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1.
Bioengineering (Basel) ; 11(4)2024 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-38671805

RESUMEN

BACKGROUND: Facial recognition systems utilizing deep learning techniques can improve the accuracy of facial recognition technology. However, it remains unclear whether these systems should be available for patient identification in a hospital setting. METHODS: We evaluated a facial recognition system using deep learning and the built-in camera of an iPad to identify patients. We tested the system under different conditions to assess its authentication scores (AS) and determine its efficacy. Our evaluation included 100 patients in four postures: sitting, supine, and lateral positions, with and without masks, and under nighttime sleeping conditions. RESULTS: Our results show that the unmasked certification rate of 99.7% was significantly higher than the masked rate of 90.8% (p < 0.0001). In addition, we found that the authentication rate exceeded 99% even during nighttime sleeping. Furthermore, the facial recognition system was safe and acceptable for patient identification within a hospital environment. Even for patients wearing masks, we achieved a 100% success rate for authentication regardless of illumination if they were sitting with their eyes open. CONCLUSIONS: This is the first systematical study to evaluate facial recognition among hospitalized patients under different situations. The facial recognition system using deep learning for patient identification shows promising results, proving its safety and acceptability, especially in hospital settings where accurate patient identification is crucial.

2.
Int Heart J ; 65(2): 211-217, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38556332

RESUMEN

Duchenne muscular dystrophy (DMD) is an intractable X-linked myopathy caused by dystrophin gene mutations. Patients with DMD suffer from progressive muscle weakness, inevitable cardiomyopathy, increased heart rate (HR), and decreased blood pressure (BP). The aim of this study was to clarify the efficacy and tolerability of ivabradine treatment for DMD cardiomyopathy.A retrospective analysis was performed in 11 patients with DMD, who received ivabradine treatment for more than 1 year. Clinical results were analyzed before (baseline), 6 months after, and 12 months after the ivabradine administration.The initial ivabradine dose was 2.0 ± 1.2 mg/day and the final dose was 5.6 ± 4.0 mg/day. The baseline BP was 95/64 mmHg. A non-significant BP decrease to 90/57 mmHg was observed at 1 month but it recovered to 97/62 mmHg at 12 months after ivabradine administration. The baseline HR was 93 ± 6 bpm and it decreased to 74 ± 12 bpm at 6 months (P = 0.011), and to 77 ± 10 bpm at 12 months (P = 0.008). A linear correlation (y = 2.2x + 5.1) was also observed between the ivabradine dose (x mg/day) and HR decrease (y bpm). The baseline LVEF was 38 ± 12% and it significantly increased to 42 ± 9% at 6 months (P = 0.011) and to 41 ± 11% at 12 months (P = 0.038). Only 1 patient with the lowest BMI of 11.0 kg/m2 and BP of 79/58 mmHg discontinued ivabradine treatment at 6 months, while 1-year administration was well-tolerated in the other 10 patients.Ivabradine decreased HR and increased LVEF without lowering BP, suggesting it can be a treatment option for DMD cardiomyopathy.


Asunto(s)
Cardiomiopatías , Distrofia Muscular de Duchenne , Humanos , Ivabradina/uso terapéutico , Distrofia Muscular de Duchenne/complicaciones , Distrofia Muscular de Duchenne/tratamiento farmacológico , Distrofia Muscular de Duchenne/genética , Estudios Retrospectivos , Cardiomiopatías/complicaciones , Cardiomiopatías/tratamiento farmacológico , Distrofina/genética
3.
Heart Rhythm ; 2024 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-38367891

RESUMEN

BACKGROUND: Variants in the KCNQ1 gene, encoding the α-subunit of the slow component of delayed rectifier K+ channel Kv7.1, cause long QT syndrome (LQTS) type 1. The location of variants may be one of the factors in determining prognosis. However, detailed genotype-phenotype relationships associated with C-terminus variants remain unelucidated. OBJECTIVE: We investigated the clinical characteristics and variant-specific arrhythmic risks in patients with LQTS carrying Kv7.1 C-terminus variants. METHODS: The study comprises 202 consecutive patients with LQTS (98 probands and 104 family members) who carry a rare heterozygous variant in the Kv7.1 C-terminus. Their clinical characteristics and arrhythmic events were investigated. RESULTS: We identified 36 unique C-terminus variants (25 missense and 11 non-missense). The p.R366W variant was identified in 8 families, and p.T587M was identified in 21 families in large numbers from northwestern Japan. As for the location of the variant, we found that the variants in highly conserved regions and nonhelical domains were associated with longer QTc intervals compared with the variants in other regions. Both p.R366W and p.T587M variants are located in the highly conserved and functionally pivotal regions close to helices A and D, which are associated with calmodulin binding and channel assembly (tetramerization), respectively. The probands carrying p.T587M and p.R366W variants had worse arrhythmia outcomes compared with those with other C-terminus variants. The haplotype analysis of p.T587M families was suggestive of a founder effect. CONCLUSION: The arrhythmic risk of C-terminus variants in Kv7.1 in LQTS is not homogeneous, and locations of variants can be a determining factor for prognosis.

5.
PLoS One ; 17(7): e0271796, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35862440

RESUMEN

BACKGROUND: Gain-of-function mutations in CACNA1C encoding Cav1.2 cause syndromic or non-syndromic type-8 long QT syndrome (LQTS) (sLQT8 or nsLQT8). The cytoplasmic domain (D)Ⅰ-Ⅱ linker in Cav1.2 plays a pivotal role in calcium channel inactivation, and mutations in this site have been associated with sLQT8 (such as Timothy syndrome) but not nsLQT8. OBJECTIVE: Since we identified a novel CACNA1C mutation, located in the DⅠ-Ⅱ linker, associated with nsLQTS, we sought to reveal its biophysical defects. METHODS: Target panel sequencing was employed in 24 genotype-negative nsLQTS probands (after Sanger sequencing) and three family members. Wild-type (WT) or R511Q Cav1.2 was transiently expressed in tsA201 cells, then whole-cell Ca2+ or Ba2+ currents (ICa or IBa) were recorded using whole-cell patch-clamp techniques. RESULTS: We identified two CACNA1C mutations, a previously reported R858H mutation and a novel R511Q mutation located in the DⅠ-Ⅱ linker. Four members of one nsLQTS family harbored the CACNA1C R511Q mutation. The current density and steady-state activation were comparable to those of WT-ICa. However, persistent currents in R511Q-ICa were significantly larger than those of WT-ICa (WT at +20 mV: 3.3±0.3%, R511Q: 10.8±0.8%, P<0.01). The steady-state inactivation of R511Q-ICa was weak in comparison to that of WT-ICa at higher prepulse potentials, resulting in increased window currents in R511Q-ICa. Slow component of inactivation of R511Q-ICa was significantly delayed compared to that of WT-ICa (WT-tau at +20 mV: 81.3±3.3 ms, R511Q-tau: 125.1±5.0 ms, P<0.01). Inactivation of R511Q-IBa was still slower than that of WT-IBa, indicating that voltage-dependent inactivation (VDI) of R511Q-ICa was predominantly delayed. CONCLUSIONS: Delayed VDI, increased persistent currents, and increased window currents of R511Q-ICa cause nsLQT8. Our data provide novel insights into the structure-function relationships of Cav1.2 and the pathophysiological roles of the DⅠ-Ⅱ linker in phenotypic manifestations.


Asunto(s)
Canales de Calcio Tipo L , Síndrome de QT Prolongado , Canales de Calcio Tipo L/genética , Humanos , Síndrome de QT Prolongado/genética , Mutación
7.
Circ Arrhythm Electrophysiol ; 15(3): e010572, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-35225649

RESUMEN

BACKGROUND: CaM (calmodulin), encoded by 3 separate genes (CALM1, CALM2, and CALM3), is a multifunctional Ca2+-binding protein involved in many signal transduction events including ion channel regulation. CaM variants may present with early-onset long QT syndrome (LQTS), catecholaminergic polymorphic ventricular tachycardia, or sudden cardiac death. Most reported variants occurred de novo. We identified a novel CALM3 variant, p.Asn138Lys (N138K), in a 4-generation family segregating with LQTS. The aim of this study was to elucidate its pathogenicity and to compare it with that of p.D130G-CaM-a variant associated with a severe LQTS phenotype. METHODS: We performed whole exome sequencing for a large, 4-generation family affected by LQTS. To assess the effect of the detected CALM3 variant, the intrinsic Ca2+-binding affinity was measured by stoichiometric Ca2+ titrations and equilibrium titrations. L-type Ca2+ and slow delayed rectifier potassium currents (ICaL and IKs) were recorded by whole-cell patch-clamp. Cav1.2 and Kv7.1 membrane expression were determined by optical fluorescence assays. RESULTS: We identified 14 p.N138K-CaM carriers in a family where 2 sudden deaths occurred in children. Several members were only mildly affected compared with CaM-LQTS patients to date described in literature. The intrinsic Ca2+-binding affinity of the CaM C-terminal domain was 10-fold lower for p.N138K-CaM compared with wild-type-CaM. ICaL inactivation was slowed in cells expressing p.N138K-CaM but less than in p.D130G-CaM cells. Unexpectedly, a larger IKs current density was observed in cells expressing p.N138K-CaM, but not for p.D130G-CaM, compared with wild-type-CaM. CONCLUSIONS: The p.N138K CALM3 variant impairs Ca2+-binding affinity of CaM and ICaL inactivation but potentiates IKs. The variably expressed phenotype of this variant compared with previously published de novo LQTS-CaM variants is likely explained by a milder impairment of ICaL inactivation combined with IKs augmentation.


Asunto(s)
Calmodulina/genética , Síndrome de QT Prolongado , Taquicardia Ventricular , Calmodulina/metabolismo , Humanos , Síndrome de QT Prolongado/diagnóstico , Síndrome de QT Prolongado/genética , Mutación , Miocitos Cardíacos/metabolismo , Fenotipo , Taquicardia Ventricular/etiología
8.
J Clin Biochem Nutr ; 69(3): 311-316, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34857995

RESUMEN

In clinical practice, edoxaban is sometimes prescribed for off-label use based on the hypothesis that it is as safe and effective as warfarin. However, there is limited safety information on off-label use due to lack of clinical trial. We aimed to analyze the tolerability of off-label use of edoxaban and to identify patient characteristics associated with major bleeding as adverse effects. Patients under edoxaban treatment between January 2017 and December 2017 were enrolled in this retrospective cohort study. The incidence of major bleeding with off-label use compared with on-label use was analyzed using by log-rank test. Univariate and multivariate regression analysis were undertaken to detect independent variables with significant odds ratio that associated with major bleeding. After the exclusion criteria were applied, the patients were divided into two groups: off-label group (n = 30) and on-label group (n = 161). Incidence of major bleeding was found to be higher in the off-label group (13.3%) than in the on-label group (3.7%) (p<0.05). Multivariate adjustment showed that the off-label use or portal vein thrombosis and patients with history of major bleeding has significantly higher incidence of major bleeding. We demonstrated that off-label use of edoxaban may be a significant risk factor for major bleeding.

9.
J Electrocardiol ; 69: 111-118, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34656916

RESUMEN

BACKGROUND: Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an inherited arrhythmogenic syndrome and a cause of exercise-related sudden death. CPVT has been reported to be caused by gain of function underlying a mutation of cardiac ryanodine receptor (RyR2). METHODS: In a family with a CPVT patient, genomic DNA was extracted from peripheral blood lymphocytes, and the RyR2 gene underwent target gene sequence using MiSeq. The activity of wild-type (WT) and mutant RyR2 channel were evaluated by monitoring Ca2+ signals in HEK293 cells expressing WT and mutant RyR2. We investigated a role of a RyR2 mutation in the recent tertiary structure of RyR2. RESULTS: Though a 17-year-old man diagnosed as CPVT had implantable cardioverter defibrillator (ICD) and was going to undergo catheter ablation for the control of paroxysmal atrial fibrillation, he suddenly died at the age of twenty-one because of ventricular fibrillation which was spontaneously developed after maximum inappropriate ICD shocks against rapid atrial fibrillation. The genetic test revealed a de novo RyR2 mutation, Gln4936Lys in mosaicism which was located at the α-helix interface between U-motif and C-terminal domain. In the functional analysis, Ca2+ release from endoplasmic reticulum via the mutant RyR2 significantly increased than that from WT. CONCLUSION: A RyR2 mutation, Gln4936Lys, to be documented in a CPVT patient with exercise-induced ventricular tachycardias causes an excessive Ca2+ release from the sarcoplasmic reticulum which corresponded to clinical phenotypes of CPVT. The reduction of inappropriate shocks of ICD is essential to prevent unexpected sudden death in patients with CPVT.


Asunto(s)
Desfibriladores Implantables , Taquicardia Ventricular , Adolescente , Muerte Súbita Cardíaca/etiología , Electrocardiografía , Células HEK293 , Humanos , Masculino , Mutación , Canal Liberador de Calcio Receptor de Rianodina/genética , Taquicardia Ventricular/genética , Taquicardia Ventricular/terapia
10.
Biol Pharm Bull ; 44(8): 1060-1066, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34334491

RESUMEN

Optimization of medication therapy for the elderly is a matter of rapidly growing importance, which is addressed by pharmacists through comprehensive reviews. In this study, the impact of medication review by pharmacists on medication optimization and avoidance of adverse drug events (ADE) was investigated, as well as differences in the triggers for pharmaceutical intervention to allow for optimization of medication by patient age. Data for this study were collected from reports recorded between April 2013 and March 2019 for patients admitted to the Hiroshima University Hospital. In response to pharmacists' proposals, prescriptions were modified in 18932 cases, comprising 17% of the total 111479 patients during hospitalization. The frequency of such intervention was higher in elderly patients aged ≥65 years than in those <65 years (20 vs. 14%, p < 0.01). The reasons for pharmacists' intervention were primarily (67%) medication history or clinical symptoms in all age groups. Patient complaint was a minor reason in patients aged ≥75 years, accounting for only 2% of all interventions; laboratory results were a more typical reason, accounting for 24% of all interventions. These findings reveal the importance of pharmacists' interventions for optimizing medication and preventing ADEs, particularly in elderly patients. Thus, pharmacists must evaluate the medications and conditions, including laboratory results, in the medical records of elderly patients more carefully than those of younger patients as elderly patients might be unable to communicate about subjective symptoms.


Asunto(s)
Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/prevención & control , Hospitales Universitarios , Revisión de Medicamentos , Servicios Farmacéuticos , Farmacéuticos , Servicio de Farmacia en Hospital , Adolescente , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Atención a la Salud , Hospitalización , Humanos , Lactante , Recién Nacido , Japón , Persona de Mediana Edad , Preparaciones Farmacéuticas , Estudios Retrospectivos , Adulto Joven
11.
Surg Today ; 51(12): 2000-2005, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34232373

RESUMEN

The treatment of a thyroid carcinoma extending into the thoracic cavity with severe airway stenosis is difficult, since there is a risk of acute respiratory decompensation at every stage of anesthesia. Extracorporeal membrane oxygenation (ECMO) is a life support technique for maintaining both the cardiac and respiratory functions. It is used for the management of acute, severe, reversible respiratory or cardiac failure refractory to conventional management. We herein describe the use of ECMO for the anesthetic management of an elderly patient with severe airway stenosis caused by thyroid carcinoma invasion, which underwent total thyroidectomy with the resection of four tracheal rings and end-to-end anastomosis under a median sternotomy. Although the risks and benefits should be carefully weighed before a decision to use ECMO is made, the use of ECMO in the management of general anesthesia may be a rational and effective strategy for maintaining oxygenation.


Asunto(s)
Anestesia General/métodos , Oxigenación por Membrana Extracorpórea , Cáncer Papilar Tiroideo/patología , Cáncer Papilar Tiroideo/cirugía , Neoplasias de la Tiroides/patología , Neoplasias de la Tiroides/cirugía , Estenosis Traqueal/etiología , Estenosis Traqueal/cirugía , Anciano , Femenino , Humanos , Invasividad Neoplásica , Índice de Severidad de la Enfermedad , Cáncer Papilar Tiroideo/complicaciones , Neoplasias de la Tiroides/complicaciones , Resultado del Tratamiento
13.
Genet Med ; 23(1): 47-58, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-32893267

RESUMEN

PURPOSE: Stringent variant interpretation guidelines can lead to high rates of variants of uncertain significance (VUS) for genetically heterogeneous disease like long QT syndrome (LQTS) and Brugada syndrome (BrS). Quantitative and disease-specific customization of American College of Medical Genetics and Genomics/Association for Molecular Pathology (ACMG/AMP) guidelines can address this false negative rate. METHODS: We compared rare variant frequencies from 1847 LQTS (KCNQ1/KCNH2/SCN5A) and 3335 BrS (SCN5A) cases from the International LQTS/BrS Genetics Consortia to population-specific gnomAD data and developed disease-specific criteria for ACMG/AMP evidence classes-rarity (PM2/BS1 rules) and case enrichment of individual (PS4) and domain-specific (PM1) variants. RESULTS: Rare SCN5A variant prevalence differed between European (20.8%) and Japanese (8.9%) BrS patients (p = 5.7 × 10-18) and diagnosis with spontaneous (28.7%) versus induced (15.8%) Brugada type 1 electrocardiogram (ECG) (p = 1.3 × 10-13). Ion channel transmembrane regions and specific N-terminus (KCNH2) and C-terminus (KCNQ1/KCNH2) domains were characterized by high enrichment of case variants and >95% probability of pathogenicity. Applying the customized rules, 17.4% of European BrS and 74.8% of European LQTS cases had (likely) pathogenic variants, compared with estimated diagnostic yields (case excess over gnomAD) of 19.2%/82.1%, reducing VUS prevalence to close to background rare variant frequency. CONCLUSION: Large case-control data sets enable quantitative implementation of ACMG/AMP guidelines and increased sensitivity for inherited arrhythmia genetic testing.


Asunto(s)
Síndrome de Brugada , Síndrome de QT Prolongado , Arritmias Cardíacas/diagnóstico , Arritmias Cardíacas/epidemiología , Arritmias Cardíacas/genética , Síndrome de Brugada/genética , Pruebas Genéticas , Humanos , Síndrome de QT Prolongado/diagnóstico , Síndrome de QT Prolongado/epidemiología , Síndrome de QT Prolongado/genética , Mutación , Regulación de la Población
16.
Artículo en Inglés | MEDLINE | ID: mdl-32936022

RESUMEN

Background - Mutation/variant-site specific risk stratification in long-QT syndrome type 1 (LQT1) has been well investigated, but it is still challenging to adapt current enormous genomic information to clinical aspects caused by each mutation/variant. We assessed a novel variant-specific risk stratification in LQT1 patients. Methods - We classified a pathogenicity of 141 KCNQ1 variants among 927 LQT1 patients (536 probands) based on the American College of Medical Genetics and Genomics (ACMG) and Association for Molecular Pathology (AMP) guidelines and evaluated whether the ACMG/AMP-based classification was associated with arrhythmic risk in LQT1 patients. Results - Among 141 KCNQ1 variants, 61 (43.3%), 55 (39.0%), and 25 (17.7%) variants were classified into pathogenic (P), likely pathogenic (LP), and variant of unknown significance (VUS), respectively. Multivariable analysis showed that proband (HR = 2.53; 95%CI = 1.94-3.32; p <0.0001), longer QTc (≥500ms) (HR = 1.44; 95%CI = 1.13-1.83; p = 0.004), variants at membrane spanning (MS) (vs. those at N/C terminus) (HR = 1.42; 95%CI = 1.08-1.88; p = 0.01), C-loop (vs. N/C terminus) (HR = 1.52; 95%CI = 1.06-2.16; p = 0.02), and P variants [(vs. LP) (HR = 1.72; 95%CI = 1.32-2.26; p <0.0001), (vs. VUS) (HR = 1.81; 95%CI = 1.15-2.99; p = 0.009)] were significantly associated with syncopal events. The ACMG/AMP-based KCNQ1 evaluation was useful for risk stratification not only in family members but also in probands. A clinical score (0~4) based on proband, QTc (≥500ms), variant location (MS or C-loop) and P variant by ACMG/AMP guidelines allowed identification of patients more likely to have arrhythmic events. Conclusions - Comprehensive evaluation of clinical findings and pathogenicity of KCNQ1 variants based on the ACMG/AMP-based evaluation may stratify arrhythmic risk of congenital long-QT syndrome type 1.

17.
J Am Heart Assoc ; 9(17): e015709, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32812471

RESUMEN

Background Myotonic dystrophy type 1 involves cardiac conduction disorders. Cardiac conduction disease can cause fatal arrhythmias or sudden death in patients with myotonic dystrophy type 1. Methods and Results This study enrolled 506 patients with myotonic dystrophy type 1 (aged ≥15 years; >50 cytosine-thymine-guanine repeats) and was treated in 9 Japanese hospitals for neuromuscular diseases from January 2006 to August 2016. We investigated genetic and clinical backgrounds including health care, activities of daily living, dietary intake, cardiac involvement, and respiratory involvement during follow-up. The cause of death or the occurrence of composite cardiac events (ie, ventricular arrhythmias, advanced atrioventricular blocks, and device implantations) were evaluated as significant outcomes. During a median follow-up period of 87 months (Q1-Q3, 37-138 months), 71 patients expired. In the univariate analysis, pacemaker implantations (hazard ratio [HR], 4.35; 95% CI, 1.22-15.50) were associated with sudden death. In contrast, PQ interval ≥240 ms, QRS duration ≥120 ms, nutrition, or respiratory failure were not associated with the incidence of sudden death. The multivariable analysis revealed that a PQ interval ≥240 ms (HR, 2.79; 95% CI, 1.9-7.19, P<0.05) or QRS duration ≥120 ms (HR, 9.41; 95% CI, 2.62-33.77, P < 0.01) were independent factors associated with a higher occurrence of cardiac events than those observed with a PQ interval <240 ms or QRS duration <120 ms; these cardiac conduction parameters were not related to sudden death. Conclusions Cardiac conduction disorders are independent markers associated with cardiac events. Further investigation on the prediction of occurrence of sudden death is warranted.


Asunto(s)
Arritmias Cardíacas/fisiopatología , Trastorno del Sistema de Conducción Cardíaco/complicaciones , Muerte Súbita Cardíaca/prevención & control , Distrofia Miotónica/complicaciones , Marcapaso Artificial/estadística & datos numéricos , Actividades Cotidianas , Adulto , Cuidados Posteriores , Bloqueo Atrioventricular/epidemiología , Bloqueo Atrioventricular/terapia , Muerte Súbita Cardíaca/epidemiología , Ingestión de Alimentos , Femenino , Estado de Salud , Humanos , Incidencia , Japón/epidemiología , Masculino , Persona de Mediana Edad , Distrofia Miotónica/genética , Distrofia Miotónica/mortalidad , Modelos de Riesgos Proporcionales , Estudios Retrospectivos
18.
Eur J Pharmacol ; 883: 173378, 2020 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-32710951

RESUMEN

The slowly and rapidly activating delayed rectifier K+ channels (IKs and IKr, respectively) contribute to the repolarization of ventricular action potential in human heart and thereby determine QT interval on an electrocardiogram. Loss-of-function mutations in genes encoding IKs and IKr cause type 1 and type 2 long QT syndrome (LQT1 and LQT2, respectively), accompanied by a high risk of malignant ventricular arrhythmias and sudden cardiac death. This study was designed to investigate which cardiac electrophysiological conditions exaggerate QT-prolonging and arrhythmogenic effects of sevoflurane. We used the O'Hara-Rudy dynamic model to reconstruct human ventricular action potential and a pseudo-electrocardiogram, and simulated LQT1 and LQT2 phenotypes by decreasing conductances of IKs and IKr, respectively. Sevoflurane, but not propofol, prolonged ventricular action potential duration and QT interval in wild-type, LQT1 and LQT2 models. The QT-prolonging effect of sevoflurane was more profound in LQT2 than in wild-type and LQT1 models. The potent inhibitory effect of sevoflurane on IKs was primarily responsible for its QT-prolonging effect. In LQT2 model, IKs was considerably enhanced during excessive prolongation of ventricular action potential duration by reduction of IKr and relative contribution of IKs to ventricular repolarization was markedly elevated, which appears to underlie more pronounced QT-prolonging effect of sevoflurane in LQT2 model, compared with wild-type and LQT1 models. This simulation study clearly elucidates the electrophysiological basis underlying the difference in QT-prolonging effect of sevoflurane among wild-type, LQT1 and LQT2 models, and may provide important information for developing anesthetic strategies for patients with long QT syndrome in clinical settings.


Asunto(s)
Potenciales de Acción/efectos de los fármacos , Frecuencia Cardíaca/efectos de los fármacos , Ventrículos Cardíacos/efectos de los fármacos , Síndrome de QT Prolongado/inducido químicamente , Modelos Cardiovasculares , Miocitos Cardíacos/efectos de los fármacos , Síndrome de Romano-Ward/inducido químicamente , Sevoflurano/toxicidad , Estudios de Casos y Controles , Simulación por Computador , Canales de Potasio de Tipo Rectificador Tardío/genética , Canales de Potasio de Tipo Rectificador Tardío/metabolismo , Ventrículos Cardíacos/metabolismo , Ventrículos Cardíacos/fisiopatología , Humanos , Síndrome de QT Prolongado/genética , Síndrome de QT Prolongado/metabolismo , Síndrome de QT Prolongado/fisiopatología , Miocitos Cardíacos/metabolismo , Propofol/toxicidad , Medición de Riesgo , Factores de Riesgo , Síndrome de Romano-Ward/genética , Síndrome de Romano-Ward/metabolismo , Síndrome de Romano-Ward/fisiopatología , Factores de Tiempo
19.
J Gen Physiol ; 152(8)2020 08 03.
Artículo en Inglés | MEDLINE | ID: mdl-32421782

RESUMEN

Recent studies using intracellular thermometers have shown that the temperature inside cultured single cells varies heterogeneously on the order of 1°C. However, the reliability of intracellular thermometry has been challenged both experimentally and theoretically because it is, in principle, exceedingly difficult to exclude the effects of nonthermal factors on the thermometers. To accurately measure cellular temperatures from outside of cells, we developed novel thermometry with fluorescent thermometer nanosheets, allowing for noninvasive global temperature mapping of cultured single cells. Various types of cells, i.e., HeLa/HEK293 cells, brown adipocytes, cardiomyocytes, and neurons, were cultured on nanosheets containing the temperature-sensitive fluorescent dye europium (III) thenoyltrifluoroacetonate trihydrate. First, we found that the difference in temperature on the nanosheet between nonexcitable HeLa/HEK293 cells and the culture medium was less than 0.2°C. The expression of mutated type 1 ryanodine receptors (R164C or Y523S) in HEK293 cells that cause Ca2+ leak from the endoplasmic reticulum did not change the cellular temperature greater than 0.1°C. Yet intracellular thermometry detected an increase in temperature of greater than ∼2°C at the endoplasmic reticulum in HeLa cells upon ionomycin-induced intracellular Ca2+ burst; global cellular temperature remained nearly constant within ±0.2°C. When rat neonatal cardiomyocytes or brown adipocytes were stimulated by a mitochondrial uncoupling reagent, the temperature was nearly unchanged within ±0.1°C. In cardiomyocytes, the temperature was stable within ±0.01°C during contractions when electrically stimulated at 2 Hz. Similarly, when rat hippocampal neurons were electrically stimulated at 0.25 Hz, the temperature was stable within ±0.03°C. The present findings with nonexcitable and excitable cells demonstrate that heat produced upon activation in single cells does not uniformly increase cellular temperature on a global basis, but merely forms a local temperature gradient on the order of ∼1°C just proximal to a heat source, such as the endoplasmic/sarcoplasmic reticulum ATPase.


Asunto(s)
Nanotecnología , Análisis de la Célula Individual , Termografía , Termómetros , Adipocitos , Animales , Calcio/metabolismo , Células HEK293 , Células HeLa , Humanos , Miocitos Cardíacos , Neuronas , Ratas , Reproducibilidad de los Resultados , Temperatura
20.
J Am Heart Assoc ; 9(4): e014006, 2020 02 18.
Artículo en Inglés | MEDLINE | ID: mdl-32067592

RESUMEN

Myotonic dystrophy is an inherited systemic disorder affecting skeletal muscle and the heart. Genetic testing for myotonic dystrophy is diagnostic and identifies those at risk for cardiac complications. The 2 major genetic forms of myotonic dystrophy, type 1 and type 2, differ in genetic etiology yet share clinical features. The cardiac management of myotonic dystrophy should include surveillance for arrhythmias and left ventricular dysfunction, both of which occur in progressive manner and contribute to morbidity and mortality. To promote the development of care guidelines for myotonic dystrophy, the Myotonic Foundation solicited the input of care experts and organized the drafting of these recommendations. As a rare disorder, large scale clinical trial data to guide the management of myotonic dystrophy are largely lacking. The following recommendations represent expert consensus opinion from those with experience in the management of myotonic dystrophy, in part supported by literature-based evidence where available.


Asunto(s)
Arritmias Cardíacas/terapia , Cardiólogos/normas , Insuficiencia Cardíaca/terapia , Distrofia Miotónica/terapia , Pautas de la Práctica en Medicina/normas , Disfunción Ventricular Izquierda/terapia , Arritmias Cardíacas/diagnóstico , Arritmias Cardíacas/etiología , Arritmias Cardíacas/mortalidad , Consenso , Factores de Riesgo de Enfermedad Cardiaca , Insuficiencia Cardíaca/diagnóstico , Insuficiencia Cardíaca/etiología , Humanos , Distrofia Miotónica/complicaciones , Distrofia Miotónica/diagnóstico , Distrofia Miotónica/mortalidad , Pronóstico , Medición de Riesgo , Disfunción Ventricular Izquierda/diagnóstico , Disfunción Ventricular Izquierda/etiología , Disfunción Ventricular Izquierda/mortalidad
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