RESUMO
UNLABELLED: Radiofrequency (RF) ablation is a curative treatment for many different types of cardiac arrhythmias but its application has been more limited in the paediatric population. We here describe RF paediatric ablation experience at a 400-bed University Hospital in a western Venezuelan province and compare it with the results reported in other countries. METHODS: One hundred and fifty five patients under 18 years of age who where submitted to RF ablation between 1994 and 2007 were included. The patients were 12.8+/-3.4 year-old (rank: 3-17 years); 59% were female. Nine patients were submitted to more than one procedure. AV nodal re-entrant tachycardia and atrio-ventricular re-entrant tachycardias mediated by accessory pathways made up 83% of the ablations. The overall success rate was 91.5%. In the AV nodal re-entrant tachycardia and atrial flutter, success rate almost reached 100%. Ablation was successful in 93% of the patients with the Wolff-Parkinson-White syndrome. The overall complication rate was 5% with 0.6% of major complications and 0% death rate. The results were comparable to those recently reported by the cooperative paediatric ablation registry in the United States of America and by a large hospital in Taiwan. CONCLUSION: RF ablation is a curative therapy with a high success rate and very low complication rates in the paediatric population at the Cardiovascular Research Institute of the University Hospital of The Andes in Venezuela.
Assuntos
Ablação por Cateter , Taquicardia por Reentrada no Nó Atrioventricular/mortalidade , Taquicardia por Reentrada no Nó Atrioventricular/cirurgia , Síndrome de Wolff-Parkinson-White/mortalidade , Síndrome de Wolff-Parkinson-White/cirurgia , Adolescente , Flutter Atrial/mortalidade , Flutter Atrial/cirurgia , Criança , Pré-Escolar , Feminino , Mortalidade Hospitalar , Hospitais Universitários/estatística & dados numéricos , Humanos , Masculino , Marca-Passo Artificial , Complicações Pós-Operatórias/mortalidade , Complicações Pós-Operatórias/terapia , Venezuela/epidemiologiaRESUMO
An 18-year-old girl had been suffering from palpitations for 3 years. After a normal and asymptomatic pregnancy, she became highly symptomatic with more than 6 tachycardia paroxysms a week, many of them requiring emergency hospitalizations because of hemodynamic collapse. The electrophysiological evaluation revealed dual A-V nodal pathways and the presence of 4 accessory pathways (3 in the left A-V ring: lateral, posterior, and posteroseptal, 1 right posteroseptal) with 5 types of atrioventricular tachycardia and atrial flutter. The 4 accessory pathways and the slow A-V nodal pathway were successfully ablated, and the patient has been asymptomatic for 12 months without taking antiarrhythmic drugs.
Assuntos
Complicações Cardiovasculares na Gravidez/fisiopatologia , Taquicardia Supraventricular/fisiopatologia , Adolescente , Ablação por Cateter , Eletrocardiografia , Técnicas Eletrofisiológicas Cardíacas , Feminino , Sistema de Condução Cardíaco/anormalidades , Sistema de Condução Cardíaco/cirurgia , Humanos , Gravidez , Taquicardia Supraventricular/cirurgiaRESUMO
UNLABELLED: Assuming that blood pressure control could induce a shortening of the inter-atrial conduction time and prevent atrial fibrillation occurrence, we studied the inter-atrial conduction time in hypertensive patients with left ventricular hypertrophy. METHODS: Sixty-eight (26 male) 58.34+/-8.08-year-old patient participated in the study. All were in sinus rhythm and had abnormal blood pressure (163+/-18/95+/-9 mm Hg). Their cardiac mass index was increased (151+/-43 g/m(2) SC) and their left atrial dimension was normal (3.67+/-0.54 cm). The inter-atrial conduction time was measured in the echocardiogram from the beginning of the electrocardiographic P wave to the beginning of the A wave in the mitral Doppler signal and was corrected for heart rate. Heart rhythm disturbances were monitored clinically and by means of a Holter. Most patients were treated with angiotensin antagonists. RESULTS: It was found that arterial blood pressure decreased significantly after treatment and that the P-A interval was significantly reduced (71.4+/-14.5 vs. 63.9+/-11.5 ms). During the follow-up, no patient complained of arrhythmia symptoms or exhibited atrial fibrillation in the Holter recording. CONCLUSION: In this selected group of patients with hypertensive heart disease (left ventricular hypertrophy), an effective blood pressure control was accompanied by a significant decrease in the inter-atrial conduction time. It is possible that these effects prevent atrial fibrillation.
Assuntos
Pressão Sanguínea , Átrios do Coração/fisiopatologia , Sistema de Condução Cardíaco/fisiopatologia , Hipertensão/prevenção & controle , Hipertrofia Ventricular Esquerda/fisiopatologia , Idoso , Inibidores da Enzima Conversora de Angiotensina , Fibrilação Atrial/etiologia , Fibrilação Atrial/prevenção & controle , Ecocardiografia Doppler , Eletrocardiografia , Feminino , Humanos , Hipertensão/fisiopatologia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de TempoRESUMO
OBJECTIVE: To determine whether an algorythm designed at our Electrophysiology Unit could facilitate the electrocardiographic diagnosis of tachyarrhythmias. METHODS: Twenty two first-year cardiology residents, general practitioners and last-year medical students attended an electrophysiology course. One hundred ECG of tachyarrhythmic patients were distributed to the participants who were then randomly divided into 2 groups. Group A analyzed the ECG with the help of the algorythm, whereas Group B analyzed them without it. Results were compared to those obtained by an electrophysiologist. RESULTS: Group A diagnosis coincided with that of the electrophysiologist in 41% of the cases. In Group B the concordance reached 64% (p = 0.0000013). There was no between-group difference regarding the type and number of uninterpreted ECG. CONCLUSIONS: The decision tree increases diagnostic accuracy in less expert hands. This could in turn entail an improvement in the therapeutic measures applied to the study of arrhythmias.
Assuntos
Algoritmos , Taquicardia/diagnóstico , Eletrocardiografia , HumanosRESUMO
BACKGROUND: Patients with myocardial infarction and left ventricular dysfunction are at risk for sudden death. This research was conducted to determine the applicability and safety of a bedside programmed stimulation protocol to determine the risk for sudden death in these patients. METHODS: Four hundred and twelve patients with acute myocardial infarction were studied. Left ventricular ejection fraction was evaluated by means of an echocardiogram. Ventricular arrhythmia, late potentials and heart rate variability were determined by means of Holter recordings. Fifty patients (60 +/- 14-year-old; 85% male) presented a left ventricular ejection fraction lower than 0.40 (0.36 +/- 0.10) associated with late potentials, low heart rate variability or ventricular arrhythmia greater than Lown I. After a central venous access was placed under fluoroscopy guidance and ECG monitoring, a quadripolar catheter was advanced to the right ventricular apex to perform programmed ventricular stimulation with up to three extrastimuli. The patients were followed-up to determine in-hospital morbidity and/or mortality. RESULTS: No patient suffered complications. Ventricular tachycardia or ventricular fibrillation was induced in six patients. All of them received amiodarone and in five an automatic cardioverter-defibrillator was implanted. After a 22 +/- 6 month follow-up, five patients had received appropriate discharges from the implanted device and none had suffered from arrhythmic sudden death. CONCLUSION: Bedside programmed stimulation is a safe and useful means for sudden death risk stratification in post myocardial infarction patients. It moreover presents the advantage of being cheaper than conventionally used procedures.
Assuntos
Morte Súbita/prevenção & controle , Infarto do Miocárdio/terapia , Morte Súbita/etiologia , Estimulação Elétrica , Eletrofisiologia , Estudos de Viabilidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/complicações , Sistemas Automatizados de Assistência Junto ao Leito , Medição de RiscoRESUMO
BACKGROUND: Little is known about the correlation between the inter-atrial conduction time (IACT) measured at the electrophysiology laboratory and the interval measured from the beginning of the electrocardiographic P wave to the initiation of the A wave in the mitral Doppler signal (P-A interval). HYPOTHESIS: IACT can be assessed by means of echo-Doppler. METHODS: We studied 21 patients who were referred to our arrhythmia clinic for evaluation of supraventricular tachycardia. During the electrophysiological study, the IACT was measured from the first rapid deflection of the A wave recorded with the high right atrial catheter to the A wave recorded with the coronary sinus catheter. An independent observer measured the P-A interval. Both the electrophysiological and echo-Doppler measurements were corrected for heart rate. RESULTS: P-A interval was slightly longer than IACT (83.36 +/- 23.91 vs 80.77 +/- 24.11 msec; p = 0.042), but a very good correlation was found between both measurements (r2 = 0.94). CONCLUSIONS: IACT can be non-invasively assessed by measuring the P-A interval.
Assuntos
Ecocardiografia Doppler , Átrios do Coração/fisiopatologia , Sistema de Condução Cardíaco/fisiopatologia , Taquicardia Supraventricular/fisiopatologia , Adulto , Interpretação Estatística de Dados , Eletrocardiografia , Eletrofisiologia , Feminino , Frequência Cardíaca , Humanos , Masculino , Pessoa de Meia-Idade , Análise de Regressão , Fatores de TempoRESUMO
BACKGROUND: Little is known about the correlation between the inter-atrial conduction time (IACT) measured at the electrophysiology laboratory and the interval measured from the beginning of the electrocardiographic P wave to the initiation of the A wave in the mitral Doppler signal (P-A interval). HYPOTHESIS: IACT can be assessed by means of echo-Doppler. METHODS: We studied 21 patients who were referred to our arrhythmia clinic for evaluation of supraventricular tachycardia. During the electrophysiological study, the IACT was measured from the first rapid deflection of the A wave recorded with the high right atrial catheter to the A wave recorded with the coronary sinus catheter. An independent observer measured the P-A interval. Both the electrophysiological and echo-Doppler measurements were corrected for heart rate. RESULTS: P-A interval was slightly longer than IACT (83.36 +/- 23.91 vs 80.77 +/- 24.11 msec; p = 0.042), but a very good correlation was found between both measurements (r2 = 0.94). CONCLUSIONS: IACT can be non-invasively assessed by measuring the P-A interval.
Assuntos
Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Ecocardiografia Doppler , Átrios do Coração , Sistema de Condução Cardíaco , Taquicardia Supraventricular , Interpretação Estatística de Dados , Eletrocardiografia , Eletrofisiologia , Frequência Cardíaca , Análise de Regressão , Fatores de TempoRESUMO
Se han descrito fascículos accesorios postero-septales ubicados dentro de divertículos del seno coronario. Aquí describimos el caso de un paciente que sufría episodios recurrentes de taquicardia supraventricular paroxística causada por un fascículo accesorio oculto localizado en la región anterolateral del anillo mitral. En el paciente también había un divertículo del seno coronario asociado con una vena coronaria aneurismática. En el estudio electrofisiológico, se indujo una taquicardia supraventricular ortodrómica que utilizaba el fascículo accesorio descrito, por lo que se realizó una ablación exitosa del fascículo y la paciente se hizo asintomática. Nuestro caso da prueba de la coexistencia de fascículos accesorios ocultos (ubicados en sitios distantes) y de un divertículo del seno coronario y una vena coronaria aneurismática.
Assuntos
Humanos , Feminino , Adulto , Vasos Coronários , Septos Cardíacos , Taquicardia Supraventricular , Aneurisma CoronárioRESUMO
El tratamiento de las arritmias cardíacas sufrió cambios importantes en la última década. Una de las innovaciones de mayor intéres es la fulguración con radiofrecuencia de focos arritmogénicos. Este trabajo muestra los resultados obtenidos en el Centro de Investigaciones Cardiovasculares de la Universidad de Los Andes (Venezuela) con el uso de fulguración por radiofrecuencia para el tratamiento de arritmias cardíacas. Efectuamos 130 procedimiento en 121 pacientes (81 mujeres) de 34,32 ñ 16,69 años de edad. La fulguración tuvo éxito en el 92 por ciento de los pacientes. Separados en subgrupos, la eficacia fue de 100 por ciento en taquicardia supraventricular (TSV) por reentrada nodal, 90 por ciento en las TSV por fascículo de Kent (incluye woll-parkinson), 70 por ciento en flutter auricular, y 100 por ciento en los casos de fibrilación auricular y taquicardia ventricular. En el 89 por ciento de los pacientes, el estudio electrofisiológico y la fulguración se efectuaron en una sola sesión. No hubo muertes. Se presentaron complicaciones en 6 por ciento de los casos. El promedio de duración del procedimiento fue de 2,7 horas (28 minutos de fluroscopia). La fulguración con radiofrecuencia es un procedimiento seguro y eficaz para curar arritmias cuando se efectúa con una técnica apropiada. Hemos tenido un porcentaje de éxitos y de complicaciones similar al de reputados centros del exterior. Considerados que la fulguración con radiofrecuencia es el tratamiento de elección para las TSV por reentrada nodal y por fascículo accesorios. Es también una modalidad alterna atractiva para el tratamiento de flutter auricular y de formas seleccionadas de taquicardia ventricular y fibrilación auricular
Assuntos
Humanos , Masculino , Feminino , Arritmias Cardíacas , Resultado do TratamentoRESUMO
It has been stated that curare has no direct effect upon the heart because the cardiac muscle is deprived of nicotine receptors. While performing an experimental work, we noticed that when high doses of curare were administered to frogs, a change in cardiac activity occurred. In order to elucidate whether the cardiac effects of curare wee the results of a direct action or a reflex response, we studie the effects of increasing doses of d-tubocurarine on the rate and contractility of 8 isolated and perfused frogs'hearts. After testing the d-tubocurarine effects on the heart rate and contractility, we added either acetylcholine, atropine, atenonol or verapamil in orden to find out whether any change ocurred in the cardiac effects produced byd-tubocurarine. Thirty seven measurements were carriet out and it wasfound that 1) high doses (between 1 and 15 micrograms) of d-tubocurarine produced a highly significant decrease in heart rate an contractility; 2) d-tubocurarine did not avoid the acetycholine effect; 3) atropine, atenonol and verapamil did not interfere with d-tubocurarine effects. We conclude that high doses of d-tubocurarine produce "dosis-dependent" heart rate and contratility reductions. These effects are not mediated by muscarinic receptors beta-1 receptors or the show calcium channels
Assuntos
Animais , Acetilcolina/administração & dosagem , Acetilcolina/efeitos adversos , Coração/efeitos dos fármacos , Curare/administração & dosagem , Curare/uso terapêutico , Miocárdio/metabolismo , Miocárdio/patologia , Tubocurarina , Tubocurarina/efeitos adversosRESUMO
Estudiamos los efectos del líquido pericárdico y su contenido de NaCl sobre la amplitud del complejo QRS del electrocardiograma (ECG), en ratas Wistar sometidas a toracotomía y pericardiectomía. Se registró un ECG de control y otro después de secar el epicardio con aire a temperatura ambiente. Bajo registro de ECG, se colocaron sucesivamente, en el epicardio seco 0,3 cc de las siguientes soluciones: dextrosa al 5% y NaCl al 0,45%, 0,9%, 1,35% y 1,8%. Las variaciones de amplitud del QRS se expresaron en porcentajes y se analizaron estadísticamente con prueba de Newman-Keuls, análisis de varianza, de regresión y de correlación. Encontramos que: 1) La desecación del pericardio produjo una disminución de 20% en la amplitud del QRS (p < 0,01). 2) Al humedecer ese órgano con las soluciones, la amplitud del QRS aumentó de inmediato entre 24 y 59% (p < 0,01). 3) El aumento de amplitud del QRS con solución de dextrosa fue menor que con las soluciones de NaCl (p < 0,05). 4) La solución de NaCl al 0,9% fue la que produjo el mayor aumento de amplitud del QRS (p < 0,05). 5) La concentración de NaCl y el aumento de amplitud del QRS tienen una correlación polinomial, parabólica y débil (r = 0,45 con p < 0,1). Los resultados sugieren que la presencia de líquido pericárdico y su contenido de NaCl influyen sobre la amplitud del QRS y que la variación no es simplemente función de la conductividad del líquido pericárdico