Potential drug targets for gastroesophageal reflux disease and Barrett's esophagus identified through Mendelian randomization analysis.

Gastroesophageal reflux disease (GERD) is a prevalent chronic ailment, and present therapeutic approaches are not always effective. This study aimed to find new drug targets for GERD and Barrett's esophagus (BE). We obtained genetic instruments for GERD, BE, and 2004 plasma proteins from recently published genome-wide association studies (GWAS), and Mendelian randomization (MR) was employed to explore potential drug targets. We further winnowed down MR-prioritized proteins through replication, reverse causality testing, colocalization analysis, phenotype scanning, and Phenome-wide MR. Furthermore, we constructed a protein-protein interaction network, unveiling potential associations among candidate proteins. Simultaneously, we acquired mRNA expression quantitative trait loci (eQTL) data from another GWAS encompassing four different tissues to identify additional drug targets. Meanwhile, we searched drug databases to evaluate these targets. Under Bonferroni correction (P < 4.8 × 10-5), we identified 11 plasma proteins significantly associated with GERD. Among these, 7 are protective proteins (MSP, GPX1, ERBB3, BT3A3, ANTR2, CCM2, and DECR2), while 4 are detrimental proteins (TMEM106B, DUSP13, C1-INH, and LINGO1). Ultimately, C1-INH and DECR2 successfully passed the screening process and exhibited similar directional causal effects on BE. Further analysis of eQTLs highlighted 4 potential drug targets, including EDEM3, PBX3, MEIS1-AS3, and NME7. The search of drug databases further supported our conclusions. Our study indicated that the plasma proteins C1-INH and DECR2, along with 4 genes (EDEM3, PBX3, MEIS1-AS3, and NME7), may represent potential drug targets for GERD and BE, warranting further investigation.

Optimizing transseptal puncture guided by three-dimensional mapping: the role of a unipolar electrogram in a needle tip.

AIMS: A three-dimensional electroanatomic mapping system-guided transseptal puncture (3D-TSP), without fluoroscopy or echocardiography, has been only minimally reported. Indications for 3D-TSP remain unclear. Against this background, this study aims to establish a precise technique and create a workflow for validating and selecting eligible patients for fluoroless 3D-TSP. METHODS AND RESULTS: We developed a new methodology for 3D-TSP based on a unipolar electrogram derived from a transseptal needle tip (UEGM tip) in 102 patients (the derivation cohort) with intracardiac echocardiography (ICE) from March 2018 to February 2019. The apparent current of injury (COI) was recorded at the muscular limbus of the foramen ovalis (FO) on the UEGM tip (sinus rhythm: 2.57 ± 0.95 mV, atrial fibrillation: 1.92 ± 0.77 mV), which then disappeared or significantly reduced at the central FO. Changes in the COI, serving as a major criterion to establish a 3D-TSP workflow, proved to be the most valuable indicator for identifying the FO in 99% (101/102) of patients compared with three previous techniques (three minor criteria) of reduction in atrial unipolar or bipolar potential and FO protrusion. A total of 99.9% (1042/1043) patients in the validation cohort underwent successful 3D-TSP through the workflow from March 2019 to July 2023. Intracardiac echocardiography guidance was required for 6.6% (69/1042) of patients. All four criteria were met in 740 patients, resulting in a 100% pure fluoroless 3D-TSP success rate. CONCLUSION: In most patients, fluoroless 3D-TSP was successfully achieved using changes in the COI on the UEGM tip. Patients who met all four criteria were considered suitable for 3D-TSP, while those who met none required ICE guidance.

Activating α7nAChR helps post-myocardial infarction healing by regulating macrophage polarization via the STAT3 signaling pathway.

BACKGROUND: Monocytes/macrophages play critical roles in inflammation and cardiac remodeling following myocardial infarction (MI). The cholinergic anti-inflammatory pathway (CAP) modulates local and systemic inflammatory responses by activating α7 nicotinic acetylcholine receptors (α7nAChR) in monocytes/macrophages. We investigated the effect of α7nAChR on MI-induced monocyte/macrophage recruitment and polarization and its contribution to cardiac remodeling and dysfunction. METHODS: Adult male Sprague Dawley rats underwent coronary ligation and were intraperitoneally injected with the α7nAChR-selective agonist PNU282987 or the antagonist methyllycaconitine (MLA). RAW264.7 cells were stimulated with lipopolysaccharide (LPS) + interferon-gamma (IFN-γ) and treated with PNU282987, MLA, and S3I-201 (a STAT3 inhibitor). Cardiac function was evaluated by echocardiography. Masson's trichrome and immunofluorescence were used to detect cardiac fibrosis, myocardial capillary density, and M1/M2 macrophages. Western blotting was used to detect protein expression, and the proportion of monocytes was measured using flow cytometry. RESULTS: Activating the CAP with PNU282987 significantly improved cardiac function and reduced cardiac fibrosis and 28-day mortality after MI. On days 3 and 7 post-MI, PNU282987 reduced the percentage of peripheral CD172a + CD43low monocytes and the infiltration of M1 macrophages in the infarcted hearts, whereas it increased the recruitment of peripheral CD172a + CD43high monocytes and M2 macrophages. Conversely, MLA exerted the opposite effects. In vitro, PNU282987 inhibited M1 macrophage polarization and promoted M2 macrophage polarization in LPS + IFN-γ-stimulated RAW264.7 cells. These PNU282987-induced changes in LPS + IFN-γ-stimulated RAW264.7 cells were reversed by administering S3I-201. CONCLUSION: Activating α7nAChR inhibits the early recruitment of pro-inflammatory monocytes/macrophages during MI and improves cardiac function and remodeling. Our findings suggest a promising therapeutic target for regulating monocyte/macrophage phenotypes and promoting healing after MI.

A prognostic nomogram to predict survival in elderly patients with small-cell lung cancer: a large population-based cohort study and external validation.

BACKGROUND: Age is an independent prognostic factor for small cell lung cancer (SCLC). We aimed to construct a nomogram survival prediction for elderly SCLC patients based on the Surveillance, Epidemiology, and End Results (SEER) database. METHODS: A total of 2851 elderly SCLC patients from the SEER database were selected as a primary cohort, which were randomly divided into a training cohort and an internal validation cohort. Additionally, 512 patients from two institutions in China were identified as an external validation cohort. We used univariate and multivariate to determine the independent prognostic factors and establish a nomogram to predict survival. The value of the nomogram was evaluated by calibration plots, concordance index (C-index) and decision curve analysis (DCA). RESULTS: Ten independent prognostic factors were determined and integrated into the nomogram. Calibration plots showed an ideal agreement between the nomogram predicted and actual observed probability of survival. The C-indexes of the training and validation groups for cancer-specific survival (CSS) (0.757 and 0.756, respectively) based on the nomogram were higher than those of the TNM staging system (0.631 and 0.638, respectively). Improved AUC value and DCA were also obtained in comparison with the TNM model. The risk stratification system can significantly distinguish individuals with different survival risks. CONCLUSION: We constructed and externally validated a nomogram to predict survival for elderly patients with SCLC. Our novel nomogram outperforms the traditional TNM staging system and provides more accurate prediction for the prognosis of elderly SCLC patients.

Capped Keggin Type Polyoxometalate-Based Inorganic-Organic Hybrids Involving In Situ Ligand Transformation as Supercapacitors and Efficient Electrochemical Sensors for Detecting Cr(VI).

To construct polyoxometalate-based complexes as electrode materials for supercapacitors and electrochemical sensors, we intentionally used in situ ligand transformation during the reaction. Two complexes based on polyoxometalates capped by zinc ions, H{Zn4(DIBA)4[(DIBA)(HPO2)]2(α-PMoVI8MoV4O40Zn2)} (1) and [ε-PMoV8MoVI4O37(OH)3Zn4(HDBIBA)2]·6H2O (2) [DIBA = 3,5-di(1H-imidazol-1-yl)benzoic acid, and DBIBA = 3,5-bis(1H-benzoimidazol-1-yl)benzoic acid], have been prepared successfully. The DIBA and DBIBA ligands were generated in situ from initial materials 3,5-di(1H-imidazol-1-yl)benzonitrile and 3,5-di(1H-benzoimidazol-1-yl)benzonitrile. The three-dimensional structure of 1 consisted of two-dimensional interpenetrating layers and polyoxometalate-based chains composed of bicapped α-PMo12Zn2 polyoxoanions and phosphite-modified DIBA ligands. In 2, a kind of tetracapped ε-PMo12Zn4 polyoxoanion exists, which was further linked by DBIBA ligands into a one-dimensional chain. Two complexes could be employed as not only electrode materials for supercapacitors with specific capacitances of 171.17 F g-1 for 1 and 146.77 F g-1 for 2 at 0.5 A g-1 but also efficient electrochemical sensors for detecting Cr(VI) with excellent limits of detection of 0.026 µM for 1 and 0.035 µM for 2, which represents a hopeful approach for exploiting polyoxometalate-based complexes as supercapacitor and electrochemical sensor materials.

Exosomes derived from umbilical cord mesenchymal stem cells alleviate viral myocarditis through activating AMPK/mTOR-mediated autophagy flux pathway.

Human umbilical cord mesenchymal stem cell-derived exosomes (hucMSC-exosomes) have been implicated as a novel therapeutic approach for tissue injury repair and regeneration, but the effects of hucMSC-exosomes on coxsackievirus B3 (CVB3)-induced myocarditis remain unknown. The object of the present study is to investigate whether hucMSC-exosomes have therapeutic effects on CVB3-induced myocarditis (VMC). HucMSC-exosomes were identified using nanoparticle tracking analysis (NTA), transmission electron microscopy (TEM) and Western blot. The purified hucMSC-exosomes tagged with PKH26 were tail intravenously injected into VMC model mice in vivo and used to administrate CVB3-infected human cardiomyocytes (HCMs) in vitro, respectively. The effects of hucMSC-exosomes on myocardial pathology injury, proinflammatory cytokines and cardiac function were evaluated through haematoxylin and eosin (H&E) staining, quantitative polymerase chain reaction (qPCR) and Doppler echocardiography. The anti-apoptosis role and potential mechanism of hucMSC-exosomes were explored using TUNEL staining, flow cytometry, immunohistochemistry, Ad-mRFP-GFP-LC3 transduction and Western blot. In vivo results showed that hucMSC-exosomes (50 µg iv) significantly alleviated myocardium injury, shrank the production of proinflammatory cytokines and improved cardiac function. Moreover, in vitro data showed that hucMSC-exosomes (50 µg/mL) inhibited the apoptosis of CVB3-infected HCM through increasing pAMPK/AMPK ratio and up-regulating autophagy proteins LC3II/I, BECLIN-1 and anti-apoptosis protein BCL-2 as well as decreasing pmTOR/mTOR ratio, promoting the degradation of autophagy flux protein P62 and down-regulating apoptosis protein BAX. In conclusion, hucMSC-exosomes could alleviate CVB3-induced myocarditis via activating AMPK/mTOR-mediated autophagy flux pathway to attenuate cardiomyocyte apoptosis, which will be benefit for MSC-exosome therapy of myocarditis in the future.

In Situ Ligand-Transformation-Involved Synthesis of Inorganic-Organic Hybrid Polyoxovanadates as Efficient Heterogeneous Catalysts for the Selective Oxidation of Sulfides.

By intentionally involving in situ ligand transformation in the reaction system, two inorganic-organic hybrid polyoxovanadates (POVs), [Co(HDTBA)V2O6] (1) and [Ni(H2O)2(DTBA)2V2O4(OH)2]·4H2O (2), have been synthesized by using a hydrothermal method, where the 3,5-di[1,2,4]triazol-1-ylbenzoic acid (HDTBA) ligand originated from in situ hydrolysis of 3,5-di[1,2,4]triazol-1-ylbenzonitrile in the self-assembly process. The inorganic layers [Co2(V4O12)]n containing [V4O12]4- circle clusters were linked by HDTBA ligands to yield a 3D framework structure of compound 1. There existed a kind of binuclear [(DTBA)2V2O4(OH)2]2- vanadium cluster grafted directly by two DTBA ligands through the sharing of carboxyl oxygen atoms in compound 2, further extended into a 2D layer by nickel centers. The investigations on the catalytic properties indicated that compounds 1 and 2 as heterogeneous catalysts, especially 2, owned satisfying catalytic performances for catalyzing the selective oxidation of sulfides to sulfoxides in the presence of tert-butyl hydroperoxide as an oxidant, accompanied by excellent conversion of 100% and selectivity of above 99%, providing a promising way for developing inorganic-organic hybrid POVs as effective heterogeneous catalysts for catalyzing the selective oxidation of sulfides.

Implication of the distinctive bipolar intracardiac electrograms for ventricular arrhythmias arising from different regions of ventricular outflow tract.

AIMS: To investigate the characteristics of bipolar intracardiac electrograms (bi-EGMs) in target sites of ventricular arrhythmias (VAs) originating from different regions of ventricular outflow tract (VOT). METHODS AND RESULTS: Two hundred and seventy patients undergoing first-time ablation for VAs originated from distal great cardiac vein (DGCV), aortic sinus cusps (ASCs), or pulmonary sinus cusps (PSCs) were enrolled in present study. Local intracardiac bipolar recordings on 243 successful sites and 506 attempted but unsuccessful ablation sites were analysed. Specific potentials in bi-EGMs on successful sites were more common compared with unsuccessful sites (76.95%, 187/243 vs. 25.49%, 129/506, P < 0.05). A total of 60.00% (81/135) patients in ASCs group presented a presystolic short-duration fractionated potential, higher than 23.21% (13/56) in DGCV and 23.08% (12/52) in PSCs (all P < 0.05); 44.23% (23/52) patients in PSC group showed a presystolic high-amplitude discrete potential, while 1.79% (1/56) in DGCV and 2.22% (3/135) in ASCs (all P < 0.05); 41.07% (23/56) patients in DGCV group showed bi-EGMs of presystolic long-duration multicomponent fractionated potential, which was significantly higher than 3.85% (2/52) in PSCs and 4.44%(6/135) in ASCs (all P < 0.05). CONCLUSION: Distinctive morphology of bi-EGMs during VAs can be found in different regions of VOT, which probably due to changes in the arrangements of myocardial sleeves. Correct identification and better understanding of the distinctive features of these bi-EGMs with regards to the anatomic location was important, the presence of specific potentials may add help in successful ablation.

Electrophysiology in the time of coronavirus: coping with the great wave.

AIMS: To chart the effect of the COVID-19 pandemic on the activity of interventional electrophysiology services in affected regions. METHODS AND RESULTS: We reviewed the electrophysiology laboratory records in three affected cities: Wenzhou in China, Milan in Italy, and London in the UK. We inspected catheter lab records and interviewed electrophysiologists in each centre to gather information on the impact of the pandemic on working patterns and on the health of staff members and patients. There was a striking decline in interventional electrophysiology activity in each of the centres. The decline occurred within a week of the recognition of widespread community transmission of the virus in each region and shows a striking correlation with the national figures for new diagnoses of COVID-19 in each case. During the period of restriction, workflow dropped to <5% of normal, consisting of emergency cases only. In two of three centres, electrophysiologists were redeployed to perform emergency work outside electrophysiology. Among the centres studied, only Wenzhou has seen a recovery from the restrictions in activity. Following an intense nationwide programme of public health interventions, local transmission of COVID-19 ceased to be detectable after 18 February allowing the electrophysiology service to resume with a strict testing regime for all patients. CONCLUSION: Interventional electrophysiology is vulnerable to closure in times of great social difficulty including the COVID-19 pandemic. Intense public health intervention can permit suppression of local disease transmission allowing resumption of some normal activity with stringent precautions.

Eliciting α7-nAChR exerts cardioprotective effects on ischemic cardiomyopathy via activation of AMPK signalling.

Our previous studies have reported that agonist of α7 nicotinic acetylcholine receptors prevented electrophysiological dysfunction of rats with ischaemic cardiomyopathy (ICM) by eliciting the cholinergic anti-inflammatory pathway (CAP). Adenosine monophosphate-activated protein kinase (AMPK) signalling is widely recognized exerting cardioprotective effect in various cardiomyopathy. Here, we aimed to investigate whether the protective effects of the CAP are associated with AMPK signalling in ICM. In vivo, coronary artery of rats was ligated for 4 weeks to induce the ICM and then treated with PNU-282987 (CAP agonist) and BML-275 dihydrochloride (AMPK antagonist) for 4 weeks. In vitro, primary macrophages harvested from rats were induced inflammation by Lipopolysaccharide (LPS) treatment and then treated with PNU-282987 and BML-275 dihydrochloride. In vivo, exciting CAP by PUN-282987 elicited an activation of AMPK signalling, alleviated ventricular remodeling, modified the cardiac electrophysiological function, reduced the cardiac expression of collagens and inflammatory cytokines and maintained the integrity of ultrastructure in the ischemic heart. However, the benefits of CAP excitation were blunted by AMPK signaling antagonization. In vitro, excitation of the CAP was observed inhibiting the nuclear transfer of NF-κB p65 of macrophages and promoting the transformation of Ly-6Chigh macrophages into Ly-6Clow macrophages. However, inhibiting AMPK signalling by BML-275 dihydrochloride reversed the CAP effect on LPS-treated macrophages. Finally, our findings suggest that eliciting the CAP modulates the inflammatory response in ICM through regulating AMPK signalling.

Low-intensity pulsed ultrasound attenuates cardiac inflammation of CVB3-induced viral myocarditis via regulation of caveolin-1 and MAPK pathways.

The aggressive immunological activity elicited by acute viral myocarditis contributes to a large amount of cardiomyocytes loss and poor prognosis of patients in clinic. Low-intensity pulsed ultrasound (LIPUS), which is an effective treatment modality for osteoarthropathy, has been recently illustrated regulating the overactive inflammatory response in various diseases. Here, we aimed to investigate whether LIPUS could attenuate coxsackievirus B3 (CVB3) infection-induced injury by coordinating the inflammatory response. Male BALB/c mice were inoculated intraperitoneally with CVB3 to establish the model of acute viral myocarditis. LIPUS treatment was given on Day 1, Day 1, 3 and Day 1, 3, 5 post-inoculation, respectively. All mice were followed up for 14 days. Day 1, 3, 5 LIPUS treatment significantly improved the survival rate, attenuated the ventricular dysfunction and ameliorated the cardiac histopathological injury of CVB3-infected mice. Western blotting analysis showed Day 1, 3, 5 LIPUS treatment decreased pro-inflammatory cytokines, increased the activation of caveolin-1 and suppressed p38 mitogen-activated protein kinase (MAPK) and extracellular signal-regulated kinase (ERK) signallings in heart tissue. RAW264.7 cells were treated with lipopolysaccharides (LPS) to simulate the augmented inflammatory response in vivo. LIPUS treatment on RAW264.7 inhibited the expression of pro-inflammatory cytokines, activated caveolin-1 and suppressed p38 MAPK and ERK signallings. Transfecting RAW264.7 with caveolin-1 siRNA blunted the suppression of pro-inflammatory cytokines and MAPK signallings by LIPUS treatment. Taken together, we demonstrated for the first time that LIPUS treatment attenuated the aggressive inflammatory response during acute viral myocarditis. The underlying mechanism may be activating caveolin-1 and suppressing MAPK signallings.

Radiofrequency catheter ablation of ventricular arrhythmias arising from the region above pulmonary valve.

BACKGROUND: Ventricular arrhythmias (VAs) arising from the origin above pulmonary valve lack comprehensive investigation. This study aimed to disclose the characteristics and radiofrequency catheter ablation (RFCA) outcomes for those VAs. METHODS: One hundred six VAs arising from the region above pulmonary valve treated with RFCA were included in this study. RESULTS: Seventy-five cases were identified in the pulmonary sinus cusps (PSCs, 32 in left sinus cusp (PLC), 15 in right (PRC), 28 in anterior (PAC)) and 31 cases were in the main stem of pulmonary artery (MSPA, 18 above PLC (LMSPA), 3 above PRC (RMSPA), 10 above PAC (AMSPA)). Compared with PSCs VAs, MSPA VAs exhibited a higher R wave amplitude in the inferior leads, a total inferior R amplitude > 5.1 mV predicting MSPA origins. LMSPA, RMSPA and AMSPA VAs resembled PLC, PRC and PAC VAs in electrocardiographic characteristics respectively. No electrophysiological differences were found between PSCs and MSPA VAs. The irrigated-up catheter and R0 Swartz long sheath were more utilized for ablation of PSCs VAs than for MSPA VAs. All these VAs were successfully eliminated by RFCA. CONCLUSION: VAs arising from the origin above pulmonary valve were common. Based on certain electrocardiographic characteristics, they could be roughly located, which contributed to an effective RFCA.

Common and distinctive electrocardiographic characteristics and effective catheter ablation of idiopathic ventricular arrhythmias originating from different areas of ventricular septum adjacent to atrioventricular annulus.

OBJECTIVE: To investigate electrocardiographic (ECG) characteristics and radiofrequency catheter ablation (RFCA) efficacy for premature ventricular complexes (PVCs) and idiopathic ventricular tachycardias (IVTs) originating from ventricular septum areas adjacent to atrioventricular annulus (VS-AVA). METHODS: Among 1,505 consecutive PVCs/IVTs cases, 106 (7.04%) were confirmed as origin of VS-AVA guided by both fluoroscopy and three-dimensional mapping system during RFCA. Characteristics of surface 12-lead ECG were analyzed. RESULTS: The overall success rate for RFCA of PVCs/IVTs originating from VS-AVA was 82.08% (87/106), common ECG characteristics were: mainly positive R wave on lead I; dominant-positive R on aVL (91/106, 85.85%) for most, r (1/106, 0.94%) or qr (14/106, 13.21%) in few; QS or qs on aVR; and decreasing R wave amplitude and increasing S wave depth on II, III, and aVF from superior to inferior septum; and S wave on at least one inferior lead (generally III). Distinctive ECG features were: precordial transition zone before or after V2 for septum adjacent to mitral (MA, 19/19, 100.0%) or tricuspid (TA, 74/87,85.05%) annulus origin; initial r wave and rS on V1 for superior septum near TA (above His bundle) origin (9/10, 90.0%) with no initial r wave for most other origins; and QS on V1 for mid-inferior septum near TA origin (73/77, 94.81%) and QR (Qr, qR or qr) on V1 for septum near MA origin (17/19, 89.47%). CONCLUSION: Distinctive ECG characteristics of PVCs/IVTs originating from VS-AVA aid in origin localization guiding effective RFCA.

Case presentation: implantation of cardiac resynchronization therapy pacemaker via the coronary sinus in a patient with triple valve replacement.

BACKGROUND: In patients with triple valve replacement developing third-degree atrioventricular block (AVB), the most appropriate approach for permanent pacemaker implantation remains questionable. CASE PRESENTATION: In this case presentation, we first described the approach of implantation of the cardiac resynchronization therapy pacemaker (CRT-P) via one bipolar pacing lead in middle cardiac vein (MCV) and one quadripolar pacing lead in anterior interventricular vein (AIV) in a patient developing complete AVB, who had been previously diagnosed with rheumatic valvular heart disease with triple valve replaced. After the CRT-P implantation, the two pacing leads in coronary sinus (CS) provided a dual-site ventricular pacing from the anterior septum and posterior septum, which resulted in a narrow QRS complex and an increased ventricular synchrony. During the long-term follow-up, no deterioration of heart function was documented and pacing parameters remained good. CONCLUSION: In this patient developing complete AVB with triple valve replaced, our approach of CRT-P implantation provides an effective and reliable ventricular pacing, and is an alternative option when transvenous right ventricular pacing, transseptal left ventricular pacing and transpericardial epicardium pacing are not possible. Further prospective randomized trials are required to confirm the efficiency of our approach of dual-site ventricular pacing by CRT-P in this kind patients.

The safety of catheter ablation for premature ventricular contractions in patients without structural heart disease.

BACKGROUND: Patients with frequent premature ventricular contractions (PVCs) are often symptomatic. Catheter ablation was usually indicated to eliminate symptoms in patients with PVCs-induced cardiomyopathy. Currently, PVCs-ablation is also applied for patients with PVCs and no structural heart diseases (SHD); however, the safety and efficacy of ablation in these patients remains unclear. METHODS: In this retrospective study, data from patients who underwent ablation for PVCs from January 2010 to December 2016 at our hospital was retrieved. Predictors of complications and acute procedural success were evaluated. RESULTS: A total of 1231 patients (mean age 47.8 ± 16.8 years, 59% female) were included. The overall complication rate was 2.7%, and the most common complication was hydropericardium. Two ablation-related mortalities occurred. One patient died of coronary artery injury during the procedure and the other died from infectious endocarditis. Location (left ventricle and epicardium) was the main predictor of complications, with right ventricular outflow tract (RVOT) predicting fewer complications. The acute procedural success rate was 94.1% in all patients. The main predictor of acute procedural success was RVOT origin, while an epicardial origin was a predictor of procedural failure. CONCLUSION: Locations of left ventricle and epicardium were predictors of procedural complications for patients with PVCs. Therefore, ablation is not recommended in these patients. For other origins of PVCs, particularly RVOT origin, ablation is a safety and effective treatment.

Loss of TRADD attenuates pressure overload-induced cardiac hypertrophy through regulating TAK1/P38 MAPK signalling in mice.

We investigated the role of tumour necrosis factor receptor (TNFR)-associated death domain (TRADD) on pressure overload-induced cardiac hypertrophy and the underlying molecular mechanisms by using a TRADD deficiency mice model. 6-8 weeks wild-type and TRADD knockout mice were performed to transverse aorta constriction (TAC) or sham operation (6-8 mice for each group). 14 days after TAC, cardiac function was measured by echocardiography, as well as by pathological and molecular analyses of heart samples. The expressions of cardiac hypertrophic and fibrotic markers were detected by qPCR. Phosphorylated and total TAK1, Akt, and p38 MAPK levels were examined by Western blotting. The ratios of lung or heart/body weight, wall thickness/chamber diameter of left ventricular and cross area of cardiomyocyte were significantly reduced in TRADD knockout (KO) mice than those of wild-type mice after TAC. Moreover, cardiac hypertrophic and fibrotic markers were downregulated in TRADD knockout mice than those of wild-type mice following TAC. Protein expression analysis showed phosphorylated TAK1, p38 MAPK and AKT were upregulated after TAC in both wild-type and TRADD KO mice, phosphorylation of TAK1 and p38 MAPK was reduced more remarkably after TRADD deficiency, while phosphorylated AKT expression was similar between TRADD KO and wild-type mice following TAC. Our data suggest that TRADD KO blunts pressure overload-induced cardiac hypertrophy through mediating TAK1/p38 MAPK but not AKT phosphorylation in mice.

Origins location of the outflow tract ventricular arrhythmias exhibiting qrS pattern or QS pattern with a notch on the descending limb in lead V1.

BACKGROUND: Ventricular outflow tract(VOT) ventricular arrhythmias(VAs) presenting qrS pattern or QS pattern with a notch on the descending limb in lead V1 were consistently thought of arising from the commissure between left and right coronary cusp (L-RCC) by previous studies. However, we found they could originate from other anatomic structures in VOT. This study aimed to investigate the exact origin of this kind VAs. METHODS: Forty-nine patients of VOT premature ventricular contrations/ventricular tachycardia(PVCs/VT) with lead V1 presenting qrS pattern or QS pattern with a notch on the descending limb undergoing successful radiofrequency catheter ablation(RFCA) in our center were analyzed. RESULTS: 12-lead electrocardiogram(ECG) of these PVCs/VT were summarized. Among these PVCs/VT, 37 cases exhibited qrS morphology in lead V1, 12 cases presented QS pattern with a notch on the descending limb in the same lead. Based on the successful ablation sites, these PVCs/VT were divided into 2 groups: (1)Right ventricular outflow tract(RVOT) group (26 cases), and (2) Left ventricular outflow tract (LVOT) group(23 cases, 4 cases originating from the left coronary cusp(LCC), 2 from the right coronary cusp(RCC), 16 from the L-RCC, 1 from the area inferior to LCC(ILCC)). The ECG characteristics of each PVCs/VT were analyzed. Among these PVCs/VT, applying the precordial transitional zone index(TZ index) < 0 to predict LVOT origin was demonstrated with sensitivity of 95.65%, specificity of 96.15%, positive predicting value(PPV) of 95.65% and negative predicting value(NPV) of 96.15%. In LVOT group, further applying the r, R, m,or Rs morphology in lead I to predict L-RCC and RCC origin was demonstrated with sensitivity of 94.44%, specificity of 60.00%, PPV of 89.47% and NPV of 75.00%. CONCLUSIONS: Ventricular outflow tract PVCs/VT with lead V1 presenting qrS pattern or QS pattern with a notch on descending limb not only arising from L-RCC, but also RVOT, LCC, RCC and ILCC. Combining TZ index and QRS morphology in lead I to predict origin site of these kind VAs is a convenient, simple and reliable method and facilitates the RFCA procedure.

Approach selection of radiofrequency catheter ablation for ventricular arrhythmias originating from the left ventricular summit: potential relevance of Pseudo Delta wave, Intrinsicoid deflection time, maximal deflection index.

BACKGROUND: Ventricular arrhythmias (VAs) originating from the left ventricular summit is a challenge for radiofrequency catheter ablation (RFCA). The present study aimed to investigate the appropriate RFCA strategy for VAs originating from the left ventricular summit. METHODS: Forty-five consecutive patients with VAs arising from the left ventricular summit were successfully ablated at our cardiac electrophysiology center and reviewed in the study. RESULTS: Thirty-two cases of VAs were eliminated in the left ventricular endocardium by retrograde transaortic (n = 22, 22/45, 48.9%) or antegrade transseptal (n = 10, 10/45, 22.2%) approaches, the other 13 cases were eliminated in the left ventricular epicardium by distal great cardiac vein (DGCV) approach (n = 13, 13/45, 28.9%). Though these VAs were similar in electrocardiographic (ECG) morphology, the pseudo delta waves (PDW), intrinsicoid deflection time (IDT), maximal deflection index (MDI) differed among them, PDW >53 ms, IDT > 74 ms, MDI > 0.45 strongly indicated that ablating left ventricular summit VAs by DGCV approach. During mean follow-up of 19.5 ± 13.2 (range, 3-60) months, 2 (4.4%) patients experienced VAs recurrence. CONCLUSION: This retrospective study showed that VAs of left ventricular summit origin can be effectively cured with RFCA. For these VAs, prolonged PdW, IDT, MDI indicating RFCA by DGCV approach can be attempted firstly.

Where is the exact origin of narrow premature ventricular contractions manifesting qR in inferior wall leads?

BACKGROUND: In recent years, radiofrequency catheter ablation(RFCA) has been established as an effective therapy for idiopathic premature ventricular contractions (PVCs), however, its effect on the narrow PVCs (QRS duration < 130 msec) with qR pattern in inferior leads, may not been fully concluded. METHODS: Characteristics of 12-lead electrocardiogram (ECG) and electrophysiologic recordings were analyzed in 40 patients with symptomatic PVCs manifesting narrow QRS complex with qR pattern in inferior leads. The procedure of RFCA was performed based on pace mapping and activation mapping. RESULTS: Among the 40 patients with narrow PVCs, complete elimination of PVCs was achieved by RFCA in 35 patients during a median follow-up period of 23 months. Successful ablation was achieved on 19 patients at the sites where earliest Purkinje potentials were recorded in left ventricular anterosuperior septum, thus PVCs arising from left anterior fascicle (LAF) were confirmed, for these PVCs, the QRS morphology were right bundle branch and left posterior fascicle block (RBBB + LPFB) with rightward axis, the average QRS duration 116.07 ± 7.96 ms, R or rsR'in lead V1,with transition zone ahead of lead V1 in precordial leads. Another 16 successful RFCA were achieved by energy delivery at interleaflet triangle(ILT) between right coronary cusp(RCC) and left coronary cusp(LCC) where no Purkinje potentials were recorded, for narrow PVCs arising from the L-RCC ILT, the QRS morphology were similar to the PVCs arising from LAF but much narrower in QRS duration (100.44 ± 3.49 vs. 116.07 ± 7.96 ms, p < 0.05), they were also R or Rs in lead V1 with the transition zone ahead of lead V1. For 5 symptomatic narrow PVCs failed to the procedure of RFCA, their electrocardiographic characteristics showed that the narrowest QRS duration (91.80 ± 6.94 vs. 100.44 ± 3.49, 116.07 ± 7.96 ms, p < 0.05), rs or rS (r/s or r/S≦1) morphology in lead V1 with the precordial transition zone behind lead V3. CONCLUSIONS: Most of idiopathic PVCs of narrow QRS duration (<130 msec) with qR pattern in inferior leads can be cured by the procedure of RFCA. On the basis of our study, we proposed that for narrow PVCs presenting qR pattern in inferior leads, when the ablation procedure failed at proximity of LAF within left anterosuperior septum, mapping and ablation in L-RCC ILT can be tried. The present findings can be helpful for planning catheter ablation for narrow PVCs manifesting qR in inferior leads.

Increased cardiac remodeling in cardiac-specific Flt-1 receptor knockout mice with pressure overload.

Vascular endothelial growth factor (VEGF) inhibition has previously been shown to have damaging effects on the heart. Because the role of Flt-1 (a phosphotyrosine kinase receptor for VEGF) in cardiac function and hypertrophy is unclear, we generated mice lacking Flt-1 only in their cardiomyocytes (Flt-1 KO). The hearts from 8- to 10-week-old mice were measured by using echocardiography and histology. No significant differences were seen in fraction shortening, cross-sectional area of cardiomyocytes, and interstitial collagen fraction between littermate controls and KO mice at baseline. To test the hypothesis that Flt-1 is involved in cardiac remodeling, we performed transverse aorta constriction (TAC) by ligating the transverse ascending aorta. Four weeks after TAC, echocardiography of the mice was performed, and the hearts were excised for pathological analysis and Western blotting. No difference in mortality was found between Flt-1 KO mice and controls; however, KO mice showed a greater cardiomyocyte cross-sectional area and interstitial collagen fraction than controls. Western blotting indicated that AKT was activated less in Flt-1 KO hearts after TAC compared with that in control hearts. Thus, Flt-1 deletion in cardiomyocytes increased hypertrophy, fibrosis, and regression of AKT phosphorylation. Our study suggests that Flt-1 plays a critical role in cardiac hypertrophy induced by pressure overload via the activation of AKT, which seems to be cardioprotective.