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.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
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.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
6.2018 Korean Heart Rhythm Society Guidelines for Antiarrhythmic Drug Therapy in Non-valvular Atrial Fibrillation.
Ki Woon KANG ; Jaemin SHIM ; Jinhee AHN ; Dae In LEE ; Jun KIM ; Boyoung JOUNG ; Kee Joon CHOI
Korean Journal of Medicine 2018;93(2):140-152
Rhythm control therapy is the main strategy for restoring and maintaining sinus rhythm in patients with non-valvular atrial fibrillation (NVAF). Sinus rhythm is better restored and maintained with antiarrhythmic drugs than with placebo treatment. In addition, catheter ablation or combination therapy is more effective than antiarrhythmic drugs for treating NVAF. However, in most clinical trials to date, rhythm control therapy has resulted in neutral clinical outcomes compared with rate control therapy. The decision to undergo rhythm control therapy should be based on age, atrial fibrillation (AF)-related symptoms, type of AF, structural heart disease, and underlying comorbidities. For now, rhythm control therapy is indicated to improve symptoms in patients with NVAF who have refractory symptoms after adequate rate control therapy. The Korean Heart Rhythm Society organized the Korean AF Management Guideline Committee and analyzed all available data, including South Korean patients with NVAF. This review article provides general principles and detailed methodology for rhythm control therapy in South Korean patients with NVAF.
Anti-Arrhythmia Agents
;
Atrial Fibrillation*
;
Catheter Ablation
;
Comorbidity
;
Drug Therapy*
;
Heart Diseases
;
Heart*
;
Humans
7.Use of Cardiac Computed Tomography and Magnetic Resonance Imaging in Case Management of Atrial Fibrillation with Catheter Ablation
Hee Gone LEE ; Jaemin SHIM ; Jong il CHOI ; Young Hoon KIM ; Yu Whan OH ; Sung Ho HWANG
Korean Journal of Radiology 2019;20(5):695-708
Atrial fibrillation (AF) is the most common arrhythmia associated with the risk of morbidity and mortality in clinical patients. AF is considered as an arrhythmia type that develops and progresses through close connection with cardiac structural arrhythmogenic substrates. Since the introduction of catheter ablation-mediated electrical isolation of arrhythmogenic substrates, cardiac imaging indicates improved treatment outcome and prognosis with appropriate candidate selection, ablation catheter guidance, and post-ablation follow-up. Currently, cardiac computed tomography (CCT) and cardiovascular magnetic resonance (CMR) imaging are essential in the case management of AF at both pre-and post-procedural stages of catheter ablation. In this review, we discuss the roles and technical considerations of CCT and CMR imaging in the management of patients with AF undergoing catheter ablation.
Arrhythmias, Cardiac
;
Atrial Fibrillation
;
Case Management
;
Catheter Ablation
;
Catheters
;
Follow-Up Studies
;
Humans
;
Magnetic Resonance Imaging
;
Mortality
;
Prognosis
;
Treatment Outcome
8.2021 Korean Heart Rhythm Society Guidelines for Catheter or Surgical Ablation of Atrial Fibrillation
Woo-Hyun LIM ; Jaemin SHIM ; Ji-Hyun LEE ; Boyoung JOUNG
Korean Journal of Medicine 2022;97(1):5-22
Rhythm control therapy is used in atrial fibrillation (AF) management to improve AF-related symptoms along with rate control. AF catheter ablation is effective in maintaining sinus rhythm and has an acceptable complication rate. Compared with antiarrhythmic drugs, AF catheter ablation is superior with respect to arrhythmia-free survival and improvement in the quality of life. Therefore, AF ablation is recommended for rhythm control after the failure of antiarrhythmic drugs and is sometimes considered a first-line therapy for AF patients. Radiofrequency and cryoballoon ablation show similar efficacy, with slightly different complication profiles. Surgery for AF is also an effective rhythm control therapy and should be considered in patients undergoing cardiac surgery or in those with failed catheter ablation. For patients undergoing AF catheter ablation, performing ablation under uninterrupted warfarin or non-vitamin K oral anticoagulant treatment is recommended for periprocedural stroke risk management. Here, we review existing data and discuss the general principles of AF catheter and surgical ablation in patients with AF.
9.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.
10.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.