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1.
Arch. cardiol. Méx ; Arch. cardiol. Méx;93(2): 164-171, Apr.-Jun. 2023. tab, graf
Article in English | LILACS-Express | LILACS | ID: biblio-1447247

ABSTRACT

Abstract Background: In 1996 Iturralde et al. published an algorithm based on the QRS polarity to determine the location of the accessory pathways (AP), this algorithm was developed before the massive practice of invasive electrophysiology. Purpose: To validate the QRS-Polarity algorithm in a modern cohort of subjects submitted to radiofrequency catheter ablation (RFCA). Our objective was to determinate its global accuracy and its accuracy for parahisian AP. Methods: We conducted a retrospective analysis of patients with Wolff-Parkinson-White (WPW) syndrome who underwent an electrophysiological study (EPS) and RFCA. We employed the QRS-Polarity algorithm to predict the AP anatomical location and we compared this result with the real anatomic location determined in the EPS. To determine accuracy, the Cohen's kappa coefficient (k) and the Pearson correlation coefficient were used. Results: A total of 364 patients were included (mean age 30 years, 57% male). The global k score was 0.78 and the Pearson's coefficient was 0.90. The accuracy for each zone was also evaluated, the best correlation was for the left lateral AP (k of 0.97). There were 26 patients with a parahisian AP, who showed a great variability in the ECG features. Employing the QRS-Polarity algorithm, 34.6% patients had a correct anatomical location, 42.3% had an adjacent location and only 23% an incorrect location. Conclusion: The QRS-Polarity algorithm has a good global accuracy; its precision is high, especially for left lateral AP. This algorithm is also useful for the parahisian AP.


Resumen Antecedentes: En 1996 Iturralde y colaboradores publicaron un algoritmo basado en la polaridad del QRS para determinar la ubicación de las vías accesorias (VA), este algoritmo fue desarrollado antes de la práctica masiva de la electrofisiología invasiva. Objetivo: Validar el algoritmo de la polaridad del QRS en una cohorte moderna de sujetos sometidos a ablación con catéter por radiofrecuencia (ACRF). Nuestro objetivo fue determinar su precisión global y su precisión para las VA parahisianas. Métodos: Realizamos un análisis retrospectivo de pacientes con síndrome de Wolff-Parkinson-White (WPW) a los que se les realizó estudio electrofisiológico (EEF) y ACRF. Empleamos el algoritmo de la polaridad del QRS para predecir la ubicación anatómica de la VA y comparamos este resultado con la ubicación anatómica real determinada en el EEF. Para determinar la precisión se utilizaron el coeficiente kappa de Cohen (k) y el coeficiente de correlación de Pearson. Resultados: Se incluyeron un total de 364 pacientes (edad media 30 años, 57 % varones). La puntuación k global fue de 0,78 y el coeficiente de Pearson de 0,90. También se evaluó la precisión para cada zona, la mejor correlación fue para las VA laterales izquierdas (k de 0.97). Hubo 26 pacientes con VA parahisianas, que mostraron una gran variabilidad en las características del ECG. Empleando el algoritmo de la polaridad del QRS, el 34,6 % de los pacientes tenía una ubicación anatómica correcta, el 42,3 % tenía una ubicación adyacente y solo el 23 % una ubicación incorrecta. Conclusión: El algoritmo de la polaridad del QRS tiene una buena precisión global; su precisión es alta, especialmente para VA lateral izquierdo. Este algoritmo también es útil para la VA parahisiana.

2.
Rev. invest. clín ; Rev. invest. clín;73(3): 145-153, May.-Jun. 2021. tab, graf
Article in English | LILACS-Express | LILACS | ID: biblio-1280451

ABSTRACT

ABSTRACT Background: Andersen-Tawil syndrome (ATS) is a cardiac channelopathy that is inherited in an autosomal dominant way, and it is characterized by a triad of periodic paralysis, ventricular arrhythmias, and includes some dysmorphic features with incomplete penetrance and variable expression that result in a challenging diagnosis. Objective: The objective of the study was to describe the cardiac and extra-cardiac phenotype in a cohort of patients with ATS at risk of sudden cardiac death (SCD) to improve its early clinical identification. Methods: In an observational, transversal study, with a deviant case sampling, four female patients with ATS at high risk of SCD were included in the study. They carried the heterozygous pathogenic variants c.407C>T [p.Ser136Phe], c.652C>T [p.Arg218Trp] (n=2), and c.431G>C [p.Gly144Ala] in the KCNJ2 gene. Patients were evaluated by a cardiologist, a clinical geneticist, and a physiatrist. Results: One patient had the classical facial phenotype and the other three had subtle manifestations. The group of patients presented a diverse set of clinical data such as: triangular face, broad forehead, broadening of medial eyebrows, auricular pits, low-set ears, eyelid ptosis, thin lips, mandibular hypoplasia, and diverse types of dental alterations, single transverse palmar crease, camptodactyly, and syndactyly. Long-exercise test showed a decrement in the percentage amplitude up to 44%, classifying patients in IV or V types according to Fournier’s scale. Conclusions: Extra-cardiac manifestations were a common finding in this series of ATS type1 at high risk of SCD. Its recognition could help the clinician in the early identification of patients with ATS, especially for the cardiologist since they are commonly referred only for evaluation of ventricular arrhythmias.

3.
Medicina (B.Aires) ; Medicina (B.Aires);80(3): 271-274, jun. 2020. tab
Article in Spanish | LILACS | ID: biblio-1125078

ABSTRACT

Ante la pandemia de COVID-19 (del inglés coronavirus disease 2019), uno de los fármacos propuesto para su tratamiento es la hidroxicloroquina. Se revisan aquí aspectos cardiológicos del uso de cloroquina e hidroxicloroquina. Se realizó una revisión no sistemática en la literatura médica orientada a la búsqueda de información acerca de su seguridad y eficacia como antimaláricos y antivirales, así como en el tratamiento prolongado de enfermedades reumatológicas. Se halló un efecto antiinflamatorio con reducción de eventos cardiovasculares a largo plazo, una cardiopatía muy infrecuente por un efecto lisosomal del fármaco, y a nivel hemodinámico hipotensión, taquicardia, y prolongación del intervalo QT, exacerbado si se combina con azitromicina. Sin embargo, la tasa de eventos adversos cardíacos de la hidroxicloroquina y la cloroquina fue baja.


Due to the coronavirus disease 2019 (COVID-19) pandemic, a wide number of compounds are under scrutiny regarding their antiviral activity, one of them being hydroxychloroquine. Cardiac aspects of the use of chloroquine and hydroxychloroquine are reviewed in this manuscript. A non-systematic review of the medical literature was performed. Information about their safety and efficacy as antimalarials, antivirals, as well as in the long-term treatment of rheumatic diseases was collected. We found an anti-inflammatory effect with reduction of long-term cardiovascular events, a very infrequent heart disease due to a lysosomal effect of the drug, and at the hemodynamic level hypotension, tachycardia, and QT interval prolongation, exacerbated when combined with azithromycin. However, the rate of adverse cardiac events of hydroxychloroquine (and chloroquine) was low.


Subject(s)
Humans , Antiviral Agents/adverse effects , Pneumonia, Viral/drug therapy , Cardiovascular Diseases/chemically induced , Chloroquine/adverse effects , Coronavirus Infections/drug therapy , Betacoronavirus , Hydroxychloroquine/adverse effects , Risk Factors , Antirheumatic Agents/adverse effects , Pandemics , SARS-CoV-2 , COVID-19 , Heart/drug effects , Hemodynamics/drug effects , Anti-Inflammatory Agents/adverse effects
5.
Arch. cardiol. Méx ; Arch. cardiol. Méx;90(1): 69-76, Jan.-Mar. 2020. tab
Article in English | LILACS | ID: biblio-1131008

ABSTRACT

Abstract Atrial fibrillation (AF) is a frequent arrhythmia; its prevalence is near 2% in the general population; in Mexico, more than one-half million people are affected. AF needs to be considered as a public health problem. Because AF is an independent risk factor associated with mortality, due to embolic events, heart failure, or sudden death; early diagnosis is of utmost importance. In unstable patients with a recent onset of AF, electrical cardioversion should be practiced. In stable patients, once thromboembolic measures have been taken, it is necessary to assess whether it is reasonable to administer an antiarrhythmic drug to restore sinus rhythm or performed electrical cardioversion. For recidivating cases of paroxysmal and persistent presentation, the most effective strategy is performed pulmonary vein isolation with either radiofrequency or cryoballoon energy. Permanent AF is that in which recovery of sinus rhythm is not possible, the distinguishing feature of this phase is the uncontrollable variability of the ventricular frequency and could be treated pharmacologically with atrioventricular (AV) nodal blockers or with a VVIR pacemaker plus AV nodal ablation. The presence of AF has long been associated with the development of cerebral and systemic (pulmonary, limb, coronary, renal, and visceral) embolism. The prevention of embolisms in “valvular” AF should perform with Vitamin K antagonists (VKA). For patients with AF not associated with mitral stenosis or a mechanical valve prosthesis, a choice can be made between anticoagulant drugs, VKA, or direct oral anticoagulants. Antiplatelet agents have the weakest effect in preventing embolism.


Resumen La fibrilación auricular (FA) es una arritmia frecuente; su prevalencia es cercana al 2% en la población general, en México se ven afectados más de medio millón de personas por eso debe considerarse como un problema de salud pública. Debido a que la FA es un factor de riesgo independiente asociado a mortalidad, por eventos embólicos, insuficiencia cardíaca o muerte súbita, la identificación y diagnóstico temprano es de suma importancia. En el inicio reciente de FA en pacientes inestables, se debe practicar la cardioversión eléctrica. En pacientes estables, una vez que se han tomado medidas tromboembólicas, es necesario evaluar si es razonable administrar un medicamento antiarrítmico para restaurar el ritmo sinusal o realizar una cardioversión eléctrica. Para los casos que recidivan, ya sea paroxística o persistente, la estrategia más efectiva es realizar el aislamiento de la venas pulmonares con radiofrecuencia o crioablación con balón. La FA permanente es aquella en la que no es posible la recuperación del ritmo sinusal, la característica distintiva de esta fase de la FA es la variabilidad incontrolable de la frecuencia ventricular. Puede tratarse farmacológicamente con bloqueadores nodales AV o con un marcapasos VVIR mas ablación del nodo AV. La presencia de FA se ha asociado durante mucho tiempo con el desarrollo de embolia cerebral y sistémica (pulmonar, de extremidades, coronaria, renal y visceral). La prevención de embolias en la FA “valvular” debe realizarse con antagonistas de la vitamina K (AVK). Para los pacientes con FA no asociados con estenosis mitral o una prótesis valvular mecánica, se puede elegir entre medicamentos anticoagulantes, AVK o anticoagulantes orales directos (DOAC). Los agentes antiplaquetarios tienen el efecto más débil para prevenir la embolia.


Subject(s)
Humans , Atrial Fibrillation/therapy , Thromboembolism/prevention & control , Anticoagulants/administration & dosage , Atrial Fibrillation/complications , Atrial Fibrillation/epidemiology , Thromboembolism/etiology , Electric Countershock/methods , Risk Factors , Cryosurgery/methods , Fibrinolytic Agents/administration & dosage , Radiofrequency Ablation/methods , Mexico/epidemiology , Anti-Arrhythmia Agents/administration & dosage
6.
Rev. invest. clín ; Rev. invest. clín;71(4): 226-236, Jul.-Aug. 2019. tab, graf
Article in English | LILACS | ID: biblio-1289691

ABSTRACT

Abstract Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a potentially lethal disease, whose characteristic ventricular tachycardias are adrenergic-dependent. Although rare, CPVT should be considered in the differential diagnosis of young individuals with exercise-induced syncope. Mutations in five different genes (RYR2, CASQ2, CALM1, TRDN, and TECRL) are associated with the CPVT phenotype, although RYR2 missense mutations are implicated in up to 60 % of all CPVT cases. Genetic testing has an essential role in the diagnosis, management, pre-symptomatic diagnosis, counseling, and treatment of the proband; furthermore, genetic information can be useful for offspring and relatives. By expert consensus, CPVT gene testing is a Class I recommendation for patients with suspected CPVT. Beta-adrenergic and calcium-channel blockers are the cornerstones of treatment due to the catecholaminergic dependence of the arrhythmias. Unresponsive patients are treated with an implantable cardioverter-defibrillator to reduce the risk of sudden cardiac death. In the present article, a brief review of the genetic and molecular mechanisms of this intriguing disease is provided.


Subject(s)
Humans , Death, Sudden, Cardiac/prevention & control , Tachycardia, Ventricular/diagnosis , Defibrillators, Implantable , Syncope/diagnosis , Genetic Testing , Tachycardia, Ventricular/genetics , Tachycardia, Ventricular/therapy , Diagnosis, Differential , Mutation
7.
Rev. invest. clín ; Rev. invest. clín;71(2): 124-132, Mar.-Apr. 2019. tab
Article in English | LILACS | ID: biblio-1289678

ABSTRACT

Abstract Background Vasovagal syncope (VVS) is a frequent clinical condition in which a genetic background seems to be implicated. Considering that the adrenergic receptors (ARs) may play a role in VVS, the present study has as principal aim to determine if the α- and β-AR (ADRA and ADRB) gene polymorphisms are associated with an increased risk to have a positive head-up tilt table (HUTT) test in patients with VVS. Methods: Nine polymorphisms in the ADRA1A (rs1048101, rs1383914, rs574584, and rs573542), ADRB1 (rs1801252 and rs1801253), ADRB2 (rs1042713 and rs1042714), and ADRB3 (rs4994) genes were analyzed using the 5’ exonuclease TaqMan genotyping assay in a group of 134 patients with VVS. Results Under different models, the rs1801252 (OR = 8.63, 95% CI: 0.95-78.72, Precessive = 0.02), rs1042713 (OR = 1.94, 95% CI: 1.02-3.66, Padditive = 0.04), and rs4994 (OR = 2.46, 95% CI: 1.01-6.01, Pdominant = 0.042 and OR = 2.62, 95% CI: 1.04-6.63, Pover-dominant = 0.03) polymorphisms were associated with increased risk for a positive HUTT. All models were adjusted for statistically significant covariates. Conclusion These results suggest that some polymorphisms of the β-AR genes could contribute to a positive tilt test in patients with VVS.


Subject(s)
Humans , Male , Female , Adult , Young Adult , Receptors, Adrenergic, beta/genetics , Tilt-Table Test , Syncope, Vasovagal/diagnosis , Polymorphism, Genetic , Syncope, Vasovagal/genetics , Genotype
10.
Arch. cardiol. Méx ; Arch. cardiol. Méx;87(1): 5-12, ene.-mar. 2017. tab
Article in Spanish | LILACS | ID: biblio-887488

ABSTRACT

Resumen: Objetivo: La fibrilación auricular (FA) es una de las arritmias más comunes, y su prevalencia aumenta con la edad. Se asocia con alto riesgo de embolia cerebral. La prevención de dichas tromboembolias se realiza mediante anticoagulantes orales, que en nuestro país parecen estar subutilizados. El Registro CARMEN-AF tiene como objetivo primario determinar cuál es el estado actual de la tromboprofilaxis de la FA no valvular en México. Como objetivo secundario pretende conocer la morbimortalidad asociada a la FA no valvular en por lo menos un año de seguimiento. Métodos: El Registro CARMEN-AF es un estudio observacional, longitudinal, multicéntrico y nacional sobre el empleo de los anticoagulantes orales en pacientes con FA no-valvular que pretende la inclusión de pacientes mayores de 18 años de edad diagnosticados con FA no valvular durante los últimos 6 meses y con al menos un factor de riesgo para desarrollar una tromboembolia de acuerdo con la escala de CHA2DS2-Vasc. Serán recolectados datos demográficos y clínicos en las visitas clínicas habituales a lo largo de un seguimiento de 2 años. El reclutamiento comenzó el 19 de septiembre de 2014 y se prevé la inclusión del último paciente el 18 de septiembre de 2016. Se estima la inclusión de 1,200 pacientes dada la incidencia de FA reportada a nivel mundial y tomando en consideración la población mexicana total. Conclusiones: El registro de FA y riesgo embólico en México (CARMEN-AF) permitirá conocer el estado actual de la tromboprofilaxis en pacientes con FA no valvular y permitirá obtener una panorámica del cumplimiento de las guías nacionales e internacionales de práctica clínica en esta materia.


Abstract: Objective: Atrial fibrillation (AF) is one of the most common arrhythmias, and its prevalence increase with age. It is associated with high risk of stroke. The prevention of such thromboembolism is done with oral anticoagulants, which in our country seem to be underused. CARMEN-AF registry aims primarily to determine the current status of thromboprophylaxis of non-valvular AF in Mexico. A secondary objective is to know the morbidity and mortality associated with non-valvular AF in at least one year of follow-up. Methods: CARMEN-AF registry is an observational, longitudinal, multicenter, and national survey about the use of oral anticoagulants in patients with non-valvular AF. Patients 18 years old or older, diagnosed with AF during the last 6 months, and with at least one risk factor of thromboembolism based in the CHA2DS2-Vasc score are being selected. Demographic and clinical data will be collected during the visits to their usual clinic with a follow-up of 2 years. The recruitment began on September 19, 2014, and the inclusion of the last patient is expected on September 18, 2016. According to the reported incidence of AF globally and taking into account the total Mexican population, the inclusion of 1,200 patients is estimated. Conclusions: The Atrial Fibrillation and Embolic Risk Registry (CARMEN-AF) will reveal the current status of thromboprophylaxis in patients with non-valvular AF, and will allow to get an overview of the national and international clinical practice guidelines accomplishment in this area.


Subject(s)
Humans , Atrial Fibrillation/complications , Thromboembolism/etiology , Thromboembolism/epidemiology , Registries , Research Design , Thromboembolism/prevention & control , Administration, Oral , Risk Factors , Longitudinal Studies , Mexico , Anticoagulants/administration & dosage
12.
Arch. cardiol. Méx ; Arch. cardiol. Méx;85(1): 68-72, ene.-mar. 2015. ilus, tab
Article in English | LILACS | ID: lil-746424

ABSTRACT

Hereditary sudden cardiac death syndromes comprise a wide range of diseases resulting from alteration in cardiac ion channels. Genes involved in these syndromes represent diverse mutations that cause the altered encoding of the diverse proteins constituting these channels, thus affecting directly the currents of the corresponding ions. In the present article we will briefly review how to arrive to a clinical diagnosis and we will present the results of molecular genetic studies made in Mexican subjects attending the SCD Syndromes Clinic of the National Institute of Cardiology of Mexico City.


Los síndromes hereditarios de muerte súbita cardíaca comprenden una amplia gama de enfermedades resultantes de la alteración en los canales iónicos cardíacos. Los genes implicados en estos síndromes presentan mutaciones que causan alteraciones de las diversas proteínas que constituyen estos canales y que, por lo tanto, afectan directamente a las diferentes corrientes iónicas. En el presente artículo se revisa brevemente la forma de llegar a un diagnóstico clínico de dichos síndromes y se presentan los resultados de los estudios genéticos moleculares realizados en sujetos mexicanos que asisten a la Clínica de Síndromes Hereditarios de Muerte Súbita del Instituto Nacional de Cardiología Ignacio Chávez.


Subject(s)
Adolescent , Child , Child, Preschool , Female , Humans , Male , Middle Aged , Young Adult , Death, Sudden, Cardiac , Heart Arrest/diagnosis , Heart Arrest/genetics , Molecular Diagnostic Techniques , Sequence Analysis, DNA , Mexico , Syndrome
14.
Arch. cardiol. Méx ; Arch. cardiol. Méx;84(4): 278-285, oct.-dic. 2014. ilus, tab
Article in Spanish | LILACS | ID: lil-744062

ABSTRACT

El síndrome de Andersen-Tawil resulta de la alteración de canales de potasio, se hereda de forma autosómica dominante y se cataloga como el tipo 7 de los síndromes de QT largo congénitos. El gen afectado es el KCNJ2, el cual codifica la proteína Kir2.1 que forma el canal de potasio rectificador interno («inward rectifier¼). Este canal interviene en la estabilización del potencial de membrana en reposo y controla la duración del potencial de acción en el sistema musculoesquelético y cardíaco. En miocitos ventriculares, es un componente responsable de la rectificación de la corriente de potasio en la fase 3 del potencial de acción. Debido a que Kir2.1 está presente en el sistema musculoesquelético, corazón y cerebro, las alteraciones de esta proteína dan origen a las principales características del síndrome: parálisis flácida, arritmias ventriculares y alteraciones leves a moderadas en el desarrollo del esqueleto, especialmente en manos y pies. En la presente revisión se aborda esta enfermedad desde el punto de vista del diagnóstico clínico y molecular con énfasis en sus manifestaciones cardíacas.


The Andersen-Tawil syndrome is a cardiac ion channel disease that is inherited in an autosomal dominant way and is classified as type 7 of the congenital long QT syndromes. Affected gene is KCNJ2, which forms the inward rectifier potassium channel designated Kir2.1. This protein is involved in stabilizing the resting membrane potential and controls the duration of the action potential in skeletal muscle and heart. It also participates in the terminal repolarization phase of the action potential in ventricular myocytes and is a major component responsible for the correction in the potassium current during phase 3 of the action potential repolarization. Kir 2.1 channel has a predominant role in skeletal muscle, heart and brain. Alterations in this channel produce flaccid paralysis, arrhythmias, impaired skeletal development primarily in extremities and facial area. In this review we address the disease from the point of view of clinical and molecular diagnosis with emphasis on cardiac manifestations.


Subject(s)
Humans , Andersen Syndrome/diagnosis , Andersen Syndrome/genetics , Andersen Syndrome/complications , Heart Diseases/etiology , Pedigree
16.
Arch. cardiol. Méx ; Arch. cardiol. Méx;83(4): 244-248, oct.-dic. 2013. ilus, tab
Article in English | LILACS | ID: lil-703024

ABSTRACT

Introduction: Radiofrequency ablation of scar related right atrial flutter is challenging. Long procedures, prolonged fluoroscopic times and high percentages of recurrences are of concern. We present a simple and progressive approach based on a single electroanatomic map of the right atrium. Methods: Twenty-two consecutive patients with atrial flutter and history of cardiac surgery were included. An electrophysiologic study was performed to define localization (left or right) and cavo-tricuspid isthmus participation using entrainment mapping. After a critical isthmus was localized, ablation was performed with an external irrigated tip catheter with a power limit of 30 W. Potential ablation sites were confirmed by entrainment. Results: The predominant cardiopathy was atrial septal defect. All arrhythmias were localized in the right atrium; mean cycle length of the clinical flutter was 274 ± 31 ms. Only 40% had cavo-tricuspid isthmus participation. None of the patients with successful ablation had recurrences after 13 ± 9.4 months of follow-up. Conclusions: A progressive approach with only one activation/voltage CARTO® map of the atrium and ablation of all potential circuits is a highly effective method for ablating scar related macroreentrant atrial arrhythmias.


Introducción: La ablación con radiofrecuencia de flutter auricular relacionado con cicatrices posquirúrgicas es compleja. Procedimientos prolongados, con tiempos de fluoroscopia altos y una tasa de recurrencia elevada son problemas habituales. Mostramos un abordaje simple y progresivo basado en un solo mapa de cartografía electroanatómica de la aurícula derecha. Métodos: Se incluyeron 22 pacientes consecutivos con flutter auricular e historia de cirugía cardiaca. Se realizó estudio electrofisiológico para definir la localización del circuito de flutter (derecho o izquierdo) y la participación o no del istmo cavotricuspideo mediante encarrilamiento. Una vez localizado la zona de conducción lenta o critica del circuito, se realizó ablación con radiofrecuencia con catéter de irrigación externa a 30W. Posteriormente se llevó a cabo ablación de todos los circuitos potenciales. Resultados: La cardiopatía más dominante fue la comunicación interauricular. Todas las arritmias se localizaron en la aurícula derecha. El ciclo de flutter fue de 274 ± 31 ms. En solo 40% de los casos se demostró participación del istmo cavotricuspideo. No se observaron recurrencias de la arritmia durante un seguimiento de 13 ± 9.4 meses. Conclusiones: Este abordaje escalonado con un solo mapa CARTO® de activación/voltaje de la aurícula y la ablación de todos los circuitos potenciales es altamente efectivo para el tratamiento de arritmias por macrorreentrada relacionadas con cicatriz posquirúrgica.


Subject(s)
Adult , Aged , Child , Female , Humans , Male , Middle Aged , Young Adult , Catheter Ablation/methods , Cicatrix/complications , Cicatrix/surgery , Tachycardia/etiology , Tachycardia/surgery , Heart Atria
17.
Arch. cardiol. Méx ; Arch. cardiol. Méx;82(3): 243-247, jul.-sept. 2012. ilus
Article in Spanish | LILACS | ID: lil-685339

ABSTRACT

El intervalo QT mide tanto la repolarización como la despolarización. Aprender a medir el intervalo QT y saber corregirlo (QTc) para la frecuencia cardiaca (FC) es básico, pues permite establecer el diagnóstico de un síndrome de QT largo (SQTL). El intervalo QTc puede variar en duración e incluso morfología, dependiendo de la hora y del día. Existe una respuesta adaptativa disminuida del intervalo QTc a los cambios en la FC, que se conoce como histéresis del QT. Viskin ha introducido una prueba clínica bastante sencilla para confirmar el diagnóstico de SQTL, que se basa en la "hipoadaptación" del intervalo QT al ponerse de pie, y que en el electrocardiograma (ECG) de superficie da la apariencia de un "estiramiento del QT". Asimismo, ha acuñado el término de "aturdimiento del QT" para hacer referencia al fenómeno de que el intervalo QTc no regresa al valor inicial basal, a pesar de recuperarse la FC basal después del ortostatismo. En este artículo se muestran algunos ejemplos y la manera de realizar la prueba de Viskin.


The QT interval measures both repolarization and depolarization. Learning to measure the QT interval and know how to correct (QTc) for heart rate (HR) is essential for the diagnosis of long QT syndrome (LQTS). The QTc interval changes in duration and even morphology depending on the time of the day and on a day-to-day basis. A diminished adaptive response of the QTc interval to changes in HR is known as QT hysteresis. Viskin has introduced a very simple clinical test to confirm the diagnosis of LQTS based on the "hypoadaptation" of the QT when standing. This phenomenon gives the appearance of a "stretching of the QT" on the surface ECG. Likewise, he has coined the term "QT stunning" to refer to the phenomenon that the QTc interval does not return to baseline despite recovery of baseline HR after standing. This article shows some examples of the Viskin’s test.


Subject(s)
Humans , Electrocardiography , Long QT Syndrome/diagnosis , Diagnostic Techniques, Cardiovascular , Electrocardiography/methods
18.
Arch. cardiol. Méx ; Arch. cardiol. Méx;82(2): 170-180, abr.-jun. 2012. tab
Article in Spanish | LILACS | ID: lil-657954

ABSTRACT

Las revistas biomédicas utilizan la declaración de posibles conflictos de intereses para garantizar la credibilidad y la transparencia del proceso científico. Sin embargo, las revistas no abordan la declaración de conflictos de intereses de manera sistemática ni uniforme. Recientes esfuerzos editoriales conjuntos han abierto el camino a la aplicación de herramientas uniformes para la declaración de conflictos de intereses. En este artículo se presenta una visión integral sobre cuestiones clásicas relacionadas con los conflictos de intereses desde un punto de vista editorial. Además, a partir de los datos de un estudio transversal basado en el empleo de un cuestionario estandarizado, se comentan nuevas apreciaciones sobre las políticas y los actuales procedimientos editoriales relativos a los conflictos de intereses en las diversas revistas cardiovasculares nacionales de la Sociedad Europea de Cardiología.


Disclosure of potential conflicts of interest is used by biomedical journals to guarantee credibility and transparency of the scientific process. Conflict of interest disclosure, however, is not systematically nor consistently dealt with by journals. Recent joint editorial efforts paved the way towards the implementation of uniform vehicles for conflicts of interest disclosure. This paper provides a comprehensive editorial perspective on classical conflict of interest-related issues. New insights into current conflicts of interest policies and practices among European Society of Cardiology national cardiovascular journals, as derived from a cross-sectional survey using a standardized questionnaire, are discussed.


Subject(s)
Authorship/standards , Conflict of Interest , Disclosure , Editorial Policies , Periodicals as Topic , Cardiology , Data Collection , Disclosure/standards , Drug Industry/economics , Drug Industry , Europe , Periodicals as Topic/standards , Research Support as Topic , Societies, Medical
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