Search

Introduction and objectives: In December 2019, SARS-CoV-2, was discovered as the agent of COVID-19 disease. Cardiac arrhythmias have been reported as frequent but their incidence is unknown. The aim of this research was to assess the real incidence of cardiac arrhythmias among COVID-19 patients admitted to Portuguese hospitals and to understand the underlying prognostic implications. Methods: The Portuguese Association of Arrhythmology, Pacing and Electrophysiology (APAPE) conducted a survey in Portuguese hospitals to assess the occurrence of arrhythmias in COVID-19 patients, their clinical characteristics, the use of experimental therapies and the impact on QT interval. Results: Twenty hospitals participated, reporting 692 hospitalized patients. An arrhythmic episode occurred in 81 (11.7%) and 64 (79%) had detailed information on these episodes. New onset arrhythmias occurred in 41 (64%) patients, 45 (70.3%) male, median age 73.5 (61-80.3) years. There were 51 (79.7%) with associated comorbidities, mainly arterial hypertension (41, 64.1%). Of 53 patients (82.3%) on experimental therapy, 7 (10.9%) had an increased QTc interval. Regarding arrhythmias, two patients (3.1%) had ventricular tachycardia, 5 (7.8%) sinus bradycardia, 17 (26.6%) paroxysmal supraventricular tachycardia and 40 (62.5%) atrial fibrillation or flutter. At the time of reporting, there had been no deaths due to arrhythmic syndrome or related complications. Conclusions: In a population of COVID-19 patients. The incidence of cardiac arrhythmias is high but not associated with increased cardiac mortality although it does though occur frequently in extremely ill patients and with multiple organ failure. Regardless of the use of experimental drugs, the incidence of ventricular arrhythmias is low and atrial fibrillation and other supraventricular arrhythmias are the most prevalent arrythmias. Resumo: Introdução e objetivos: Em dezembro de 2019, o SARS-CoV-2 foi descoberto como agente da doença Covid-19. As arritmias cardíacas são reportadas como frequentes, mas a sua incidência é desconhecida. O objetivo deste trabalho foi entender a incidência de arritmias em doentes Covid-19 tratados em hospitais portugueses e entender as suas implicações prognósticas. Métodos: A Associação Portuguesa de Arritmologia, Pacing e Electrofisiologia (APAPE) conduziu um inquérito em hospitais portugueses, documentando a ocorrência de arritmias em doentes com Covid-19, as suas caraterísticas clínicas, o uso de terapêutica experimental e o seu impacto no intervalo QT. Resultados: Participaram 20 hospitais, reportando 692 doentes hospitalizados. Ocorreram episódios arrítmicos em 81 (11,7%), 64 (79%) com informação adicional. Documentaram-se arritmias de novo em 41 (64%) doentes, 45 (79%) do sexo masculino, idade mediana 73,5 (61-80,3) anos. Destes, 51 (79,7%) tinham comorbilidades associadas, maioritariamente hipertensão arterial (41, 64,1%). Dos 53 (82,3%) doentes sob terapêutica experimental, 7 (10,9%) tiveram aumento do intervalo QTc. Tiveram taquicardia ventricular 2 (3,1%) doentes, 5 (7,8%) bradicardia sinusal, 17 (26,6%) taquicardia paroxística supraventricular e 40 (7,8%) fibrilhação ou flutter auricular. Nenhum doente teve morte por causa arrítmica ou complicações associadas, à data do registo. Conclusões: Numa população de doentes com Covid-19, a incidência de arritmias é elevada, mas não associada a aumento de mortalidade cardíaca, apesar da ocorrência mais frequente em doentes graves e com falência multiorgânica. Independentemente do uso de terapêuticas experimentais, a incidência de arritmias ventriculares é baixa e a fibrilhação auricular e outras arritmias supraventriculares são as arritmias mais prevalentes.

As the demand for plastics only increases, new methods are required to economically and sustainably increase plastic usage without landfill and environmental accumulation. In addition, the use of biofillers is encouraged as a way to reduce the cost of the final resin by incorporating agricultural and industrial waste by-products, such as rice hulls and coffee chaff to further reduce waste being sent to landfills. Crystalline poly(ethylene terephthalate) (CPET) is a resin commonly used for microwave and ovenable food packaging containers that have not been fully explored for recycling. In this article, we investigate how the incorporation of biofillers at 5% wt. and 10% wt. impacts critical polymer properties. The thermal and mechanical properties were not significantly altered with the presence of rice hulls or coffee chaff in the polymer matrix at 5% wt. loading, but some reduction in melt temperature, thermal stability, and maximum stress and strain was more noticed at 10% wt. The complex viscosity was also reduced with the introduction of biofillers. The levels of heavy metals of concern, such as Cd, Cr, and Pb, were below the regulatory limits applicable in the United States and Europe. Additional studies are suggested to improve the performance of CPET/biofiller blends by pre-treating the biofiller and using compatibilizers.

Introduction A history of preoperative atrial fibrillation (AF) has been found to be associated with unfavorable outcomes, higher risks of non-response to cardiac resynchronization therapy (CRT) and loss of biventricular pacing (BivP). We aimed to assess the impact of AF and BivP on long-term outcomes in heart failure patients treated with CRT. Methods We retrospectively enrolled 227 patients undergoing CRT implantation between 2013 and 2020 according to the current guidelines. 118 patients were included in our analysis, from whom all data were available. Clinical, electrocardiographic and echocardiographic parameters were evaluated at baseline and 6 months after CRT. Response to CRT was defined as an increase in left ventricular ejection fraction (LVEF) >10%. We considered an effective delivery of BivP >98%. The primary endpoint was the composite endpoint of hospitalization due to HF or death for any cause. Results 118 patients were included (mean age 69±11 years, 66.1% males, 39.8% ischemic etiology; baseline LVEF was 27,6±6%). Patients were divided into AF (n=42; 35,6%) and sinus rhythm (SR (n=76); 18 patients had permanent AF. AF patients had higher index left atrial volume and left ventricular mass (p98% vs 30,3% of AF patients (p During follow-up, there were significant differences between AF and SR patients in the primary endpoint (73,8% vs 42,6%, p Conclusion Pre - procedural AF and BivP are independent predictors of the occurrence of a primary endpoint of hospitalization due to HF or death for any cause in HF patients submitted to CRT. Funding Acknowledgement Type of funding sources: None.

Background Brugada syndrome (BS) is a heritable channelopathy with male predominance. Males (M) seem to have a higher risk of arrhythmic events, although, there is limited data regarding gender differences in BS. Aim To compare the differences between genders in a Portuguese sample of BS patients (pts). Methods Single-center retrospective study of BS pts followed by the Arrhythmology Department. Pts were divided according to gender and compared regarding baseline characteristics and electrocardiographic (ECG) parameters that possibly predict the arrhythmic risk (significative S wave in DI, R wave sign, Tpeak-Tend interval and fragmented QRS). The events during follow-up were syncope of probable arrhythmic origin, ventricular tachycardia/ventricular fibrillation (VT/VF) and sudden cardiac death (SCD). Results A total of 165 pts were included; 64 (39%) were female (F) and the mean age at diagnosis was 47±15 years. The diagnosis was made by family screening (FS) in 72 (44%) pts. Sixty-seven pts (41%) had spontaneous type 1 pattern, 59 (36%) had history of syncope and 5 (3%) had history of aborted SCD. A positive genetic test was identified in 41 (25%) pts. Sixty-three (38%) pts were referred for an electrophysiological study (EEF) which was positive in 17 (27%) pts. A cardioverter-defibrillator was implanted in 45 (27%) pts. Females were more often diagnosed by FS (64% vs 31%, p Regarding ECG parameters, females had shorter QRS interval (104±12 vs 115±18 ms, p Conclusion In BS, female pts are more often diagnosed by FS and have less spontaneous type 1 pattern. Gender appears to affect basal ECG characteristics in BS, namely in parameters that may predict arrhythmic risk. Further studies are important to clarify the role of gender in prognosis and risk stratification of BS pts. Funding Acknowledgement Type of funding sources: None.

Background The value of eletrophisiologic study (EPS) with programmed ventricular stimulation for risk stratification in patients with Brugada Syndrome (BS) remains controversial. Purpose The aim of this study is to determine the clinical and electrocardiographic predictors of positive EPS and to evaluate whether the induction of malignant ventricular dysrhythmias in the EPS is a predictor of events Methods A retrospective study was carried out of patients with spontaneous type 1 Brugada pattern followed up in Arrhythmology consultation at our Hospital. From this population, patients who underwent EPS for stratification of dysrhythmic risk were selected. Clinical and electrocardiographic variables were analyzed. Hospital records and monitoring data from cardiac devices were consulted. Statistical analysis was performed using SPSS 20.0. Results Fourty nine patients were included, with a mean age at the beginning of follow-up of 45±14 years, 40 (82%) of whom were male. In 16 individuals (33%) the EPS was positive with induction of malignant ventricular dysrhythmias. All patients with positive EPS implanted an implantable cardioverter-defibrillator and of the 32 patients with negative EPS, 10 implanted an implantable event recorder. The group of patients with positive EPS had a higher proportion of male patients (88% vs 78%). The median follow-up time was 31 months. The family history of sudden death, family history of BS, or identification of a genetic variant classified as pathogenic or probably pathogenic did not present any relationship with EPS positivity. Of the analyzed electrocardiographic markers, PR interval (178±29 vs 171±27) and QRS duration (119±24 vs 113±15) tended to be longer in patients with positive EPS. Additionally, it was found that 74% of patients with a QRS of less than 120 ms had a negative EPS. In the analysis of the value of EPS in the stratification of dysrhythmic risk, it was found that of all the patients who suffered events (4), 75% had positive EPS. Of the patients with negative EPS, only 3% (1) presented events in the follow-up. However, there was no significant association between these variables. Conclusion In this population, the analysed clinical elements did not correlate with the EPS result. Although there was no statistical significance, there was a tendency for patients with narrower QRS to be more likely to have negative EPS. Accordingly with published data, it was found that the EPS result was not a predictor of events during the follow-up period, which highlights the difficulty of risk stratification in patients with BS. Funding Acknowledgement Type of funding sources: None.

Introduction Cardiac resynchronization therapy (CRT) has been of great benefit to many heart failure (HF) patients with reduced ejection fraction (EF) and intraventricular conduction delay. However, approximately 30% of patients fail to respond to CRT. We investigated baseline characteristics that might influence response to CRT. Methods We retrospectively enrolled 227 patients undergoing CRT implantation between 2013 and 2020 according to the guidelines. 118 patients were included in our analysis, from whom all data were available. Clinical, electrocardiographic and echocardiographic parameters were evaluated at baseline and 6 months after CRT implantation. Response to CRT was defined as an increase in left ventricular ejection fraction (LVEF) >10%. Right ventricular systolic dysfunction (RVSD) was defined as S' velocity Results 118 patients were included (mean age 69±11 years, 66.1% males, 39.8% ischemic etiology; 35,6% atrial fibrillation, baseline LVEF 27,6±6%). After 6 months of CRT, 65 patients (55.1%) were considered responders. Responders were more frequently female than non responders (43,1% vs 22,6, p=0.02). Atrial fibrillation and CKD were more prevalent in non responders (47,2% vs 26,2%, p=0.018; 62,3% vs 21,5%, p Conclusion From a range of preoperative characteristics, multivariate analysis only identified RVSD and CKD as independent predictors of CRT response, with S' Funding Acknowledgement Type of funding sources: None.

Background Brugada syndrome (BS) is a rare inherited channelopathy associated with sudden cardiac death (SCD) and family screening (FS) of index patients (pts) is recommended. However, data about pts identified through FS is lacking. Aim To compare index pts to non-index pts identified through systematic FS. Methods Single-center retrospective study of BS pts followed by the Arrhythmology Department. FS was offered to 1st degree relatives of all index pts through primary care services and a once-weekly voluntary open appointment. Genetic counselling was performed when indicated. Index and non-index pts were compared regarding baseline characteristics and events during the follow-up (syncope of probable arrhythmic origin, ventricular tachycardia/ventricular fibrillation (VT/VF) and SCD). Results We included 165 pts (61% males, mean age 47±15 years) and 72 (44%) were identified through FS. Non-index pts were diagnosed at a younger age (42±14 vs 51±14 years, p Genetic testing was performed in 38 (53%) non-index pts: 6 had a pathogenic SCN5A mutation, 18 a likely pathogenic SCN5A mutation and 12 a mutation of uncertain significance. At diagnosis, 24 (33%) non-index pts had history of syncope, 3 (4%) had nocturnal agonal respiration and 11 (15%) had palpitations with no differences between both groups (p=.119). Non-index pts were less likely to implant a cardioverterdefibrillator (14% vs 38%, p=.001). During a median follow-up of 28 (IQR 16–41) months, 10 (6%) pts had an event - 2 (3%) in the non-index group (2 syncope) and 8 (9%) in the index group (1 syncope; 7 VT/VF) - with no significative differences between groups (p=.432). There were nocardiovascular deaths. Conclusions FS identified a considerable proportion of BS pts. Non-index pts were younger at the time of the diagnosis and had less spontaneous type 1 pattern. No differences were found in events between index and non-index pts, however, the event rate was low. Systematic FS can identify individuals at risk of SCD earlier, allowing close monitoring and, when indicated, appropriate treatment. Funding Acknowledgement Type of funding sources: None.

Introduction Cardiac resynchronization therapy (CRT) is an established treatment for heart failure (HF) patients, however one-third of the patients fail to benefit from CRT. The relationship between the QRS duration, severity of mechanical dyssynchrony and efficacy of CRT is not completely understood. We determined if QRS duration shortening after CRT implantation was predictive of left ventricular reverse remodelling. Methods We retrospectively enrolled 227 patients undergoing CRT implantation between 2013 and 2020 according to the guidelines. 88 patients were included in our analysis, from whom all data were available, and these represent our sample. Clinical, electrocardiographic and echocardiographic parameters were evaluated at baseline and after 6 months of CRT implantation. Response to CRT was defined as a reduction in left ventricular end-diastolic volume (LVEDV) >15%. Linear regression models were used. Results 88 patients were included (mean age 69±10 years, 62.5% males, 36.4% ischemic etiology). Baseline left ventricular ejection fraction (LVEF) was 27,5±5,8% and LVEDV was 181±69 ml. After 6 months of CRT, 52 patients (59.1%) were considered responders. Baseline LVEDV was superior in responders when compared with non responders (199±85 ml vs 168±53 ml, p=0.038). No significant differences were noted in male gender (p=0.823), ischemic cardiomyopathy (p=0.065), LVEF (p=0.853), atrial fibrillation (p=0.390), left bundle branch block (p=0.950) or biventricular pacing (p=0.154) between them. QRS duration at baseline was similar between responders and non-responders (165±17 ms vs 163±17 ms, p=0.620). After 6 months of CRT, the reduction of QRS duration in responders was significantly higher than non-responders (p QRS duration was reduced from 165±17 ms to 136±15 ms in responders vs 163±17 ms to 160±17 ms in non-responders, (p Conclusion QRS duration shortening after CRT implantation was predictive of LV reverse remodelling in end-stage heart failure patients. Further prospective studies should be conducted to assess the prognostic value of QRS narrowing in response to CRT. Funding Acknowledgement Type of funding sources: None.

Resumo: Em até um terço dos casos de morte súbita, a autópsia médico‐legal é «branca», estando já contemplada nas recomendações internacionais a possibilidade da realização de autópsia molecular. A importância do teste genético post mortem prende‐se com a identificação de doenças hereditárias, frequentemente doenças com padrão de transmissão autossómico dominante, sendo possível, através de consulta e rastreio de parentes, identificar elementos na família com a doença, não raramente portadores assintomáticos de uma mutação, havendo espaço para alterar o curso de vida dos mesmos. Os autores apresentam três casos clínicos que reforçam o quão importante é o estudo genético post mortem, assim como o estudo familiar e a integração dos dados numa consulta de cardiologia, seja arritmologia, consulta de doença coronária ou miocardiopatias, dependendo da patologia específica, podendo modificar o curso da doença em muitos parentes. Abstract: In up to one‐third of cases of sudden death, the medico‐legal autopsy finding is inconclusive, and the option to perform a molecular autopsy is covered in international guidelines. The importance of postmortem genetic testing lies in its ability to identify hereditary diseases, often those with an autosomal dominant transmission pattern, and, through consultations and screening of relatives, to identify family members with a pathogenic mutation, who are often asymptomatic, providing an opportunity to change the course of their lives. The authors present three clinical cases that highlight the importance of postmortem genetic studies and family studies, as well as the integration of the data obtained in a cardiology consultation, which may be for arrhythmology, coronary disease or cardiomyopathy, depending on the specific condition. This could modify the course of the disease in many relatives. Palavras‐chave: Autópsia, Teste genético post mortem, Canalopatias, Síndrome de Brugada, Keywords: Autopsy, Postmortem genetic testing, Channelopathies, Brugada syndrome

In up to one-third of cases of sudden death, the medico-legal autopsy finding is inconclusive, and the option to perform a molecular autopsy is covered in international guidelines. The importance of postmortem genetic testing lies in its ability to identify hereditary diseases, often those with an autosomal dominant transmission pattern, and, through consultations and screening of relatives, to identify family members with a pathogenic mutation, who are often asymptomatic, providing an opportunity to change the course of their lives. The authors present three clinical cases that highlight the importance of postmortem genetic studies and family studies, as well as the integration of the data obtained in a cardiology consultation, which may be for arrhythmology, coronary disease or cardiomyopathy, depending on the specific condition. This could modify the course of the disease in many relatives. Resumo: Em até um terço dos casos de morte súbita, a autópsia médico-legal é “branca”, estando já contemplada nas recomendações internacionais a possibilidade da realização de autópsia molecular. A importância do teste genético post mortem prende-se com a identificação de doenças hereditárias, frequentemente doenças com padrão de transmissão autossómico dominante, sendo possível, através de consulta e rastreio de parentes, identificar elementos na família com a doença, não raramente portadores assintomáticos de uma mutação, havendo espaço para alterar o curso de vida dos mesmos. Os autores apresentam três casos clínicos que reforçam o quão importante é o estudo genético post mortem, assim como o estudo familiar e a integração dos dados numa consulta de cardiologia, seja arritmologia, consulta de doença coronária ou miocardiopatias, dependendo da patologia específica, podendo modificar o curso da doença em muitos parentes. Keywords: Autopsy, Postmortem genetic testing, Channelopathies, Brugada syndrome, Palavras-chave: Autópsia, Teste genético post mortem, Canalopatias, Síndrome de Brugada

Introduction: Sleep apnea syndrome (SAS) is a common respiratory disorder that is particularly prevalent in patients with cardiovascular disease. Diagnosis is based on polysomnography. In patients with cardiac implantable electronic devices (CIEDs), the prevalence of SAS may reach 60%. The aim of this study was to assess the value of CIEDs in screening for SAS. Methods: This prospective study included patients with CIEDs with an algorithm for sleep apnea. The frequency response function was activated and simplified polysomnography was performed. The device’s data were collected on the day of the polygraph. Results: The sample included 29 patients, with a mean age of 76.1 years, 71.4% male. The prevalence of SAS was 77%. For SAS, the agreement between polysomnography and the device was kappa = 0.54 (p = 0.001, 95% CI 0.28-0.81) (moderate agreement); for moderate to severe SAS, the agreement was kappa = 0.73 (p

Background Implantable loop recorders (ILR) improved diagnostic yield in unexplained syncope patients (pts). Data on possible predictive factors for bradycardia requiring device implantation in these pts is limited. We aim to identify clinical predictors for device implantation due to a significant bradyarrhythmia in patients who underwent ILR insertion for the study of syncopal/presyncopal (S/pS) events. Methods Single-center retrospective study of patients who implanted an ILR for the study of unexplained S/pS episodes between 2013 and 2018. The primary endpoint was a documented bradyarrhythmia requiring device implantation during the follow-up. Results A total of 251 pts were included. Mean age was 68±15 years and 53% were female. The majority of pts (220; 88%) had normal ejection fraction. Fifty-two (21%) pts had atrial fibrillation (AF). Regarding basal electrocardiographic characteristics, 34 (14%) pts had 1st degree auriculo-ventricular block (AVB), 31 (12%) pts had left bundle branch block (L-BBB), 22 (9%) pts had R-BBB and 13 (5%) pts had bifascicular block. During a median follow-up of 20 (IQR 9–34) months, 74 (29%) pts required device implantation because of a significant bradyarrhythmia (92% pacemaker, 4% CRT, 4% ICD). Median duration from ILR until device implantation was 5 (IQR 1–10) months. The indications were sick-sinus-syndrome in 47 (64%) pts, advanced AV block in 23 (31%) pts and symptomatic slow AF in 4 (5%) pts. Patients who required device implantation were older (73±12 vs 66±15 years, p In a logistic regression model, age >75 years (HR: 1.7; 95% CI: 1.1–2.8) and the presence of AF (HR: 1.8; 95% CI: 1.1–3.0) were independent predictors for device implantation. Conclusion An older age and the presence of AF were independent predictors for device therapy in pts who implanted an ILR for the study of S/pS. These factors may identify a higher risk group and should be considered in the initial workup of these pts. Funding Acknowledgement Type of funding source: None

Introduction: Brugada syndrome (BrS) is a channelopathy associated with ventricular arrhythmias and sudden cardiac death. In patients at high risk of sudden death, an implantable cardioverter-defibrillator is indicated. Subcutaneous implantable cardioverter-defibrillators (S-ICDs) are an alternative to transvenous systems, with reduced risk of infection and complications associated with system extraction or explantation. Objective: To test electrocardiographic eligibility for S-ICD placement after exercise stress testing (EST) in patients with BrS. Methods: The sample included 35 consecutive patients with BrS. Electrocardiographic eligibility was assessed using the Boston Scientific model 2889 EMBLEM™ S-ICD automated screening tool, in four phases: decubitus and orthostatism, and before and after EST. Those who had at least one acceptable vector in the four measurements were considered eligible. Results: In this study, 71.4% of patients were male and mean age was 53.86±12 years. In screening prior to EST, 14.3% of patients (n=5) were not eligible for an S-ICD. There was a statistically significant association between ineligibility and presence of complete right bundle branch block and history of syncope. After EST, 16.7% of initially eligible patients no longer had eligible vectors (n=5). Conclusion: In this study, 16.7% of patients previously eligible for an S-ICD were no longer eligible after EST. This result demonstrates the importance of screening after EST in all patients with BrS and with indication for an S-ICD, and may influence decisions concerning which ICD to implant or whether to institute pharmacological measures that avoid inappropriate therapies. Resumo: Introdução: A síndrome de Brugada (SBr) é uma canalopatia associada ao desenvolvimento de arritmias ventriculares e morte súbita cardíaca. Pacientes com alto risco devem ser orientados para a colocação um cardioversor-desfibrilhador. O cardioversor-desfibrilhador implantável subcutâneo (CDI-S) é uma alternativa ao sistema transvenoso, com menor risco de infeção e complicações associadas à extração/explante do sistema. Objetivos: Testar a elegibilidade eletrocardiográfica para colocação de CDI-S após prova de esforço (PE) em pacientes com SBr. Métodos: A amostra incluiu 35 pacientes, consecutivos, com SBr. A elegibilidade eletrocardiográfica foi avaliada pela ferramenta de rastreio automática, Boston-Emblem S-ICD (Modelo 2889)®, em quatro fases: decúbito e ortostatismo, antes e depois da PE – foram considerados elegíveis indivíduos que tinham pelo menos um vetor aceitável nas quatro fases. Resultados: Neste estudo, 71,4% dos pacientes eram do sexo masculino, com idade média de 53,86±12 anos. No rastreio anterior à PE, 14,3% dos pacientes (n=5) não eram elegíveis para o implante de CDI-S. Demonstrou-se uma associação significativa entre não elegibilidade e a presença de bloqueio de ramo direito e história de síncope. Após a PE, 16,7% dos pacientes inicialmente elegíveis deixaram de ter vetores aceitáveis para a implantação de CDI-S (n=5). Conclusão: Neste estudo, 16,7% dos pacientes previamente elegíveis para CDI-S deixaram de o ser após a PE. Estes resultados demonstram a relevância do rastreio após PE em todos os pacientes com SBr e com indicação para CDI-S, influenciando a decisão do sistema a implantar ou medidas farmacológicas que evitem casos de terapias inadequadas.

Sleep Apnea Syndrome (SAS) is a prevalent respiratory disease with marked expression in the population with cardiovascular disease. The diagnosis is based on polysomnography. In patients with cardiac implantable electronic devices (CIED), the prevalence of SAS may reach 60%. The objective of this study was to evaluate the value of DEC in the SAS screening.Prospective study that included patients with CIED with sleep apnea algorithm. The frequency response function was activated and simplified polygraphy was performed. The data of the device were collected on the day of the polygraph.The sample included 29 patients, with a mean age of 76.1 years, 71.4% of the male gender. The prevalence of SAS was 77%. For SAS, the agreement between polysomnography and the Pacemaker was Kappa = 0.54 (p = 0.001), 95% CI (0.28, 0.81) (moderate agreement); for moderate to severe SAS, the agreement was Kappa = 0.73 (p0.001), 95% CI (0.49, 0.976) (substantial agreement). Severe SAS was obtained: sensitivity 60%, specificity 100%, positive predictive value 100%, negative predictive value 60% and diagnostic accuracy 75%; for moderate to severe SAS: sensitivity of 90%, specificity of 83%, positive predictive values of 90% and negative of 87.5%, with a diagnostic accuracy of 87.5%.SAS is highly prevalent in patients with CIED. The values obtained through these devices have a strong positive correlation with the Apnea-Hypopnea Índex, which makes them a good tool for the screening of severe SAS.

Congenital long QT syndrome (LQTS) is a rare hereditary disease, with an incidence of 1 in 2000, characterized by prolonged ventricular repolarization and malignant ventricular tachyarrhythmias. We report the case of a 30-year-old woman, previously diagnosed with neurocardiogenic syncope, in whom LQTS was identified. The patient received an implantable cardioverter-defibrillator due to polymorphic ventricular tachycardia under beta-blocker therapy. Molecular genetic testing identified three mutations in heterozygosity in the KCNH2, KCNQ1 and SCN5A genes, which is a rare finding and is associated with worse prognosis. Resumo: A síndrome do QT longo congénito (SQTLC) é uma doença hereditária rara, com uma incidência de uma em cada 2000 pessoas, caracterizada por uma repolarização ventricular prolongada e por taquiarritmias ventriculares malignas.Reportamos o caso de uma doente de 30 anos, com diagnóstico prévio de síncope neurocardiogénica, em que identificamos a SQTLC. A doente implantou cardioversor-desfibrilhador implantável por taquicardia ventricular polimórfica apesar da terapêutica com bloqueador beta.Foram identificadas nesta doente três mutações em heterozigotia nos genes KCNH2, KCNQ1 e SCN5A, achado raro que lhe confere um pior prognóstico. Keywords: Long QT syndrome, Triple mutation, KCNH2 gene, KCNQ1 gene, SCN5A gene, Polymorphic ventricular tachycardia, Palavras-chave: Síndrome QT longo, Mutação trigénica, Gene KCNH2, Gene KCNQ1, Gene SCN5A, Taquicardia ventricular polimórfica

The aim of this prospective registry is to evaluate a new algorithm designed to reduce the percentage of unnecessary ventricular pacing (%VP) in patients implanted with a dual-chamber pacemaker, through a dedicated pacing mode (called AAISafeR2) operating in AAI mode with back-up ventricular pacing in DDD mode, and to describe the incidence and distribution of atrioventricular (AV) block in this population. Investigators were free to assign patients to AAISafeR2 mode or to standard DDD (if AAISafeR was contraindicated, mainly due to permanent high-degree AV block). Patients underwent routine follow-up visits at 3, 6, 12, 18 and 24 months after implantation. At each follow-up visit, data were retrieved from pacemaker memories and analyzed to extract %VP and incidence of AV block. Up to December 2006, 158 patients (94 men, mean age 69 +/- 14 years) from nine Portuguese centers had been consecutively included. We also determined the distribution of AV block (according to the criteria used by the pacemaker to classify AV block and switch to DDD mode). AAISafeR was shown to be effective in reducing unnecessary VP in our patient population. The analysis also reveals a high incidence of paroxysmal AV block, often unknown at the time of implantation. There were no complications associated with AAISafeR programming.

Retrospective analysis of the initial experience at our department with an implantable loop recorder (ILR) for the evaluation of patients with recurrent syncope, palpitations or dizziness.We studied ten patients aged 31-65 (52.3) years referred to our center after an inconclusive evaluation that included ECG, Holter monitoring, events recorder, stress test, echocardiogram and electrophysiological study. Seven patients had structural heart disease. We used a Reveal Plus (Medtronic, USA) ILR, which allows up to 41 minutes of electrocardiographic recording, over a period of 24 months, patient or device activated, according to the programmed parameters. Follow-up was scheduled every three months or after every event activated by the patient. Symptoms and recorded events were analyzed.Eight patients activated events, out of a total of 45 episodes, and five patients reported two or more symptoms. Dizziness was reported by five patients (24 episodes), palpitations by three (seven episodes), syncope by three (seven episodes) and nonspecific symptoms by five patients (seven episodes). The first symptom occurred between the twelfth day and the sixth month after implantation. Four episodes (three syncope and one dizziness) occurred with significant AV conduction disturbance (complete or high grade AV block) and in 41 episodes no rhythm or AV disturbance was recorded. Thirty events were automatically activated. There were no device-related complications. None of the patients died during follow-up.