22 research outputs found
Estratificação não invasiva do risco disrítmico em doentes com Síndrome de Brugada
Trabalho Final do Curso de Mestrado Integrado em Medicina, Faculdade de Medicina, Universidade de Lisboa, 2016Introdução: A estratificação do risco disrítmico é de extrema importância na Síndrome de Brugada (SB). Diversos marcadores não invasivos têm sido recentemente investigados, mas a sua acuidade permanece controversa. Objectivos: Caracterizar uma população com SB por métodos não invasivos e proceder à comparação das suas características em função da expressão fenotípica da doença (padrão electrocardiográfico e estado sintomático). Métodos: Procedeu-se a uma avaliação transversal no âmbito de um estudo observacional prospectivo de doentes com SB com padrão tipo 1 espontâneo ou indutível. Os doentes foram submetidos a avaliação clínica e, em parte da população, procedeu-se a avaliação não-invasiva adicional com realização de electrocardiograma (ECG) com registo das derivações V1, V2, V3, V1-3ºEIC, V2-3ºEIC, V3-R e V4-R e avaliação de potenciais tardios por signal-averaged ECG (SAECG) nas derivações convencionais de Frank e nas derivações modificadas para o ventrículo direito, com medição da duração do QRS filtrado (fQRS), da raiz quadrada da voltagem nos 40 ms terminais do QRS (RMS40) e da duração da porção terminal do QRS com amplitude de sinal <40 μV (LAS40). Nos doentes com padrão espontâneo tipo 2 ou 3, avaliou-se a variação das características dos potenciais tardios por SAECG durante provocação farmacológica com flecainida. Resultados: Foram avaliados 55 doentes (46 ± 13 anos; 78% do sexo masculino), 15 dos quais sintomáticos, incluindo 3 doentes com história de disritmias ventriculares malignas. Observou-se maior frequência de alterações no ECG (disponível com as derivações direitas em 38 doentes) e no SAECG (realizado em 33 doentes) entre os doentes sintomáticos, incluindo padrão tipo 1 espontâneo, bloqueio de ramo direito, padrão de repolarização precoce anterolateral, maior somatório do número de spikes de fragmentação do QRS e potenciais tardios ventriculares. Adicionalmente, observou-se variação das características dos potenciais tardios, sobretudo nas derivações modificadas, em função da expressão fenotípica da doença. Nos 20 doentes sem padrão tipo 1 espontâneo submetidos a prova de flecainida, verificou-se a capacidade de precipitação de potenciais tardios em até 80% desses doentes. Conclusão: As alterações electrocardiográficas e no estudo de potenciais tardios por SAECG são muito frequentes nos doentes com SB e correlacionam-se com a expressão fenotípica da doença. Serão necessários estudos prospectivos de grande dimensão e duração de seguimento para clarificar a sua utilidade para finalidade de estratificação prognóstica.Introduction: In Brugada Syndrome (BS), disrhytmic risk stratification is extremely important. Several non-invasive markers have been recently investigated, but its accuracy is still controversial.
Objectives: To characterize a BS population using non-invasive methods and compare its characteristics according the disease phenotype expression (electrocardiograph pattern and symptomatic status).
Methods: Within a prospective observational study of BS patients with spontaneous or inducible type 1 pattern, a transversal evaluation has been done. Patients have been submitted to a clinical assessment and, in a part of them, it has also been made a non-invasive evaluation throughout: an electrocardiogram (ECG) with V1, V2, V3, V1-3ºEIC, V2-3ºEIC, V3-R and V4-R leads records; late potentials evaluation using signal-averaged ECG (SAECG) in Frank´s conventional leads and modified leads for right ventricle, measuring filtered QRS duration (fQRS), root mean square voltage of the terminal 40ms in the filtered QRS complex (RMS40) and duration of low-amplitude signals <40 μV in the terminal filtered QRS complex (LAS40). In patients with type 2 or 3 spontaneous pattern, during flecainide challenge test, the late potentials by SAECG characteristics variation has been evaluated.
Results: 55 patients (46 ± 13 years; 78% males) have been studied, 15 of them symptomatic including 3 with malignant ventricular disrhytmias antecedents. A more frequent ECG changes (available with right leads in 38 patients) and in the SAECG (performed in 33 patients) have been noticed among the symptomatic ones. These changes include: spontaneous type 1 pattern, right bundle-brunch block, early repolarization anterolateral pattern, QRS fragmentation spikes number is bigger considering the set of leads, and ventricular late potentials. Additionally, late potentials characteristics variation has been observed, mainly in modified leads, according the disease phenotypic expression. In the 20 patients without spontaneous type 1 pattern subjected to flecanide challenge test, in almost 80% has been verified the capacity to induce late potentials to appear.
Conclusion: In patients with BS, both electrocardiographic and late potential analyze by SAECG changes are quite common and correlated with the disease phenotypic expression. Great sized prospective studies will be required, with considerable follow-up time, in order to clarify the usefulness of these changes as prognostic stratifiers
Registos geomorfológicos e sedimentares do Plio-Plistocénico de Peniche - Atouguia da Baleia Geomorfological and sedimentary records of the Plio-Pleistocene of Peniche - Atouguia da Baleia
A characterization and interpretation of the Pliocene and Pleistocene geomorphological and sedimentary records of Peniche - Atouguia da Baleia littoral are here presented. The methods comprised literature review but also geomorphology, lithostratigraphy and sedimentology. Several wave-cut surfaces were characterized and mapped, respectively, at: 33-36 m, poorly preserved and considered produced by the important marine incursion dated as 3.7 Ma; 24-28 m, very large, that could correlate with the MIS9e (ca. 340-300 ka) and covered by pebbly sands with an “old” Acheulian industry; 15-19 m, that could correlate with the MIS7 (245-185 ka), covered by pebbly sands with an Acheulian industry; and 4-7 m, with a marine conglomerate, clearly related with the MIS5 (high sea-level at ca. 130-80 ka and temperate climate). The succession of aeolian fine sands intercalated with levels rich in fossils and Mousterian artefacts correlates with the interval 80-12ka (MS4, MS3 and MSI2), coeval with a low sea-level and cold climate conditions
Plio-Quaternary coastal uplift along the western Iberian margin: insights from dated marine terraces (Peniche, central Portugal)
This study provides a detailed geomorphological study of the Peniche Peninsula, located in westernmost Iberia, a resistant rocky limestone headland subjected to high energy Atlantic Ocean coastal processes. We have used field mapping, surveying, sedimentary facies analysis, geochronology (electron spin resonance [ESR]; U-Series), but also identification of fossils and lithic artefacts, in order to: 1) reconstruct styles and timing of paleoenvironmental changes, 2) correlate to Marine Isotope Stages (MIS), and 3) quantify coastal uplift rates during the Quaternary. The marine terrace deposits, comprising calcite cemented conglomerates and siliciclastic sandstones, sometimes capped by travertines, were studied in detail along the SW sector of the peninsula, at the Furninha Cave site.
The mapping (1/10,000 scale) and dating results obtained allow to identify several marine levels and to correlate them to MIS’s: 1) a culminant wave-cut platform at 29-33 m (above mean sea level) (Pm), with a probable age of 3.7 Ma; 2) a wave-cut platform at 24-28 m (Tm1), dated as 883±120 ka, probably correlated with high sea level conditions spanning ca.1000-790 ka (MIS25-19); 3) a wave-cut platform at 19-21 m (Tm2), with a beach conglomerate and sandstone, dated as 707±32 ka and correlated to 790-680 ka (MIS17); 4) a wave-cut platform at 14-16 m (Tm3), with a beach conglomerate and sandstone, and capping travertine, probably recording aggradation during 620-460 ka (MIS15-13) (ESR: 598±160, 563±63, 490±44 ka; U-series: >620 ka); 5) a wave-cut platform at 11-13 m (Tm4), with beach conglomerate and sandstone followed by travertine, dated as 315±48 ka, probably recording 430-275 ka (MIS11-9); 6) a wave-cut platform at 6-9 m (Tm5), with beach conglomerate, sandstone and travertine, dated as 288±53 ka, probably spanning 290-180 ka (MIS7); 7) a wave-cut platform at 4.0 m (Tm6), probably spanning 125-85 ka (MIS5); 8) aeolian sand units, respectively, of Late Pleistocene and Holocene age; 9) modern beach sediments, ranging from sands to boulders.
A long term Plio-Quaternary corrected uplift rate of 0.004-0.006 m/ka is obtained using the Pm level as a key geomorphic marker (eustatic level = +10-20 m). In contrast, for the last ~1 Ma the inset Pleistocene marine terrace levels (Tm1-Tm6) indicate apparent short-term uplift rates between 0.02 and 0.05 m/ka (means of 0.03 to 0.04 m/ka) and corrected short-term uplift rates between -0.05 and 0.05 m/ka (means of -0.02 to 0.05 m/ka).
This study demonstrates that the Quaternary compressive reactivation of the Western Iberian Margin has determined coastal low to moderate uplift rates; active tectonics play an important role in the geomorphic expression and distribution of Pleistocene marine terraces, recording vertical ground motions (uplift/subsidence) superimposed onto global sea-level oscillations
The value of multiparametric prediction scores in heart failure varies with the type of follow‐up after discharge: a comparative analysis
© 2023 The Authors. ESC Heart Failure published by John Wiley & Sons Ltd on behalf of European Society of Cardiology. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.Aims: Multiple prediction score models have been validated to predict major adverse events in patients with heart failure. However, these scores do not include variables related to the type of follow-up. This study aimed to evaluate the impact of a protocol-based follow-up programme of patients with heart failure regarding scores accuracy for predicting hospitalizations and mortality occurring during the first year after hospital discharge.
Methods and results: Data from two heart failure populations were collected: one composed of patients included in a protocol-based follow-up programme after an index hospitalization for acute heart failure and a second one-the control group-composed of patients not included in a multidisciplinary HF management programme after discharge. For each patient, the risk of hospitalization and/or mortality within a period of 12 months after discharge was calculated using four different scores: BCN Bio-HF Calculator, COACH Risk Engine, MAGGIC Risk Calculator, and Seattle Heart Failure Model. The accuracy of each score was established using the area under the receiver operating characteristic curve (AUC), calibration graphs, and discordance calculation. AUC comparison was established by the DeLong method. The protocol-based follow-up programme group included 56 patients, and the control group, 106 patients, with no significant differences between groups (median age: 67 years vs. 68.4 years; male sex: 58% vs. 55%; median ejection fraction: 28.2% vs. 30.5%; functional class II: 60.7% vs. 56.2%, I: 30.4% vs. 31.9%; P = not significant). Hospitalization and mortality rates were significantly lower in the protocol-based follow-up programme group (21.4% vs. 54.7%; P < 0.001 and 5.4% vs. 17.9%; P < 0.001, respectively). When applied to the control group, COACH Risk Engine and BCN Bio-HF Calculator had, respectively, good (AUC: 0.835) and reasonable (AUC: 0.712) accuracy to predict hospitalization. There was a significant reduction of COACH Risk Engine accuracy (AUC: 0.572; P = 0.011) and a non-significant accuracy reduction of BCN Bio-HF Calculator (AUC: 0.536; P = 0.1) when applied to the protocol-based follow-up programme group. All scores showed good accuracy to predict 1 year mortality (AUC: 0.863, 0.87, 0.818, and 0.82, respectively) when applied to the control group. However, when applied to the protocol-based follow-up programme group, a significant predictive accuracy reduction of COACH Risk Engine, BCN Bio-HF Calculator, and MAGGIC Risk Calculator (AUC: 0.366, 0.642, and 0.277, P < 0.001, 0.002, and <0.001, respectively) was observed. Seattle Heart Failure Model had non-significant reduction in its acuity (AUC: 0.597; P = 0.24).
Conclusions: The accuracy of the aforementioned scores to predict major events in patients with heart failure is significantly reduced when they are applied to patients included in a multidisciplinary heart failure management programme.This work was supported by national funds, Fundação para a Ciência e a Tecnologia, reference number UIDB/00306/2020.info:eu-repo/semantics/publishedVersio
Non‐invasive telemonitoring improves outcomes in heart failure with reduced ejection fraction : a study in high‐risk patients
© 2020 The Authors. ESC Heart Failure published by John Wiley & Sons Ltd on behalf of the European Society of Cardiology. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.Aims: Non-invasive telemonitoring (TM) in patients with heart failure (HF) and reduced left ventricular ejection fraction (HFrEF) may be useful in the early diagnosis of HF decompensation, allowing therapeutic optimization and avoiding re-hospitalization. We describe a TM programme in this population and evaluate its effectiveness during a 12 month period.
Methods and results: We conducted a single-centre study of patients discharged from hospital after decompensated HF, allocated into three groups: prospective TM programme, prospective HF protocol follow-up programme (PFP) with no TM facilities, and retrospective propensity-matched usual care (UC). TM effectiveness was assessed by all-cause hospitalizations and mortality; HF-related hospitalization (HFH), days lost to unplanned hospital admissions/death, functional capacity and quality of life (New York Heart Association, Kansas City Cardiomyopathy Questionnaire, 6 min walk test, and plasma N-terminal pro-brain natriuretic peptide) were also evaluated. A total of 125 patients were included [65.9 ± 11.9 years, 32% female, left ventricular ejection fraction 27% (21-32)]. TM was similar to PFP regarding effectiveness; TM reduced all-cause hospitalization and mortality (HR 0.27; 95% CI 0.11-0.71; P < 0.01) and HFH (HR 0.29; 95% CI 0.10-0.89; P < 0.05) as compared with UC. TM reduced the average number of days lost due to unplanned hospital admissions or all-cause death as compared with PFP (5.6 vs. 12.4 days, P < 0.05) and UC (5.6 vs. 48.8 days, P < 0.01). Impact on quality of life was similar between TM and PFP (P = 0.36).
Conclusions: In patients with HFrEF and recent HF hospitalization, non-invasive TM reduced 12 month all-cause hospitalization/mortality and HFH as compared with usual care. TM also reduced the number of days lost due to unplanned hospital admission/death as compared with either an optimized protocol-based follow-up programme or usual care.This work was supported by National Health System programme with specific budget attributed to non-invasive TM of HF patients. TM was performed in cooperation with Linde Healthcare®, which had no role in the data interpretation or writing of the report. The corresponding author had full access to all the data in the study and had the final responsibility for the decision to submit for publication.info:eu-repo/semantics/publishedVersio
Marine terrace staircases of western Iberia: uplift rate patterns from rocky limestone coasts of central Portugal (Cape Espichel and Raso)
The Western Iberian passive margin is under compressive tectonic reactivation resulting in spatial
and temporal variations in surface uplift. This uplift can be quantified in coastal settings using
staircases of wave-cut platforms developed onto rocky headlands. This study focuses on two marine
terrace staircases of central Portugal: Cape Raso (west of Lisbon) and Cape Espichel (western
Arrábida mountain chain). Geomorphic and stratigraphic analyses identified four marine terraces
above sea level at Cape Raso area and twelve at Cape Espichel. ESR and pIRIR dating were used to
develop a chronological framework for the staircases, from which uplift rates were calculated.
Using the interaction between the global mean sea-level elevations in the Quaternary and the local
uplift rate (Roberts et al., 2013) the marine terraces were correlated with Marine Isotope Stages
(MIS). At Cape Raso, Tm1 (+38 m) corresponds to MIS 17 (712-676 ka), Tm2 (+34 m) corresponds
to the MIS 15 (621-563 ka) and was reworked during the MIS 11 (399-408 ka), Tm3 (+ 22 m)
correlates with MIS 13 (533-478 ka) and was reworked during the highstand of MIS 9 (330-316 ka)
and Tm4 (+9 m) correlates with MIS 7 (243 -191 ka). At Cape Espichel, a correlation was found
between the relative sea-level elevations of the eight lowest terraces with several MISs (MIS 5 until
MIS 17). The correlation becomes unclear for terraces older than MIS 17, translating into an
apparent decrease in uplift rate towards older times. Either in Cape Raso or Espichel, the terrace
staircases do not correlate in all cases with sea level high stands sequentially. For instance, the
palaeoshoreline elevation of MIS 11 is higher than the palaeoshoreline of MIS 13. This suggests that
marine terraces have been formed by superposition of multiple sea-level fluctuations in a long-term
uplift context, but with an uplift rate low enough to allow the reworking of older shorelines during
subsequent MISs.
At Cape Raso, the dating of Tm2 correlated with MIS 15 allows for an estimation of an uplift rate of
~0.07 m/ka for this coast, seemingly decreasing over the last ~125 ka. At Cape Espichel, the
chronological framework of Tm5 and Tm6 allows associations with MIS 15 and MIS 11, respectively.The estimated mean uplift rate from MIS 5e to MIS 17 was ~0.14m/ka. For times older than MIS 17
(up to ca. 3.7 Ma) the uplift rate was lower than during the last ~125 ka (~0.04 m/ka). The present
elevations of the late Zanclean wave-cut platform, represented by the Raso Cape Platform (~100 m)
and the Cape Espichel (up to ~220 m) platforms, further express the differential uplift between the
study areas for the last ~3.7 Ma.
References:
Roberts, G.P., Meschis, M., Houghton, S., Underwood, C., Briant R.M., 2013. The implications of
revised Quaternary paleo-shoreline chronologies for the rates of active extension and uplift in the
upper plate of subduction zones. Quaternary Science Reviews 78, 169-187
Marine terrace staircases of western Iberia: uplift rate patterns from rocky limestone coasts of central Portugal (Cape Espichel and Raso)
The Western Iberian passive margin is under compressive tectonic reactivation resulting in spatial
and temporal variations in surface uplift. This uplift can be quantified in coastal settings using
staircases of wave-cut platforms developed onto rocky headlands. This study focuses on two marine
terrace staircases of central Portugal: Cape Raso (west of Lisbon) and Cape Espichel (western
Arrábida mountain chain). Geomorphic and stratigraphic analyses identified four marine terraces
above sea level at Cape Raso area and twelve at Cape Espichel. ESR and pIRIR dating were used to
develop a chronological framework for the staircases, from which uplift rates were calculated.
Using the interaction between the global mean sea-level elevations in the Quaternary and the local
uplift rate (Roberts et al., 2013) the marine terraces were correlated with Marine Isotope Stages
(MIS). At Cape Raso, Tm1 (+38 m) corresponds to MIS 17 (712-676 ka), Tm2 (+34 m) corresponds
to the MIS 15 (621-563 ka) and was reworked during the MIS 11 (399-408 ka), Tm3 (+ 22 m)
correlates with MIS 13 (533-478 ka) and was reworked during the highstand of MIS 9 (330-316 ka)
and Tm4 (+9 m) correlates with MIS 7 (243 -191 ka). At Cape Espichel, a correlation was found
between the relative sea-level elevations of the eight lowest terraces with several MISs (MIS 5 until
MIS 17). The correlation becomes unclear for terraces older than MIS 17, translating into an
apparent decrease in uplift rate towards older times. Either in Cape Raso or Espichel, the terrace
staircases do not correlate in all cases with sea level high stands sequentially. For instance, the
palaeoshoreline elevation of MIS 11 is higher than the palaeoshoreline of MIS 13. This suggests that
marine terraces have been formed by superposition of multiple sea-level fluctuations in a long-term
uplift context, but with an uplift rate low enough to allow the reworking of older shorelines during
subsequent MISs.
At Cape Raso, the dating of Tm2 correlated with MIS 15 allows for an estimation of an uplift rate of
~0.07 m/ka for this coast, seemingly decreasing over the last ~125 ka. At Cape Espichel, the
chronological framework of Tm5 and Tm6 allows associations with MIS 15 and MIS 11, respectively.The estimated mean uplift rate from MIS 5e to MIS 17 was ~0.14m/ka. For times older than MIS 17
(up to ca. 3.7 Ma) the uplift rate was lower than during the last ~125 ka (~0.04 m/ka). The present
elevations of the late Zanclean wave-cut platform, represented by the Raso Cape Platform (~100 m)
and the Cape Espichel (up to ~220 m) platforms, further express the differential uplift between the
study areas for the last ~3.7 Ma.
References:
Roberts, G.P., Meschis, M., Houghton, S., Underwood, C., Briant R.M., 2013. The implications of
revised Quaternary paleo-shoreline chronologies for the rates of active extension and uplift in the
upper plate of subduction zones. Quaternary Science Reviews 78, 169-187
Síntese do estado de conhecimentos e propostas de investigação sobre a geo-arqueologia dos terraços no Baixo Tejo
Através dos registos geomorfológicos e sedimentares, os rios fornecem relevantes
arquivos de mudanças paleoambientais, nomeadamente paleoclimáticas.
As sucessões sedimentares melhor datadas são as mais importantes, com as idades
numéricas dos respetivos dos eventos sedimentares, de fósseis e de materiais
arqueológicos, obtidas por uma variedade de técnicas. Os arquivos fluviais do
Quaternário fornecidos pelo rio Tejo em Portugal (Baixo Tejo) constituem um
importante repositório de dados para estudos da evolução da dinâmica sedimentar
e da paisagem, bem como da ocupação humana pré-histórica. O atual estado de
conhecimentos resultantes das sucessivas abordagens usando métodos da geomorfologia,
litostratigrafia, arqueologia e datação numérica no estudo dos terraços do
Baixo Tejo é aqui sumariado. Também se apresentam os principais tópicos a necessitar
esclarecimento e propostas de futuras linhas de investigação
Nova técnica de preservação do fluxo na veia cefálica durante implantação de marca-passo ipsilateral a fístula arteriovenosa
© The AuthorsVascular patrimony is a major concern in patients with end-stage renal disease. As patients on chronic hemodialysis programs experience increasing survival rates, they frequently face multiple vascular access failures and may need recurrent central venous catheter insertions and fistula/grafts reinterventions to optimize their arteriovenous accesses. In addition, heart failure and heart rhythm disorders are frequent comorbidities in this population, and pacemaker or implantable cardiac defibrillator (ICD) implantation are frequently indicated. The estimated prevalence of Cardiovascular Electronic Implantable Devices (CIED) implantation in patients on chronic hemodialysis is about 10%. We aimed to describe a new technique for pacemaker implantation, which consisted in preserving cephalic vein ipsilateral to arteriovenous fistula flow, and in evaluating clinical outcomes of this technique over 12 months.info:eu-repo/semantics/publishedVersio
Quaternary Earth-science and Palaeolithic conservation initiatives in the Tejo (Tagus), Portugal: Comparison with the Lower Thames, UK
Geoconservation measures in the River Tejo, the Portuguese reach of the Tagus, are compared with those in the Thames downstream of London (UK). Both are fluvio-estuarine reaches with staircases of Pleistocene depositional terraces, each with important sedimentary, palaeontological and archaeological records. In both rivers, conservation measures are in place that aim to protect these records, promote research and inform the public. Inevitably there are differences in approach. Whereas Thames Quaternary interests are protected by a network of British statutory site designations, outreach is to the fore in the Tejo. Contrasting examples are highlighted here. The Tejo has interpretative materials in local museums and detailed explanatory displays at the low-terrace archaeo-geological site of Foz do Enxarrique, near the border with Spain, and at other sites. The Thames, in contrast, has few examples of physical outreach provision and limited formal protection for Pleistocene archaeological material outside the geological network, although extensive informal protection is provided by interaction between local geological groups and county and local-authority administrations. There is also a considerable difference in the degree of threat, with the Tejo above Lisbon being a relatively undeveloped valley, albeit with sporadic quarrying for aggregate, whereas the Lower Thames is an established area for infrastructure development, lying to the east of London, close to the river crossing of the orbital motorway. The different climate in the two regions profoundly influences the longevity of exposures in Quaternary deposits, with significant implications for management strategies. The comparison exercise reveals that each region would benefit from greater development of approaches used more prominently in the other; outreach measures in the Portuguese style would greatly enhance some of the Thames sites, but formal designation of Tejo exposures could prevent damaging operations being undertaken by owners who lack knowledge of their value, as exemplified by a case study of sites at Alpiarça, ~ 130 km upstream from Lisbon