Introdução: A miocardiopatia hipertrófica é a mais frequente doença cardiovascular de origem genética e está associada a arritmias e morte cardiovascular. O aumento do átrio esquerdo e a fibrilação atrial são considerados marcadores de morte por insuficiência cardíaca em pacientes com miocardiopatia hipertrófica. A apneia obstrutiva do sono é o distúrbio respiratório do sono mais comum, caracterizando-se por episódios recorrentes de colapso parcial ou total das vias aéreas superiores durante o sono. A apneia obstrutiva do sono é muito prevalente entre as populações com doença cardiovascular, como hipertensão arterial e insuficiência cardíaca, e está associada a remodelamento cardíaco e arritmias. Objetivos: O objetivo deste estudo foi determinar a prevalência dos distúrbios respiratórios do sono em pacientes com miocardiopatia hipertrófica e avaliar a associação da apneia obstrutiva do sono com o remodelamento cardíaco (ventricular e atrial) e fibrilação atrial em pacientes com miocardiopatia hipertrófica. Métodos: Foram estudados pacientes consecutivos estáveis clinicamente, com um diagnóstico confirmado de miocardiopatia hipertrófica acompanhados no Instituto do Coração do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo. Os pacientes foram submetidos à avaliação clínica, questionário de sonolência, bioquímica sanguínea, ecocardiograma e monitorização respiratória noturna com poligrafia portátil. Foi utilizado um valor de corte de 15 e 30 apneias e hipopneias por hora de registro para o diagnóstico de apneia obstrutiva do sono e apneia obstrutiva do sono grave, respectivamente. Resultados: Foram avaliados 80 pacientes consecutivos com miocardiopatia hipertrófica. Apneia obstrutiva do sono foi diagnosticada em 32 pacientes (40%). Apneia obstrutiva do sono grave esteve presente em 17 pacientes (21%). Pacientes com apneia obstrutiva do sono foram significativamente mais velhos (56 [41-64] vs. 39 [30-53] anos, p < 0,001), apresentaram maior índice de massa corporal (28,2 ± 3,5 vs. 25,2 ± 5,2 Kg/m2, p < 0,01), maior dimensão do átrio esquerdo (45 [42-53] vs. 41 [39-47] mm, p = 0.01) e maior diâmetro da aorta (34 [30-37] vs. 29 [28-32] mm, p < 0,001) em comparação com pacientes sem apneia obstrutiva do sono. Dois modelos de regressão linear múltipla para identificar os fatores associados ao aumento do átrio esquerdo e da aorta ascendente mostraram que o índice de apneia e hipopneia foi a única variável associada ao aumento atrial (p = 0,05) e da aorta (p = 0,01), respectivamente. A fibrilação atrial permanente esteve presente em 31% vs. 6% dos pacientes com e sem apneia obstrutiva do sono, respectivamente (p < 0,01). A apneia obstrutiva do sono (p = 0,03) e o diâmetro do átrio esquerdo (p = 0,03) foram os únicos fatores independentemente associados à fibrilação atrial em um modelo multivariado. Conclusão: A apneia obstrutiva do sono é muito prevalente em pacientes com miocardiopatia hipertrófica e está associada com aumento do átrio esquerdo e da aorta ascendente. A apneia obstrutiva do sono está independentemente associada à fibrilação atrial, um fator de risco para óbito cardiovascular nesta população / Background: Hypertrophic cardiomyopathy is the most common genetic cardiovascular disease and is associated with arrhythmias and cardiovascular death. Left atrial enlargement and atrial fibrillation are considered markers for death due to heart failure in patients with hypertrophic cardiomyopathy. Obstructive sleep apnea is the most common sleep disordered breathing and is characterized by recurrent episodes of partial or complete collapse of the upper airway during sleep. Obstructive sleep apnea is extremely prevalent among populations with cardiovascular disease, such as systemic hypertension and heart failure and is independently associated with heart remodelling and arrhythmias. Objectives: The aim of this study was to determine the prevalence of sleep disordered breathing in consecutive patients with hypertrophic cardiomyopathy and evaluate the association of obstructive sleep apnea with heart remodelling (ventricular and atrial) and with atrial fibrillation in patients with hypertrophic cardiomyopathy. Methods: We studied consecutive clinically stable patients with a confirmed diagnosis of hypertrophic cardiomyopathy followed in the Heart Institute Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, by clinical evaluation, sleep questionnaire, biochemical blood analysis, echocardiography and sleep study (overnight portable respiratory monitoring). We used a cut-off value of 15 and 30 apneas and hypopneas per hour of recording in the sleep study for the diagnosis of obstructive sleep apnea and severe obstructive sleep apnea, respectively. Results: We evaluated 80 consecutive patients with hypertrophic cardiomyopathy. Obstructive sleep apnea was present in 32 patients (40%). Severe obstructive sleep apnea was present in 17 patients (21%). Patients with obstructive sleep apnea were significantly older (56 [41-64] vs. 39 [30-53] years, p < 0.001), presented higher body mass index (28.2 ± 3.5 vs. 25.2 ± 5.2 Kg/m2, p < 0.01), increased left atrial diameter (45 [42-53] vs. 41 [39-47] mm, p = 0.01) and aorta diameter (34 [30-37] vs. 29 [28-32] mm, p < 0.001) compared with patients without obstructive sleep apnea. Two models of stepwise multiple linear regression to identify variables associated with left atrial and ascending aorta enlargement showed that apnea-hypopnea index was the only variable associated with left atrial enlargement (p = 0.05) and aorta diameter (p = 0.01), respectively. Permanent atrial fibrillation was present in 31% vs. 6% in patients with and without obstructive sleep apnea, respectively (p < 0.01). Obstructive sleep apnea (p = 0.03) and left atrial diameter (p = 0.03) were the only factors independently associated with atrial fibrillation in a multivariate model. Conclusions: Obstructive sleep apnea is highly prevalent in patients with hypertrophic cardiomyopathy and it is associated with left atrial and ascending aorta enlargement. Obstructive sleep apnea is independently associated with atrial fibrillation, a risk factor for cardiovascular death in this population

Ziel der Studie war es, den Einfluss des Geschlechts auf die Klinik, die medikamentöse Therapie und den Gebrauch von Interventionen bei Patienten mit terminaler dilatativer Kardiomyopathie (DCM) nach Vorstellung zur Herztransplantation zu untersuchen. Es wurden 702 konsekutive DCM-Patienten (110 Frauen, 592 Männer) rekrutiert, die sich am Deutschen Herzzentrum Berlin zur Herztransplatation vorstellten und während eines Zeitraumes von im Mittel 4,3 Jahren beobachtet wurden. Die Diagnose DCM wurde durch Herzkatheter bestätigt. Etwa 300 Variablen zu Basisparametern, medikamentöser Therapie, Interventionen und Outcome wurden pro Patient analysiert. Der kombinierte Endpunkt wurde als das Auftreten eines von drei Ereignissen definiert: Tod auf der Warteliste, Herztransplantation oder Implantation eines Assist-Device. Die Ereignisanalyse wurde mittels multivariater Regression und Kaplan-Meier-Statistik durchgeführt. Bei Erstvorstellung zeigten Frauen und Männer keine Unterschiede in Alter, LVEF und LVEDD (% der Norm, für Alter und BSA korrigiert), aber bei Symptomatik, RVEF, linksatrialem Durchmesser, Vorhofflimmern und Beta1-Autoantikörpern. Frauen wurden signifikant früher transplantiert als Männer (112,3 +/- 117,5 vs. 340,7 +/- 332,1 Tage auf der Warteliste; p = 0,0001). Stärkste unabhängige Prädiktoren für Ereignisse bei beiden Geschlechtern waren korrigierter LVEDD und RVEF. Bei Frauen erhöhte Vorhofflimmern das Ereignisrisiko 3fach (2,905; CI: 1,406 - 6,001), wohingegen das Outcome bei Männern durch Vorhofflimmern nicht beinflusst wurde. Alter bei Erstvorstellung, Belastungsdyspnoe und Immunadsorption waren zusätzliche Prädiktoren bei Männern. Zusammenfassung: Geschlechterunterschiede bei klinischen Basisparametern können Behandlung und Outcome von DCM-Patienten beeinflussen. Vorhofflimmern ist bei männlichen Patienten nicht mit einem schlechteren Outcome assoziiert, bewirkt jedoch eine 3fache Erhöhung des Ereignisrisikos bei weiblichen Patienten. / The goal of this study was to determine the influence of gender on clinical parameters, on medical treatment and use of interventions in patients with end-stage dilated cardiomyopathy (DCM) presenting for heart transplantation. We enrolled 702 consecutive patients (592 men and 110 women) with DCM who presented at the German Heart Institute Berlin for heart transplantation and were followed for an average time of 4.3 years. Diagnosis of DCM was confirmed by cardiac catheterization. About 300 variables of baseline characteristics, medical treatment, interventions, and outcome per patient were analysed. The combined end point was defined as the occurrence of one of three events: death on the waiting list, heart transplantation or cardiac assist device implantation and was analyzed by multivariate regression and Kaplan- Meier-statistics. At presentation women and men did not differ in age, LVEF and LVEDD (% of normal, corrected for age and BSA) but in symptoms, RVEF, left atrial size, atrial fibrillation, and beta-adreno-receptor auto-antibodies. Women were transplanted significantly earlier than men (mean 112.3+/-117.5 vs 340.7+/- 332.1 days on the waiting list; p value 0.0001). Strongest independent predictors for events in both sexes were corrected LVEDD and RVEF. In women, AF increased the risk for events 3fold (2,905; CI: 1.406 – 6.001) whereas in men AF did not predict outcome. Age at first presentation, dyspnoea, and immunoadsorption were additional predictors in men. In patients with DCM, gender differences in baseline characteristics may influence management and outcome. Atrial fibrillation is not associated with a poorer outcome in men but threefold increases the risk in women.

Introdução: a fibrilação atrial (FA) é a arritmia mais frequente na prática clínica estando associada à elevada taxa de morbidade e mortalidade. O risco de acidente vascular cerebral (AVC) apresenta-se aumentado em pacientes com FA e há evidência de aumento progressivo do risco com o avançar da idade. A detecção precoce da FA pode permitir a antecipação terapêutica e consequente redução de morbimortalidade. Vários recursos diagnósticos têm sidos utilizados com essa finalidade incluindo o marca-passo cardíaco definitivo (MPD) que permite armazenar registros de elevada frequência no canal atrial. Sistemas atuais de monitoramento remoto contínuo (MRC) do portador de MPD permitem a identificação e o envio diário à distância destes eventos armazenados pelo dispositivo. Objetivo: definir o papel do MRC na detecção e no manejo da FA em idosos portadores de MPD. Método: foi um estudo prospectivo e randomizado com seleção consecutiva de 300 idosos (60 anos ou mais) entre março/2007 e janeiro/2010, em ritmo sinusal e com indicação para implante ou troca de MPD. Os pacientes (P) foram randomizados para grupo de intervenção (GI) em monitoramento remoto contínuo (n=150) e grupo controle (GC) em seguimento convencional (n=150) com consultas agendadas para 30, 90, 180 dias e posteriormente a cada seis meses até dois anos de seguimento. No GI foram realizadas consultas extras motivadas por alertas automáticos de FA com duração mínima de 2,5 horas enviados pelo sistema de MRC. Resultados: o tempo de seguimento médio foi de 435 dias. Não houve diferença entre os grupos (GI x GC) em relação à idade (75,5 x 74,3 anos, p=0,44), sexo (feminino 54,7% x 57,4%, p=0,46), indicação do MPD (BAV 89,7% x 88,7%; p=0,84) e eventos clínicos (incidência de FA 25,3% x 19,3%, p=0,42; AVC 1,4% x 0%, p=0,44 e óbitos 8,6% x 5,3%, p=0,16). Houve mais documentação eletrocardiográfica da FA no GI (10%) em comparação ao GC (4%), p=0,027 e o MPD detectou corretamente a FA em 95,2% desses casos. O tempo para a primeira recorrência da FA foi de 79 x 128 dias; p=0,005. O número de dias em FA foi menor no GI (16 dias; IConf 95%: 8,89 a 23,18) em relação ao GC (51,9 dias; IConf 95%: 21,89 a 81,93), p=0,028. Baseados no escore CHADS2 houve mais pacientes com indicação para terapia antitrombótica no GI (p=0,008). Foram realizadas 55 consultas extras motivadas pelo sistema de MRC com necessidade de mudança terapêutica em 81% dos casos (36% antitrombóticos, 20% antiarrítmicos, 13% reprogramação MPD e 12% cardioversão). Conclusões: o MRC proporcionou menor tempo para a detecção da FA reduzindo o número de dias em arritmia devido à antecipação da terapêutica. Houve mais pacientes com documentação eletrocardiográfica da FA e submetidos à terapia antitrombótica no GI. Os alertas automáticos do sistema de MRC apresentaram importância clínica na maioria das consultas extras havendo necessidade de modificações na terapia antiarrítmica e antitrombótica, assim como na reprogramação do MPD. Os resultados deste estudo destacam o MRC como ferramenta auxiliar no manejo da FA em idosos portadores de MPD / Introduction: atrial fibrillation (AF) is the most common arrhythmia in clinical practice and it is related to high prevalence of morbidity and mortality. The annual risk of stroke is increased in AF patients especially with advancing age. Early AF detection should anticipate the management of AF which can reduces morbidity and mortality. Atrial high rate episodes device detected is a good diagnostic tool in PM carriers and these events can be sent daily to the doctor by continuous remote monitoring (CRM) systems. The aim of this study was to determine the role of CRM to detect and in the management of AF in elderly pacemaker patients. Method: It was a randomized and prospective study. Between March/2007 and January/2010 we selected 300 consecutive patients with an indication to atrioventricular pacemaker implantation or generator change. There were included patients in sinus rhythm with 60 years old or more. They were randomized in remote group (RG=150) and control (CG=150). Follow-up (FU) was scheduled in 30, 90 and 180 days and after, 6/6 months until two years. Patients in RG had extra appointment if automatic AF alerts (minimum AF burden of 2.5 hours) were sent by CRM. Results: FU mean time was 435 days. There were no difference between studied groups (RG vs. CG) in age (75.5 vs. 74.3 years, P=0.44); gender (female 54.7% vs. 57.4%, P=0.46); pacemaker indication due to sick sinus syndrome 10.3% vs. 11.3% and AV block 89.7% vs. 88.7%, P=0.84; AF incidence 25.3% vs. 19.3%, P=0.42; stroke 1.4% vs. 0%, P=0.44 and death 8.6% vs. 5.3%, P=0.16. AF was documented by electrocardiogram in 21 patients (RG=10% vs. CG=4%, P=0.027) and the pacemakers detected AF correctly in 95,2%. Median time to first AF recurrence was 79 vs. 128 days, P=0.005. The mean AF days was 16.0 (IC95%; 8.89 to 23.18) vs. 51.91 (IC95%; 21.89 to 81.93); P=0.028. According CHADS2 score, there were more patients with an antithrombotic therapy indication in RG (P=0.008). In 55 extra appointments, there was a therapy change in 81% of them (36% antithrombotic therapy, 20% arrhythmic therapy, 13% pacemaker programming and 12% electrical cardioversion). Conclusion: CRM allowed earlier AF detection which reduced AF days by anticipated therapy. In RG, the time to detection of first AF recurrence was lower than in the conventional approach. There were more AF documented by EKG and more patients with an indication to antithrombotic therapy in RG. Most of extra appointment needed a therapy change with regard to antithrombotic or antiarrhythmic therapy and device programming. The results of this study point out the CRM like a good auxiliary tool in the management of AF in elderly pacemaker patients

Objetivo. Verificar se as características espectrais dos eletrogramas atriais (EgA) em ritmo sinusal (RS) se correlacionam com a presença de gânglios parassimpáticos cardíacos. Materiais e Resultados. Treze pacientes encaminhados para submeter-se a ablação de fibrilação atrial (FA) foram incluídos de forma prospectiva. Previamente ao início da ablação, realizou-se o registro de EgA em RS em uma série de regiões anatômicas pré-determinadas, seguindo-se uma ordem sequencial. Em seguida, aplicou-se estímulos elétricos de alta frequência (20 Hz de frequência, amplitude de 100 V e duração de pulso de 4 ms), nos mesmos locais. Uma resposta vagal evocada foi definida como um súbito aumento no intervalo RR ou a indução de bloqueio na condução átrio-ventricular imediatamente após a aplicação do estímulo de alta-frequência (EAF). Procedeu-se à análise espectral dos sinais atriais em RS registrados, com amostragem de 1000 Hz, janela Hanning. No total, 1488 EgA oriundos de 186 locais anatômicos foram registrados, sendo 129 de regiões com resposta vagal negativa e 57 correspondentes a regiões de resposta vagal positiva. A duração do eletrograma e o número de deflecções foram similares nos pontos com resposta vagal positiva e negativa. A densidade de potência espectral em locais de resposta vagal positiva, no entanto, foi menor entre 26 e 83 Hz, e maior entre 107 e 200 Hz, comparados com os locais de resposta negativa. A área sobre a curva entre 120 e 170 Hz normalizada para a área total do espectro foi testada como um novo parâmetro diagnóstico. A análise de curva ROC demonstrou que o valor area 120-170 / area total > 0,14 foi capaz de identificar locais de inervação vagal com sensibilidade de 70,9% e especificidade de 72,1%. Conclusão. A análise espectral de sinais atriais durante RS é um método factível e simples de mapear os locais de inervação parassimpática cardíaca, sem a necessidade de qualquer tipo de estimulação / Objective. To verify whether spectral components of atrial electrograms (AE) during sinus rhythm (SR) correlate with cardiac ganglionated plexus (GP) sites. Methods and Results. Thirteen patients undergoing atrial fibrillation (AF) ablation were prospectively enrolled. Prior to radio frequency application, endocardial AE were recorded with a sequential point-by-point approach. Electrical stimuli were delivered at 20 Hz, amplitude 100 V, and pulse width of 4 msec. A vagal response was defined as a high-frequency stimulation (HFS) evoked AV block or a prolongation of RR interval. Spectral analysis was performed on single AE during SR, sampling rate of 1000 Hz, Hanning window. Overall, 1488 SR electrograms were analyzed from 186 different left atrium sites, 129 of them corresponding to negative vagal response sites and 57 to positive response sites. The electrogram duration and the number of deflections were similar in positive and negative response sites. Spectral power density of sites with vagal response was lower between 26 and 83 Hz and higher between 107 and 200 Hz compared with negative response sites. The area between 120 and 170 Hz normalized to the total spectrum area was tested as a diagnostic parameter. ROC curve analysis demonstrated that an area 120-170 / area total value > 0,14 identified vagal sites with 70,9% sensitivity and 72,1% specificity. Conclusions. Spectral analysis of AE during SR is feasible and simple method of mapping the cardiac autonomic nervous system (ANS), with no stimulation required

A fibrilação atrial (FA) é a arritmia mais comum no pós-operatório de cirurgia cardíaca. Apesar de estar relacionada a alterações estruturais, alguns pacientes, mesmo que sem tais condições, ainda assim, cursam com fibrilação atrial no pós-operatório (FAPO) causando aumento no tempo de internação e custos. Estudos recentes vem ampliando o conhecimento sobre pequenos fragmentos de RNA, chamados de microRNAs (miRNAs) que podem interferir diretamente no aparecimento de algumas doenças na área cardiovascular. O objetivo do presente estudo é: 1) comparar a expressão dos miRNAs 1, 23 e 26 entre pacientes com e sem FAPO; 2) comparar nos grupos a expressão destes miRNAs entre os período pré e pós-cirúrgico; 3)comparar a expressão dos genes GJA1, KCNJ2, CACNB1, CACNA1C e KCNN3 entre os tempos pré e pós-cirúrgico no grupo FAPO; 4) comparar estes últimos genes no tecido atrial; 5) comparar os genes relacionados à produção de interleucinas (IL)-1, 6 e fator de necrose tumoral alfa (TNF?) entre os grupos e entre os tempos pré e pós-cirúrgico; 6)avaliar as características clínicas e evolutivas da população estudada. Pacientes submetidos à cirurgia de revascularização miocárdica foram submetidos à coleta de 20ml de sangue pré e pós-cirurgia bem como fragmento de tecido atrial. Um total de 143 pacientes compuseram os grupos: FAPO (24 pacientes), controle genético (24 pacientes) e controle total (97 pacientes + 24 grupo controle genético). Do ponto de vista clínico observou-se maior idade, tempo de anóxia, tempo de internação em terapia intensiva e hospitalar no grupo FAPO. A análise genética revelou menor expressão do miRNA-23 no grupo FAPO (p=0,02). A comparação entre os períodos pré e pós-cirúrgico revelou redução dos três miRNAs no tempo pós-cirúrgico (p<0,05) e dos genes relacionados às proteínas de canal (p<0,05). A comparação no tecido não evidenciou alterações entre os grupos. Os genes relacionados ás citocinas revelaram redução no período pós-cirúrgico (p<0,05) em ambos os grupos. Concluiu-se que o miRNA-23 pode ter implicação no surgimento da FAPO e outros miRNAs não estudados devem estar envolvidos neste processo uma vez que houve redução de outros genes de canais relacionados ao aparecimento de FAPO. / Atrial fibrillation (AF) is the most common arrhythmia after cardiac surgery. AF is related to cardiac structural changes although a group of patients still remains developing post-operative atrial fibrillation (FAPO) even without those changes, leading to more days in the hospital and costs. Recent studies showed that short fragments of RNA, called microRNA (miRNA) can contribute to the development of several diseases in the cardiovascular area. The aim of this study is to 1) compare the expression of miRNA-1, 23 and 26 between the group with and without FAPO; 2) compare, in the FAPO group, the expression of these miRNAs in the pre and post-surgery periods; 3) compare the expression of GJA1, KCNJ2, CACNB1, CACNA1C e KCNN3 genes between the pre and post-surgery periods; 4) compare this genes in atrial tissue; 5) compare the genes related to inflammation cytokines as interleukin(IL)-1, 6 and alpha tumoral necrosis factor between the groups in the pre and post-surgery periods; 6) evaluate clinical and evaluative patterns of the study population. Twenty milliliters of blood samples in the pre and post-operative periods and an atrial fragment were extracted from patients submitted to coronary artery bypass graft surgery. A total of 143 patients were divided in the FAPO group (24 patients), genetic control group (24 patients) and a total control (97 + 24 genetic control patients). The clinical analysis showed bigger age and clamp-time, more days in the intensive care unit and hospital in the FAPO group. The genetic analysis revealed less expression of miRNA-23 in the FAPO group (p=0.02). The comparison between the pre and post-surgery periods showed reduction in the three studied miRNAs (p<0.05) and reduction in the genes related to the production of the membrane protein channel sites. The comparisons in the atrial tissue didn´t show any difference in the study groups. The cytokines showed post-surgery reduction (p<0.05) in both groups. The conclusion is that miRNA-23 can be implicated in FAPO as others miRNAs not studied can also be, once there was a significative reduction in the genes related to FAPO development.

Introdução: A miocardiopatia hipertrófica é a mais frequente doença cardiovascular de origem genética e está associada a arritmias e morte cardiovascular. O aumento do átrio esquerdo e a fibrilação atrial são considerados marcadores de morte por insuficiência cardíaca em pacientes com miocardiopatia hipertrófica. A apneia obstrutiva do sono é o distúrbio respiratório do sono mais comum, caracterizando-se por episódios recorrentes de colapso parcial ou total das vias aéreas superiores durante o sono. A apneia obstrutiva do sono é muito prevalente entre as populações com doença cardiovascular, como hipertensão arterial e insuficiência cardíaca, e está associada a remodelamento cardíaco e arritmias. Objetivos: O objetivo deste estudo foi determinar a prevalência dos distúrbios respiratórios do sono em pacientes com miocardiopatia hipertrófica e avaliar a associação da apneia obstrutiva do sono com o remodelamento cardíaco (ventricular e atrial) e fibrilação atrial em pacientes com miocardiopatia hipertrófica. Métodos: Foram estudados pacientes consecutivos estáveis clinicamente, com um diagnóstico confirmado de miocardiopatia hipertrófica acompanhados no Instituto do Coração do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo. Os pacientes foram submetidos à avaliação clínica, questionário de sonolência, bioquímica sanguínea, ecocardiograma e monitorização respiratória noturna com poligrafia portátil. Foi utilizado um valor de corte de 15 e 30 apneias e hipopneias por hora de registro para o diagnóstico de apneia obstrutiva do sono e apneia obstrutiva do sono grave, respectivamente. Resultados: Foram avaliados 80 pacientes consecutivos com miocardiopatia hipertrófica. Apneia obstrutiva do sono foi diagnosticada em 32 pacientes (40%). Apneia obstrutiva do sono grave esteve presente em 17 pacientes (21%). Pacientes com apneia obstrutiva do sono foram significativamente mais velhos (56 [41-64] vs. 39 [30-53] anos, p < 0,001), apresentaram maior índice de massa corporal (28,2 ± 3,5 vs. 25,2 ± 5,2 Kg/m2, p < 0,01), maior dimensão do átrio esquerdo (45 [42-53] vs. 41 [39-47] mm, p = 0.01) e maior diâmetro da aorta (34 [30-37] vs. 29 [28-32] mm, p < 0,001) em comparação com pacientes sem apneia obstrutiva do sono. Dois modelos de regressão linear múltipla para identificar os fatores associados ao aumento do átrio esquerdo e da aorta ascendente mostraram que o índice de apneia e hipopneia foi a única variável associada ao aumento atrial (p = 0,05) e da aorta (p = 0,01), respectivamente. A fibrilação atrial permanente esteve presente em 31% vs. 6% dos pacientes com e sem apneia obstrutiva do sono, respectivamente (p < 0,01). A apneia obstrutiva do sono (p = 0,03) e o diâmetro do átrio esquerdo (p = 0,03) foram os únicos fatores independentemente associados à fibrilação atrial em um modelo multivariado. Conclusão: A apneia obstrutiva do sono é muito prevalente em pacientes com miocardiopatia hipertrófica e está associada com aumento do átrio esquerdo e da aorta ascendente. A apneia obstrutiva do sono está independentemente associada à fibrilação atrial, um fator de risco para óbito cardiovascular nesta população / Background: Hypertrophic cardiomyopathy is the most common genetic cardiovascular disease and is associated with arrhythmias and cardiovascular death. Left atrial enlargement and atrial fibrillation are considered markers for death due to heart failure in patients with hypertrophic cardiomyopathy. Obstructive sleep apnea is the most common sleep disordered breathing and is characterized by recurrent episodes of partial or complete collapse of the upper airway during sleep. Obstructive sleep apnea is extremely prevalent among populations with cardiovascular disease, such as systemic hypertension and heart failure and is independently associated with heart remodelling and arrhythmias. Objectives: The aim of this study was to determine the prevalence of sleep disordered breathing in consecutive patients with hypertrophic cardiomyopathy and evaluate the association of obstructive sleep apnea with heart remodelling (ventricular and atrial) and with atrial fibrillation in patients with hypertrophic cardiomyopathy. Methods: We studied consecutive clinically stable patients with a confirmed diagnosis of hypertrophic cardiomyopathy followed in the Heart Institute Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, by clinical evaluation, sleep questionnaire, biochemical blood analysis, echocardiography and sleep study (overnight portable respiratory monitoring). We used a cut-off value of 15 and 30 apneas and hypopneas per hour of recording in the sleep study for the diagnosis of obstructive sleep apnea and severe obstructive sleep apnea, respectively. Results: We evaluated 80 consecutive patients with hypertrophic cardiomyopathy. Obstructive sleep apnea was present in 32 patients (40%). Severe obstructive sleep apnea was present in 17 patients (21%). Patients with obstructive sleep apnea were significantly older (56 [41-64] vs. 39 [30-53] years, p < 0.001), presented higher body mass index (28.2 ± 3.5 vs. 25.2 ± 5.2 Kg/m2, p < 0.01), increased left atrial diameter (45 [42-53] vs. 41 [39-47] mm, p = 0.01) and aorta diameter (34 [30-37] vs. 29 [28-32] mm, p < 0.001) compared with patients without obstructive sleep apnea. Two models of stepwise multiple linear regression to identify variables associated with left atrial and ascending aorta enlargement showed that apnea-hypopnea index was the only variable associated with left atrial enlargement (p = 0.05) and aorta diameter (p = 0.01), respectively. Permanent atrial fibrillation was present in 31% vs. 6% in patients with and without obstructive sleep apnea, respectively (p < 0.01). Obstructive sleep apnea (p = 0.03) and left atrial diameter (p = 0.03) were the only factors independently associated with atrial fibrillation in a multivariate model. Conclusions: Obstructive sleep apnea is highly prevalent in patients with hypertrophic cardiomyopathy and it is associated with left atrial and ascending aorta enlargement. Obstructive sleep apnea is independently associated with atrial fibrillation, a risk factor for cardiovascular death in this population

<p>Atrial fibrillation is a common disease. With pharmacological therapy most patients with atrial fibrillation have moderate or little symptoms, but a number of patients have severely symptomatic disease. This study evaluates two new non-pharmacological therapies for atrial fibrillation, the Maze procedure and atrial overdrive pacing.</p><p>In the patients planned for Maze surgery the quality of life, assessed with the SF-36 questionnaire, was very low before the operation. The quality of life was markedly improved 6 and 12 months after the Maze operation, and was comparable to values of the general Swedish population.</p><p>In the patients with sinus rhythm before surgery, the atrial size and transport function was assessed with echocardiography, and the autonomic balance was assessed with heart rate variability (HRV). The sizes of both atria were reduced and the transmitral early filling / atrial filling (E/A) ratio was increased at 6 months after the operation compared to before. A progressive increase of the E/A ratio was seen during the 24 months follow-up period, indicating a progressive decline of the left atrial transport function.</p><p>All components of HRV, including the parameters expressing sympathetic and parasympathetic modulation, were markedly decreased early after the Maze procedure compared to before. Late after the operation all components of HRV were still markedly depressed. This is interpreted as a partial autonomic denervation of the heart</p><p>Single-site right atrial overdrive pacing with two different levels of overdriving was compared with no pacing in patients with paroxysmal atrial fibrillation in a cross-over study. Overdrive pacing reduced the median number of episodes of atrial fibrillation with 50% compared to no pacing. There was no difference between medium rate overdrive pacing and high rate overdrive pacing.</p>

Atrial fibrillation is a common disease. With pharmacological therapy most patients with atrial fibrillation have moderate or little symptoms, but a number of patients have severely symptomatic disease. This study evaluates two new non-pharmacological therapies for atrial fibrillation, the Maze procedure and atrial overdrive pacing. In the patients planned for Maze surgery the quality of life, assessed with the SF-36 questionnaire, was very low before the operation. The quality of life was markedly improved 6 and 12 months after the Maze operation, and was comparable to values of the general Swedish population. In the patients with sinus rhythm before surgery, the atrial size and transport function was assessed with echocardiography, and the autonomic balance was assessed with heart rate variability (HRV). The sizes of both atria were reduced and the transmitral early filling / atrial filling (E/A) ratio was increased at 6 months after the operation compared to before. A progressive increase of the E/A ratio was seen during the 24 months follow-up period, indicating a progressive decline of the left atrial transport function. All components of HRV, including the parameters expressing sympathetic and parasympathetic modulation, were markedly decreased early after the Maze procedure compared to before. Late after the operation all components of HRV were still markedly depressed. This is interpreted as a partial autonomic denervation of the heart Single-site right atrial overdrive pacing with two different levels of overdriving was compared with no pacing in patients with paroxysmal atrial fibrillation in a cross-over study. Overdrive pacing reduced the median number of episodes of atrial fibrillation with 50% compared to no pacing. There was no difference between medium rate overdrive pacing and high rate overdrive pacing.

Background: Despite the recent improvements in surgical techniques and postoperative patient care, atrial fibrillation (AF) remains the most frequent complication after cardiac surgery. Although postoperative AF is often regarded as a benign clinical condition, this arrhythmia has significant adverse effects on patient recovery and postoperative survival. Its exact pathophysiology has not yet been elucidated. The present thesis aims to analyze AF risk factors and their interaction, pre-existing histological explanatory alterations of the atrium, the AF impact on postoperative survival and the compliance of a prophylactic drug regimen. Methods: During a 10-year period, consecutive cardiac surgery cases with complete data on AF occurrence and postoperative survival were extracted. All patients were operated on for coronary or valvular surgery, with cardiopulmonary bypass (CPB). Hospital and long-term survival data were obtained from Swedish population registry. Study I) Isolated coronary artery bypass grafting (CABG, n=7056), aortic valve replacement (n=690) and their combination (n=688) were considered. Independent AF risk factors and AF effects on early and 1 year mortality were investigated. Study II) Patients affected by postoperative AF among isolated CABG patients (n=7621), valvular surgeries (n=995) and their combination (n=879) were studied. Long-term survival was obtained and prognostic factors identified. Study III) Seventy patients were randomized to on-pump (n=35) or off-pump (n=35) CABG. Samples from the right atrial appendage were collected and histology was evaluated by means of light and electronic microscopy with reference to preexistent alterations related to postoperative AF. Study IV) Cardiac surgery patients with complete data on smoking status (n=3245) were reviewed. Effects of smoking on AF development and interaction among variables were explored. Study V) CABG patients without clinical contraindications to receive oral sotalol (80 mg twice daily) and magnesium were prospectively enrolled (n = 49) and compared with a matched contemporary control CABG group (n = 844). The clinical compliance to the AF prophylactic drug regimen was tested. Results: The overall AF incidence was around 26%, subdivided into 23%, 40% and 45% for isolated CABG, valve procedures and their combined surgeries, respectively. Age was the strongest predictor of postoperative AF. Coronary disease superimposed risk factors with reference to myocardial conditions at CPB weaning. Considering the preoperative smoking condition, smokers demonstrated a reduced AF incidence compared to non-smokers (20% versus 27%, p&lt;0.001). An interaction between smoking status and inotropic support was observed: without this interaction smoking conferred a 46% risk reduction of AF (p=0.011). At the histological level, myocyte vacuolization and nuclear derangement represented anatomical independent AF predictors (p=0.002 and p=0.016, respectively). CPB exposure was not associated to postoperative AF nor histological changes. Although, postoperative AF increases the length of hospitalization in all patient groups, it did not affect the hospital survival. However, AF independently impaired the late survival, a phenomenon seen in the CABG group only. With reference to the tested sotalolmagnesium drug regimen, only 55% of CABG patients were compliant to the treatment, with marginal effects on AF occurrence. Conclusions: In addition to age, details at the CPB weaning period, pre-existing histopathological changes, the hyperadrenergic state and catecholamines are key mechanisms in the pathophysiology of postoperative AF. In particular, the CPB period hides valuable information for timely AF prophylactic stratifications. Further, compliance effects due to patient selection should also be considered in a prophylactic therapy model. Postoperative AF increases late mortality after isolated CABG surgery, but not after valvular procedures. Although the mechanisms are unclear, our results draw the attention to possible AF recurrence after hospital discharge, indicating a strict postoperative surveillance.

A finite-element model of a two-dimensional slice of human atrial tissue for the study of the electrograms and propagation of action potentials is presented. Action potential propagation is described by a reaction-diffusion model coupled with the complex Courtemanche et al. atrial cell model. The effects of recording electrode size and location on electrograms are presented. Action potential propagation as a result of atrial fibrillation ablation therapy is also modeled by defining a lesion area with decreased electrical conductivity. The effect of electrical conductivity and geometry of the lesion was also studied. It is shown that the success rate of atrial fibrillation ablation therapy is primarily correlated with the creation of continuous ablation lines and also the formation of fibrous tissue.