RESUMEN
BACKGROUND: An unannounced balance loss during walking, i.e., balance perturbation, is a stressful event that changes the activity of the Sympathetic Nervous System (SNS). We examined SNS response to unannounced balance perturbation during walking, simulating real-life conditions of balance loss. RESEARCH QUESTION: Do laboratory-induced unannounced balance losses during walking cause a sympathetic response, and if so - does it habituate after a series of perturbations? METHODS: 34 young adults underwent a series of six successive unannounced balance perturbations while walking on a treadmill. Sympathetic activity was monitored continuously using Electrodermal Activity and compared before and immediately after each unannounced perturbation. RESULTS: All perturbations elicited a significant increase in Electrodermal Activity (p<0.001), indicating a phasic increase in the sympathetic drive. The relative phasic increase of Electrodermal Activity caused by the first perturbation was significantly higher than the last perturbation (p<0.05). Three types of Electrodermal Activity behavior were observed: Steady level tonic SNS activity, increased SNS activity, and decreased SNS activity. SIGNIFICANCE: Balance loss during walking triggers phasic SNS response, this response habituates after a series of unannounced balance perturbations. In addition, three distinct patterns of tonic sympathetic activity may imply variations in the ability of the SNS response to habituate across individuals.
RESUMEN
ZnT1 is a major zinc transporter that regulates cellular zinc homeostasis. We have previously shown that ZnT1 has additional functions that are independent of its activity as a Zn2+ extruder. These include inhibition of the L-type calcium channel (LTCC) through interaction with the auxiliary ß-subunit of the LTCC and activation of the Raf-ERK signaling leading to augmented activity of the T-type calcium channel (TTCC). Our findings indicate that ZnT1 increases TTCC activity by enhancing the trafficking of the channel to the plasma membrane. LTCC and TTCC are co-expressed in many tissues and have different functions in a variety of tissues. In the current work, we investigated the effect of the voltage-gated calcium channel (VGCC) ß-subunit and ZnT1 on the crosstalk between LTCC and TTCC and their functions. Our results indicate that the ß-subunit inhibits the ZnT1-induced augmentation of TTCC function. This inhibition correlates with the VGCC ß-subunit-dependent reduction in ZnT1-induced activation of Ras-ERK signaling. The effect of ZnT1 is specific, as the presence of the ß-subunit did not change the effect of endothelin-1 (ET-1) on TTCC surface expression. These findings document a novel regulatory function of ZnT1 serving as a mediator in the crosstalk between TTCC and LTCC. Overall, we demonstrate that ZnT1 binds and regulates the activity of the ß-subunit of VGCC and Raf-1 kinase and modulates surface expression of the LTCC and TTCC catalytic subunits, consequently modulating the activity of these channels.
Asunto(s)
Canales de Calcio Tipo L , Canales de Calcio Tipo T , Calcio/metabolismo , Canales de Calcio Tipo L/metabolismo , Canales de Calcio Tipo T/metabolismo , Proteínas Proto-Oncogénicas c-raf/metabolismo , Animales , XenopusRESUMEN
The utility of rodents for research related to atrial fibrillation (AF) is growing exponentially. However, the obtained arrhythmic waveforms are often mixed with ventricular signals and the ability to analyze regularity and complexity of such events is limited. Recently, we introduced an implantable quadripolar electrode adapted for advanced atrial electrophysiology in ambulatory rats. Notably, we have found that the implantation itself leads to progressive atrial remodeling, presumably because of mechanical loading of the atria. In the present study, we developed an algorithm to clean the atrial signals from ventricular mixing and thereafter quantify the AF substrate in an objective manner based on waveform complexity. Rats were sequentially examined 1-, 4-, and 8-wk postelectrode implantation using a standard AF triggering protocol. Preburst ventricular mixing was sampled and automatically subtracted based on QRS detection in the ECG. Thereafter, the "pure" atrial signals were analyzed by Lempel-Ziv complexity algorithm and a complexity ratio (CR) was defined for each signal by normalizing the postburst to the preburst values. Receiver operating characteristic (ROC) curve analysis indicated an optimal CR cutoff of 1.236 that detected irregular arrhythmic events with high sensitivity (94.5%), specificity (93.1%), and area under the curve (AUC) (0.96, 95% confidence interval, 0.945-0.976). Automated and unbiased analysis indicated a gradual increase in signal complexity over time with augmentation of high frequencies in power spectrum analysis. Our findings indicate that CR algorithm detects irregularity in a highly efficient manner and can also detect the atrial remodeling induced by electrode implantation. Thus, CR analysis can strongly facilitate standardized AF research in rodents.NEW & NOTEWORTHY Rodents are increasingly used in AF research. However, because of technical difficulties including atrial waveform mixing by ventricular signals, most studies do not discriminate between irregular (i.e., AF) and regular atrial arrhythmias. Here, we develop an unbiased computerized tool to "pure" the atrial signals from ventricular mixing and thereafter analyze AF substrate based on the level of irregularity in an objective manner. This novel tool can facilitate standardized AF research in rodents.
Asunto(s)
Fibrilación Atrial , Remodelación Atrial , Ratas , Animales , Fibrilación Atrial/diagnóstico , Atrios Cardíacos , Algoritmos , Electrodos Implantados , Electrocardiografía/métodosRESUMEN
BACKGROUND: The medical school admission process is complicated, perhaps reflecting unresolved debates concerning the most important skills necessary to become an ideal physician. The Goldman Medical School at Ben-Gurion University in Israel is known for placing great emphasis on the personal attributes of candidates in addition to their academic excellence. To this end, 1-h consecutive interviews are embedded in the admission process. This study aims to determine whether there is an association between candidates' personal interview ratings and the ratings assigned to these students at the conclusion of their 6th year internal medicine sub-internship. METHODS: Our study sample included 136 students who were admitted to the medical school in 2015, and who completed their 6th year internal medicine sub-internship in 2019-2020. Our data were derived from the admissions information for each candidate and from structured interviews concerning medical competence and personal traits, which were completed by medical personnel who were in contact with these students during their clinical rounds. RESULTS: Higher interview ratings of candidates during the admission process were associated with a higher probability that students would be evaluated as top-rated internists 6 years later (Odds Ratio (OR) = 9.4, p-value = 0.049), independent of gender (OR for male vs female = 0.2, p-value = 0.025) and age (OR = 1.3 per each year, p-value = 0.115). Although significant, the numeric difference in interview rating was relatively small (median 9.5 and 9.4 for top-rated and not top-rated internists, respectively). CONCLUSIONS: Our study shows that high personal interview ratings assigned to candidates as part of the medical school admission process are predictive of high performance ratings of students after they complete their 6th year internal medicine sub-internships. These findings demonstrate the value and importance of using semi-structured personal interviews in the medical school admission process.
Asunto(s)
Internado y Residencia , Estudiantes de Medicina , Cognición , Femenino , Humanos , Medicina Interna , Masculino , Criterios de Admisión Escolar , Facultades de Medicina , Estudiantes de Medicina/psicologíaRESUMEN
CONTEXT: Lower fasting ghrelin levels (FGL) are associated with obesity and metabolic syndrome. OBJECTIVE: We aimed to explore the dynamics of FGL during weight loss and its metabolic and adiposity-related manifestations beyond weight loss. METHODS: This was a secondary analysis of a clinical trial that randomized participants with abdominal obesity/dyslipidemia to 1 of 3 diets: healthy dietary guidelines (HDG), Mediterranean diet (MED), or green-MED diet, all combined with physical activity (PA). Both MED diets were similarly hypocaloric and included 28 g/day walnuts. The green-MED group further consumed green tea (3-4 cups/day) and a Wolffia globosa (Mankai) plant green shake. We measured FGL and quantified body fat depots by magnetic resonance imaging at baseline and after 18 months. RESULTS: Among 294 participants (body mass index = 31.3 kg/m2; FGL = 504 ± 208 pg/mL; retention rate = 89.8%), lower FGL was associated with unfavorable cardiometabolic parameters such as higher visceral adipose tissue (VAT), intrahepatic fat, leptin, and blood pressure (P < 0.05 for all; multivariate models). The ∆FGL18-month differed between men (+7.3 ± 26.6%) and women (-9.2% ± 21.3%; P = 0.001). After 18 months of moderate and similar weight loss among the MED groups, FGL increased by 1.3%, 5.4%, and 10.5% in HDG, MED, and green-MED groups, respectively (P = 0.03 for green-MED vs HDG); sex-stratified analysis revealed similar changes in men only. Among men, FGL18-month elevation was associated with favorable changes in insulin resistance profile and VAT regression, after adjusting for relative weight loss (HbA1c: r = -0.216; homeostatic model of insulin resistance: r = -0.154; HDL-c: r = 0.147; VAT: r = -0.221; P < 0.05 for all). Insulin resistance and VAT remained inversely related with FGL elevation beyond that explained by weight loss (residual regression analyses; P < 0.05). CONCLUSION: Diet-induced FGL elevation may reflect insulin sensitivity recovery and VAT regression beyond weight loss, specifically among men. Green-MED diet is associated with greater FGL elevation.
Asunto(s)
Dislipidemias/dietoterapia , Ghrelina/sangre , Síndrome Metabólico/dietoterapia , Obesidad Abdominal/dietoterapia , Pérdida de Peso , Adiposidad , Adulto , Dieta Mediterránea , Dislipidemias/sangre , Dislipidemias/metabolismo , Ayuno , Femenino , Ghrelina/metabolismo , Humanos , Grasa Intraabdominal/diagnóstico por imagen , Grasa Intraabdominal/metabolismo , Imagen por Resonancia Magnética , Masculino , Síndrome Metabólico/sangre , Síndrome Metabólico/metabolismo , Persona de Mediana Edad , Obesidad Abdominal/sangre , Obesidad Abdominal/diagnóstico , Obesidad Abdominal/metabolismo , Factores Sexuales , Resultado del TratamientoRESUMEN
Patients with life-threatening arrhythmias are often treated with cardiac implantable electronic devices (CIEDs), such as pacemakers and implantable cardioverter defibrillators (ICDs). Recent advancements in CIEDs have enabled advanced functionality and connectivity that make such devices (particularly ICDs) vulnerable to cyber-attacks. One of the most dangerous attacks on CIED ecosystems is a data manipulation attack from a compromised programmer device that sends malicious clinical programmings to the CIED. Such attacks can affect the CIED functioning and impact patient's survival and quality of life. In this paper, we propose Cardio-ML - an automated system for the detection of malicious clinical programmings that is based on machine learning algorithms and a novel missing values resemblance framework. Our system is designed to detect new variants of existing attacks and, more importantly, new unknown (zero-day) attacks, aimed at ICDs. We collected 1651 legitimate clinical programmings from 514 patients, over a four-year period, from programmer devices at two medical centers. Our collection also includes 28 core malicious functionalities created by cardiac electrophysiology experts that were later used to create different variants of malicious programmings. Cardio-ML was evaluated extensively in three comprehensive experiments and showed high detection capabilities in most attack scenarios. We achieved perfect classification results for detecting newly created variants of existing core malicious functionalities, with an AUC of 100%; for completely new unknown (zero-day) malicious clinical programmings, an AUC of 80% was obtained, which is 14% better than the state-of-the-art method. We were able to further improve our detection results by identifying the best combination of legitimate and zero-day malicious programmings in the dataset, achieving an AUC of 87%. CIED clinical programmings have many parameters without values for a large number of samples (programmings). To cope with the extreme amount of missing values in our dataset, we developed a novel missing values-based resemblance framework and evaluated it using three dataset-creation approaches: a standard expert-driven approach, our novel data-driven approach, and a combined approach incorporating both approaches. The results showed that our novel framework handles missing values in the data better than the expert-driven approach which yields an empty dataset. In particular, the combined approach showed a 40% improvement in data utilization compared to the data-driven approach.
Asunto(s)
Desfibriladores Implantables , Calidad de Vida , Ecosistema , Electrónica , Humanos , Aprendizaje AutomáticoRESUMEN
BACKGROUND: Non-Vitamin K antagonist oral anticoagulants (NOACs) emerged as an alternative with comparable or superior efficacy and safety to vitamin K antagonists (VKAs) for stroke prevention in patients with non-valvular atrial fibrillation (AF). OBJECTIVES: The aim of the current study was to investigate the patterns, predictors, timelines and temporal trends of shifting from VKAs to NOACs. METHODS: In this retrospective observational study, the computerized database of a large healthcare provider in Israel, Maccabi Healthcare Services, was searched to identify patients with AF for whom either a VKA or NOAC was prescribed between 2012 and 2015. Time from diagnosis to therapy initiation and to shifting between therapies was evaluated. RESULTS: Out of 6987 eligible AF incident patients, 2338 (33.4%) initiated treatment with a VKA and 2221 (31.7%) with a NOAC. In addition, 5259 prevalent patients were analyzed. During the study period, NOAC prescriptions proportion among the newly diagnosed cases increased from 32 to 68.4% (p for trend < 0.001). The median time from diagnosis to first dispensing was greater in NOAC than VKA and decreased among patients treated with NOAC during the study period (2012: 1.9 and 0.3 months, 2015: 0.7 and 0.2 months, respectively). During follow-up, 3737 (49%) patients (54.3% and 47.1% of the incident and prevalent cases, respectively), shifted from a VKA to a NOAC, after a median of 22 months and 39 months in the incident and prevalent cases, respectively, decreasing throughout the study period. Female gender, younger age, southern district, higher CHADS2 and CHA2DS2-VASC score, non-smoking, and treatment with antiplatelets were associated with a greater likelihood for therapy shift. Shifting from a NOAC to a VKA decreased over time from 8 to 4.5% in 2012 to 0.5% and 0.7% in 2015 in the incident and prevalent groups, p < 0.001 respectively. CONCLUSIONS: Shifting from VKA to NOAC occurred in 50% of the cases, more frequently among incident cases, and younger patients with greater stroke risk. Shifting from a NOAC to a VKA was much less frequent, yet it occurred more often in incident cases and decreased over time. A socially and economically sensitive program to optimize the initiation of OAC therapy upon diagnosis is warranted.
Asunto(s)
Anticoagulantes/administración & dosificación , Fibrilación Atrial/tratamiento farmacológico , Sustitución de Medicamentos/tendencias , Pautas de la Práctica en Medicina/tendencias , Accidente Cerebrovascular/prevención & control , Vitamina K/antagonistas & inhibidores , Administración Oral , Factores de Edad , Anciano , Anciano de 80 o más Años , Anticoagulantes/efectos adversos , Fibrilación Atrial/diagnóstico , Fibrilación Atrial/epidemiología , Toma de Decisiones Clínicas , Bases de Datos Factuales , Utilización de Medicamentos/tendencias , Femenino , Humanos , Incidencia , Israel/epidemiología , Masculino , Persona de Mediana Edad , Prevalencia , Estudios Retrospectivos , Medición de Riesgo , Factores de Riesgo , Accidente Cerebrovascular/diagnóstico , Accidente Cerebrovascular/epidemiología , Factores de Tiempo , Resultado del TratamientoRESUMEN
INTRODUCTION: Atrial fibrillation (AF) is a major increasing public health problem worldwide, with clinical and epidemiological differences between men and women. However, contemporary population-level data on incidence and survival are scarce. AIM: To evaluate sex-specific contemporary trends in the incidence, prevalence, and long-term survival of non-valvular AF in a real-world setting. METHODS: AF patients diagnosed between 2007-2015, insured by a large, state-mandated health organization in Israel (Maccabi Healthcare Services) were included. AF was diagnosed based on registered diagnoses. Patients with valvular disease, active malignancy, cardiac surgery ≤ 6 months, or recent pregnancy, were excluded. Annual incidence rate, period prevalence, and 5-year survival for each calendar year during the study period, were calculated. RESULTS: A total of 15,409 eligible patients (8,288 males, 7,121 females) were identified. Males were more likely to be younger, have higher rates of underlying diseases (ischemic heart disease, heart failure, and chronic obstructive pulmonary disease), but with lower rates of hypertension and chronic kidney diseases as compared to female patients. During the study period, age-adjusted incidence decreased both in men: (-0.020/1,000-person year, p-for trend = 0.033) and, women (-0.025/1,000 person-year p = 0.009). The five-year survival rate was significantly higher among men vs. women (77.1% vs. 71.5%, respectively, p<0.001). Age-adjusted prevalence increased significantly among men (+0.102 per year, p-for trend<0.001) yet decreased among women (-0.082 per year, p-for trend = 0.005). A significant trend toward improved long-term survival was observed in women and not in men. CONCLUSIONS: The current study shows significant sex-related disparities in the incidence, prevalence, and survival of AF patients between 2007-2015; while the adjusted incidence of both has decreased over-time, prevalence and mortality decreased significantly only in women.
Asunto(s)
Fibrilación Atrial/diagnóstico , Anciano , Anciano de 80 o más Años , Fibrilación Atrial/epidemiología , Fibrilación Atrial/mortalidad , Comorbilidad , Femenino , Humanos , Israel/epidemiología , Masculino , Persona de Mediana Edad , Prevalencia , Factores Sexuales , Tasa de SupervivenciaRESUMEN
BACKGROUND: A Mediterranean diet is favourable for cardiometabolic risk. OBJECTIVE: To examine the residual effect of a green Mediterranean diet, further enriched with green plant-based foods and lower meat intake, on cardiometabolic risk. METHODS: For the DIRECT-PLUS parallel, randomised clinical trial we assigned individuals with abdominal obesity/dyslipidaemia 1:1:1 into three diet groups: healthy dietary guidance (HDG), Mediterranean and green Mediterranean diet, all combined with physical activity. The Mediterranean diets were equally energy restricted and included 28 g/day walnuts. The green Mediterranean diet further included green tea (3-4 cups/day) and a Wolffia globosa (Mankai strain; 100 g/day frozen cubes) plant-based protein shake, which partially substituted animal protein. We examined the effect of the 6-month dietary induction weight loss phase on cardiometabolic state. RESULTS: Participants (n=294; age 51 years; body mass index 31.3 kg/m2; waist circumference 109.7 cm; 88% men; 10 year Framingham risk score 4.7%) had a 6-month retention rate of 98.3%. Both Mediterranean diets achieved similar weight loss ((green Mediterranean -6.2 kg; Mediterranean -5.4 kg) vs the HDG group -1.5 kg; p<0.001), but the green Mediterranean group had a greater reduction in waist circumference (-8.6 cm) than the Mediterranean (-6.8 cm; p=0.033) and HDG (-4.3 cm; p<0.001) groups. Stratification by gender showed that these differences were significant only among men. Within 6 months the green Mediterranean group achieved greater decrease in low-density lipoprotein cholesterol (LDL-C; green Mediterranean -6.1 mg/dL (-3.7%), -2.3 (-0.8%), HDG -0.2 mg/dL (+1.8%); p=0.012 between extreme groups), diastolic blood pressure (green Mediterranean -7.2 mm Hg, Mediterranean -5.2 mm Hg, HDG -3.4 mm Hg; p=0.005 between extreme groups), and homeostatic model assessment for insulin resistance (green Mediterranean -0.77, Mediterranean -0.46, HDG -0.27; p=0.020 between extreme groups). The LDL-C/high-density lipoprotein cholesterol (HDL-C) ratio decline was greater in the green Mediterranean group (-0.38) than in the Mediterranean (-0.21; p=0.021) and HDG (-0.14; p<0.001) groups. High-sensitivity C-reactive protein reduction was greater in the green Mediterranean group (-0.52 mg/L) than in the Mediterranean (-0.24 mg/L; p=0.023) and HDG (-0.15 mg/L; p=0.044) groups. The green Mediterranean group achieved a better improvement (-3.7% absolute risk reduction) in the 10-year Framingham Risk Score (Mediterranean-2.3%; p=0.073, HDG-1.4%; p<0.001). CONCLUSIONS: The green MED diet, supplemented with walnuts, green tea and Mankai and lower in meat/poultry, may amplify the beneficial cardiometabolic effects of Mediterranean diet. TRIAL REGISTRATION NUMBER: This study is registered under ClinicalTrials.gov Identifier no NCT03020186.
RESUMEN
AIMS: Many tachy-brady syndrome (TBS) patients, are implanted a permanent pacemaker (PPM) to allow continuation of anti-arrhythmic drug (AAD) therapy to maintain sinus rhythm. Many of these PPM's are implanted as a preventive measure, in absence of symptomatic bradycardia. Our primary aim was to evaluate pacing use among these patients and find predictors for PPM use. Our secondary aim was to appreciate the portion of these patients who progress to permanent atrial fibrillation (AF). METHODS: Retrospective study of TBS patients implanted a PPM as preventive measure, dividing cases into defined categories regarding highest percent atrial and ventricular pacing documented in PPM clinic visits during 3 year follow-up (F/U) period. Patients' baseline characteristics and AAD therapy were compared between cases with a major (>90%) pacing use and cases with <90% pacing use to find predictors for pacing use. Multivariable logistic regression was applied to identify independent variables associated with major pacing use. RESULTS: Our study included 119 TBS patients. Most (86.5%) TBS patients had a moderate (>50%) pacing use and 58% had a major pacing use. Significant association was found between pre-implant severe sinus bradycardia (<40 bpm), first degree atrioventricular block and amiodarone treatment to major pacing use on univariate analysis and severe sinus bradycardia was significantly associated with major pacing on multivariate analysis as well. Only minority (16.8%) of TBS patients progressed to permanent AF during the study F/U period. CONCLUSION: Our study reveals most TBS patients succeed to maintain sinus rhythm using an AAD with a significant pacing use, suggesting preventive PPM implantation might be advantageous in these cases. Pre-implant severe sinus bradycardia (<40 bpm) is a possible predictor for major pacing use in this population.
Asunto(s)
Fibrilación Atrial/terapia , Bradicardia/terapia , Estimulación Cardíaca Artificial/estadística & datos numéricos , Síndrome del Seno Enfermo/terapia , Anciano , Antiarrítmicos/uso terapéutico , Fibrilación Atrial/tratamiento farmacológico , Fibrilación Atrial/etiología , Bradicardia/tratamiento farmacológico , Bradicardia/etiología , Femenino , Atrios Cardíacos/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Síndrome del Seno Enfermo/complicaciones , Síndrome del Seno Enfermo/tratamiento farmacológicoRESUMEN
BACKGROUND: Paroxysmal atrial fibrillation (AF) can be caused by gain-of-function mutations in genes, encoding the cardiac potassium channel subunits KCNJ2, KCNE1, and KCNH2 that mediate the repolarizing potassium currents Ik1, Iks, and Ikr, respectively. METHODS: Linkage analysis, whole-exome sequencing, and Xenopus oocyte electrophysiology studies were used in this study. RESULTS: Through genetic studies, we showed that autosomal dominant early-onset nocturnal paroxysmal AF is caused by p.S447R mutation in KCND2, encoding the pore-forming (α) subunit of the Kv4.2 cardiac potassium channel. Kv4.2, along with Kv4.3, contributes to the cardiac fast transient outward K+ current, Ito. Ito underlies the early phase of repolarization in the cardiac action potential, thereby setting the initial potential of the plateau phase and governing its duration and amplitude. In Xenopus oocytes, the mutation increased the channel's inactivation time constant and affected its regulation: p.S447 resides in a protein kinase C (PKC) phosphorylation site, which normally allows attenuation of Kv4.2 membrane expression. The mutant Kv4.2 exhibited impaired response to PKC; hence, Kv4.2 membrane expression was augmented, enhancing potassium currents. Coexpression of mutant and wild-type channels (recapitulating heterozygosity in affected individuals) showed results similar to the mutant channel alone. Finally, in a hybrid channel composed of Kv4.3 and Kv4.2, simulating the mature endogenous heterotetrameric channel underlying Ito, the p.S447R Kv4.2 mutation exerted a gain-of-function effect on Kv4.3. CONCLUSIONS: The mutation alters Kv4.2's kinetic properties, impairs its inhibitory regulation, and exerts gain-of-function effect on both Kv4.2 homotetramers and Kv4.2-Kv4.3 heterotetramers. These effects presumably increase the repolarizing potassium current Ito, thereby abbreviating action potential duration, creating arrhythmogenic substrate for nocturnal AF. Interestingly, Kv4.2 expression was previously shown to demonstrate circadian variation, with peak expression at daytime in murine hearts (human nighttime), with possible relevance to the nocturnal onset of paroxysmal AF symptoms in our patients. The atrial-specific phenotype suggests that targeting Kv4.2 might be effective in the treatment of nocturnal paroxysmal AF, avoiding adverse ventricular effects.
Asunto(s)
Potenciales de Acción/genética , Fibrilación Atrial , Mutación , Canales de Potasio Shal , Animales , Fibrilación Atrial/genética , Fibrilación Atrial/metabolismo , Fibrilación Atrial/patología , Fibrilación Atrial/fisiopatología , Femenino , Humanos , Masculino , Ratones , Persona de Mediana Edad , Canales de Potasio Shal/genética , Canales de Potasio Shal/metabolismoRESUMEN
BACKGROUND: Multiform fascicular tachycardia (FT) was recently described as a ventricular tachycardia (VT) that has a reentrant mechanism using multiple fascicular branches and produces alternate fascicular VT forms. Ablating the respective fascicle may cause a change in the reentrant circuit resulting in a change in morphology. Ablation of the septal fascicle is crucial for successful treatment. OBJECTIVES: To describe four cases of FT in which ablation induced a change in QRS morphologies and aggravated clinical course. METHODS: Four out of 57 consecutive FT cases at three institutions were retrospectively analyzed and found to involve multiform FT. These cases underwent electrophysiological study, fascicular potential mapping, and electroanatomical mapping. All patients initially had FT with right bundle branch block (RBBB) and superior axis morphology. RESULTS: Radiofrequency catheter ablation (RFCA) targeting the distal left posterior fascicle (LPF) resulted in a second VT with an RBBB-inferior axis morphology that sometimes became faster and/or incessant and/or verapamil-refractory in characteristics. RFCA in the upper septum abolished the second VT with no complications and uneventful long-term follow-up. CONCLUSIONS: The change in FT morphology during ablation may be associated with a change in clinical course when shifting from one route to another and may aggravate symptoms. Targeting of the proximal conduction system (such as bifurcation, LPF, left anterior fascicle, high septal/auxiliary pathway) may serve to solve this problem.
Asunto(s)
Fascículo Atrioventricular , Bloqueo de Rama , Ablación por Catéter/métodos , Técnicas Electrofisiológicas Cardíacas/métodos , Taquicardia Ventricular , Adulto , Fascículo Atrioventricular/fisiopatología , Fascículo Atrioventricular/cirugía , Bloqueo de Rama/diagnóstico , Bloqueo de Rama/fisiopatología , Bloqueo de Rama/cirugía , Electrocardiografía/métodos , Ventrículos Cardíacos/diagnóstico por imagen , Ventrículos Cardíacos/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Taquicardia Ventricular/diagnóstico , Taquicardia Ventricular/etiología , Taquicardia Ventricular/fisiopatología , Taquicardia Ventricular/prevención & control , Tiempo , Resultado del TratamientoRESUMEN
PURPOSE: Multisite cardiac resynchronization therapy (MSCRT) with dual-vein left ventricular (LV) pacing has theoretical advantages over conventional CRT in faster and more physiological LV activation. We aimed to define indications, feasibility, safety, acute, and long-term results of MSCRT. METHODS: All patients implanted with MSCRT during 2008-2014 in a single center were reviewed and analyzed. RESULTS: Thirty-nine patients (90% CRT-defibrillators, 64 ± 9 years, 85% male, 74% ischemic etiology) were included. Four groups of indications were recognized: (1) significant tricuspid regurgitation (TR) in patients planned for device implantation without right ventricular lead (n = 3). Follow-up (f/u) of 4 ± 3 years showed major symptomatic improvement in all, with stable LV size and function and deferral of valve surgery; (2) severe heart failure with reduced ejection fraction (HFrEF) and refractory ventricular tachycardia (VT) (n = 4). Except for 1 early death for acute renal failure, all others showed no VT episodes and HF improvement (f/u 4.5 ± 0.5 years); (3) severe HFrEF and wide QRS (≥ 150 ms) or failure of biventricular pacing to narrow QRS during implantation (n = 5). One patient had periprocedural mortality. The others had major clinical improvement; (4) severe HF and narrow QRS/RBBB (n = 27). 23/24 patients with available f/u of 3 ± 1.7 years improved clinically and 57% had EF improvement. In 3 patients, LV1 was disabled and one had LV2 dislodgement. CONCLUSIONS: MSCRT is feasible, safe, and valuable in selected patients with a need to avoid RV lead during device implantation, refractory VT with no other solution, severe HFrEF with wide QRS or CRT non-responsiveness, and severe HF without LBBB. Randomized controlled studies are required.
Asunto(s)
Terapia de Resincronización Cardíaca/métodos , Ecocardiografía Transesofágica/métodos , Insuficiencia Cardíaca/diagnóstico por imagen , Insuficiencia Cardíaca/terapia , Sistema de Registros , Anciano , Estimulación Cardíaca Artificial/métodos , Estimulación Cardíaca Artificial/mortalidad , Terapia de Resincronización Cardíaca/mortalidad , Estudios de Factibilidad , Femenino , Estudios de Seguimiento , Insuficiencia Cardíaca/mortalidad , Humanos , Masculino , Persona de Mediana Edad , Marcapaso Artificial , Selección de Paciente , Recuperación de la Función , Recurrencia , Estudios Retrospectivos , Medición de Riesgo , Tasa de Supervivencia , Resultado del TratamientoRESUMEN
Organophosphates (OP) are used extensively as pesticides and as chemical weapons. Cardiotoxicity is a major concern in survivors of the acute poisoning. To characterize the delayed cardiac effects of OP, rats were poisoned by intraperitoneal administration of dichlorvos. In group I, poisoning (0.25-, 0.75-, 1.4-LD50) was followed by application of atropine and obidoxime. In group II, poisoning (0.35-, 0.5-LD50) was done without antidotes. Cardiac evaluation included electrocardiography and echocardiography 2- and 6-week post-exposure, arrhythmia susceptibility following administration of Isoproterenol (150 mcg/kg), and histological evaluation. All poisoned animals displayed cholinergic symptoms. In group I, all animals exposed to 1.4-LD50 (n = 3) had profound convulsions and died despite antidote treatment. However, in the lower doses, all animals survived and no cardiac abnormalities were noted during follow-up. In group II, six animals had convulsions and died. Surviving animals had mild but significant prolongation of corrected QT at both 2 and 6 weeks, compared to shams. There were no notable echocardiographic, gravimetric, or histological differences between poisoned and sham animals. Our data indicate that dichlorvos poisoning is associated with QT prolongation without anatomical or histopathological abnormalities. This new model can be used to elaborate the molecular mechanism\s of QT prolongation following OP poisoning.
Asunto(s)
Potenciales de Acción , Diclorvos , Sistema de Conducción Cardíaco/fisiopatología , Frecuencia Cardíaca , Síndrome de QT Prolongado/inducido químicamente , Intoxicación por Organofosfatos/etiología , Potenciales de Acción/efectos de los fármacos , Animales , Antídotos/farmacología , Atropina/farmacología , Cardiotoxicidad , Modelos Animales de Enfermedad , Sistema de Conducción Cardíaco/efectos de los fármacos , Frecuencia Cardíaca/efectos de los fármacos , Síndrome de QT Prolongado/tratamiento farmacológico , Síndrome de QT Prolongado/fisiopatología , Masculino , Cloruro de Obidoxima/farmacología , Intoxicación por Organofosfatos/tratamiento farmacológico , Intoxicación por Organofosfatos/fisiopatología , Ratas Sprague-Dawley , Factores de TiempoRESUMEN
OBJECTIVES: Transradial access for percutaneous coronary intervention (PCI) reduces procedural complications however, there are concerns regarding the potential for increased exposure to ionizing radiation to the primary operator. We evaluated the efficacy of a lead-attenuator in reducing radiation exposure during transradial PCI. METHODS AND RESULTS: This was a non-randomized, prospective, observational study in which 52 consecutive patients were assigned to either standard operator protection (n = 26) or the addition of the lead attenuator across their abdomen/pelvis (n = 26). In the attenuator group patients were relatively older with a higher prevalence of peripheral vascular disease (67.9 vs 58.7 p = 0.0292 and 12% vs 7.6% p < 0.001 respectively). Despite similar average fluoroscopy times (12.3 ± 9.8 min vs. 9.3 ± 5.4 min, p = 0.175) and average examination doses (111866 ± 80790 vs. 91,268 ± 47916 Gycm2, p = 0.2688), the total radiation exposure to the operator, at the thyroid level, was significantly lower when the lead-attenuator was utilized (20.2% p < 0.0001) as compared to the control group. Amongst the 26 patients assigned to the lead-attenuator, there was a significant reduction in measured radiation of 94.5% (p < 0.0001), above as compared to underneath the lead attenuator. CONCLUSIONS: Additional protection with the use of a lead rectangle-attenuator significantly lowered radiation exposure to the primary operator, which may confer long-term benefits in reducing radiation-induced injury. ADVANCES IN KNOWLEDGE: This is the first paper to show that a simple lead attenuator almost completely reduced the scattered radiation at very close proximity to the patient and should be considered as part of the standard equipment within catheterization laboratories.
RESUMEN
Traditionally, proteins are considered to perform a single role, be it as an enzyme, a channel, a transporter or as a structural scaffold. However, recent studies have described moonlighting proteins that perform distinct and independent functions; for example, TRPM7 is both an ion channel and a kinase. ZnT-1 is a member of the Carrier Diffusion Facilitator family that is expressed throughout the phylogenetic tree from bacteria to humans. Since its cloning in 1995, ZnT-1 is considered a major extruder of Zn2+ based on its capability to protect cells against zinc toxicity. Recently, we reported that ZnT-1 inhibits the L-type calcium channel (LTCC), a major Zn2+ and Ca2+ entry pathway. Here we show that ZnT-1 is a dual-function protein by demonstrating that its abilities to exchange Zn2+/H+ and to inhibit the LTCC are independent of each other and are mediated by different parts of the protein. Specifically, mutations in the membrane-spanning helices that render ZnT-1 unable to transport zinc do not prevent it from inhibiting the LTCC. Moreover, a fragment consisting of the intracellular ZnT-1 C-terminal, which lacks all ion-transfer segments, inhibits the LTCC as efficiently as wild-type ZnT-1. Our data therefore indicates that ZnT-1 performs two structurally independent functions related to zinc homeostasis.
Asunto(s)
Canales de Calcio Tipo L/química , Proteínas de Transporte de Catión/metabolismo , Xenopus/fisiología , Zinc/farmacología , Secuencia de Aminoácidos , Animales , Células CHO , Canales de Calcio Tipo L/metabolismo , Proteínas de Transporte de Catión/genética , Cricetinae , Cricetulus , Citoplasma/efectos de los fármacos , Citoplasma/metabolismo , Células HEK293 , Homeostasis , Humanos , Transporte Iónico , Proteínas Mutantes/genética , Proteínas Mutantes/metabolismo , Mutación , Oocitos/citología , Oocitos/efectos de los fármacos , Oocitos/metabolismo , Alineación de SecuenciaRESUMEN
AIMS: Cardiac resynchronization therapy (CRT) with a defibrillator (CRT-D) has downsides of high cost and inappropriate shocks compared to CRT without a defibrillator (CRT-P). Recent data suggest that the survival benefit of implantable cardioverter defibrillator (ICD) therapy is attenuated in the older age group. We hypothesized that, among octogenarians eligible for cardiac resynchronization therapy, CRT-P confers similar morbidity and mortality benefits as CRT-D. METHODS AND RESULTS: We compared morbidity and mortality outcomes between consecutive octogenarian patients eligible for CRT therapy who underwent CRT-P implantation at Barzilai MC (n = 142) vs. those implanted with CRT-D for primary prevention indication who were prospectively enrolled in the Israeli ICD Registry (n = 104). Among the 246 study patients, mean age was 84 ± 3 years, 74% were males, and 66% had ischaemic cardiomyopathy. Kaplan-Meier survival analysis showed that at 5 years of follow-up the rate of all-cause mortality was 43% in CRT-P vs. 57% in the CRT-D group [log-rank P = 0.13; adjusted hazard ratio (HR) = 0.79, 95% CI 0.46-1.35, P = 0.37]. Kaplan-Meier analysis also showed no significant difference in the rates of the combined endpoint of heart failure or death (46 vs. 60%, respectively, log-rank P = 0.36; adjusted HR was 0.85, 95% CI 0.51-1.44, P = 0.55). A Cox proportional hazard with competing risk model showed that re-hospitalizations for cardiac cause were not different for the two groups (adjusted HR 1.35, 95% CI 0.7-2.6, P = 0.37). CONCLUSION: Our data suggest that, in octogenarians with systolic heart failure, CRT-P therapy is associated with similar morbidity and mortality outcomes as CRT-D therapy.
Asunto(s)
Dispositivos de Terapia de Resincronización Cardíaca , Terapia de Resincronización Cardíaca/mortalidad , Desfibriladores Implantables , Cardioversión Eléctrica/instrumentación , Cardioversión Eléctrica/mortalidad , Insuficiencia Cardíaca/terapia , Prevención Primaria/instrumentación , Factores de Edad , Anciano de 80 o más Años , Terapia de Resincronización Cardíaca/efectos adversos , Causas de Muerte , Distribución de Chi-Cuadrado , Cardioversión Eléctrica/efectos adversos , Femenino , Insuficiencia Cardíaca/diagnóstico , Insuficiencia Cardíaca/mortalidad , Insuficiencia Cardíaca/fisiopatología , Humanos , Israel , Estimación de Kaplan-Meier , Modelos Logísticos , Masculino , Readmisión del Paciente , Puntaje de Propensión , Modelos de Riesgos Proporcionales , Estudios Prospectivos , Sistema de Registros , Factores de Riesgo , Factores de Tiempo , Resultado del TratamientoRESUMEN
AIMS: Cardiopoietic cells, produced through cardiogenic conditioning of patients' mesenchymal stem cells, have shown preliminary efficacy. The Congestive Heart Failure Cardiopoietic Regenerative Therapy (CHART-1) trial aimed to validate cardiopoiesis-based biotherapy in a larger heart failure cohort. METHODS AND RESULTS: This multinational, randomized, double-blind, sham-controlled study was conducted in 39 hospitals. Patients with symptomatic ischaemic heart failure on guideline-directed therapy (n = 484) were screened; n = 348 underwent bone marrow harvest and mesenchymal stem cell expansion. Those achieving > 24 million mesenchymal stem cells (n = 315) were randomized to cardiopoietic cells delivered endomyocardially with a retention-enhanced catheter (n = 157) or sham procedure (n = 158). Procedures were performed as randomized in 271 patients (n = 120 cardiopoietic cells, n = 151 sham). The primary efficacy endpoint was a Finkelstein-Schoenfeld hierarchical composite (all-cause mortality, worsening heart failure, Minnesota Living with Heart Failure Questionnaire score, 6-min walk distance, left ventricular end-systolic volume, and ejection fraction) at 39 weeks. The primary outcome was neutral (Mann-Whitney estimator 0.54, 95% confidence interval [CI] 0.47-0.61 [value > 0.5 favours cell treatment], P = 0.27). Exploratory analyses suggested a benefit of cell treatment on the primary composite in patients with baseline left ventricular end-diastolic volume 200-370 mL (60% of patients) (Mann-Whitney estimator 0.61, 95% CI 0.52-0.70, P = 0.015). No difference was observed in serious adverse events. One (0.9%) cardiopoietic cell patient and 9 (5.4%) sham patients experienced aborted or sudden cardiac death. CONCLUSION: The primary endpoint was neutral, with safety demonstrated across the cohort. Further evaluation of cardiopoietic cell therapy in patients with elevated end-diastolic volume is warranted.