Impact of inter-lesion distance and first-pass isolation on outcomes of pulmonary venous isolation for paroxysmal atrial fibrillation.

BACKGROUND: Contiguity of ablation lesions is a critical determinant of success for paroxysmal atrial fibrillation (PAF) ablation. Evidence supports maintaining an inter-lesional distance (ILD) ≤ 6 mm during pulmonary venous isolation (PVI). Meanwhile, first-pass isolation (FPI) on PVI outcome in follow-up was not deeply studied. The impact of ILD and FPI on PAF ablation outcomes was investigated. METHODS: Consecutive PAF patients who underwent first-time antral PVI were recruited. Coordinates of ablation points were extracted from the electro-anatomical mapping system and analyzed using custom-developed software to determine the ILD. A gap is defined as ILD greater than 6 mm. FPI was defined as the achievement of PVI by encircling the ipsilateral veins while simultaneously recording their electrical activity using a multipolar catheter. The primary endpoint was freedom from documented atrial arrhythmias including AF, atrial tachycardia (AT), or atrial flutter (AFL) lasting longer than 30 s during follow-up. RESULTS: A total of 105 patients underwent first-time antral PVI. During 13.3 ± 0.6 months of follow-up, atrial arrhythmias recurrence was noted in 22.9% of the patients. Atrial arrhythmia recurrence was significantly higher in patients with more gaps (> 2) (37.0% versus 11.9%, P < 0.01), and the number of gaps was an independent predictor of AF/AT/AFL recurrence. (Hazard ratio [HR] 1.20, 95% CI 1.03-1.40, P = 0.02). The group with FPI for at least one ipsilateral pair of PVs exhibited a decreased number of gaps (2.0 versus 7.0, P < 0.01) and demonstrated a significant correlation with a reduction of recurrence (HR 0.26, 95% CI 0.09-0.71, P = 0.01). Among 16 patients who underwent repeat ablation, the number of gaps during the index PVI was associated with PV reconnection (PVR) (P < 0.01). CONCLUSIONS: Gaps created during PVI are a modifiable determinant of AF/AT/AFL recurrence, and avoidance of gaps is crucial to improve clinical outcomes of PAF ablation. In addition, FPI exhibited a strong predictive capability for clinical success in patients with PAF.

Oral anticoagulants increased 30-day survival in sepsis patients complicated with atrial fibrillation: a retrospective analysis from MIMIC-IV database.

Background: The severity of sepsis is associated with systemic clotting activation. Atrial fibrillation (AF) is the most commonly observed arrhythmia in patients with sepsis and can lead to a poor prognosis. The aim of this study is to elucidate the association between oral anticoagulants and survival from septic patients complicated with AF. Methods: The data of 8,828 septic patients, including 2,955 AF and 5,873 without AF, were all originated from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. Patients with sepsis and AF are divided into OAC- group (n = 1,774) and OAC+ group (n = 1,181) based on OAC therapy. Septic patients with no AF were considered as the control group (n = 5,873, sepsis and no AF group). The main outcome endpoint was the survival rate of 30 day. The secondary outcome endpoint was the length of stay (LOS) from intensive care unit and hospital. Propensity score matching (PSM) was used to adjust the influence of superfluous factors, and a restricted mean survival time (RMST) analysis was used for calculating the benefit of survival time and survival rate. Analysis including univariate and multivariate logistic regression analysis was conducted to find prognosis-related predictors. Results: After PSM, the OAC+group had a higher 30-day survival rate compared to the OAC- group (81.59% vs. 58.10%; P < 0.001) in the ICU. Despite the higher survival, the hospital LOS (14.65 days vs. 16.66 days; P = 0.15) and ICU LOS (6.93 days vs. 5.92 days; P = 0.02) were prolonged at OAC+ group than OAC- group. No difference was found in survival rate of 30 day between the sepsis patients using warfarin and patients using NOAC (85.60% vs. 79.84%, P = 0.12). The sepsis patients using warfarin had a prolonged LOS in ICU and hospital compared with the sepsis patients using NOAC. In the vasopressor subgroup, patients who received NOAC therapy were associated with a reduced 30-day survival rate (73.57% vs. 84.03%; P = 0.04) and reduced LOS in ICU and hospital than those on warfarin therapy. Conclusion: This study demonstrated that oral anticoagulants may increase the 30-day survival rate of patients with sepsis and AF.

A machine learning approach to differentiate wide QRS tachycardia: distinguishing ventricular tachycardia from supraventricular tachycardia.

BACKGROUND: Differential diagnosis of wide QRS tachycardia (WQCT) has been a challenging issue. Published algorithms to distinguish ventricular tachycardia (VT) and supraventricular tachycardia (SVT) have limited diagnostic capabilities. METHODS: A total of 278 patients with WQCT from January 2010 to March 2022 were enrolled. The electrophysiological study confirmed SVT in 154 patients and VT in 65 ones. Two hundred nineteen WQCT 12-lead ECGs were randomly divided into development cohort (n = 165) and testing cohort (n = 54) data sets. The development cohort was split into a training group (n = 115) and an internal validation group (n = 50). Forty ECG features extracted from the 219 WQCT ECGs are fed into 9 iteratively trained ML algorithms. This novel ML algorithm was also compared with four published algorithms. RESULTS: In the development cohort, the Gradient Boosting Machine (GBM) model displayed the maximum area under curve (AUC) (0.91, 95% confidence interval (CI) 0.81-1.00). In the testing cohort, the GBM model had a higher AUC of 0.97 compared to 4 validated ECG algorithms, namely, Brugada (0.68), avR (0.62), RWPTII (0.72), and LLA algorithms (0.70). Accuracy, sensitivity, specificity, negative predictive value, and positive predictive value of the GBM model were 0.94, 0.97, 0.90, 0.94, and 0.95, respectively. CONCLUSIONS: A GBM ML model contributes to distinguishing SVT from VT based on surface ECG features. In addition, we were able to identify important indicators for distinguishing WQCT.

Identification of a Novel 7-bp Deletion in the α-Globin Gene Cluster in One Chinese Family.

Deletional α-thalassemia is characterized by reduced hemoglobin A2 and involves the deletion of a few nucleotides, which is a rare hereditary disease. However, the detection of rare mutations using commonly used genetic tests is highly challenging. In the present study, next-generation sequencing (NGS) was used to identify a novel 7-bp deletion α-thalassemia in one individual from a Chinese family. Hematological parameters of the family members were determined using an automated cell counter, and hemoglobin electrophoresis was performed using a capillary electrophoresis system. Subsequently, NGS was performed on the genomic DNA of the patient and her family members. The 7-bp deletion (named Hb Honghe [HBA1: c.401_407delGCACCGT]) of α-thalassemia in the α-globin gene was confirmed using Sanger sequencing. The patient's father was also a heterozygous carrier of HBA1: c.401_407delGCACCGT deletion, but not her mother or sister. The application of the combined molecular approach is essential for the accurate diagnosis of rare thalassemia. This study reports a novel case of α- thalassemia. The characterization of the mutation might provide new insights into genetic counseling and accurate diagnosis of thalassemia.

Survival benefits of oral anticoagulation therapy in acute kidney injury patients with atrial fibrillation: a retrospective study from the MIMIC-IV database.

OBJECTIVE: To find out the effect of different oral anticoagulation therapies (OAC) on mortality rate in patients with acute kidney injury (AKI) and atrial fibrillation (AF).DesignA retrospective study. SETTING: This study was conducted in the Medical Information Mart for Intensive Care IV database. PARTICIPANTS: A total of 19 672 patients diagnosed with AKI. MAIN OUTCOME MEASURES: Patients were categorised into three groups: (1) AF; (2) AKI and AF, OAC-; (3) AKI and AF, OAC+. The primary endpoint was 30-day mortality. Secondary endpoints were the length of stay (LOS) in the intensive care unit (ICU) and hospital. Propensity score matching (PSM) and Cox proportional hazards model adjusted confounding factors. Linear regression was applied to assess the associations between OAC treatment and LOS. RESULTS: After PSM, 2042 pairs of AKI and AF patients were matched between the patients who received OAC and those without anticoagulant treatment. Cox regression analysis showed that, OAC significantly reduce 30-day mortality compared with non-OAC (HR 0.30; 95% CI 0.25 to 0.35; p<0.001). Linear regression analysis revealed that OAC prolong LOS in hospital (11.3 days vs 10.0 days; p=0.013) and ICU (4.9 days vs 4.4 days; p<0.001). OAC did not improve survival in patients with haemorrhage (HR 0.67; 95% CI 0.34 to 1.29; p=0.23). Novel OAC did not reduce mortality in acute-on-chronic renal injury (HR 2.03; 95% CI 1.09 to 3.78; p=0.025) patients compared with warfarin. CONCLUSION: OAC administration was associated with improved short-term survival in AKI patients concomitant with AF.

From cis-Lobeline to trans-Lobeline: Study on the Pharmacodynamics and Isomerization Factors.

Lobeline is an alkaloid derived from the leaves of an Indian tobacco plant (Lobelia inflata), which has been prepared by chemical synthesis. It is classified as a partial nicotinic agonist and has a long history of therapeutic usage ranging from emetic and respiratory stimulant to tobacco smoking cessation agent. The presence of both cis and trans isomers in lobeline is well known, and many studies on the relationship between the structure and pharmacological activity of lobeline and its analogs have been reported. However, it is a remarkable fact that no studies have reported the differences in pharmacological activities between the two isomers. In this article, we found that different degrees of isomerization of lobeline injection have significant differences in respiratory excitatory effects in pentobarbital sodium anesthetized rats. Compared with cis-lobeline injections, the respiratory excitatory effect was significantly reduced by 50.2% after administration of injections which contained 36.9% trans-lobeline. The study on the influencing factors of isomerization between two isomers shown that this isomerization was a one-way isomerism and only converted from cis to trans, where temperature was the catalytic factor and pH was the key factor. This study reports a new discovery. Despite the widespread use of ventilators, first-aid medicines such as nikethamide and lobeline has retired to second line, but as a nonselective antagonist with high affinity for a4b2 and a3b2 nicotinic acetylcholine receptors (nAChRs). In recent years, lobeline has shown great promise as a therapeutic drug for mental addiction and nervous system disorders, such as depression, Alzheimer disease and Parkinson disease. Therefore, we suggest that the differences between two isomers should be concerned in subsequent research papers and applications.

[Size distribution characteristics of particulate mercury on haze and non-haze days].

With the rapid economic development, China suffers from the severe haze and atmospheric mercury pollution. Particulate mercury transport has an important significance in its global cycle. In order to investigate the distribution characteristics of particulate mercury, 12 degrees Nano-moudi (6.2-9.9 µm, 3.1-6.2 µm, 1.8-3.1 µm, 1.0-1.8 µm, 0.56-1.0 µm, 0.32-0.56 µm, 0.18- 0.32 µm, 0.10-0.18 µm, 0.056-0.10 µm, 0.032-0.056 µm, 0.018-0.032 µm, 0.010-0.018 µm) impactor was used to measure the size distributions of atmospheric particulate mercury on both haze and non-haze days in Shanghai. The results indicated that particulate mercury levels were positively correlated with those of the particles. The average concentration of particulate mercury (0.31 ng x m (-3)) on haze days was 2-3 times than that on non-haze days (0.11 ng x m(-3)). The mass size distributions of aerosols and particulate mercury showed bimodal distributions. The peak shifted from 0.56-1.0 µm and 3.1-6.2 µm on haze days to 0.32-0.56 µm and 3.1-6.2 µm on non-haze days. The particles with aerodynamic diameter smaller than 1 µm which could stay for a long time and transport for a long distance, had higher particulate mercury concentrations. The average contribution of particulate mercury to total PM aerosol were higher on haze days (0.029 ng x µg(-1)) than on non-haze days (0.015 ng x µg(-1)), indicating that secondary particles typically grew faster than mercury during the haze pollution events. The particulate mercury concentration in accumulation mode was 2.06 ng x m(-3) on haze days, while it was 0.55 ng x m(-3) on non-haze days. The large increase of the accumulation mode particles was a main reason for the formation of haze. Emissions from the coal burning as well as road surface dust and dust from long-range transport accounted for the serious pollution on haze days.

Effect of pressure and tail suspension on the growth of rat skeletal muscle / 医用生物力学

Objective To investigate effects of pressure and tail suspension on the growth of rat skeletal muscles by establishing the tail-suspended rat model and pressure-induced rat model, respectively. Methods Thirty-six male Sprague-Dawley rats were randomly divided into three groups: the control-group (CON), the tail-suspended group (SUS), the pressure group (PRE), and each group was undergoing two stages (7, 14 d) for observation. At the end of the experiment, the muscle wet weight/body weight (Mww/Bw), muscle fiber cross-sectional area (MFCSA), muscle fiber diameter (MFD) of soleus and extensor digitorum longus (EDL) and the IGF-1 concentration were measured, respectively. Results For both the SUS group and PRE group with 7d, their Mww/Bw, MFCSA and MFD of soleus were significantly reduced (P<0.05) as compared to the CON group, which were reduced by 23.52%, 14.26%, 13.47% in PRE group, respectively , while these indexes in SUS group were reduced by 23.52%, 33.07%, 25.09%, respectively. Meanwhile, the decrease of Mww/Bw, MFCSA and MFD in PRE group with 14d was reduced by 20.51%, -10.49%, -5.73%, respectively, which was less than that in PRE group with 7d. However, the decrease of Mww/Bw in SUS group with 14d reached 46.15%, showing significantly higher than that of the SUS group with 7d. For the IGF-1 concentration and EDL changes, no remarkable differences were found among the CON, PRE and SUS groups. Conclusions The impact of pressure on the process of soleus growth is different from that of the suspension (disuse). During the early stage of pressure application, the deep tissue injury mainly with inflammatory responses can be found in the muscle. When the muscle cells adapt to the pressure environment, they may produce a functional adaptation to growth. Therefore, such effect of socket pressure on skeletal muscle should be considered in clinic for prosthetic socket design or rehabilitation training, which will help protect the muscle tissues.

Advances of residual limb muscle atrophy in biomechanics research / 医用生物力学

Muscle atrophy of the stumps after lower limb amputation has always been a crucial factor resulted in inefficient clinical rehabilitation and athletic recovery for the amputated patients. Therefore, understanding the initiating and developing mechanism of muscle atrophy is very important for the improvement of amputation，restoration training and prosthetic design，which is also widely concerned in the prosthetic rehabilitation field. This paper will review the advances of residual limb muscle atrophy researches on the approaches and models，the mechanical properties of the residual limb，the micro pathologic characteristics as well as the prevention strategies of muscle atrophy in recent years. It can be concluded that further researches are needed to study the special physiologic and mechanical environment in residual limb, which affected the growth of muscle cells as well as the dynamic balance of the muscle protein synthesis and decomposition before completely understanding the mechanism of residual limb muscle atrophy and definitely clarifying its real cause.