Browsing by Author "Oliveira, MM"
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- Ablation Strategies for Different Types of Atrial Fibrillation in Europe: Results of the ESC-EORP EHRA Atrial Fibrillation Ablation Long-Term RegistryPublication . Schmidt, B; Brugada, J; Arbelo, E; Laroche, C; Bayramova, S; Bertini, M; Letsas, K; Pison, L; Romanov, A; Scherr, D; Tilz, R; Maggioni, A; Adragao, P; Lund, J; Haman, L; Oliveira, MM; Dagres, NAims: The ESC EORP EHRA Atrial Fibrillation (AF) Ablation Long-Term registry was designed to assess management and outcomes of AF catheter ablation procedures in Europe. To investigate the current ablation approaches and their outcomes for patients with paroxymal AF (PAF) and non-PAF in Europe. Methods and results: Data from index ablations were collected in 27 European countries at 104 centres in a prospective fashion. Pre-procedural, procedural, and 1-year follow-up data were captured on a web-based electronic case record form. Data on the ablation procedure were available for 3446 patients. Of these, 2513 patients and 933 patients underwent pulmonary vein isolation (PVI) or PVI plus (PVIplus) additional ablation, respectively. The ablation strategy was limited to PVI in 81% and 56% of patients in the PAF and non-PAF group, respectively (P < 0.001). In the non-PAF group, left atrial linear ablation and ablation of complex fragmented atrial electrograms were more commonly performed. Arrhythmias recurrence after PVI was 29% and 39% in the PAF and non-PAF group, respectively (P < 0.001) and 42% after PVIplus in both groups. Atrial fibrillation related hospital admissions were more common in the PVIplus group (20% vs. 14%). A very low procedural complication rate was observed. No relevant differences were observed with regard to repeat ablation (PVI 9% and PVIplus 11%). Conclusion: In patients with PAF and non-PAF, the ablation strategies of PVI and PVIplus led to similar arrhythmia-free survival rates after 1 year. A considerable hospital readmission rate was noted.
- Acute Vagal Modulation of Electrophysiology of the Atrial and Pulmonary Veins Increases Vulnerability to Atrial FibrillationPublication . Oliveira, MM; Nogueira da Silva, M; Geraldes, V; Xavier, R; Laranjo, S; Silva, V; Postolache, G; Cruz Ferreira, R; Rocha, IVagal activity is thought to influence atrial electrophysiological properties and play a role in the initiation and maintenance of atrial fibrillation (AF). We evaluated the effects of acute vagal stimulation on atrial conduction, refractoriness of atrial and pulmonary veins (PVs) and inducibility of AF. An open-chest epicardial approach was performed in New Zealand White rabbits with preserved autonomic innervation. Atrial electrograms were obtained with four unipolar electrodes placed epicardially along the atria (n = 22) and an electrode adapted to the proximal left PV (n = 10). The cervical vagus nerve was stimulated with bipolar platinum electrodes (20 Hz). Epicardial activation was recorded in sinus rhythm, and effective refractory periods (ERPs), dispersion of refractoriness and conduction times from high-lateral right atrium (RA) to high-lateral left atrium (LA) and PVs assessed at baseline and during vagal stimulation. Burst pacing (50 Hz, 10 s), alone or combined with vagal stimulation, was applied to the right (RAA) and left atrial appendage (LAA) and PVs to induce AF. At baseline, ERPs were lower in PVs than in LA and LAA, but did not differ significantly from RA and RAA, and there was a significant delay in the conduction time from RA to PVs compared with the activation time from RA to LA (P < 0.01). During vagal stimulation, ERP decreased significantly at all sites, without significant differences in the dispersion of refractoriness, and the atrial conduction times changed from 39 ± 19 to 49 ± 9 ms (RA to PVs; n.s.) and from 14 ± 7 to 28 ± 12 ms (RA to LA; P = 0.01). Induction of AF was reproducible in 50% of cases with 50 Hz and in 82% with 50 Hz combined with vagal stimulation (P < 0.05). During vagal stimulation, AF cycle length decreased at all sites, and AF duration changed from 1.0 ± 0.9 to 14.0 ± 10.0 s (P < 0.01), with documentation of PV tachycardia in three cases. In 70% of the animals, AF ceased immediately after interruption of vagal stimulation. We conclude that in the intact rabbit heart, vagal activity prolongs interatrial conduction and shortens atrial and PV ERP, contributing to the vulnerability to the induction and maintenance of AF. This model may be useful in the assessment of the autonomic influence in the mechanisms underlying AF.
- Alterações da Actividade Autonómica Durante o Teste de Inclinação em Doentes com Fibrilhação Auricular Paroxística: Análise com WaveletsPublication . Oliveira, MM; Nogueira da Silva, M; Timóteo, AT; Feliciano, J; Silva, S; Xavier, R; Rocha, I; Silva-Carvalho, L; Cruz Ferreira, RThe autonomic nervous system (ANS) is known to be an important modulator in the pathogenesis of paroxysmal atrial fibrillation (PAF). Changes in ANS control of heart rate variability (HRV) occur during orthostatism to maintain cardiovascular homeostasis. Wavelet transform has emerged as a useful tool that provides time-frequency decomposition of the signal under investigation, enabling intermittent components of transient phenomena to be analyzed. AIM: To study HRV during head-up tilt (HUT) with wavelet transform analysis in PAF patients and healthy individuals (normals). METHODS: Twenty-one patients with PAF (8 men; age 58 +/- 14 yrs) were examined and compared with 21 normals (7 men, age 48 +/- 12 yrs). After a supine resting period, all subjects underwent passive HUT (60 degrees) while in sinus rhythm. Continuous monitoring of ECG and blood pressure was carried out (Task Force Monitor, CNSystems). Acute changes in RR-intervals were assessed by wavelet analysis and low-frequency power (LF: 0.04-0.15 Hz), high-frequency power (HF: 0.15-0.60 Hz) and LF/HF (sympathovagal) were calculated for 1) the last 2 min of the supine period; 2) the 15 sec of tilting movement (TM); and 3) the 1st (TT1) and 2nd (TT2) min of HUT. Data are expressed as means +/- SEM. RESULTS: Baseline and HUT RR-intervals were similar for the two groups. Supine basal blood pressure was also similar for the two groups, with a sustained increase in PAF patients, and a decrease followed by an increase and then recovery in normals. Basal LF, HF and LF/ HF values in PAF patients were 632 +/- 162 ms2, 534 +/- 231 ms2 and 1.95 +/- 0.39 respectively, and 1058 +/- 223 ms2, 789 +/- 244 ms2 and 2.4 +/- 0.36 respectively in normals (p = NS). During TM, LF, HF and LF/HF values for PAF patients were 747 +/- 277 ms2, 387 +/- 94 ms2 and 2.9 +/- 0.6 respectively, and 1316 +/- 315 ms2, 698 +/- 148 ms2 and 2.8 +/- 0.6 respectively in normals (p < 0.05 for LF and HF). During TF1, LF, HF and LF/ HF values for PAF patients were 1243 +/- 432 ms2, 302 +/- 88 ms2 and 7.7 +/- 2.4 respectively, and 1992 +/- 398 ms2, 333 +/- 76 ms2 and 7.8 +/- 0.98 respectively for normals (p < 0.05 for LF). During TF2, LF, HF and LF/HF values for PAF patients were 871 +/- 256 ms2, 242 +/- 51 ms2 and 4.7 +/- 0.9 respectively, and 1263 +/- 335 ms2, 317 +/- 108 ms2 and 8.6 +/- 0.68 respectively for normals (p < 0.05 for LF/HF). The dynamic profile of HRV showed that LF and HF values in PAF patients did not change significantly during TM or TT2, and LF/HF did not change during TM but increased in TT1 and TT2. CONCLUSION: Patients with PAF present alterations in HRV during orthostatism, with decreased LF and HF power during TM, without significant variations during the first minutes of HUT. These findings suggest that wavelet transform analysis may provide new insights when assessing autonomic heart regulation and highlight the presence of ANS disturbances in PAF.
- An Unusual Pacemaker-Induced TachycardiaPublication . Coutinho-Cruz, M; Portugal, G; Silva Cunha, P; Oliveira, MM
- Angioplastia Coronária no Enfarte Agudo do Miocárdio: Impacto do Timing da Revascularização na Alternância da Onda TaPublication . Pelicano, NJ; Oliveira, MM; Nogueira da Silva, M; Anão, A; Feliciano, J; Fiarresga, A; Alves, S; Silva, S; Quininha, JEncontra-se bem estabelecido que, na abordagem terapêutica do enfarte agudo do miocárdio (EAM), a trombólise e a angioplastia coronária percutânea (ACTP) permitem diminuir a mortalidade e melhorar o prognóstico, sendo esse benefício tanto maior quanto menor o tempo decorrido entre o evento isquémico e o procedimento terapêutico. No entanto, não está ainda estabelecido qual o impacto que o atraso da implementação dessas terapêuticas tem no desenvolvimento de taquidisritmias ventriculares e por consequência no resultado da alternância da onda T(TWA), que representa um método reconhecido para avaliação da vulnerabilidade ventricular às referidas arritmias. Objectivo: Analisar os resultados da TWA por microvoltagem numa população submetida a ACTP na sequência de EAM e avaliar a influência do timing de revascularização miocárdica nos resultados da TWA. Métodos: Estudámos 79 doentes (67 do sexo masculino; 57 ± 11 anos) consecutivos, admitidos por EAM e sujeitos a revascularização miocárdica por ACTP durante o internamento. A TWA foi avaliada utilizando um aparelho da HeartTwave System (Cambridge Heart, Inc., Bedford, Massachusetts) nos 30 dias pós-EAM. Durante a realização de uma prova de esforço em tapete rolante com protocolo manual, com o objectivo de elevar a frequência cardíaca até aos 110 batimentos por minuto, realizou-se o registo electrocardiográfico através da aplicação de sete eléctrodos standard e outros sete eléctrodos sensores de alta-resolução, especialmente concebidos para redução do «ruído», dispostos segundo as derivações ortogonais de Frank(X,Y, Z). A TWA foi considerada positiva quando se verificou a presença de alternância da onda T de magnitude ³ 1,9 μV de forma consistente e mantida (> 1 minuto), com início para frequências cardíacas < 110 batimentos/minuto ou quando esta alternância se verificou em doentes em repouso. Foi considerada negativa quando se conseguiu obter dados sem artefactos durante pelo menos um minuto, com frequências > 105 batimentos/minuto, sem atingir critério de positividade e indeterminada se não podia ser classificada como positiva ou negativa. Foram excluídos doentes com EAM ou revascularização miocárdica (cirúrgica ou percutânea) prévios, os que apresentavam insuficiência cardíaca congestiva, com fibrilhação auricular, > 10 extrassístoles por minuto, pacemaker definitivo, bradicárdia < 40 bpm, complexos QRS com duração > 130 ms ou sob terapêutica anti-arrítmica. Considerámos como marcador de risco para a ocorrência de eventos arrítmicos ventriculares malignos a presença de TWA positiva ou indeterminada. (TWA «nãonegativa»). Os resultados da TWA foram comparados entre o grupo de doentes submetidos a ACTP nas primeiras 24 horas pós-EAM (Grupo A; n = 45) e o grupo de doentes submetidos a ACTP > 24 horas pós-EAM. (Grupo B; n = 34) Resultados: A TWA foi positiva em 16 doentes (20,2%) e negativa em 56 (70,9%). Em 7 casos (8,9%), o resultado do teste foi considerado indeterminado. A TWA foi «não-negativa» em 29,1% da população. No grupo A a TWA foi “não-negativa” em 9 doentes (20 %) (6 com TWA positiva e três com TWA indeterminada) e negativa em 36 doentes (80 %) e no grupo B foi «não-negativa» em 14 doentes (41%) (10 com TWA positiva e quatro com TWA indeterminada) e negativa em 20 (59 %) (p < 0,05). Não se encontraram diferenças entre os dois grupos no que respeita à fracção de ejecção ventricular esquerda. No seguimento até aos 60 dias após a alta hospitalar não foram documentados eventos arrítmicos ventriculares, síncopes ou óbito. Foram reinternados cinco doentes (7 %) por recorrênciade angor. Conclusões: Numa população de sobreviventes de EAM encontrámos uma prevalência de TWA não negativa de 29 %, apesar da revascularização miocárdica com ACTP. A ACTP, quando efectuada nas primeiras 24 horas após o início do EAM, reduz de forma significativa o número de doentes com TWA não negativa,sugerindo que esta intervenção precoce poderá baixar o risco arrítmico destes doentes e influenciar favoravelmente o prognóstico pós-EAM. O impacto da morte súbita na mortalidade pós-EAM justifica estudos prospectivos de maiores dimensões
- Aspectos Psicossociais Associados à Percepção da Dor Pós-Operatória em Indivíduos Submetidos a Cirurgia CoronáriaPublication . Leal, E; Pais Ribeiro, JL; Oliveira, MM; Roquette, JObjectivo: Identificar os factores psicossociais que influenciam a percepção da dor pós-operatória em doentes submetidos a cirurgia de revascularização do miocárdio (CRM). Material e Métodos: Estudo exploratório correlacional de 91 doentes (71 homens e 20 mulheres) submetidos a CRM (pontagem aortocoronária) por esternotomia. A idade média era de 63,8 ± 9,6 anos (entre 39 e 84). Foram utilizados os seguintes instrumentos: Escala Analógica Visual às 24, 48 e 96 horas do pós-operatório; Questionário de Caracterização Demográfica; Mental Health Inventory de 5 itens; Percepção de Saúde Geral (SF-36); Escala de Expectativas de Dor; Escala de Percepção de Apoio; Escala de Expectativas de Auto-eficácia; Satisfação com o tratamento, médicos e enfermeiros (American Pain Society Questionnaire) aplicados às 96 horas após a cirurgia. Resultados: Os doentes que apresentaram expectativas elevadas de dor, percepcionaram maior apoio, apresentaram níveis elevados de auto-eficácia para lidar com a dor ou, se pertenciam ao sexo masculino, sentiram menos dor. De igual modo, os doentes que apresentaram melhor saúde mental, percepcionaram a sua saúde como boa e os doentes que expressaram maior satisfação com o tratamento sentiram menos dor. A dor não foi influenciada pela idade, grau de escolaridade ou pela satisfação com a conduta de médicos e enfermeiros. Conclusão: Após as primeiras 48 horas do pós-operatório, a experiência de dor é influenciada por factores psicossociais, em particular pela expectativa de dor, expectativa de auto-eficácia, apoio percebido, percepção da saúde geral, percepção de saúde mental e satisfação com o tratamento para a dor. Perante os resultados, evidencia-se a necessidade de conjugar conhecimentos no sentido de dar respostas mais alargadas e de carácter multidisciplinar no tratamento da dor pós-operatória em CRM devendo, a par de outros aspectos, focar-se na gestão das expectativas dos doentes.
- Benefícios da Terapêutica de Ressincronização Cardíaca na «Miocardiopatia Muito Dilatada»Publication . Lousinha, A; Oliveira, MM; Feliciano, J; Galrinho, A; Branco, LM; Silva Cunha, P; Hamad, H; Ramos, R; Abreu, J; Leal, A; Santos, S; Soares, RM; Nogueira da Silva, M; Cruz Ferreira, RINTRODUCTION: Recent clinical trials have studied parameters that could predict response to cardiac resynchronization therapy (CRT) in patients with advanced heart failure. Left ventricular end-diastolic dimension (LVEDD) is regarded as a possible predictor of response to CRT. OBJECTIVE: To study the response to CRT in patients with very dilated cardiomyopathy, i.e. those at a more advanced stage of the pathology, analyzing both the responder rate and reverse remodeling in two groups of patients classified according to LVEDD. METHODS: We performed a retrospective analysis of 71 patients who underwent CRT (aged 62 +/- 11 years; 65% male; 93% in NYHA functional class > or = III; 31% with ischemic cardiomyopathy; left ventricular ejection fraction [LVEF] 25.6 +/- 6.8%; 32% in atrial fibrillation; QRS 176 +/- 31 ms). Twenty-two (31%) patients with LVEDD > or = 45 mm/m2 (49.2 +/- 3.5 mm/m2) were considered to have very dilated cardiomyopathy (Group A) and 49 patients had LVEDD > 37 mm/m2 and < 45 mm/m2 (39.4 +/- 3.8 mm/m2) (Group B). All patients were assessed by two-dimensional echocardiography at baseline and six months after CRT. The following parameters were analyzed: NYHA functional class, LVEF and LVEDD. Responders were defined clinically (improvement of > or = 1 NYHA class) and by echocardiography, with a minimum 15% increase over baseline LVEF combined with a reduction in LVEDD (reverse remodeling). RESULTS: There were no significant differences in baseline demographic characteristics between the two groups. At six-month followup, we observed an improvement in LVEF (delta 8.5 +/- 11.8%) and a reduction in LVEDD (delta 3.7 +/- 6.8 mm/m2), with fifty-seven (79%) patients being classified as clinical responders. The percentage of patients with reverse remodeling was similar in both groups (64% vs. 73%, p = NS), as were percentages of improved LVEF (delta 6.3 +/- 11% vs. delta 9.6 +/- 12%; p = NS) and decreased LVEDD (delta 3.7 +/- 5.5 mm/m2 vs. delta 3.7 +/- 7.4 mm/m2; p = NS). We found a higher percentage of clinical responders in patients with very dilated cardiomyopathy (96% vs. 72%, p < 0.05). CONCLUSION: In this study, a significant number of responders showed reverse remodeling after CRT. Although a higher percentage of patients with very dilated cardiomyopathy showed improvement in functional class, the extent of reverse remodeling was similar in both groups.
- Cardiac Pacing in Severe Recurrent Reflex Syncope and Tilt-Induced AsystolePublication . Brignole, M; Russo, V; Arabia, F; Oliveira, MM; Pedrote, A; Aerts, A; Rapacciuolo, A; Boveda, S; Deharo, JC; Maglia, G; Nigro, G; Giacopelli, D; Gargaro, A; Tomaino, MAim: The benefit of cardiac pacing in patients with severe recurrent reflex syncope and asystole induced by tilt testing has not been established. The usefulness of tilt-table test to select candidates for cardiac pacing is controversial. Methods and results: We randomly assigned patients aged 40 years or older who had at least two episodes of unpredictable severe reflex syncope during the last year and a tilt-induced syncope with an asystolic pause longer than 3 s, to receive either an active (pacing ON; 63 patients) or an inactive (pacing OFF; 64 patients) dual-chamber pacemaker with closed loop stimulation (CLS). The primary endpoint was the time to first recurrence of syncope. Patients and independent outcome assessors were blinded to the assigned treatment. After a median follow-up of 11.2 months, syncope occurred in significantly fewer patients in the pacing group than in the control group [10 (16%) vs. 34 (53%); hazard ratio, 0.23; P = 0.00005]. The estimated syncope recurrence rate at 1 year was 19% (pacing) and 53% (control) and at 2 years, 22% (pacing) and 68% (control). A combined endpoint of syncope or presyncope occurred in significantly fewer patients in the pacing group [23 (37%) vs. 40 (63%); hazard ratio, 0.44; P = 0.002]. Minor device-related adverse events were reported in five patients (4%). Conclusion: In patients aged 40 years or older, affected by severe recurrent reflex syncope and tilt-induced asystole, dual-chamber pacemaker with CLS is highly effective in reducing the recurrences of syncope. Our findings support the inclusion of tilt testing as a useful method to select candidates for cardiac pacing.
- Cardiac Resynchronization System Implantation Guided by Three-Dimensional Electroanatomic MappingPublication . Cunha, PS; Santos, H; Oliveira, MM
- Cardiodesfibrilhador Implantável com Eléctrodo de Choque Subcutâneo AdicionalPublication . Piçarra, B; Silva Cunha, P; Oliveira, MM; Nogueira da Silva, M; Conceição, JM; Cruz Ferreira, R