.70 ± 18 seconds, and 36.56 ± 15 seconds, respectively.
Conclusion
Deep active learning reduced annotation time and enabled efficient training on limited LGE-CMRI.
9.Improvement in Image Quality and Visibility of Coronary Arteries, Stents, and Valve Structures on CT Angiography by Deep Learning Reconstruction
Chuluunbaatar OTGONBAATAR ; Jae-Kyun RYU ; Jaemin SHIN ; Ji Young WOO ; Jung Wook SEO ; Hackjoon SHIM ; Dae Hyun HWANG
Korean Journal of Radiology 2022;23(11):1044-1054
Objective:
This study aimed to investigate whether a deep learning reconstruction (DLR) method improves the image quality, stent evaluation, and visibility of the valve apparatus in coronary computed tomography angiography (CCTA) when compared with filtered back projection (FBP) and hybrid iterative reconstruction (IR) methods.
Materials and Methods:
CCTA images of 51 patients (mean age ± standard deviation [SD], 63.9 ± 9.8 years, 36 male) who underwent examination at a single institution were reconstructed using DLR, FBP, and hybrid IR methods and reviewed.CT attenuation, image noise, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and stent evaluation, including 10%– 90% edge rise slope (ERS) and 10%–90% edge rise distance (ERD), were measured. Quantitative data are summarized as the mean ± SD. The subjective visual scores (1 for worst -5 for best) of the images were obtained for the following: overall image quality, image noise, and appearance of stent, vessel, and aortic and tricuspid valve apparatus (annulus, leaflets, papillary muscles, and chordae tendineae). These parameters were compared between the DLR, FBP, and hybrid IR methods.
Results:
DLR provided higher Hounsfield unit (HU) values in the aorta and similar attenuation in the fat and muscle compared with FBP and hybrid IR. The image noise in HU was significantly lower in DLR (12.6 ± 2.2) than in hybrid IR (24.2 ± 3.0) and FBP (54.2 ± 9.5) (p < 0.001). The SNR and CNR were significantly higher in the DLR group than in the FBP and hybrid IR groups (p < 0.001). In the coronary stent, the mean value of ERS was significantly higher in DLR (1260.4 ± 242.5 HU/mm) than that of FBP (801.9 ± 170.7 HU/mm) and hybrid IR (641.9 ± 112.0 HU/mm). The mean value of ERD was measured as 0.8 ± 0.1 mm for DLR while it was 1.1 ± 0.2 mm for FBP and 1.1 ± 0.2 mm for hybrid IR. The subjective visual scores were higher in the DLR than in the images reconstructed with FBP and hybrid IR.
Conclusion
DLR reconstruction provided better images than FBP and hybrid IR reconstruction.
10.Evaluation of Left Atrial Appendage Isolation Using Cardiac MRI after Catheter Ablation of Atrial Fibrillation: Paradox of Appendage Reservoir
Hyungjoon CHO ; Yongwon CHO ; Jaemin SHIM ; Jong-il CHOI ; Young-Hoon KIM ; Yu-Whan OH ; Sung Ho HWANG
Korean Journal of Radiology 2021;22(4):525-534
Objective:
To assess the effect of left atrial appendage (LAA) isolation on LAA emptying and left atrial (LA) function using cardiac MRI in patients who underwent successful catheter ablation of atrial fibrillation (AF).
Materials and Methods:
This retrospective study included 84 patients (mean age, 59 ± 10 years; 67 males) who underwent cardiac MRI after successful catheter ablation of AF. According to the electrical activity of LAA after catheter ablation, patients showed either LAA isolation or LAA normal activity. The LAA emptying phase (LAA-EP, in the systolic phase [SP] or diastolic phase), LAA emptying flux (LAA-EF, mL/s), and LA ejection fraction (LAEF, %) were evaluated by cardiac MRI.
Results:
Of the 84 patients, 61 (73%) and 23 (27%) patients showed LAA normal activity and LAA isolation, respectively.Incidence of LAA emptying in SP was significantly higher in LAA isolation (91% vs. 0%, p < 0.001) than in LAA normal activation. LAA-EF was significantly lower in LAA isolation (40.1 ± 16.2 mL/s vs. 80.2 ± 25.1 mL/s, pp < 0.001) than in LAA normal activity. Furthermore, LAEF was significantly lower in LAA isolation (23.7% ± 11.2% vs. 31.1% ± 16.6%, p = 0.04) than in LAA normal activity. Multivariate analysis demonstrated that the LAA-EP was independent from LAEF (p = 0.01).
Conclusion
LAA emptying in SP may be a critical characteristic of LAA isolation, and it may adversely affect the LAEF after catheter ablation of AF.