Endovenous radiofrequency ablation using a new bipolar electrode in a canine model: a new endovenous radiofrequency electrode

Purpose@#This study aimed to determine the effectiveness and safety of a newly developed endovenous radiofrequency (RF) catheter compared with that of the existing RF catheter in a canine model. @*Methods@#Seven dogs underwent ablation using 1 control catheter (ClosureFAST, CF; Covidien) and 1 experimental catheter (VENISTAR, VS; STARmed Co., Ltd.) in the femoral and cephalic veins. The ablated vein was evaluated macroscopically (2,3,5-triphenyltetrazolium chloride staining, TTC), microscopically (hematoxylin and eosin staining), and ultrasonographically. Vessel injury score was used to evaluate the ablating effect objectively. Veins from 1 dog were evaluated on the day of ablation, while in the remaining 6 dogs, the ablated veins were evaluated 2 weeks later. @*Results@#A total of 23 veins (CF, 11 veins; VS, 12 veins) were ablated in 7 dogs. Non–TTC-stained vein wall areas were identified in all ablated veins. No significant difference was observed in the mean vessel injury score (2.54 ± 1.16 vs. 2.42 ± 1.13, P = 0.656) and the mean vessel wall thickness (0.32 ± 0.03 mm vs. 0.31 ± 0.05 mm, P = 0.212) between CF and VS. There was no blood flow in all veins ablated with VS, whereas there was remaining blood flow in 1 vein ablated with CF. Perivenous complication was not observed. @*Conclusion@#Endovenous RF ablation using a newly developed VS RF catheter seems to provide comparable occlusion rate and degree of vein wall injury without perivenous adverse events compared to the most commonly used RF catheter (CF).

Prediction of renal recovery following sepsis-associated acute kidney injury requiring renal replacement therapy using contrast-enhanced ultrasonography

Microcirculatory dysfunction plays a critical role in sepsis-associated acute kidney injury (S-AKI) development; however, its impact on renal recovery remains uncertain. We investigated the association between cortical microcirculatory function assessed using contrast-enhanced ultrasonography (CEUS) and renal recovery after S-AKI needing renal replacement therapy (RRT). Methods: This retrospective study included 23 patients who underwent CEUS among those who underwent acute RRT for S-AKI. In addition, we acquired data from 17 healthy individuals and 18 patients with chronic kidney disease. Renal recovery was defined as sustained independence from RRT for at least 14 days. Results: Of the CEUS-derived parameters, rise time, time to peak, and fall time were longer in patients with S-AKI than in healthy individuals (p = 0.045, 0.01, and 0.096, respectively). Fourteen patients (60.9%) with S-AKI receiving RRT experienced renal recovery; and these patients had higher values of peak enhancement, wash-in area under the curve (AUC), wash-in perfusion index, and washout AUC than those without recovery (p = 0.03, 0.01, 0.03, and 0.046, respectively). We evaluated the receiver operating characteristic curve and found that the peak enhancement, wash-in AUC, wash-in perfusion index, and wash-out AUC of CEUS derivatives estimated the probability of renal recovery after S-AKI requiring RRT (p = 0.03, 0.01, 0.03, and 0.04, respectively). Conclusion: CEUS-assessed cortical microvascular perfusion may predict renal recovery following S-AKI that requires RRT. Further studies are essential to validate the clinical utility of microcirculatory parameters obtained from CEUS to estimate renal outcomes in various etiologies and severities of kidney disease.

Aortic Annulus Detection Based on Deep Learning for Transcatheter Aortic Valve Replacement Using Cardiac Computed Tomography

Background@#To propose a deep learning architecture for automatically detecting the complex structure of the aortic annulus plane using cardiac computed tomography (CT) for transcatheter aortic valve replacement (TAVR). @*Methods@#This study retrospectively reviewed consecutive patients who underwent TAVR between January 2017 and July 2020 at a tertiary medical center. Annulus Detection Permuted AdaIN network (ADPANet) based on a three-dimensional (3D) U-net architecture was developed to detect and localize the aortic annulus plane using cardiac CT. Patients (N = 72) who underwent TAVR between January 2017 and July 2020 at a tertiary medical center were enrolled. Ground truth using a limited dataset was delineated manually by three cardiac radiologists. Training, tuning, and testing sets (70:10:20) were used to build the deep learning model. The performance of ADPANet for detecting the aortic annulus plane was analyzed using the root mean square error (RMSE) and dice similarity coefficient (DSC). @*Results@#In this study, the total dataset consisted of 72 selected scans from patients who underwent TAVR. The RMSE and DSC values for the aortic annulus plane using ADPANet were 55.078 ± 35.794 and 0.496 ± 0.217, respectively. @*Conclusion@#Our deep learning framework was feasible to detect the 3D complex structure of the aortic annulus plane using cardiac CT for TAVR. The performance of our algorithms was higher than other convolutional neural networks.

De Novo ANCA-Negative Pauci-Immune Crescentic Glomerulonephritis After COVID-19 mRNA Vaccination: A Case Report

To prevent the spread of the coronavirus disease 2019 (COVID-19) pandemic, vaccines have been authorized for emergency use and implemented worldwide. We present a case of de novo glomerulonephritis (GN) after use of the COVID-19 mRNA vaccine BNT162b2.A 48-year-old man with no relevant medical history was referred for sudden and persistent worsening of renal insufficiency 1.5 months after the second vaccine dose. He had arthralgia and skin rash a week after vaccination. Abdominal pain and diarrhea started 2 weeks later, and he was admitted to the hospital for enteritis treatment. Colonoscopy showed multiple ulcerations and petechiae suggestive of vasculitis in the terminal ileum. After prednisolone therapy, his gastrointestinal symptoms improved, but his renal function continued to deteriorate. Based on kidney biopsy findings and nephrotic-range proteinuria (5,306 mg/24 hours), he was diagnosed with anti-neutrophil cytoplasmic autoantibody (ANCA)-negative pauci-immune crescentic GN (CrGN). He received high-dose steroid pulse therapy and oral cyclophosphamide, and then, gradually underwent steroid tapering, with improvement in proteinuria and renal function over several weeks. Several cases of GN suspected to be related to COVID-19 vaccines have been reported. To our knowledge, this is the first case report of ANCA-negative pauci-immune crescentic CrGN with extrarenal involvement after COVID-19 mRNA vaccination. Our finding expands the spectrum of COVID-19 vaccine-associated GN.

Two Years of Experience and Methodology of Korean COVID-19 Living Clinical Practice Guideline Development

Background@#In Korea, during the early phase of the coronavirus disease 2019 (COVID-19) pandemic, we responded to the uncertainty of treatments under various conditions, consistently playing catch up with the speed of evidence updates. Therefore, there was high demand for national-level evidence-based clinical practice guidelines for clinicians in a timely manner. We developed evidence-based and updated living recommendations for clinicians through a transparent development process and multidisciplinary expert collaboration. @*Methods@#The National Evidence-based Healthcare Collaborating Agency (NECA) and the Korean Academy of Medical Sciences (KAMS) collaborated to develop trustworthy Korean living guidelines. The NECA-supported methodological sections and 8 professional medical societies of the KAMS worked with clinical experts, and 31 clinicians were involved annually. We developed a total of 35 clinical questions, including medications, respiratory/critical care, pediatric care, emergency care, diagnostic tests, and radiological examinations. @*Results@#An evidence-based search for treatments began in March 2021 and monthly updates were performed. It was expanded to other areas, and the search interval was organized by a steering committee owing to priority changes. Evidence synthesis and recommendation review was performed by researchers, and living recommendations were updated within 3–4 months. @*Conclusion@#We provided timely recommendations on living schemes and disseminated them to the public, policymakers and various stakeholders using webpages and social media.Although the output was successful, there were some limitations. The rigor of development issues, urgent timelines for public dissemination, education for new developers, and spread of several new COVID-19 variants have worked as barriers. Therefore, we must prepare systematic processes and funding for future pandemics.

Clinical Implication of Maumgyeol Basic Service–the 2 Channel Electroencephalography and a Photoplethysmogram–based Mental Health Evaluation Software

Objective@#Maumgyeol Basic service is a mental health evaluation and grade scoring software using the 2 channels EEG and photoplethysmogram (PPG). This service is supposed to assess potential at-risk groups with mental illness more easily, rapidly, and reliably. This study aimed to evaluate the clinical implication of the Maumgyeol Basic service. @*Methods@#One hundred one healthy controls and 103 patients with a psychiatric disorder were recruited. Psychological evaluation (Mental Health Screening for Depressive Disorders [MHS-D], Mental Health Screening for Anxiety Disorders [MHS-A], cognitive stress response scale [CSRS], 12-item General Health Questionnaire [GHQ-12], Clinical Global Impression [CGI]) and digit symbol substitution test (DSST) were applied to all participants. Maumgyeol brain health score and Maumgyeol mind health score were calculated from 2 channel frontal EEG and PPG, respectively. @*Results@#Participants were divided into three groups: Maumgyeol Risky, Maumgyeol Good, and Maumgyeol Usual. The Maumgyeol mind health scores, but not brain health scores, were significantly lower in the patients group compared to healthy controls. Maumgyeol Risky group showed significantly lower psychological and cognitive ability evaluation scores than Maumgyeol Usual and Good groups. Maumgyel brain health score showed significant correlations with CSRS and DSST. Maumgyeol mind health score showed significant correlations with CGI and DSST. About 20.6% of individuals were classified as the No Insight group, who had mental health problems but were unaware of their illnesses. @*Conclusion@#This study suggests that the Maumgyeol Basic service can provide important clinical information about mental health and be used as a meaningful digital mental healthcare monitoring solution to prevent symptom aggravation.

Hydrophilic guidewire usage under ultrasound guidance in facilitating catheter advancement during endovenous treatment of incompetent great saphenous veins

Purpose@#This study was performed To investigate the use of hydrophilic guidewires for facilitating catheter advancement during varicose vein treatment using radiofrequency ablation (RFA) or cyanoacrylate closure (CAC). @*Methods@#From March 2016 to April 2019, 463 limbs of 285 with incompetent great saphenous veins were subjected to RFA (321 limbs of 197 patients) or CAC (142 limbs of 88 patients). Procedure records were reviewed for the use of a hydrophilic guidewire, reason for the guidewire usage, and diameter of the guidewire. @*Results@#A hydrophilic guidewire was used to facilitate catheter advancement to treat 92 of 463 limbs (19.9%). For RFA, a guidewire was used to treat 53 of 321 limbs (16.5%). Among them, 15 limbs (28.3%) had vasospasm, and 38 limbs (71.7%) had venous tortuosity. For CAC, guidewire was used for 39 of 142 limbs (27.5%). Among them, 10 limbs (25.6%) had vasospasm, 23 limbs (59.0%) had venous tortuosity, and 6 limbs (15.4%) had repeated engagement of a J-tip guidewire into the varicose tributaries. In CAC, the frequency of hydrophilic guidewire usage was higher than that in RFA (P = 0.006). All varicose vein treatment sessions were technically successful. @*Conclusion@#Hydrophilic guidewire usage could facilitate catheter advancement when hindered by vasospasm, tortuosity of the saphenous vein, or repeated engagement into the varicose tributaries.

Possibility of Combined Meningitis in Under 90-Day-Old Infants With Urinary Tract Infection

Purpose@#Urinary tract infections (UTIs) are the most common serious bacterial infections in young infants. Lumbar puncture (LP) has been used to diagnose coexisting meningitis in infants under 90 days of age with suspected UTI in many hospitals. However, the incidence of bacterial meningitis associated with UTIs is low. We aimed to describe the prevalence of concomitant bacterial meningitis in young infants with UTIs. @*Methods@#The medical records of infants with the first episode of UTI admitted to the ChungAng University Hospital from January 2010 to December 2019 were retrospectively reviewed. Infants aged < 90 days who underwent LP with initial evaluation were included. Demographic and clinical features, laboratory findings, and imaging findings were collected and analyzed. @*Results@#Eighty-six infants with UTIs were enrolled in the study. The median age was 61.5 days (interquartile range, 42.3–73.8 days) and boys (90.7%) were predominant. Escherichia coli was the most common pathogen (n=80, 93.0%) and followed by Klebsiella species (n=5, 5.8%). Fifteen (18.1%) specimens produced extended spectrum β-lactamase (ESBL). Five (5.8%) infants had positive blood culture results. Seven (8.1%) infants showed pleocytosis in the cerebrospinal fluid, but none had coexisting bacterial meningitis. Twenty-four (30.8%) infants showed renal dilatation or hydronephrosis on ultrasonography. Dimercaptosuccinic acid (DMSA) scans revealed cortical defects in 17 (21.3%) infants while voiding cystourethrography revealed vesicoureteral reflux in 6 (46.2%) infants. @*Conclusion@#Co-existing bacterial meningitis was not observed in young infants with UTIs. LP could not be routinely performed considering the clinical condition of <90 days old UTI patients.

Key factors to establish the ovalbumininduced atopic dermatitis minipig model: age and body weight / 한국실험동물학회지

Background@#Given its similar structure and immune response to the human skin, porcine is a good model for dermal studies. Here, we sensitized ovalbumin (Ova) on minipig back skin for 2–4 weeks to induce chronic atopic dermatitis (AD). @*Results@#Gross observation, serum cytokine level, epidermal thickness, and epidermal integrity did not change after 4 weeks of Ova induction compared with the control, indicating AD modeling failure. Only the neutrophils in the blood and macrophages in bronchoalveolar lavage fluid changed slightly until 3 or 2 weeks after Ova sensitization, respectively. The successful and failed Ova-induced AD minipig models only differ in age and body weight of the minipigs. The minipigs, 12 months old with a 30-kg median weight, had a two-fold thicker dermis than minipigs 8–10 months old, with an 18.97-kg median weight, resulting in impaired Ova permeability and immune response. @*Conclusion@#Age and body weight are key factors that should be considered when developing an Ova-induced AD minipig model.

Semi-Quantitative Scoring of Late Gadolinium Enhancement of the Left Ventricle in Patients with Ischemic Cardiomyopathy: Improving Interobserver Reliability and Agreement Using Consensus Guidance from the Asian Society of Cardiovascular Imaging-Practical Tutorial (ASCI-PT) 2020

Objective@#This study aimed to evaluate the effect of implementing the consensus statement from the Asian Society of Cardiovascular Imaging-Practical Tutorial 2020 (ASCI-PT 2020) on the reliability of cardiac MR with late gadolinium enhancement (CMR-LGE) myocardial viability scoring between observers in the context of ischemic cardiomyopathy. @*Materials and Methods@#A total of 17 cardiovascular imaging experts from five different countries evaluated CMR obtained in 26 patients (male:female, 23:3; median age [interquartile range], 55.5 years [50–61.8]) with ischemic cardiomyopathy. For LGE scoring, based on the 17 segments, the extent of LGE in each segment was graded using a five-point scoring system ranging from 0 to 4 before and after exposure according to the consensus statement. All scoring was performed via webbased review. Scores for slices, vascular territories, and total scores were obtained as the sum of the relevant segmental scores. Interobserver reliability for segment scores was assessed using Fleiss’ kappa, while the intraclass correlation coefficient (ICC) was used for slice score, vascular territory score, and total score. Inter-observer agreement was assessed using the limits of agreement from the mean (LoA). @*Results@#Interobserver reliability (Fleiss’ kappa) in each segment ranged 0.242–0.662 before the consensus and increased to 0.301–0.774 after the consensus. The interobserver reliability (ICC) for each slice, each vascular territory, and total score increased after the consensus (slice, 0.728–0.805 and 0.849–0.884; vascular territory, 0.756–0.902 and 0.852–0.941; total score, 0.847 and 0.913, before and after implementing the consensus statement, respectively. Interobserver agreement in scoring also improved with the implementation of the consensus for all slices, vascular territories, and total score. The LoA for the total score narrowed from ± 10.36 points to ± 7.12 points. @*Conclusion@#The interobserver reliability and agreement for CMR-LGE scoring for ischemic cardiomyopathy improved when following guidance from the ASCI-PT 2020 consensus statement.

Korean Clinical Imaging Guidelines for Justification of Diagnostic Imaging Study for COVID-19

To develop Korean coronavirus disease (COVID-19) chest imaging justification guidelines, eight key questions were selected and the following recommendations were made with the evidence-based clinical imaging guideline adaptation methodology. It is appropriate not to use chest imaging tests (chest radiograph or CT) for the diagnosis of COVID-19 in asymptomatic patients. If reverse transcription-polymerase chain reaction testing is not available or if results are delayed or are initially negative in the presence of symptoms suggestive of COVID-19, chest imaging tests may be considered. In addition to clinical evaluations and laboratory tests, chest imaging may be contemplated to determine hospital admission for asymptomatic or mildly symptomatic unhospitalized patients with confirmed COVID-19. In hospitalized patients with confirmed COVID-19, chest imaging may be advised to determine or modify treatment alternatives. CT angiography may be considered if hemoptysis or pulmonary embolism is clinically suspected in a patient with confirmed COVID-19. For COVID-19 patients with improved symptoms, chest imaging is not recommended to make decisions regarding hospital discharge. For patients with functional impairment after recovery from COVID-19, chest imaging may be considered to distinguish a potentially treatable disease.

Review of Inhalation Health Risks Involving Chloromethylisothiazolinone (CMIT) and Methylisothiazolinone (MIT) Used as Disinfectants in Household Humidifiers

The association between lung injury and exposure to humidifier disinfectant (HD) containing a mixture of chloromethylisothiazolinone (CMIT) and methylisothiazolinone (MIT) has been controversial in South Korea. This study conducts a literature review in order to evaluate the likelihood of CMIT/MIT reaching the lower part of the respiratory tract and causing lung injury. A literature review focused on the inhalation risk of HD containing a mixture of CMIT and MIT. The major contents included the physicochemical properties of CMIT and MIT contained in HDs and methodological reviews on substance analysis, toxicity tests and clinical cases. HD products marketed in South Korea have been reported to contain approximately 1–2% CMIT and 0.2–0.6% MIT along with magnesium nitrate (20–25%), magnesium chloride (0.2–1.0%), and water (70–75%). The types of CMIT and MIT dispersed into the air and deposited in the respiratory tract are assumed to be either gaseous substances or nanoparticles mixed with magnesium salts. The result of the literature review including clinical cases of lung injury among CMIT/MIT HD product users, demonstrated that these chemicals likely reach the lower respiratory tract and accordingly cause lung injury.A number of humidifier disinfectant-associated lung injury cases with clinical evidence should be prioritized in risk assessment of HD containing CMIT and MIT, even though there might be insufficient evidence in all related areas, including inhalation exposure assessment studies, animal testing, and epidemiological studies.

Effectiveness of 4-Week Oral Taurine Treatment for Muscle Cramps in Patients with Liver Cirrhosis:A Single-Arm Pilot Study

Purpose@#Painful muscle cramps are a common complication in liver cirrhosis patients, and no effective treatment is available.This pilot study aimed to evaluate whether taurine supplementation improves muscle cramps in Korean cirrhotic patients. @*Materials and Methods@#Ten cirrhotic patients who experienced muscle cramps one or more times/week were enrolled in this prospective single-arm study and administered with an oral taurine solution (1 g/50 mL) thrice a day for 4 weeks. Taurine was discontinued for the subsequent 4 weeks. The frequency and intensity of muscle cramps were evaluated using a questionnaire at weeks 0, 2, 4, 6, and 8 after the start of treatment. @*Results@#At baseline, the median frequency of muscle cramps was six times/week, and all patients had severe pain. Muscle cramp scores (frequency×intensity) decreased in seven patients by weeks 4 and 8 after treatment initiation. Compared to baseline muscle cramp scores [median 21, interquartile range (IQR): 8–84], median muscle cramp scores were lower at week 4 (6.5, IQR: 3–12, p=0.126) and week 8 (5, IQR: 1.5–56, p=0.066). All five patients whose baseline plasma taurine levels were below the normal limit showed increased taurine levels at week 4; 60% of them experienced improvements in their muscle cramps. Of the five patients with normal or higher taurine levels, 80% experienced an improvement in symptoms at week 4. The safety and tolerability of the 4-week taurine therapy were excellent. @*Conclusion@#Oral taurine therapy for 4 weeks improved muscle cramps safely in cirrhotic patients.

Precision Capsular Infarct Modeling to Produce Hand Motor Deficits in Cynomolgus Macaques

Stroke research in non-human primates (NHPs) with gyrencephalic brains is a critical step in overcoming the translational barrier that limits the development of new pharmaceutical and rehabilitative strategies for stroke. White-matter stroke (WMS) has a unique pathophysiology from graymatter stroke and is not well understood because of a lack of pertinent animal models. To create a precise capsular infarct model in the cynomolgus macaque, we first used electrical stimulation to map hand movements, followed by viral tracing of the hand motor fibers (hMFs). This enabled us to identify stereotactic targets in the posterior limb of the internal capsule (PLIC). Neural tracing showed that hMFs occupy the full width of the PLIC, owing to overlap with the motor fibers for the leg. Furthermore, the hMFs were distributed in an oblique shape, requiring coronal tilting of the target probe. We used the photothrombotic infarct lesioning technique to precisely destroy the hMFs within the internal capsule. Double-point infarct lesioning that fully compromised the hMFs resulted in persistent hand motor and walking deficits whereas single-point lesioning did not. Minor deviations in targeting failed to produce persistent motor deficits. Accurate stereotactic targeting with thorough involvement of motor fibers is critical for the production of a capsular infarct model with persistent motor deficits. In conclusion, the precision capsular infarct model can be translated to the NHP system to show persistent motor deficits and may be useful to investigate the mechanism of post-stroke recovery as well as to develop new therapeutic strategies for the WMS.

Epidemiology of Achilles Tendon Rupture in South Korea: Claims Data of the National Health Insurance Service from 2009 to 2017

Background@#The incidence of Achilles tendon rupture and its trend has not been studied in Asia. The purpose of this nationwide study was to analyze the trend of incidence and surgical treatment of tendon ruptures in South Korea based on sex, age, and income level of patients, as well as seasonal variation. @*Methods@#A descriptive epidemiologic study was performed based on the data collected retrospectively from the Korea National Health Insurance Service. Data of all outpatients and inpatients were collected from approximately 52 million residents of South Korea, primarily diagnosed with Achilles tendon rupture from 2009 to 2017. @*Results@#A total of 112,350 patients had Achilles tendon rupture, of which 44,248 patients underwent surgical treatment during the study period. The overall, age-specific, and sex-specific incidence of Achilles tendon rupture and surgical treatment showed an increasing trend. Patients in the age group of 41 to 50 years showed the highest increase in incidence. Regarding season, higher incidence was reported during spring and summer, whereas the lowest incidence was found in winter. Higher income level was associated with increased incidence of the condition. @*Conclusions@#The incidence of Achilles tendon rupture and surgical treatments increased rapidly in patients between 41 and 50 years of age. Patients in the higher income quintile groups experienced more Achilles tendon injury than those in lower income groups, and fewer ruptures were observed during winter.

Clinical features and predictors of masked uncontrolled hypertension from the Korean Ambulatory Blood Pressure Monitoring Registry

Background/Aims@#The clinical characteristics of patients with masked uncontrolled hypertension (MUCH) have been poorly defined, and few studies have investigated the clinical predictors of MUCH. We investigated the demographic, clinical, and blood pressure (BP) characteristics of patients with MUCH and proposed a prediction model for MUCH in patients with hypertension. @*Methods@#We analyzed 1,986 subjects who were enrolled in the Korean Ambulatory Blood Pressure Monitoring (Kor-ABP) Registry and taking antihypertensive drugs, and classified them into the controlled hypertension (n = 465) and MUCH (n = 389) groups. MUCH was defined as the presence of a 24-hour ambulatory mean systolic BP ≥ 130 mmHg and/or diastolic BP ≥ 80 mmHg in patients treated with antihypertensive drugs, having normal office BP. @*Results@#Patients in the MUCH group had significantly worse metabolic profiles and higher office BP, and took significantly fewer antihypertensive drugs compared to those in the controlled hypertension group. Multivariate logistic regression analyses identified high office systolic BP and diastolic BP, prior stroke, dyslipidemia, left ventricular hypertrophy (LVH, ≥ 116 g/m2 for men, and ≥ 96 g/m2 for women), high heart rate (≥ 75 beats/min), and single antihypertensive drug use as independent predictors of MUCH. A prediction model using these predictors showed a high diagnostic accuracy (C-index of 0.839) and goodness-of-fit for the presence of MUCH. @*Conclusions@#MUCH is associated with a high-normal increase in office BP and underuse of antihypertensive drugs, as well as dyslipidemia, prior stroke, and LVH, which could underscore achieving optimal BP control. The proposed model accurately predicts MUCH in patients with controlled office BP.

Evaluation of Left Atrial Appendage Isolation Using Cardiac MRI after Catheter Ablation of Atrial Fibrillation: Paradox of Appendage Reservoir

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.

Diagnosis of Hypersensitivity Pneumonitis: 2020 Clinical Practice Guideline

Hypersensitivity pneumonitis (HP) is an interstitial lung disease (ILD) characterized by an inhaled inciting antigen that leads to the inflammation of the lung parenchyma and small airway with immunologic reactions. Over the last decades, the most effective therapeutic option for HP has been limited to antigen avoidance. The differential diagnosis of HP from other ILDs is the beginning of treatment as well as diagnosis. However, the presence of several overlapping clinical and radiologic features makes differentiating HP from other ILDs particularly challenging. In 2020, a multidisciplinary committee of experts from the American Thoracic Society, Japanese Respiratory Society, and Asociación Latinoamericana del Tórax suggested a new clinical practice guideline classifying HP into nonfibrotic and fibrotic phenotypes on the basis of chest high-resolution CT (HRCT) findings. Therefore, we introduced a new diagnostic algorithm based on chest HRCT in the clinical practice guideline for the diagnosis of HP.

Clinical features and predictors of masked uncontrolled hypertension from the Korean Ambulatory Blood Pressure Monitoring Registry

Background/Aims@#The clinical characteristics of patients with masked uncontrolled hypertension (MUCH) have been poorly defined, and few studies have investigated the clinical predictors of MUCH. We investigated the demographic, clinical, and blood pressure (BP) characteristics of patients with MUCH and proposed a prediction model for MUCH in patients with hypertension. @*Methods@#We analyzed 1,986 subjects who were enrolled in the Korean Ambulatory Blood Pressure Monitoring (Kor-ABP) Registry and taking antihypertensive drugs, and classified them into the controlled hypertension (n = 465) and MUCH (n = 389) groups. MUCH was defined as the presence of a 24-hour ambulatory mean systolic BP ≥ 130 mmHg and/or diastolic BP ≥ 80 mmHg in patients treated with antihypertensive drugs, having normal office BP. @*Results@#Patients in the MUCH group had significantly worse metabolic profiles and higher office BP, and took significantly fewer antihypertensive drugs compared to those in the controlled hypertension group. Multivariate logistic regression analyses identified high office systolic BP and diastolic BP, prior stroke, dyslipidemia, left ventricular hypertrophy (LVH, ≥ 116 g/m2 for men, and ≥ 96 g/m2 for women), high heart rate (≥ 75 beats/min), and single antihypertensive drug use as independent predictors of MUCH. A prediction model using these predictors showed a high diagnostic accuracy (C-index of 0.839) and goodness-of-fit for the presence of MUCH. @*Conclusions@#MUCH is associated with a high-normal increase in office BP and underuse of antihypertensive drugs, as well as dyslipidemia, prior stroke, and LVH, which could underscore achieving optimal BP control. The proposed model accurately predicts MUCH in patients with controlled office BP.

Evaluation of Left Atrial Appendage Isolation Using Cardiac MRI after Catheter Ablation of Atrial Fibrillation: Paradox of Appendage Reservoir

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.