Permanent pacing in patients with Chagas' disease.

BACKGROUND: Chagas' disease is an endemic disease in most Latin American countries. The cardiomyopathy associated with this condition often requires permanent pacing due to bradycardia. The aim of this study was to compare the indications for pacemaker implantation, intraoperative measurements, and long-term follow-up of patients with Chagas' cardiomyopathy (ChCM) and ischemic cardiomyopathy (ICM) referred for pacemaker implantation. METHODS: Retrospective study including consecutive patients with ChCM (Group 1) and ICM (Group 2), who underwent pacemaker implantation in a single center. RESULTS: We analyzed 360 patients. Patients in Group 1 were younger (66.29 ± 7.01 vs 75.3 ± 7.11 years; P = 0.0001) and more often male (72% vs 60%; P = 0.05). Sinus node dysfunction (SND) was more prevalent in Group 1 (70% vs 52%; P = 0.03). Atrioventricular block was less prevalent in Group 1 (30% vs 48%; P = 0.04). No significant differences were found with respect to left ventricular ejection fraction (54.2 ± 9.1 vs 53.4 ± 8.2%; P = NS) and baseline QRS duration (119 ± 34 vs 108 ± 29 ms; P = NS). Right bundle branch block was more frequent in Group 1 (44% vs 12%; P = 0.0001), and left bundle branch block in Group 2 (6% vs 22%; P = 0.0001). Implantation time was longer in Group 1 (39 ± 19 vs 29 ± 13 minutes; P = 0.001) and was with higher atrial and ventricular pacing thresholds (1.4 ± 0.8 vs 1.0 ± 0.5 V; P = 0.001 and 1.2 ± 0.8 vs 0.6 ± 0.8 V; P = 0.001, respectively). During a follow-up of 42.8 ± 13.6 months, Group 1 had a higher incidence of new atrial fibrillation (34% vs 25.5%; P = 0.001), and there was a nonsignificant trend toward more displacements of the ventricular lead (6% vs 3.5%; P = 0.3). There were no deaths during the follow-up. CONCLUSIONS: ChCM patients receiving pacemakers are younger and more frequently have SND compared to those with ICM. Pacemaker implant is longer in patients with ChCM disease and is with higher pacing thresholds. The incidence of new atrial fibrillation during the follow-up is significantly higher in patients with ChCM.

Long-term results of slow pathway ablation in patients with atrioventricular nodal reentrant tachycardia: simple approach.

AIMS: The aim of this study was to report the short- and long-term results of slow pathway radiofrequency (RF) ablation in patients with atrioventricular (AV) nodal reentrant tachycardia (AVNRT) using a simplified approach (2 catheters and short applications of RF). MATERIALS AND METHODS: This was a retrospective study that included consecutive patients with AVNRT. We used an anatomical approach with only 2 catheters. Decremental AV nodal conduction and atrial-His conduction interval jump were measured. To detect the onset of the QRS, we used surface lead II. During the stimulation protocol, we performed S2-QRS and S3-QRS measurements. An increase in the S3-QRS3 interval of 50 milliseconds or greater in response to a decrease in the S2-QRS2 coupling interval of 10 milliseconds was defined as a discontinuous AV nodal function curve and taken as evidence of dual antegrade AV pathways. Atrioventricular nodal reentrant tachycardia was demonstrated by the presence of dual AV nodal physiology, atrial echoes, and tachycardia induction with a 1:1 AV relationship and a VA interval of less than 70 milliseconds. Short RF applications (10-15 seconds) were delivered at an intermediate point between the posteroseptal and medioseptal regions of the Koch triangle. The applications were considered effective when junctional rhythm appeared. The end point was the demonstration of slow pathway modification without AVNRT induction. RESULTS: Three hundred forty-four patients (age, 49.22 ± 17.47 years; 254 were female) were included. Discontinuous AV nodal function curves were found in 271 patients (78.77%), and short-term success was achieved in all patients. The anterograde jump in AV nodal conduction was abolished after RF in 222 patients (81.91%), and discontinuous AV nodal conduction and single AV nodal echo beats persisted in 49 cases (18%). The mean number of RF application was 7.79 ± 2.23, the mean number of effective applications was 4.63 ± 0.62, and the mean RF application time was 54.92 ± 8.03 seconds. The total procedure and fluoroscopy time was 29.45 ± 9.6 and 10.87 ± 2.36 minutes, respectively. After the procedure, all patients were followed up for a mean of 46.44 ± 18.89 months, and 7 patients (2%) presented AVNRT recurrences. Complications were observed in 4 patients (1.16%); no permanent AV block was observed. CONCLUSION: In this study, slow pathway RF ablation using a simplified approach technique is an effective and safe approach for the treatment of AVNRT.

[Systemic sclerosis complicated with syncope and complete AV block]. / Esclerosis sistémica complicada con síncope y bloqueo AV completo.

Systemic sclerosis is a complex disease that affects the connective tissue, the vascular system and the immune system. It typically produces skin and organ fibrosis. Cardiac bundle branch blocks and fascicular blocks occur in 25-75% of the cases and were found to be independent predictors of mortality. Second and third degree atrioventricular block are very rare. We present the case of a 47 year-old female with diagnosis of systemic sclerosis, presented with syncope secondary to complete atrioventricular block requiring permanent pacemaker implantation.

Proarrhythmia Induced by Propafenone: What is the Mechanism?

Propafenone, a Class IC antiarrhythmic drug, is an orally active sodium channel-blocking agent. It is effective in supraventricular tachyarrhythmias and is particularly useful in converting atrial fibrillation to sinus rhythm. In therapeutic doses, it may cause non-cardiac and cardiac toxicity, including proarrhythmia.

Surface fragmented QRS in a patient with hypertrophic cardiomyopathy and malignant arrhythmias: Is there an association?

An 18- year old woman with hypertrophic cardiomyopathy, aborted sudden cardiac death and implanted with an implantable cardioverter defibrillator (ICD), developed progressive fragmentation of her surface 12-lead electrocardiogram (ECG). During the follow-up, she presented with multiple appropriate ICD discharges. Here, we discuss the possible association between surface fragmented ECG and the risk of ventricular arrhythmias in patients with hypertrophic cardiomyopathy.

[Incessant focal atrial tachycardia arising from the right appendage: risk of tachycardia mediated cardiomyopathy. Role of the radiofrequency ablation]. / Taquicardia auricular focal incesante originada en la orejuela derecha: riesgo de taquicardiomiopatía. Rol de la ablación por radiofrecuencia.

Focal atrial tachycardias originate from different anatomic regions of the right atrium including the crista terminalis, the coronary sinus ostium, the tricuspid annulus, the interatrial septum and the right atrial appendage. The latter are characterized by being incessant and presenting poor response to antiarrhythmic treatment. They frequently evolve into tachycardiomyopathy and radiofrequency ablation is the treatment of choice. We present the case of a 36 month old girl with tachycardiomyopathy as a result of an incessant atrial tachycardia originated in the right atrial appendage. Patient underwent radiofrequency ablation.

[Complications of permanent pacemaker. Event operator dependent? Analysis of 743 consecutive patients]. / "Complicaciones del implante de marcapaso definitivo. ¿Un evento operador dependiente? Análisis de 743 pacientes consecutivos"

UNLABELLED: The complications of permanent pacemaker implant, are found among 6%-9% of patients. Different factors are related. OBJECTIVES: We evaluated the complications related with pacemaker implants and which are the independent risk factors associated with them. METHODS: Descriptive analysis, type case-controls, retrospective and prospective, including 743 consecutive patients, between January 2007 and April 2008. RESULTS: Age: 73.83 ± 12 years, 63.9% male. 43% of the patients had some degree of structural cardiopathy. There were no deaths related to pacemaker implants. Implant procedure-related complications were observed in 57 patients (7.67%), requiring a surgical intervention in 34 patients (4.57%). The most serious complications included one device-related infective endocarditis (0.13%), the entire device system was extracted, and one pneumothorax following subclavian vein puncture with insertion of a chest tube. In the multivariate analysis, low level of operator experience and preimplant heart failure were independent predictors for complications. CONCLUSIONS: In this consecutive series of patients with permanent pacemaker implant, there was a low rate of complications, similar to the reported international series. A low level of operator experience and preimplant heart failure were related.

Taquicardia auricular focal incesante originada en la orejuela derecha: riesgo de taquicardiomiopatía: rol de la ablación por radiofrecuencia / Incessant focal atrial tachycardia arising from the right appendage: risk of tachycardia mediated cardiomyopathy: role of the radiofrequency ablation

Las taquicardias auriculares focales pueden originarse en distintas regiones de la aurícula derecha, incluidos la crista terminalis, el anillo tricuspídeo, el septum interauricular y la orejuela derecha. Las originadas en esta última región anatómica se caracterizan por presentar un comportamiento incesante y mala respuesta al tratamiento farmacológico antiarrítmico, con desarrollo de taquicardiomiopatía; su tratamiento de elección es la ablación por radiofrecuencia.Presentamos el caso de una infante de 36 meses de edad, con taquicardiomiopatía secundaria a taquicardia auricular incesante de orejuela derecha, a quien se le realizó ablación por radiofrecuencia.

Focal atrial tachycardias originate from different anatomic regions of the right atrium including the crista terminalis, the coronary sinus ostium, the tricuspid annulus, the interatrial septum and the right atrial appendage. The latter are characterized by being incessant and presenting poor response to antiarrhythmic treatment. They frequently evolve into tachycardiomyopathy and radiofrequency ablation is the treatment of choice. We present the case of a 36 month old girl with tachycardiomyopathy as a result of an incessant atrial tachycardia originated in the right atrial appendage. Patient underwent radiofrequency ablation.

Taquicardia auricular focal incesante originada en la orejuela derecha: riesgo de taquicardiomiopatía: rol de la ablación por radiofrecuencia / Incessant focal atrial tachycardia arising from the right appendage: risk of tachycardia mediated cardiomyopathy: role of the radiofrequency ablation

Las taquicardias auriculares focales pueden originarse en distintas regiones de la aurícula derecha, incluidos la crista terminalis, el anillo tricuspídeo, el septum interauricular y la orejuela derecha. Las originadas en esta última región anatómica se caracterizan por presentar un comportamiento incesante y mala respuesta al tratamiento farmacológico antiarrítmico, con desarrollo de taquicardiomiopatía; su tratamiento de elección es la ablación por radiofrecuencia.Presentamos el caso de una infante de 36 meses de edad, con taquicardiomiopatía secundaria a taquicardia auricular incesante de orejuela derecha, a quien se le realizó ablación por radiofrecuencia.(AU)

Focal atrial tachycardias originate from different anatomic regions of the right atrium including the crista terminalis, the coronary sinus ostium, the tricuspid annulus, the interatrial septum and the right atrial appendage. The latter are characterized by being incessant and presenting poor response to antiarrhythmic treatment. They frequently evolve into tachycardiomyopathy and radiofrequency ablation is the treatment of choice. We present the case of a 36 month old girl with tachycardiomyopathy as a result of an incessant atrial tachycardia originated in the right atrial appendage. Patient underwent radiofrequency ablation.(AU)

Esclerosis sistémica complicada con síncope y bloqueo AV completo / Systemic sclerosis complicated with syncope and complete AV block

La esclerosis sistémica es una compleja enfermedad que afecta el tejido conectivo, el sistema vascular y el sistema inmunológico, y se caracteriza por fibrosis cutánea y de órganos viscerales. Los bloqueos de rama y los hemibloqueos se presentan en el 25 a 75% de los casos y constituyen predictores independientes de mortalidad. Los bloqueos auriculoventriculares de segundo o tercer grado son muy raros. Presentamos el caso de una mujer de 47 años de edad, con diagnóstico de esclerosis sistémica, quien presenta episodio sincopal secundario a bloqueo auriculoventricular completo con necesidad de implante de marcapasos definitivo.

Systemic sclerosis is a complex disease that affects the connective tissue, the vascular system and the immune system. It typically produces skin and organ fibrosis. Cardiac bundle branch blocks and fascicular blocks occur in 25-75% of the cases and were found to be independent predictors of mortality. Second and third degree atrioventricular block are very rare. We present the case of a 47 year-old female with diagnosis of systemic sclerosis, presented with syncope secondary to complete atrioventricular block requiring permanent pacemaker implantation.

Complicaciones del implante de marcapaso definitivo: ¿Un evento operador dependiente? Análisis de 743 pacientes consecutivos / Complications of permanent pacemaker: Event operator dependent? Analysis of 743 consecutive patients

La frecuencia de complicaciones relacionadas al implante de marcapasos, es variable y se encuentra entre 6% a 9 %, y existen diferentes factores relacionados con las mismas. Objetivos: Evaluar las distintas complicaciones relacionadas con el implante de marcapasos y determinar cuáles son los factores de riesgo independientes que las predisponen. Métodos: Análisis descriptivo, tipo casos-controles, retrospectivo y prospectivo, correspondiente a 743 consecutivos, con implante de marcapasos definitivo, entre enero de 2007 y abril de 2008. Resultados: Edad de 73.83 ± 12 años, 63.9% varones. Los pacientes con algún grado de cardiopatía estructural representaron 43%. No hubo muertes relacionadas al implante de marcapasos. Tuvieron complicaciones relacionadas con el implante 57 pacientes (7.67%); 34 casos (4.57%), requirieron de una re-intervención quirúrgica. Hubo complicaciones graves: un paciente presentó endocarditis infecciosa (0.13%) que motivó la extracción del dispositivo y otro paciente, luego de la punción venosa subclavia, presentó neumotórax con necesidad de drenaje pleural (0.13%). En el análisis multivariado, las variables independientes relacionadas fueron: un operador poco experimentado y la presencia de insuficiencia cardiaca previa al implante. Conclusiones: En esta serie consecutiva de pacientes con implante de marcapasos definitivo, la incidencia de complicaciones se correlacionó con 1) operador con poca experiencia y 2) la presencia de insuficiencia cardiaca previa al implante, se relacionaron con las mismas.

The complications of permanent pacemaker implant, are found among 6%-9% of patients. Different factors are related. Objectives: We evaluated the complications related with pacemaker implants and which are the independent risk factors associated with them. Methods: Descriptive analysis, type case-controls, retrospective and prospective, including 743 consecutive patients, between January 2007 and April 2008. Results: Age: 73.83 ± 12 years, 63.9% male. 43% of the patients had some degree of structural cardiopathy. There were no deaths related to pacemaker implants. Implant procedure-related complications were observed in 57 patients (7.67%), requiring a surgical intervention in 34 patients (4.57%). The most serious complications included one device-related infective endocarditis (0.13%), the entire device system was extracted, and one pneumothorax following subclavian vein puncture with insertion of a chest tube. In the multivariate analysis, low level of operator experience and preimplant heart failure were independent predictors for complications. Conclusions: In this consecutive series of patients with permanent pacemaker implant, there was a low rate of complications, similar to the reported international series. A low level of operator experience and preimplant heart failure were related.

Resultados del uso de marcapasos definitivo en pacientes con cardiopatía chagásica y con enfermedad coronaria / Results of the use of definitive pacemakers in patients with chagasic cardiomyopathy and in patients with coronary artery disease

En la mayoría de los países de Latinoamérica, la enfermedad de Chagas es endémica y la miocardiopatía isquémica es la primera causa de afección cardíaca. Ambas entidades conviven generando un modelo biológico y epidemiológico único, y al ser enfermedades de evolución crónica, por diversos motivos pueden requerir el implante de un marcapasos definitivo. El objetivo del presente trabajo fue comparar los motivos de implante, detalles técnicos y evolución de pacientes referidos para tratamiento con marcapasos definitivo y portadores de miocardiopatía chagásica o miocardiopatía isquémica. (AU)

Resultados del uso de marcapasos definitivo en pacientes con cardiopatía chagásica y con enfermedad coronaria / Results of the use of definitive pacemakers in patients with chagasic cardiomyopathy and in patients with coronary artery disease

En la mayoría de los países de Latinoamérica, la enfermedad de Chagas es endémica y la miocardiopatía isquémica es la primera causa de afección cardíaca. Ambas entidades conviven generando un modelo biológico y epidemiológico único, y al ser enfermedades de evolución crónica, por diversos motivos pueden requerir el implante de un marcapasos definitivo. El objetivo del presente trabajo fue comparar los motivos de implante, detalles técnicos y evolución de pacientes referidos para tratamiento con marcapasos definitivo y portadores de miocardiopatía chagásica o miocardiopatía isquémica.