Experiencia latinoamericana en crioablación de fibrilación auricular paroxística y persistente con criobalón de segunda generación. Resultados en agudo y a 12 meses / Latin-American experience in cryoablation of paroxysmal and persistent atrial fibrillation using second generation cryo-balloon. Acute success and 12 months of follow-up

Resumen Objetivo: La ablación por catéteres es una técnica habitual para tratar la fibrilación auricular (FA). Son escasos los datos prospectivos y multicéntricos con resultados a mediano plazo de la crioablación de venas pulmonares en América Latina. El objetivo es evaluar la seguridad y la eficacia de la ablación por criobalón de segunda generación en pacientes con FA paroxística o persistente en América Latina. Método: Se evaluaron las características del procedimiento y los resultados en agudo y a 12 meses Se incluyeron pacientes con FA mayores de 18 años a quienes se realizara desconexión de venas pulmonares con criobalón de segunda generación. Se definió como fallo al tratamiento cualquier episodio de FA, aleteo auricular o taquicardia auricular de más de 30 segundos fuera del periodo de cegamiento de 90 días. Resultados: Se incluyeron 218 pacientes (57 ± 11 años, 66.5% hombres, CHA2DS2-VASc 1.2 ± 1.1). Presentaron FA paroxística el 83.9%, FA persistente el 12.8% y FA persistente de larga duración el 2.3%. Quince pacientes presentaban antecedentes de aleteo auricular. Habían fracasado a una droga antiarrítmica el 89.4%. El éxito en agudo se obtuvo en 211 pacientes (96.8%). El tiempo promedio del procedimiento fue de 73.2 ± 26.7 minutos, el tiempo de fluoroscopia fue de 21.4 ± 23.9 minutos y el tiempo total de ocupación del laboratorio fue de 114.6 ± 41.3 minutos. Durante los 12 meses de seguimiento, el tiempo libre de recurrencia de FA fue del 88.6% en FA paroxística y del 73.1% en FA persistente. Veintiún pacientes (9.6%) presentaron eventos adversos relacionados con el procedimiento. Conclusiones: Estos resultados indican que la desconexión de venas pulmonares con criobalón es un tratamiento seguro y efectivo para la FA en América Latina.

Abstract Objective: Catheter ablation has become a usual technique to treat atrial fibrillation (AF). Medium-term results of prospective and multicenter data concerning pulmonary veins cryoablation in Latin America are limited. The objective is to assess the safety and efficacy of ablation by second generation cryoballoon in patients with paroxysmal atrial fibrillation (PAF) or persistent atrial fibrillation (PerAF) in Latin America. Method: We evaluate the characteristics of the procedure and the acute and 12-month results. Inclusion criteria include patients over 18 years old with AF who have a planned procedure of pulmonary veins isolation with second generation cryoballoon. Treatment failure was defined as any episode of AF, atrial flutter or atrial tachycardia greater than 30 seconds outside the 90-day blinded period. Results: A total of 218 patients (57 ± 11 years, 66.5% men, CHA2DS2-VASc 1.2 ± 1.1) were included in the study. Of these, 83.9% evidenced PAF, 12.8% PerAF, and 2.3% long-standing PerAF. Fifteen with history of atrial flutter. Most patients had failed at least one antiarrhythmic drug (89.4%). The acute success of the procedure was obtained in 211 patients (96.8%). The average procedure time was 73.2 ± 26.7 min, the fluoroscopy time was 21.4 ± 23.9 min, and the total lab occupancy time was 114.6 ± 41.3 min. During the 12-month follow-up, freedom from AF recurrence was 88.6% in PAF, and 73.1% in PerAF. Twenty-one patients experienced device or procedure-related complications (9.6%). Conclusions: These results support pulmonary veins electrical isolation with cryoballoon as an effective treatment for AF in Latin America.

Latin-American experience in cryoablation of paroxysmal and persistent atrial fibrillation using second generation cryo-balloon. Acute success and 12 months of follow-up / Experiencia latinoamericana en crioablación de fibrilación auricular paroxística y persistente con criobalón de segunda generación. Resultados en agudo y a 12 meses

Objective: Catheter ablation has become a usual technique to treat atrial fibrillation (AF). Medium-term results of prospective and multicenter data concerning pulmonary veins cryoablation in Latin America are limited. The objective is to assess the safety and efficacy of ablation by second generation cryoballoon in patients with paroxysmal atrial fibrillation (PAF) or persistent atrial fibrillation (PerAF) in Latin America. Method: We evaluate the characteristics of the procedure and the acute and 12-month results. Inclusion criteria include patients over 18 years old with AF who have a planned procedure of pulmonary veins isolation with second generation cryoballoon. Treatment failure was defined as any episode of AF, atrial flutter or atrial tachycardia greater than 30 seconds outside the 90-day blinded period. Results: A total of 218 patients (57 ± 11 years, 66.5% men, CHA2DS2-VASc 1.2 ± 1.1) were included in the study. Of these, 83.9% evidenced PAF, 12.8% PerAF, and 2.3% long-standing PerAF. Fifteen with history of atrial flutter. Most patients had failed at least one antiarrhythmic drug (89.4%). The acute success of the procedure was obtained in 211 patients (96.8%). The average procedure time was 73.2 ± 26.7 min, the fluoroscopy time was 21.4 ± 23.9 min, and the total lab occupancy time was 114.6 ± 41.3 min. During the 12-month follow-up, freedom from AF recurrence was 88.6% in PAF, and 73.1% in PerAF. Twenty-one patients experienced device or procedure-related complications (9.6%). Conclusions: These results support pulmonary veins electrical isolation with cryoballoon as an effective treatment for AF in Latin America.

Objetivo: La ablación por catéteres es una técnica habitual para tratar la fibrilación auricular (FA). Son escasos los datos prospectivos y multicéntricos con resultados a mediano plazo de la crioablación de venas pulmonares en América Latina. El objetivo es evaluar la seguridad y la eficacia de la ablación por criobalón de segunda generación en pacientes con FA paroxística o persistente en América Latina. Método: Se evaluaron las características del procedimiento y los resultados en agudo y a 12 meses Se incluyeron pacientes con FA mayores de 18 años a quienes se realizara desconexión de venas pulmonares con criobalón de segunda generación. Se definió como fallo al tratamiento cualquier episodio de FA, aleteo auricular o taquicardia auricular de más de 30 segundos fuera del periodo de cegamiento de 90 días. Resultados: Se incluyeron 218 pacientes (57 ± 11 años, 66.5% hombres, CHA2DS2-VASc 1.2 ± 1.1). Presentaron FA paroxística el 83.9%, FA persistente el 12.8% y FA persistente de larga duración el 2.3%. Quince pacientes presentaban antecedentes de aleteo auricular. Habían fracasado a una droga antiarrítmica el 89.4%. El éxito en agudo se obtuvo en 211 pacientes (96.8%). El tiempo promedio del procedimiento fue de 73.2 ± 26.7 minutos, el tiempo de fluoroscopia fue de 21.4 ± 23.9 minutos y el tiempo total de ocupación del laboratorio fue de 114.6 ± 41.3 minutos. Durante los 12 meses de seguimiento, el tiempo libre de recurrencia de FA fue del 88.6% en FA paroxística y del 73.1% en FA persistente. Veintiún pacientes (9.6%) presentaron eventos adversos relacionados con el procedimiento. Conclusiones: Estos resultados indican que la desconexión de venas pulmonares con criobalón es un tratamiento seguro y efectivo para la FA en América Latina.

Evaluación del impacto de la terapia de resincronización cardiaca en pacientes de Latinoamérica / Evaluation of the impact of cardiac resynchronisation on patients Latin America

Resumen Objetivo: medir el impacto de la terapia de resincronización cardiaca en términos de variables ecocardiográficas en pacientes de países latinoamericanos. Método: se realizó un estudio prospectivo, multicéntrico, intervencionista, en el que los pacientes elegibles fueron llevados, por primera vez, a implante de un dispositivo de resincronización cardiaca. El objetivo primario fue valorar los cambios del tamaño y la función del ventrículo izquierdo por medio de un ecocardiograma previo al implante del dispositivo y en el sexto mes. Los objetivos secundarios evaluados fueron hospitalizaciones, cambios en la clase funcional, mortalidad, calidad de vida y un score compuesto clínico basado en estos factores de evaluación global del paciente. Resultados: para cumplir el objetivo primario se analizaron datos de 75 sujetos. La edad promedio fue de 63,7 años; 21.3% fueron mujeres y 30.7% tuvieron cardiopatía isquémica. Al sexto mes de seguimiento las mediciones de volumen de fin de diástole y sístole del ventrículo izquierdo disminuyeron en promedio 37.6 ml y 37.8 ml, respectivamente. La fracción de eyección del ventrículo izquierdo en promedio se incrementó un 11%. El puntaje compuesto clínico mostró mejoría en el 86.4% de los pacientes en el sexto mes postimplante del resincronizador. Conclusiones: se observó remodelado inverso del ventrículo izquierdo y mejoría en el estado clínico de los pacientes con insuficiencia cardiaca y disfunción sistólica del ventrículo izquierdo que recibieron terapia de resincronización cardiaca en el ámbito de la práctica clínica de rutina.

Abstract Objective: To measure the impact of cardiac resynchronisation therapy in terms of cardiac ultrasound variables in patients from Latin-American countries. Method: A prospective, multicentre, interventionist study was conducted, in which the eligible patients were those that had a cardiac resynchronisation device implanted for the first time. The primary objective was to assess the changes in size and left ventricular function by means of a cardiac ultrasound carried out prior to implanting the device and in the sixth month. The secondary objectives evaluated were hospital admissions, change in functional class, mortality, quality of life, and an overall assessment of the patient using a combined clinical score based on these factors. Results: A total of 75 subjects were analysed in order to complete the primary objective. The mean age was 63.7 years; 21.3% were female, and 30.7% had ischaemic heart disease. At the sixth month, the left ventricular end-diastolic and systolic volume decreased by a mean of 37.6 ml and 37.8 ml, respectively. The left ventricular ejection fraction increased by a mean of 11%. The combined clinical score showed an improvement in 86.4% of the patients in the sixth month after the implantation of the synchronisation device. Conclusions: A reverse remodelling of the left ventricle was observed, as well as an improvement in the clinical stage of patients with heart failure and left ventricular systolic dysfunction that received cardiac resynchronisation treatment in the setting of routine clinical practice.

[New conduction disturbances and pacemaker indications after CoreValve® transcatheter aortic valve replacement. Incidence and follow up in a single center experience]. / Desarrollo de trastornos de conducción e indicaciones de marcapasos postimplante de válvula aórtica CoreValve® por vía endovascular. Incidencia y seguimiento en un solo centro.

INTRODUCTION: Transcatheter aortic valve implantation (TAVI) is currently reserved for patients with symptomatic aortic stenosis and high surgical risk. One major limiting factor related to TAVI procedural complications is conduction abnormalities and the need for permanent pacemaker implantation. OBJECTIVES: Evaluate the incidence of new conduction disturbances and pacemaker indications in patients with TAVI CoreValve® prosthesis (Medtronic Inc. Minneapolis, Minnesota, United States). METHODS: We included 28 patients, mean age 80 years. ECG parameters were evaluated previous and after implantation. All patients were monitorized during TAVI. Follow up Holter monitoring was performed at one, 6 and 12 months after the procedure and we also evaluated telemetry of implanted pacemaker. RESULTS: In previous ECG we found 7 patients had right bundle branch block and 7 patients had left bundle brunch block (LBBB). The post implant ECG showed 7 new LBBB: 3 during valvuloplasty and 4 on the end of it. Six patients required pacemaker implantation for permanent or paroxysmal complete AV block (CAVB). At one year follow up, 3 patients with LBBB during valvuloplasty had a normal ECG, one still had LBBB and one an asymptomatic CAVB found in Holter monitoring. CONCLUSIONS: Conduction abnormalities are frequent after CoreValve® aortic valve prosthesis implantation. The incidence of new LBBB was 25%. CAVB during or post TAVI require PM implantation. New LBBB may need a closer follow up because in a 3% of the cases it may progress to CAVB.

Relation of interatrial block to new-onset atrial fibrillation in patients with Chagas cardiomyopathy and implantable cardioverter-defibrillators.

Chagas cardiomyopathy is an endemic disease in Latin America. A significant proportion of patients develop atrial fibrillation (AF), which may result in stroke and increased morbidity or mortality. Interatrial block (IAB) has been associated with the development of AF in different clinical scenarios. The aim of our study was to determine whether IAB can predict new-onset AF in patients with Chagas cardiomyopathy and implantable cardioverter-defibrillators (ICDs). We conducted a retrospective study of patients with Chagas cardiomyopathy and ICDs from 14 centers in Latin America. Demographics, clinical, and device follow-up were collected. Surface electrocardiograms were scanned at 300 dpi and maximized ×8. Semiautomatic calipers were used to determine P-wave onset and offset. Partial IAB was defined as a P wave of >120 ms and advanced IAB as a P wave of >120 ms with biphasic morphology (±) in inferior leads. AF events and ICD therapies were reviewed during follow-up by 2 independent investigators. A total of 80 patients were analyzed. Mean age was 54.6 ± 10.4 years, and 52 (65%) were male. Mean left ventricular ejection fraction was 40 ± 12%. IAB was detected in 15 patients (18.8%), with 8 (10.0%) partial and 7 (8.8%) advanced. During a follow-up of 33 ± 20 months, 11 patients (13.8%) presented with new AF. IAB (partial + advanced) was strongly associated with new AF (p <0.0001) and inappropriate therapy by the ICD (p = 0.014). In conclusion, IAB (partial + advanced) predicted new-onset AF in patients with Chagas cardiomyopathy and ICDs.

Fragmented surface ECG was a poor predictor of appropriate therapies in patients with Chagas' cardiomyopathy and ICD implantation (Fragmented ECG in CHAgas' Cardiomyopathy Study).

BACKGROUND: Main causes of death in chronic Chagas' cardiomyopathy (CChC) are progressive congestive heart failure and sudden cardiac death. Implantable cardioverter defibrillators (ICD) have been proved an effective therapy to prevent sudden death in patients with CChC. Identification of predictors of sudden death remains a challenge. OBJECTIVE: To determine whether surface fragmented ECG (fQRS) helps identifying patients with CChC and ICDs at higher risk of presenting appropriate ICD therapies. METHODS: Multicenter retrospective study. All patients with CChC and ICDs were analyzed. Clinical demographics, surface ECG, and ICD therapies were collected. RESULTS: A total of 98 patients were analyzed. Another four cases were excluded due to pacing dependency. Mean age was 55.5 ± 10.4 years, male gender 65%, heart failure New York Heart Association class I 47% and II 38%. Mean left ventricular ejection fraction (LVEF) 39.6 ± 11.8%. The indication for ICD was secondary prevention in 70% of patients. fQRS was found in 56 patients (59.6%). Location of fragmentation was inferior (57.1%), lateral (35.7%), and anterior (44.6%). Rsr pattern was the more prevalent (57.1%). Predictors of appropriate therapy in the multivariate model were: increased age (P = 0.01), secondary prevention indication (P = 0.01), ventricular pacing >50% of the time (P = 0.004), and LVEF <30% (P = 0.01). The presence of fQRS did not identify patients at higher risk of presenting appropriate therapies delivered by the ICD (P = 0.87); regardless of QRS interval duration. CONCLUSIONS: fQRS is highly prevalent among patients with CChC. It has been found a poor predictor of appropriate therapies delivered by the ICD in this population.

The systolic index: a noninvasive approach for the assessment of cardiac function: implications for patients with DDD and CRT devices.

BACKGROUND: Our objective was to evaluate the systolic index (SI), the ratio between rate-corrected left ventricular ejection time (LVETc), and a preejection period surrogate (PEPsu), to assess cardiac function in patients with DDD and cardiac resynchronization therapy (CRT) pacemakers. METHODS: LVETc and PEPsu were automatically measured from electrocardiogram and finger photoplethismography. Atrioventricular (AV) and mode switch (CRT to DDD) were used as hemodynamic challenges. Performance of SI, beat-by-beat systolic blood pressure (SBP), and Doppler aortic velocity/time integral (AoVTI) were compared in 36 patients, and SI's detection of CRT to DDD mode switch in nine patients, responders to CRT. AVs were changed from 30 ms to 250 ms (20 ms steps) at constant paced heart rate, alternating with a reference AV (RefAV), to reduce hemodynamic drift. The coefficient of variation (standard deviation/mean) of SI, SBP, and AoVTI during all RefAVs were used as error marker. The percentage detection of hemodynamic changes during AV transitions was a marker of sensitivity. RESULTS: Fifty-five patients (males 62%, age 69.6 ± 17) were studied. SI detected 441 of 544 transitions (81%) versus 361 (66%) of SBP (P = 0.005). Error during RefAVs was smaller for SI (3.4%) as compared to AoVTI (7.8%, P = 0.015) and to SBP (5.7%, P = 0.005). SIs correlated with AoVTI (R from 0.71 to 0.98, all P < 0.001). SI detected all CRT to DDD changes (P < 0.001). CONCLUSION: The noninvasive SI obtained with a simple, observer-independent hemodynamic assessment procedure has higher accuracy than SBP and AoVTI and better sensitivity than SBP. It detects mechanical resynchronization in CRT and allows programming a suitable AV delay.

Lack of current implantable cardioverter defibrillator guidelines application for primary prevention of sudden cardiac death in Latin American patients with heart failure: a cross-sectional study.

AIMS: This cross-sectional study evaluated the application of accepted international implantable cardioverter defibrillator (ICD) guidelines for primary prevention of sudden cardiac death in patients with heart failure. METHODS AND RESULTS: The PLASMA (Probabilidad de Sufrir Muerte Arritmica) study was designed to characterize management of cardiac patients in Latin America. Twelve centres included 1958 consecutively admitted patients in cardiology units in 2008 and 2009. Discharged patients were evaluated for primary prevention, ICD indication and prescription by general cardiologists. Of 1711 discharged patients, 1525 (89%) had data available for evaluating indication status. Class I indications for ICD therapy were met for 153 (10%) patients based on collected data. Only 20 (13%, 95% confidence interval: 7.7-18.4%) patients with indication were prescribed an ICD. Patients prescribed an ICD were younger than patients who were not prescribed an ICD (62 vs. 68 years, P < 0.01). The reasons given by cardiologists for not prescribing an ICD for 133 patients with an indication were: indication criteria not met (75%), life expectancy <1 year (9.7%), rejection by the patient (5.2%), no medical coverage paying for the device (3.7%), psychiatric patient (2.2%), and other reasons (4.2%). CONCLUSIONS: In Latin America, international guidelines for primary prevention ICD implantation are not well followed. The main reason is that cardiologists believe that patients do not meet indication criteria, even though study data confirm that criteria are met. This poses a significant challenge and underlines the importance of continuous and improved medical education.

Razón y diseño del estudio utilidad clínica del monitor cardíaco implantable en pacientes con enfermedad de chagas: estudio reveal Chagas / Rationale and Design clinical utility of the implantable loop recorder in patients with Chagas disease

Resumén: El estudio “Utilidad clínica del monitor cardiaco implantable en pacientes con Enfermedadde Chagas”. El Estudio Reveal Chagas es un estudio prospectivo e intervencionista a realizarse en varios centros de Latinoamérica con el propósito de estudiar el posible beneficio en la detección precoz de arritmias cardiacas (bradi y/o taquiarritmias) utilizando un monitor cardiaco implantable (MCI) en pacientes con Enfermedad de Chagas diagnosticados por serologia, que cursen asintomáticos y/o mínimamente sintomáticos, que tengan trastornos electrocardiográficos y/o arrítmicos y que de manera inmediata no requieran el implante de un dispositivo de estimulación cardiaca y/o cardiodesfibrilador de acuerdo a las indicaciones universalmente aceptadas.

Abstract: Rationale and Design “Clinical Utility of the Implantable Loop Recorder in Patients with Chagas Disease “. Reveal Chagas Study is a prospective, multi center, randomized study planned to be performed in Latin-America. The main objective is to look for potential benefits of an early detection of cardiac arrhythmias (brady/tachyarrhythmias) by means of an implantable Cardiac Monitor applied to Chagas Disease´ patients. The target population will be patients without or minimal expression of symptoms, with documented ECG abnormalities or cardiac arrhythmias, in whom there is no an acceptedindication for immediate pacemaker, ICD or other cardiac device implant based on the internationalguidelines.

Predictors of all-cause 1-year mortality in implantable cardioverter defibrillator patients with chronic Chagas' cardiomyopathy.

BACKGROUND: Implantable cardioverter defibrillators (ICDs) have been used in the treatment of either sustained ventricular tachycardia or ventricular fibrillation in patients with Chagas' cardiomyopathy. This study aimed at determining mortality rate and risk factors of all-cause 1-year mortality in primary and secondary ICD patients with Chagas' cardiomyopathy. METHODS: One hundred and forty-eight Chagas' patients with ICDs were included from the Medtronic ICD Registry Latin America. All patients were followed for 1 year. RESULTS: At implant, mean age was 60.1 ± 9.4 years and 72.9% were male. Mean left ventricular ejection fraction (LVEF) was 40.1 ± 11%. Mean follow-up was 12 ± 7 months. During the follow-up, 15 patients died (10.2%). Patients who died were older (64 ±10.8 years vs 59 ± 9.1; P = 0.04), had more atrial fibrillation (13.3% vs 3.8%; P = 0.02), had lower LVEF (33.4%± 9.8 vs 40.9%± 11.3; P = 0.01), and worse functional class (III/IV 40% vs 21.8%; P = 0.03). The multivariate analysis showed that two independent predictors of all-cause 1-year mortality remained statistically significant: age more than 65 (hazard ratio [HR] = 2.85, 95% confidence interval [CI] 1.77-3.92; P = 0.03) and LVEF less than 30% (HR = 2.68, 95% CI 1.57-3.79; P = 0.04). CONCLUSION: This analysis showed that patients older than 65 years of age and with LVEF less than 30% were independent predictors of all-cause 1-year mortality in patients with chronic Chagas' cardiomyopathy.

Current and emerging therapeutic options for the treatment of chronic chagasic cardiomyopathy.

Chagas' disease is an endemic disease in Latin America caused by a unicellular parasite (Trypanosoma cruzi) that affects almost 18 million people. This condition involves the heart, causing heart failure, arrhythmias, heart block, thromboembolism, stroke, and sudden death. In this article, we review the current and emerging treatment of Chagas' cardiomyopathy focusing mostly on management of heart failure and arrhythmias. Heart failure therapeutical options including drugs, stem cells and heart transplantation are revised. Antiarrhythmic drugs, catheter ablation, and intracardiac devices are discussed as well. Finally, the evidence for a potential role of specific antiparasitic treatment for the prevention of cardiovascular disease is reviewed.

Estudo multicêntrico de pacientes submetidos a implante de cardioversor-desfibrilador implantável (CDI) na America Latina / Multi-center study of patients who underwent implants of implantable cardioverter-defibrillator (ICD) in Latin America / Estudio multicéntrico de pacientes sometidos a implante de cardioversor-desfibrilador implantable(CDI) en Latinoamérica

O ICD Register da Medtronic foi introduzido na América Latina com a finalidade de coletar dados relacionados à indicação de implantes de CDI para prevenção primária e secundária de morte súbita e ao acompanhamento de pacientes originários de Porto Rico, Caribe. México e América do Sul. Além dessa ampla variedade geográfica, também foram incluídos detalhes referentes aos cuidados de saúde recebidos como parte do tratamento. O presente estudo apresenta as características de desfecho de 910 portadores de cardiopatias tratados para prevenção primária, em comparação com aqueles nos quais o implante destinou-se à prevenção secundária.

The ICD Register was introduced to Latin America to collect data related to implant indication of ICD for the prevention of primary and secondary deaths and for the follow-up of patients from Puerto Rico, the Caribbean, Mexico and South America. In addition to this vast geographic variety, information related to the health care as part of the treatment has also been included. This study shows the characteristics of the outcome of 910 cardiopathy patients treated for primary prevention, incomparison to those whose implants were meant for secondary prevention.

El ICD Register de Medtronic fue introducido en América Latina a fin de recoger datos relacionados a la indicación de implantes de CDI para la prevención primaria y secundaria de muerte súbita y a la remisión de pacientes provenientes de Puerto Rico, Caribe, México y Sudamérica. Ademásde esa amplia variedad geográfica, también se incluyeron detalles referentes a los cuidados de saludrecibidos como parte del tratamiento. El presente estudio presenta las características de solución de 910 portadores de cardiopatías tratados para la prevención primaria, en comparación con aquellos cuyo implante se destinó a la prevención secundaria.

Implantable cardioverter defibrillators and Chagas' disease: results of the ICD Registry Latin America.

AIMS: Chagas' disease is an endemic parasitic affliction in Latin America. It is frequently associated with ventricular tachyarrhythmia and sudden death. The aim of this study is to assess the evolution of patients with Chagas' disease treated with an implantable cardioverter defibrillator (ICD). METHODS AND RESULTS: Eighty-nine chagasic patients with ICD were included for analysis from the Medtronic ICD Registry Latin America. At implant, mean age was 59 +/- 10 years, and 72% were male. Eighty-one patients (91%) had secondary prevention indications. Mean left ventricular ejection fraction was 40 +/- 11%, and mean follow-up was 12 +/- 7 months. During follow-up, six patients died (6.7%); three due to congestive heart failure, one due to sudden death, and two due to non-cardiac cause. Hospitalization occurred in seven patients. Thirty-eight patients (42%) received appropriate ICD therapies. A total of 737 episodes were detected by the ICD. The mean period between ICD implantation and the first appropriate therapy was 104 days. Electrical storms were observed in 14 of the 89 patients (15.7%). Inappropriate therapies were observed in seven patients. CONCLUSION: This registry confirms that ICD therapy provides protection by effectively terminating life-threatening arrhythmias in patients with Chagas' disease. This is especially so when patients receive the device for secondary prevention.

Prevención primaria y secundaria de muerte súibita en el ICD Registry Latin America / Primary and secondary prevention of sudden cardiac death in the icd registry-latin america

INTRODUCTION AND OBJECTIVES: The ICD Registry is an observational study conducted in Latin America to collect data on indications and follow-up care for primary or secondary prevention of sudden cardiac death patients. The objective of this study is to compare and evaluate the characteristics of primary versus secondary prevention in the patient population enrolled in the registry. METHODS: Demographic data, indication, etiology, NYHA functional class and left ventricular ejection fraction (LVEF), pharmacological treatment at implant and the type of ICD implanted were also collected. During the follow-up period the ICD therapies delivered, patient hospitalizations and mortality were evaluated. RESULTS: 507 patients were evaluated. Average age 60 +/- 14 years old, 78% male. Coronary heart disease was the most common etiology (43.6%). NYHA Functional Class I/II at the time of implant (73.6%). Average LVEF was 34 +/- 16%. Out of 507 patients, 189 received an ICD for primary prevention; 318 for secondary prevention. Primary prevention patients were older, predominantly male and had a lower EF. The rate of mortality and hospitalizations were similar between both groups with a higher rate of appropriate therapies in secondary prevention patients. CONCLUSIONS: This is the first study to demonstrate clinical characteristics of primary prevention patients in Latin America. There were no significant statistically differences in a short follow-up period in mortality or hospitalization as compared to the secondary prevention patient population in the Registry.

[Initiation mode of ventricular tachyarrhythmias in chronic Chagas' cardiomyopathy]. / Modo de inicio de las taquiarritmias ventriculares en la cardiopatía chagásica crónica.

AIM: The purpose of this study was to investigate the modes of initiation of malignant ventricular tachyarrhythmias in patients with Chagas' cardiomyopathy (ChC) with an implantable cardioverter-defibrillator (ICD) through the analysis of stored intracardiac electrograms. Specifically, we analyzed the incidence of ventricular arrhythmias preceded by the short-long-short-pattern (sls). METHODS: We analyzed 179 spontaneous malignant ventricular tachyarrhythmias episodes in 15 patients with Chagas' cardiomyopathy with an ICD. The mean cycle length in normal sinus rhythm before initiation of the malignant ventricular tachyarrhythmias, the ventricular tachycardia (VT) cycle length, the prematurity ratio and the number of ventricular premature contractions (VPCs) (single, pairs or multiple) that triggered malignant ventricular tachyarrhythmias were compared between the two different initiation modes. RESULTS: Mean age: 60.4 +/- 5.7 -years-old, mean EF, 33.2 +/- 8.5%, 9 men and 6 women. A sls-pattern was found in 43.5% of the malignant ventricular tachyarrhythmias. Baseline cycle length (795 +/- 16 vs 788 +/- 14 ms), VT cycle length (320 +/- 7.7 ms vs 329 +/- 5.7 ms) and prematurity ratio (0.57 +/- 11 vs 0.60 +/- 12) were similar between sls and non-sls-sequences. Multiple VPCs as a trigger of malignant ventricular tachyarrhythmias was significantly less often in sls-events than in non-sls events (14% vs 40%; P < 0.0001). CONCLUSIONS: In this select population of patients with ChC, we observed a high prevalence of sls-pattern just before initiation of malignant ventricular tachyarrhythmias. Multiple VPCs were often associated with a non-sls trigger mode.

Modo de inicio de las taquiarritmias ventriculares en la cardiopatía chagásica crónica / Initiation mode of ventricular tachyarrhythmias in chronic Chagas' cardiomyopathy

AIM: The purpose of this study was to investigate the modes of initiation of malignant ventricular tachyarrhythmias in patients with Chagas' cardiomyopathy (ChC) with an implantable cardioverter-defibrillator (ICD) through the analysis of stored intracardiac electrograms. Specifically, we analyzed the incidence of ventricular arrhythmias preceded by the short-long-short-pattern (sls). METHODS: We analyzed 179 spontaneous malignant ventricular tachyarrhythmias episodes in 15 patients with Chagas' cardiomyopathy with an ICD. The mean cycle length in normal sinus rhythm before initiation of the malignant ventricular tachyarrhythmias, the ventricular tachycardia (VT) cycle length, the prematurity ratio and the number of ventricular premature contractions (VPCs) (single, pairs or multiple) that triggered malignant ventricular tachyarrhythmias were compared between the two different initiation modes. RESULTS: Mean age: 60.4 +/- 5.7 -years-old, mean EF, 33.2 +/- 8.5%, 9 men and 6 women. A sls-pattern was found in 43.5% of the malignant ventricular tachyarrhythmias. Baseline cycle length (795 +/- 16 vs 788 +/- 14 ms), VT cycle length (320 +/- 7.7 ms vs 329 +/- 5.7 ms) and prematurity ratio (0.57 +/- 11 vs 0.60 +/- 12) were similar between sls and non-sls-sequences. Multiple VPCs as a trigger of malignant ventricular tachyarrhythmias was significantly less often in sls-events than in non-sls events (14% vs 40%; P < 0.0001). CONCLUSIONS: In this select population of patients with ChC, we observed a high prevalence of sls-pattern just before initiation of malignant ventricular tachyarrhythmias. Multiple VPCs were often associated with a non-sls trigger mode.

[Primary and secondary prevention of sudden cardiac death in the ICD Registry-Latin America]. / Prevención primaria y secundaria de muerte súibita en el ICD Registry Latin America.

INTRODUCTION AND OBJECTIVES: The ICD Registry is an observational study conducted in Latin America to collect data on indications and follow-up care for primary or secondary prevention of sudden cardiac death patients. The objective of this study is to compare and evaluate the characteristics of primary versus secondary prevention in the patient population enrolled in the registry. METHODS: Demographic data, indication, etiology, NYHA functional class and left ventricular ejection fraction (LVEF), pharmacological treatment at implant and the type of ICD implanted were also collected. During the follow-up period the ICD therapies delivered, patient hospitalizations and mortality were evaluated. RESULTS: 507 patients were evaluated. Average age 60 +/- 14 years old, 78% male. Coronary heart disease was the most common etiology (43.6%). NYHA Functional Class I/II at the time of implant (73.6%). Average LVEF was 34 +/- 16%. Out of 507 patients, 189 received an ICD for primary prevention; 318 for secondary prevention. Primary prevention patients were older, predominantly male and had a lower EF. The rate of mortality and hospitalizations were similar between both groups with a higher rate of appropriate therapies in secondary prevention patients. CONCLUSIONS: This is the first study to demonstrate clinical characteristics of primary prevention patients in Latin America. There were no significant statistically differences in a short follow-up period in mortality or hospitalization as compared to the secondary prevention patient population in the Registry.

Incidencia y variables asociadas con la muerte súbita en una población general. Subanálisis del estudio PRISMA / Incidence and variables associated with sudden death in a general population. Subanalysis of the PRISMA Study

Introducción y objetivos: En nuestro país no existen datos sobre la incidencia y las variables clínicas de riesgo de muerte cardíaca súbita en la población general. El presente trabajo se llevó a cabo con el propósito de conocer la tasa de muerte súbita en una población seleccionada y determinar las variables clínicas asociadas con ella. Material y métodos: Durante 2 meses se realizó un registro prospectivo y consecutivo de todas las personas mayores de 18 años fallecidas por diferentes causas en 20 ciudades del país. Mediante una entrevista al médico de cabecera o a un familiar se determinaron las causas de muerte, los antecedentes cardiovasculares, los factores de riesgo y el lugar del fallecimiento. Se definió muerte súbita a la ocurrida dentro de la hora del inicio de los síntomas. Resultados: Sobre un total de 642.021 personas se registraron 1.274 muertes. La edad media fue de 72,5 ± 17,6 años y el 52,9 por ciento eran hombres. Ochenta y una personas (6,3 por ciento) fallecieron súbitamente, lo cual representa una incidencia en el período estudiado (2 meses) de 0,126/1.000 personas. En el análisis multivariado, las variables independientes que se asociaron con muerte súbita fueron la edad mayor de 70 años (OR 1,7, IC 95 por ciento 1,04-2,77), la dislipidemia (OR 1,8, IC 95por ciento 1,07-3,06), el infarto previo (OR 1,85, IC 95por ciento 1,01-3,55) y recibir medicación cardiovascular (OR 1,98, IC 95 por ciento 1,20-3,26). El 49 por ciento de las muertes súbitas no tenían antecedentes cardiovasculares. La mayoría de las muertes súbitas fueron extrahospitalarias. Conclusiones: En esta población seleccionada, los datos sugieren que la cardiopatía coronaria parece ser un factor de riesgo para muerte súbita cardíaca que podría ser modificable aunque casi la mitad de las personas fallecieron sin antecedentes cardiovasculares.

Incidencia y variables asociadas con la muerte súbita en una población general. Subanálisis del estudio PRISMA / Incidence and variables associated with sudden death in a general population. Subanalysis of the PRISMA Study

Introducción y objetivos: En nuestro país no existen datos sobre la incidencia y las variables clínicas de riesgo de muerte cardíaca súbita en la población general. El presente trabajo se llevó a cabo con el propósito de conocer la tasa de muerte súbita en una población seleccionada y determinar las variables clínicas asociadas con ella. Material y métodos: Durante 2 meses se realizó un registro prospectivo y consecutivo de todas las personas mayores de 18 años fallecidas por diferentes causas en 20 ciudades del país. Mediante una entrevista al médico de cabecera o a un familiar se determinaron las causas de muerte, los antecedentes cardiovasculares, los factores de riesgo y el lugar del fallecimiento. Se definió muerte súbita a la ocurrida dentro de la hora del inicio de los síntomas. Resultados: Sobre un total de 642.021 personas se registraron 1.274 muertes. La edad media fue de 72,5 ± 17,6 años y el 52,9 por ciento eran hombres. Ochenta y una personas (6,3 por ciento) fallecieron súbitamente, lo cual representa una incidencia en el período estudiado (2 meses) de 0,126/1.000 personas. En el análisis multivariado, las variables independientes que se asociaron con muerte súbita fueron la edad mayor de 70 años (OR 1,7, IC 95 por ciento 1,04-2,77), la dislipidemia (OR 1,8, IC 95por ciento 1,07-3,06), el infarto previo (OR 1,85, IC 95por ciento 1,01-3,55) y recibir medicación cardiovascular (OR 1,98, IC 95 por ciento 1,20-3,26). El 49 por ciento de las muertes súbitas no tenían antecedentes cardiovasculares. La mayoría de las muertes súbitas fueron extrahospitalarias. Conclusiones: En esta población seleccionada, los datos sugieren que la cardiopatía coronaria parece ser un factor de riesgo para muerte súbita cardíaca que podría ser modificable aunque casi la mitad de las personas fallecieron sin antecedentes cardiovasculares.(AU)

Precisión del certificado de defunción comparado con la autopsia verbal: estudio PRISMA / Accuracy of the death certificate (DC) to assess the cause of death and comparison with the verbal autopsy: the PRISMA study

Los datos del certificado de defunción no reflejan ajustadamente las causas y las circunstancias de la muerte. La comparación con otros métodos de información, como la autopsia verbal, podría demostrar las falencias de los registros. Objetivos: 1. Identificar las causas de muerte en 20 ciudades argentinas mediante la autopsia verbal y compararlas con las que constan en el certificado de defunción. 2. Analizar la muerte cardiovascular en cuanto a antecedentes y factores de riesgo. Material y métodos: Se incluyeron todos los mayores de 18 años fallecidos durante 2 meses del año 2004 en las ciudades participantes. Resultados: Se constataron 1274 muertes. Según la autopsia verbal, las causas de muerte cardiovascular más frecuentes fueron insuficiencia cardíaca (23 por ciento), accidente cerebrovascular (11,3 por ciento) e infarto de miocardio (8 por ciento) y las no cardiovasculares fueron neoplasias (21,5 por cierto), neumopatías (7,6 por ciento) e infecciones (6,6 por ciento). En el 11,7 por ciento de los fallecidos no se pudo establecer claramente la causa de muerte según el certificado.La concordancia de ambos métodos para definir la causa de muerte según el coeficiente V de Cramer fue de 0,608, el valor de kappa fue de 0,614 (0,580-0,647) y el de kappa ponderado fue de 0,596 (0,555-0,637). Existió un subregistro del 9,7 por ciento de insuficiencia cardíaca según el certificado y un sobrerregistro del 6,4 por ciento en muerte por otras causas cardiovasculares conrespecto a la autopsia verbal. Los fallecidos de causa cardiovascular presentaron con más frecuencia factores de riesgo y antecedentes cardiovasculares. Conclusiones: En un porcentaje elevado de certificados de defunción no se pudo establecer claramente la causa de muerte. La mayor discordancia se registró en la muerte por insuficiencia cardíaca y otras causas cardiovasculares.