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Introduction: The impact of early recurrence of atrial tachyarrhythmia (ERAT) within the 90‐day blanking period on long‐term outcomes in atrial fibrillation (AF) patients undergoing cryoballoon ablation (CBA) is controversial. This study aimed to assess the relationship between ERAT and late recurrence of atrial tachyarrhythmia (LRAT) post‐CBA. Methods: Utilizing data from a multicenter registry in Korea (May 2018 to June 2022), we analyzed the presence and timing of ERAT (<30, 30–60, and 60–90 days) and its association with LRAT risk after CBA. LRAT was defined as any recurrence of AF, atrial flutter, or atrial tachycardia lasting more than 30 s beyond the 90 days. Results: Out of 2636 patients, 745 (28.2%) experienced ERAT post‐CBA. Over an average follow‐up period of 21.2 ± 10.3 months, LRAT was observed in 874 (33.1%) patients. Patients with ERAT had significantly lower 1‐year LRAT freedom compared to those without ERAT (42.6% vs. 85.5%, p <.001). Multivariate analysis identified ERAT as a potential predictor of LRAT, with a hazard ratio (HR) of 3.98 (95% confidence interval [CI], 3.47–4.57). Significant associations were noted across all examined time frames (HR, 3.84; 95% CI, 3.32–4.45 in <30 days, HR, 5.53; 95% CI, 4.13–7.42 in 30–60 days, and HR, 4.29; 95% CI, 3.12–5.89 in 60–90 days). This finding was consistently observed across all types of AF. Conclusion: ERAT during the 90‐day blanking period strongly predicts LRAT in AF patients undergoing CBA, indicating a need to reconsider the clinical significance of this period. [ABSTRACT FROM AUTHOR]

Background/Objectives: The effectiveness of a rhythm control strategy in patients with atrial fibrillation (AF) and reduced left ventricular ejection fraction (LVEF < 50%) in real-world practice remains uncertain. Our objective was to evaluate the real-world outcomes of a rhythm control strategy in patients with AF and reduced LVEF, focusing on changes in LV systolic function and brain natriuretic peptide (BNP) levels. Methods: The study retrospectively reviewed the medical records of 80 patients with concurrent AF and reduced LVEF who underwent rhythm control therapy between March 2015 and December 2021. Results: The patients had an average age of 63.6 years and an initial LVEF of 34.3%. Sinus rhythm was restored using anti-arrhythmic drugs (38, 47.5%) or electrical cardioversion (42, 52.5%). Over a follow-up period of 53.0 months, AF recurred in 65% of patients, with 57.7% undergoing catheter ablation. Significant improvements were noted in LVEF (from 34.3% to 55.1%, p < 0.001) and BNP levels (from 752 pg/mL to 72 pg/mL, p < 0.001) at the last follow-up. Nearly all patients (97.5%) continued with the rhythm control strategy during the follow-up period. Conclusions: In real-world settings, a rhythm control strategy proves to be feasible and effective for improving LVEF and reducing BNP levels in AF patients with reduced LVEF. [ABSTRACT FROM AUTHOR]

Aims Pulmonary vein isolation using cryoablation is effective and safe in patients with atrial fibrillation (AF). Although both obesity and underweight are associated with a higher risk for incident AF, there is limited data on the efficacy and safety following cryoablation according to body mass index (BMI) especially in Asians. Methods and results Using the Korean Heart Rhythm Society Cryoablation registry, a multicentre registry of 12 tertiary hospitals, we analysed AF recurrence and procedure-related complications after cryoablation by BMI (kg/m2) groups (BMI < 18.5, underweight, UW; 18.5–23, normal, NW; 23–25, overweight, OW; 25–30, obese Ⅰ, OⅠ; ≥30, obese Ⅱ, OⅡ). A total of 2648 patients were included (median age 62.0 years; 76.7% men; 55.6% non-paroxysmal AF). Patients were categorized by BMI groups: 0.9% UW, 18.7% NW, 24.8% OW, 46.1% OI, and 9.4% OII. Underweight patients were the oldest and had least percentage of non-paroxysmal AF (33.3%). During a median follow-up of 1.7 years, atrial arrhythmia recurred in 874 (33.0%) patients (incidence rate, 18.9 per 100 person-years). After multivariable adjustment, the risk of AF recurrence was higher in UW group compared with NW group (adjusted hazard ratio, 95% confidence interval; 2.55, 1.18–5.50, P = 0.02). Procedure-related complications occurred in 123 (4.7%) patients, and the risk was higher for UW patients (odds ratio, 95% confidence interval; 2.90, 0.94–8.99, P = 0.07), mainly due to transient phrenic nerve palsy. Conclusion Underweight patients showed a higher risk of AF recurrence after cryoablation compared with NW patients. Also, careful attention is needed on the occurrence of phrenic nerve palsy in UW patients. [ABSTRACT FROM AUTHOR]

Introduction: Influence of early atrial fibrillation (AF) ablation, particularly cryoballoon ablation (CBA), on clinical outcome during long‐term follow‐up has not been clarified. The objective was to determine whether an early CBA (diagnosis‐to‐ablation of ≤6 months) strategy could affect freedom from AF recurrence after index CBA. Methods: The study included 2605 patients from Korean CBA registry data with follow‐up >12 months after de novo CBA. The primary outcome was recurrence of atrial tachyarrhythmias (ATs) of ≥30‐s after a 3‐month blanking period. Results: Compared to patients in early CBA group, patients in late CBA group had higher prevalence of diabetes, congestive heart failure, and chronic kidney disease, and higher mean CHA2DS2‐VAS score. During mean follow‐up of >21 months, ATs recurrence was detected in 839 (32.2%) patients. The early CBA group showed a significantly lower 2‐year recurrence rate of ATs than the late CBA group (26.1% vs. 31.7%, p = 0.043). In subgroup analysis, the early CBA group showed significantly higher 1‐year and 2‐year freedom from ATs recurrence than the late CBA group only in paroxysmal atrial fibrillation (PAF) patients in overall and propensity score matched cohorts. Multivariate analysis showed that early CBA was an independent factor for preventing ATs recurrence in PAF (hazard ratio: 0.637; 95% confidence intervals: 0.412–0.984). Conclusion: Early CBA strategy, resulting in significantly lower ATs recurrence during 2‐year follow‐up after index CBA, might be considered as an initial rhythm control therapy in patients with paroxysmal AF. [ABSTRACT FROM AUTHOR]

Introduction: Early recognition and risk stratification of cardiovascular events are necessary in patients after ischemic stroke. Recent evidence suggests that elevated high-sensitive cardiac troponin is a predictor of mortality and vascular events. Therefore, we aimed to explore the prognostic role of high-sensitive cardiac troponin I (hs-TnI) on mortality and cardiovascular outcomes in patients after ischemic stroke. Methods: From August 2014 to July 2017, 1,506 patients with acute ischemic stroke were pulled consecutively in a retrospective single-center registry. Of these, 1,019 patients were selected and classified into the elevated or non-elevated hs-TnI groups according to hs-TnI level of 99th percentile upper reference limit (URL) at the time of admission for ischemic stroke. The primary outcome was a major adverse cardiac and cerebrovascular event (MACCE) during follow-up. Results: Among 1,019 patients, 708 patients were non-elevated hs-TnI group (<99th percentile URL of hs-TnI) and 311 patients were elevated hs-TnI group (≥99th percentile URL of hs-TnI). The median follow-up period was 22.5 (interquartile range 5.0–38.8) months. In a multivariable Cox regression model, the elevated hs-TnI group has a higher risk of MACCE (adjusted hazard ratio [HR]: 3.12; 95% confidence interval [CI]: 2.33–4.17; p < 0.01), all-cause mortality (adjusted HR: 4.15; 95% CI: 2.47–6.99; p < 0.01) and readmission caused by coronary revascularization (adjusted HR: 3.12; 95% CI: 1.41–6.90; p < 0.01), heart failure (adjusted HR: 2.76; 95% CI: 1.38–5.51; p < 0.01), and stroke (adjusted HR: 1.73; 95% CI: 1.07–2.78; p = 0.02) compared with the non-elevated hs-TnI group. Conclusions: Elevated hs-TnI is independently associated with higher mortality and cardiac and cerebrovascular events in patients with ischemic stroke and may serve as a valuable prognostic factor in management after ischemic stroke. [ABSTRACT FROM AUTHOR]

Background Warfarin is the only approved oral anticoagulant for long-term prophylaxis against valve thrombosis and thromboembolism in patients with mechanical heart valves. To date, apixaban for patients with double (aortic and mitral) mechanical heart valves has not been reported in the literature. Case summary We report the case of a 50-year-old female who underwent double (aortic and mitral) mechanical valve replacement in February 2017. Warfarin was prescribed after mechanical valve replacement. However, she complained of side effects of warfarin, including tingling sensation and numbness of legs, urticaria, skin rash, and nausea and voluntarily stopped taking medication. In December 2018, she was admitted to the emergency room due to ongoing chest pain. Coronary angiogram revealed embolic myocardial infarction at the left circumflex coronary artery. Nevertheless, she continued to refuse to take warfarin after anticoagulant therapy for coronary artery embolism. Given the patient's objection, we prescribed apixaban 5 mg b.i.d. since February 2019. When she was diagnosed with atrial fibrillation in April 2020, no intracardiac thrombosis was confirmed on computed tomography and electrical cardioversion was performed safely. While on apixaban, no evidence of prosthetic valve thrombosis or thrombo-embolic events was observed during a 24-month period. Conclusion We report the efficacy and safety of apixaban in a patient with atrial fibrillation and double mechanical heart valves for preventing prosthetic valve thrombus and systemic embolism. [ABSTRACT FROM AUTHOR]

Abstract Background Reduced lung function is associated with incident insulin resistance and diabetes. The aim of this study was to assess the relationship between lung function and incident type 2 diabetes in Korean men. Methods This study included 9,220 men (mean age: 41.4 years) without type 2 diabetes at baseline who were followed for five years. Subjects were divided into four groups according to baseline forced vital capacity (FVC) (% predicted) and forced expiratory volume in one second (FEV1) (% predicted) quartiles. The incidence of type 2 diabetes at follow-up was compared according to FVC and FEV1 quartiles. Results The overall incidence of type 2 diabetes was 2.2%. Reduced lung function was significantly associated with the incidence of type 2 diabetes after adjusting for age, BMI, education, smoking, exercise, alcohol, and HOMA-IR. Both FVC and FEV1 were negatively associated with type 2 diabetes (P 1 had a significantly higher odds ratio for type 2 diabetes compared with the highest quartile after adjusting for age and BMI (2.15 [95% CI 1.02-4.57] and 2.19 [95% CI 1.09-4.42]). Conclusions Reduced lung function is independently associated with the incidence of type 2 diabetes in Korean men.

The potential cancer risk associated with long‐term exposure to angiotensin receptor blockers (ARBs) is still unclear. We assessed the risk of incident cancer among hypertensive patients who were treated with ARBs compared with patients exposed to angiotensin‐converting enzyme inhibitors (ACEIs), which are known to have a neutral effect on cancer development. Using the Korean National Health Insurance Service database, we analyzed the data of patients diagnosed with essential hypertension from January 2005 to December 2012 who were aged ≥40 years, initially free of cancer, and were prescribed either ACEI or ARB (n = 293,962). Cox proportional hazard model adjusted for covariates was used to evaluate the risk of incident cancer. During a mean follow‐up of 10 years, 24,610 incident cancers were observed. ARB use was associated with a decreased risk of overall cancer compared with ACEI use (hazard ratio [HR] 0.76, 95% confidence interval [CI] 0.72‐0.80). Similar results were obtained for lung (HR 0.73, 95% CI 0.64‐0.82), hepatic (HR 0.56, 95% CI 0.48‐0.65), and gastric cancers (HR 0.74, 95% CI 0.66‐0.83). Regardless of the subgroup, greater reduction of cancer risk was seen among patients treated with ARB than that among patients treated with ACEIs. Particularly, the decreased risk of cancer among ARB users was more prominent among males and heavy drinkers (interaction P <.005). Dose‐response analyses demonstrated a gradual decrease in risk with prolonged ARB therapy than that with ACEI use. In conclusion, ARB use was associated with a decreased risk of overall cancer and several site‐specific cancers. [ABSTRACT FROM AUTHOR]

Background: Differentiation of supraventricular tachycardia (SVT) with a right bundle branch block (RBBB) pattern from ventricular tachycardia (VT) is difficult, particularly when the R/S ratio in lead V6 is below 1.0.Objective: We sought to investigate the electrocardiographic criteria for distinguishing between these arrhythmias.Methods: We investigated electrocardiographic parameters from 111 consecutive patients who had RBBB pattern wide QRS complex tachycardia with a reversed R/S ratio in lead V6 (72 VTs, 39 SVTs). Diagnostic criteria from the previous algorithms were compared with our new criterion, the RS/QRS ratio, which was defined as the ratio of the interval from the onset of the QRS complex to the nadir of the S wave, divided by the QRS width in lead V6. The RS/QRS ratio was further tested in a prospective population (31 fascicular VTs, 29 SVTs).Results: The diagnostic accuracy of previous criteria (Brugada algorithm, Vereckei algorithm, and R-wave peak time criterion) was only modest. However, the RS/QRS ratio in lead V6 was significantly lower in SVT than in VT (0.36 ± 0.04 vs 0.50 ± 0.08; P < .001). A cutoff value of the RS/QRS ratio >0.41 differentiated VT from SVT with a high diagnostic accuracy (sensitivity 97.2%; specificity 89.7%). When tested in a prospective population with fascicular VT, the diagnostic accuracy of the criteria was maintained (sensitivity 90.3%; specificity 86.2%).Conclusion: The RS/QRS ratio >0.41 in lead V6 is a simple and reliable index for distinguishing VT from SVT in RBBB pattern wide QRS complex tachycardia with a reversed R/S complex in lead V6. This criterion was particularly useful for the differential diagnosis of fascicular VT from RBBB pattern SVT. [ABSTRACT FROM AUTHOR]

BACKGROUND This study aimed to examine longitudinal associations between blood pressure (BP) categories and incident cardiovascular disease (CVD) in treated hypertensive patients without CVD. METHODS A cohort study was performed in Korean adults who underwent a comprehensive health examination from 1 January 2011 to 31 December 2016 and was followed for incident CVD via linkage to the Health Insurance and Review Agency database until the end of 2016, with a median follow-up of 4.3 years. RESULTS Among 263,532 participants, 8,418 treated hypertensive patients free of CVD at baseline were included. The incident CVD end point was defined as new hospitalization for CVD, including ischemic heart disease, stroke, and transient ischemic attack. During 32,975.6 person-years of follow-up, 200 participants developed new-onset CVD (incidence rate of 60.6 per 104 person-years). The multivariable-adjusted hazard ratio (HR; 95% confidence intervals [CI]) for CVD according to systolic blood pressure (SBP) levels (comparing SBP < 110, SBP = 120–129, SBP = 130–139, SBP = 140–149, SBP = 150–159, and SBP ≥160 to SBP 110–119 mm Hg [reference]) were 0.83 (0.53–1.30), 1.31 (0.91–1.89), 1.18 (0.74–1.87), 1.46 (0.79–2.72), 3.19 (1.25–8.12), and 5.60 (2.00–15.70), respectively. In multivariable analysis for CVD according to diastolic blood pressure (DBP) levels, HR (95% CI) of DBP < 60, DBP = 70–79, DBP = 80–89, DBP = 90–99, and DBP ≥100 compared to DBP = 60–69 mm Hg [reference]) were 0.51 (0.12–2.14), 1.13 (0.76–1.67), 1.26 (0.83–1.92), 1.62 (0.89–2.97), and 1.68 (0.51–5.55), respectively. CONCLUSIONS In this large cohort of middle-aged treated hypertensive patients, SBP < 120 mm Hg and/or DBP < 70 mm Hg were acceptable and showed a trend of protection of incident CVD. [ABSTRACT FROM AUTHOR]

Aims: Inflammation has been suggested to play a role in the pathogenesis of atrial fibrillation (AF). It is uncertain whether C-reactive protein, a robust inflammatory marker, is associated with AF incidence in Asians with lower levels of C-reactive protein compared with western population. This study aimed to determine the association between C-reactive protein and risk of AF in a large population of Koreans.Methods and results: A total of 402 946 Koreans were enrolled in a health screening programme from January 2002 to December 2013. Among them, 210 208 subjects were analysed during the mean follow-up of 4.59 years (1 062 513 person-years). Atrial fibrillation was identified by electrocardiography at every visits. Atrial fibrillation was identified in 561 subjects (0.1%) at baseline. The median (inter-quartile) baseline C-reactive protein levels were higher in subject with AF than in those without AF [0.9 mg/L (0.4-0.9) vs. 0.4 mg/L (0.2-1.0), P < 0.001]. Subjects in the highest quartile of C-reactive protein had more AF than those in the lowest quartile [adjusted odds ratio (OR) 2.02, 95% confidence interval (CI) 1.45-2.81; P< 0.001]. During a mean follow-up of 4.59 years, AF developed in 261 subjects (0.1%). The highest quartile of baseline C-reactive protein had a 1.68-fold (95% CI 1.06-2.67) increased risk of AF than the lowest quartile in multivariate Cox regression analysis.Conclusion: Baseline C-reactive protein levels are significantly associated with the prevalence of AF and the risk of AF in Korean populations even C-reactive protein concentrations are substantially lower than reported in white populations. [ABSTRACT FROM AUTHOR]

Background Idiopathic ventricular tachycardia (VT) originating from the outflow tract (OT) usually is considered a benign condition. In rare cases, patients with OT-VT suffer from syncope or even sudden cardiac death. OT-VT is frequently preceded by nonsustained VT (NSVT). Objective The purpose of this study was to clarify if the ECG parameters of NSVTs could differentiate malignant from benign OT-VT. Methods We retrospectively evaluated patients without structural heart disease who had documented OT-NSVT on ECG. ECG parameters were compared between patients with syncope, aborted sudden cardiac death, or ventricular fibrillation (malignant group, n = 36) and patients without syncope (benign group, n = 40). Results There were no differences with regard to age and gender between the malignant and benign groups. On analysis of NSVT, the first coupling interval (CI) of NSVT was comparable between the 2 groups (458 ± 87 ms vs 485 ± 95 ms, P = .212). However, the second CI of NSVT beats was significantly shorter in the malignant group (313 ± 58 ms vs 385 ± 83 ms, P < .0001). During 48-month follow-up, the benign group had a significantly lower recurrence of clinical VT than the malignant group ( P = .046). The malignant group frequently had more than 1 focus of VT, whereas the benign group showed only a single focus (1.82 vs 1.09, P = .023). Conclusion The second CI of NSVT in the malignant group was significantly shorter than that of the benign OT-VT group. Careful measurement of the second CI of NSVT may help identify the malignant form of OT-VT, enabling early treatment to prevent future cardiac events. [ABSTRACT FROM AUTHOR]

Ozone (O_3) is generated using a voltage controlled inverter of single-phase sinusoidal waveform, in contrast to the current controlled inverter using three phases as used for the control of AC motors. The generated ozone quantity is directly proportional to the frequency as well as the applied voltage of the power supply. In this paper, we propose not only a voltage control inverter running at 600 Hz and a step-up transformer from 220 V to 12 KV using an IGBT inverter, but also a fuzzy inference engine using the MAMDANI Min-Max composition so as to generate high-density ozone. We show that the proposed ozone generation system produces double the quantity of ozone at a higher efficiency level than a conventional ozone system using the current controlled inverter through actual experiments with the developed ozone system. [ABSTRACT FROM AUTHOR]

Prehypertension is associated with oxidative stress and increased arterial stiffness. While plasma homocysteine levels are associated with increased pulse wave velocity in hypertensive individuals, there is no report regarding this relationship in prehypertensives. Homocysteine levels and brachial-ankle pulse wave velocity (baPWV) were investigated in 4177 prehypertensives (3178 men, mean age 53 ± 11 years) with ankle-brachial indexes (ABIs) greater than 0.95 who had visited the Kangbuk Samsung Health Promotion Center. The subjects were subdivided into two groups according to baPWV; group I (1720 subjects) was defined as subjects with a baPWV of 1366cm/sec or lower, while group II (2457 subjects) included subjects with a baPWV greater than 1366cm/sec. Subjects were also divided into four quartile groups depending on homocysteine level. Homocysteine levels in group II were found to be significantly higher than those in group I. There were significant differences in baPWV value among the four quartile groups (quartile I, 1411 ± 213.9 cm/sec; quartile II, 1436 ± 223.3 cm/sec; quartile III, 1460 ± 220.4 cm/sec; quartile IV, 1494 ± 251.3 cm/sec; p-value <0.001). In multivariate regression models, the increasing quartile groups of homocysteine had higher odds ratios (ORs) for increased baPWV compared to that of the lowest quartile group (OR [95%% confidence interval (CI)] in the second, third, and highest quartiles: 1.41 [1.12-1.77], 1.65 [1.30-2.10], and 1.82 [1.42-2.33], respectively, p < 0.001), irrespective of confounding factors. This study indicates an independent relationship between circulating homocysteine level and arterial stiffness in prehypertensives, suggesting that circulating homocysteine level could be a useful biomarker of subclinical target organ damage in prehypertensives. [ABSTRACT FROM AUTHOR]