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1.
Nature ; 511(7510): 444-8, 2014 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-25043007

RESUMO

Quantum error correction is required for a practical quantum computer because of the fragile nature of quantum information. In quantum error correction, information is redundantly stored in a large quantum state space and one or more observables must be monitored to reveal the occurrence of an error, without disturbing the information encoded in an unknown quantum state. Such observables, typically multi-quantum-bit parities, must correspond to a special symmetry property inherent in the encoding scheme. Measurements of these observables, or error syndromes, must also be performed in a quantum non-demolition way (projecting without further perturbing the state) and more quickly than errors occur. Previously, quantum non-demolition measurements of quantum jumps between states of well-defined energy have been performed in systems such as trapped ions, electrons, cavity quantum electrodynamics, nitrogen-vacancy centres and superconducting quantum bits. So far, however, no fast and repeated monitoring of an error syndrome has been achieved. Here we track the quantum jumps of a possible error syndrome, namely the photon number parity of a microwave cavity, by mapping this property onto an ancilla quantum bit, whose only role is to facilitate quantum state manipulation and measurement. This quantity is just the error syndrome required in a recently proposed scheme for a hardware-efficient protected quantum memory using Schrödinger cat states (quantum superpositions of different coherent states of light) in a harmonic oscillator. We demonstrate the projective nature of this measurement onto a region of state space with well-defined parity by observing the collapse of a coherent state onto even or odd cat states. The measurement is fast compared with the cavity lifetime, has a high single-shot fidelity and has a 99.8 per cent probability per single measurement of leaving the parity unchanged. In combination with the deterministic encoding of quantum information in cat states realized earlier, the quantum non-demolition parity tracking that we demonstrate represents an important step towards implementing an active system that extends the lifetime of a quantum bit.

2.
Nature ; 504(7480): 419-22, 2013 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-24270808

RESUMO

Quantum error correction codes are designed to protect an arbitrary state of a multi-qubit register from decoherence-induced errors, but their implementation is an outstanding challenge in the development of large-scale quantum computers. The first step is to stabilize a non-equilibrium state of a simple quantum system, such as a quantum bit (qubit) or a cavity mode, in the presence of decoherence. This has recently been accomplished using measurement-based feedback schemes. The next step is to prepare and stabilize a state of a composite system. Here we demonstrate the stabilization of an entangled Bell state of a quantum register of two superconducting qubits for an arbitrary time. Our result is achieved using an autonomous feedback scheme that combines continuous drives along with a specifically engineered coupling between the two-qubit register and a dissipative reservoir. Similar autonomous feedback techniques have been used for qubit reset, single-qubit state stabilization, and the creation and stabilization of states of multipartite quantum systems. Unlike conventional, measurement-based schemes, the autonomous approach uses engineered dissipation to counteract decoherence, obviating the need for a complicated external feedback loop to correct errors. Instead, the feedback loop is built into the Hamiltonian such that the steady state of the system in the presence of drives and dissipation is a Bell state, an essential building block for quantum information processing. Such autonomous schemes, which are broadly applicable to a variety of physical systems, as demonstrated by the accompanying paper on trapped ion qubits, will be an essential tool for the implementation of quantum error correction.

3.
Phys Rev Lett ; 117(13): 133601, 2016 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-27715126

RESUMO

Quantum jumps of a qubit are usually observed between its energy eigenstates, also known as its longitudinal pseudospin component. Is it possible, instead, to observe quantum jumps between the transverse superpositions of these eigenstates? We answer positively by presenting the first continuous quantum nondemolition measurement of the transverse component of an individual qubit. In a circuit QED system irradiated by two pump tones, we engineer an effective Hamiltonian whose eigenstates are the transverse qubit states, and a dispersive measurement of the corresponding operator. Such transverse component measurements are a useful tool in the driven-dissipative operation engineering toolbox, which is central to quantum simulation and quantum error correction.

4.
J Intern Med ; 278(3): 303-12, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25872921

RESUMO

BACKGROUND: Elevated systolic blood pressure (SBP) and high resting heart rate (HR) are associated with cardiovascular end-points. Although the association between atrial fibrillation (AF) and SBP is well established, the relation between AF and HR remains unclear. METHODS: In patients from the ONTARGET and TRANSCEND studies with high cardiovascular disease risk (n = 27 064), new-onset AF was evaluated in relation to mean SBP, visit-to-visit variation in SBP (SBP-CV; i.e. SD/mean × 100%), mean HR and visit-to-visit variation in HR (HR-CV). RESULTS: Low mean HR (P < 0.0001) and high SBP (P = 0.0021) were associated with incident AF. High SBP-CV (P = 0.031) and HR-CV (P < 0.0001) were also associated with incident AF. After adjustment for confounders, SBP and SBP-CV were no longer significantly associated with AF. The detrimental effect of low HR was particularly evident in subjects who were not receiving treatment with beta-blockers (P = 0.014 for interaction between beta-blocker use and mean HR). In addition to low HR, high HR-CV and high SBP had additive effects on incident AF. CONCLUSIONS: Low mean HR (<60 beats min(-1) ) is independently associated with incident AF, and low HR-CV and high SBP further increase the incidence of new-onset AF in patients at high risk of cardiovascular disease.


Assuntos
Fibrilação Atrial/fisiopatologia , Frequência Cardíaca/fisiologia , Doenças Vasculares/complicações , Antagonistas Adrenérgicos beta/uso terapêutico , Fibrilação Atrial/tratamento farmacológico , Pressão Sanguínea , Humanos , Pessoa de Meia-Idade
5.
J Intern Med ; 278(1): 38-49, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25431275

RESUMO

BACKGROUND: Resting heart rate (RHR) is associated with cardiovascular disease outcomes in high-risk patients. It is not known whether RHR is predictive of renal outcomes such as albuminuria, end-stage renal disease (ESRD) or doubling of creatinine. We evaluated whether RHR could predict renal endpoints in patients at a high risk of cardiovascular disease. We also tested the effects of RHR at different levels of systolic blood pressure (SBP). METHODS: We analysed data from 28 757 patients in the ONTARGET and TRANSCEND trials. RHR and SBP were available for a mean of 4.9 ± 0.4 visits (range 3-5) within the first 2 years of the studies. Albuminuria was determined at baseline, at 2 years and at study end. RESULTS: Mean RHR was predictive of incident micro-albuminuria [hazard ratio (HR) for RHR ≥80 vs. <60 beats min(-1) 1.49, 95% confidence interval (CI) 1.29-1.71, P < 0.0001], incident macro-albuminuria (HR 1.84, 95% CI 1.39-2.42, P < 0.0001), doubling of creatinine (HR 1.47, 95% CI 1.00-2.17, P = 0.050) and ESRD (HR 1.78, 95% CI 1.00-3.16, P = 0.050), and the combined renal end-point (HR 1.51, 95% CI 1.32-1.74, P < 0.0001). Associations were robust at SBPs from <120 to ≥150 mmHg, with the lowest risk at a SBP of 130-140 mmHg. CONCLUSION: Resting heart rate is a potent predictor of these renal outcomes, as well as their combination, in patients with cardiovascular disease. RHR at all SBP levels should be considered as a possible renal disease risk predictor and should be investigated as a treatment target with RHR-reducing agents.


Assuntos
Albuminúria/fisiopatologia , Doenças Cardiovasculares/fisiopatologia , Frequência Cardíaca , Falência Renal Crônica/fisiopatologia , Idoso , Pressão Sanguínea , Doenças Cardiovasculares/complicações , Creatinina/sangue , Feminino , Humanos , Falência Renal Crônica/complicações , Masculino , Prognóstico , Fatores de Risco
6.
Phys Rev Lett ; 113(24): 247001, 2014 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-25541795

RESUMO

As the energy relaxation time of superconducting qubits steadily improves, nonequilibrium quasiparticle excitations above the superconducting gap emerge as an increasingly relevant limit for qubit coherence. We measure fluctuations in the number of quasiparticle excitations by continuously monitoring the spontaneous quantum jumps between the states of a fluxonium qubit, in conditions where relaxation is dominated by quasiparticle loss. Resolution on the scale of a single quasiparticle is obtained by performing quantum nondemolition projective measurements within a time interval much shorter than T1, using a quantum-limited amplifier (Josephson parametric converter). The quantum jump statistics switches between the expected Poisson distribution and a non-Poissonian one, indicating large relative fluctuations in the quasiparticle population, on time scales varying from seconds to hours. This dynamics can be modified controllably by injecting quasiparticles or by seeding quasiparticle-trapping vortices by cooling down in a magnetic field.

7.
Eur J Cardiothorac Surg ; 65(6)2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38856237

RESUMO

Informed by the almost unimaginable unmet need for cardiac surgery in the developing regions of the world, leading surgeons, cardiologists, editors in chief of the major cardiothoracic journals as well as representatives of medical industry and government convened in December 2017 to address this unacceptable disparity in access to care. The ensuing "Cape Town Declaration" constituted a clarion call to cardiac surgical societies to jointly advocate the strengthening of sustainable, local cardiac surgical capacity in the developing world. The Cardiac Surgery Intersociety Alliance (CSIA) was thus created, comprising The Society of Thoracic Surgeons (STS), the American Association for Thoracic Surgery (AATS), the Asian Society for Cardiovascular and Thoracic Surgery (ASCVTS), the European Association for Cardio-Thoracic Surgery (EACTS) and the World Heart Federation (WHF). The guiding principle was advocacy for sustainable cardiac surgical capacity in low-income countries. As a first step, a global needs assessment confirmed rheumatic heart disease as the overwhelming pathology requiring cardiac surgery in these regions. Subsequently, CSIA published a request for proposals to support fledgling programmes that could demonstrate the backing by their governments and health care institution. Out of 11 applicants, and following an evaluation of the sites, including site visits to the 3 finalists, Mozambique and Rwanda were selected as the first Pilot Sites. Subsequently, a mentorship and training agreement was completed between Mozambique and the University of Cape Town, a middle-income country with a comparable burden of rheumatic heart disease. The agreement entails regular video calls between the heart teams, targeted training across all aspects of cardiac surgery, as well as on-site presence of mentoring teams for complex cases with the strict observance of 'assisting only'. In Rwanda, Team Heart, a US and Rwanda-based non-governmental organization (NGO) that has been performing cardiac surgery in Rwanda and helping to train the cardiac surgery workforce since 2008, has agreed to continue providing mentorship for the local team and to assist in the establishment of independent cardiac surgery with all that entails. This involves intermittent virtual conferences between Rwandan and US cardiologists for surgical case selection. Five years after CSIA was founded, its 'Seal of Approval' for the sustainability of endorsed programmes in Mozambique and Rwanda has resulted in higher case numbers, a stronger government commitment, significant upgrades of infrastructure, the nurturing of generous consumable donations by industry and the commencement of negotiations with global donors for major grants. Extending the CSIA Seal to additional deserving programmes could further align the international cardiac surgical community with the principle of local cardiac surgery capacity-building in developing countries.


Assuntos
Procedimentos Cirúrgicos Cardíacos , Sociedades Médicas , Cirurgia Torácica , Humanos , Sociedades Médicas/organização & administração , Cirurgia Torácica/organização & administração , Países em Desenvolvimento , Saúde Global
8.
Ann Thorac Surg ; 2024 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-38864803

RESUMO

Informed by the almost unimaginable unmet need for cardiac surgery in the developing regions of the world, leading surgeons, cardiologists, editors in chief of the major cardiothoracic journals as well as representatives of medical industry and government convened in December 2017 to address this unacceptable disparity in access to care. The ensuing "Cape Town Declaration" constituted a clarion call to cardiac surgical societies to jointly advocate the strengthening of sustainable, local cardiac surgical capacity in the developing world. The Cardiac Surgery Intersociety Alliance (CSIA) was thus created, comprising The Society of Thoracic Surgeons (STS), the American Association for Thoracic Surgery (AATS), the Asian Society for Cardiovascular and Thoracic Surgery (ASCVTS), the European Association for Cardio-Thoracic Surgery (EACTS) and the World Heart Federation (WHF). The guiding principle was advocacy for sustainable cardiac surgical capacity in low-income countries. As a first step, a global needs assessment confirmed rheumatic heart disease as the overwhelming pathology requiring cardiac surgery in these regions. Subsequently, CSIA published a request for proposals to support fledgling programs that could demonstrate the backing by their governments and health care institution. Out of 11 applicants, and following an evaluation of the sites, including site visits to the 3 finalists, Mozambique and Rwanda were selected as the first Pilot Sites. Subsequently, a mentorship and training agreement was completed between Mozambique and the University of Cape Town, a middle-income country with a comparable burden of rheumatic heart disease. The agreement entails regular video calls between the heart teams, targeted training across all aspects of cardiac surgery, as well as on-site presence of mentoring teams for complex cases with the strict observance of "assisting only." In Rwanda, Team Heart, a US and Rwanda-based non-governmental organization (NGO) that has been performing cardiac surgery in Rwanda and helping to train the cardiac surgery workforce since 2008, has agreed to continue providing mentorship for the local team and to assist in the establishment of independent cardiac surgery with all that entails. This involves intermittent virtual conferences between Rwandan and US cardiologists for surgical case selection. Five years after CSIA was founded, its "Seal of Approval" for the sustainability of endorsed programs in Mozambique and Rwanda has resulted in higher case numbers, a stronger government commitment, significant upgrades of infrastructure, the nurturing of generous consumable donations by industry and the commencement of negotiations with global donors for major grants. Extending the CSIA Seal to additional deserving programs could further align the international cardiac surgical community with the principle of local cardiac surgery capacity-building in developing countries.

9.
Artigo em Inglês | MEDLINE | ID: mdl-38864805

RESUMO

Informed by the almost unimaginable unmet need for cardiac surgery in the developing regions of the world, leading surgeons, cardiologists, editors in chief of the major cardiothoracic journals as well as representatives of medical industry and government convened in December 2017 to address this unacceptable disparity in access to care. The ensuing "Cape Town Declaration" constituted a clarion call to cardiac surgical societies to jointly advocate the strengthening of sustainable, local cardiac surgical capacity in the developing world. The Cardiac Surgery Intersociety Alliance (CSIA) was thus created, comprising The Society of Thoracic Surgeons (STS), the American Association for Thoracic Surgery (AATS), the Asian Society for Cardiovascular and Thoracic Surgery (ASCVTS), the European Association for Cardio-Thoracic Surgery (EACTS) and the World Heart Federation (WHF). The guiding principle was advocacy for sustainable cardiac surgical capacity in low-income countries. As a first step, a global needs assessment confirmed rheumatic heart disease as the overwhelming pathology requiring cardiac surgery in these regions. Subsequently, CSIA published a request for proposals to support fledgling programs that could demonstrate the backing by their governments and health care institution. Out of 11 applicants, and following an evaluation of the sites, including site visits to the 3 finalists, Mozambique and Rwanda were selected as the first Pilot Sites. Subsequently, a mentorship and training agreement was completed between Mozambique and the University of Cape Town, a middle-income country with a comparable burden of rheumatic heart disease. The agreement entails regular video calls between the heart teams, targeted training across all aspects of cardiac surgery, as well as on-site presence of mentoring teams for complex cases with the strict observance of "assisting only." In Rwanda, Team Heart, a US and Rwanda-based nongovernmental organization (NGO) that has been performing cardiac surgery in Rwanda and helping to train the cardiac surgery workforce since 2008, has agreed to continue providing mentorship for the local team and to assist in the establishment of independent cardiac surgery with all that entails. This involves intermittent virtual conferences between Rwandan and US cardiologists for surgical case selection. Five years after CSIA was founded, its "Seal of Approval" for the sustainability of endorsed programs in Mozambique and Rwanda has resulted in higher case numbers, a stronger government commitment, significant upgrades of infrastructure, the nurturing of generous consumable donations by industry and the commencement of negotiations with global donors for major grants. Extending the CSIA Seal to additional deserving programs could further align the international cardiac surgical community with the principle of local cardiac surgery capacity-building in developing countries.

10.
Asian Cardiovasc Thorac Ann ; : 2184923241259191, 2024 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-38872357

RESUMO

Informed by the almost unimaginable unmet need for cardiac surgery in the developing regions of the world, leading surgeons, cardiologists, editors in chief of the major cardiothoracic journals as well as representatives of medical industry and government convened in December 2017 to address this unacceptable disparity in access to care. The ensuing "Cape Town Declaration" constituted a clarion call to cardiac surgical societies to jointly advocate the strengthening of sustainable, local cardiac surgical capacity in the developing world. The Cardiac Surgery Intersociety Alliance (CSIA) was thus created, comprising The Society of Thoracic Surgeons (STS), the American Association for Thoracic Surgery (AATS), the Asian Society for Cardiovascular and Thoracic Surgery (ASCVTS), the European Association for Cardio-Thoracic Surgery (EACTS) and the World Heart Federation (WHF). The guiding principle was advocacy for sustainable cardiac surgical capacity in low-income countries.

11.
Int J Cardiol ; 399: 131767, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38211678

RESUMO

BACKGROUND: Cardiomyopathy is an important cause of heart failure, however, there is notable lack of data on causes and manifestations of cardiomyopathy in Africa. AIMS: The African Cardiomyopathy and Myocarditis Registry Program (IMHOTEP) aims to address the knowledge gap on etiology, treatment, and outcomes of cardiomyopathy in sub-Saharan Africa. METHODS AND RESULTS: We conducted a single-center pilot study to delineate the clinical and cardiovascular magnetic resonance (CMR) phenotypes of cardiomyopathy in South African patients. Assessment of the first 99 adult incident cases [mean age 36.8 ± 12.5 years; females 53.5%] enrolled in IMHOTEP showed that dilated cardiomyopathy (n = 77) was commonest, followed by hypertrophic (n = 13), restrictive (n = 5) and arrhythmogenic (n = 4) cardiomyopathies. A broad range of etiologies were encountered with secondary causes identified in 42% of patients. Onset of symptoms in the peripartum period was observed in 47% of women, and peripartum cardiomyopathy was diagnosed in 32.1% of women recruited. In addition to electrocardiography and echocardiography, CMR was performed in 67 cases and contributed diagnostically in a third of cases. Acute inflammation was rarely observed [2%] on CMR, however, late gadolinium enhancement (LGE) was noted in 92% of cases. CONCLUSION: We report a diverse spectrum of causes of cardiomyopathy in the South African population, with secondary, potentially treatable, etiologies in a significant proportion of cases. CMR was useful in delineating specific phenotypes and etiologies, influencing clinical care. A higher-than-expected burden of LGE was observed in this young patient cohort - the implications of which are yet to be determined.


Assuntos
Cardiomiopatias , Meios de Contraste , Adulto , Humanos , Feminino , Adulto Jovem , Pessoa de Meia-Idade , África do Sul/epidemiologia , Projetos Piloto , Imagem Cinética por Ressonância Magnética/métodos , Gadolínio , Cardiomiopatias/diagnóstico por imagem , Cardiomiopatias/epidemiologia , Espectroscopia de Ressonância Magnética , Valor Preditivo dos Testes
12.
Basic Res Cardiol ; 108(4): 366, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23812247

RESUMO

Peripartum cardiomyopathy (PPCM) is a life-threatening heart disease developing towards the end of pregnancy or in the months following delivery in previously healthy women in terms of cardiac disease. Enhanced oxidative stress and the subsequent cleavage of the nursing hormone Prolactin into an anti-angiogenic 16 kDa subfragment emerged as a potential causal factor of the disease. We established a prospective registry with confirmed PPCM present in 115 patients (mean baseline left ventricular ejection fraction, LVEF: 27 ± 9 %). Follow-up data (6 ± 3 months) showed LVEF improvement in 85 % and full recovery in 47 % while 15 % failed to recover with death in 2 % of patients. A positive family history of cardiomyopathy was present in 16.5 %. Pregnancy-associated hypertension was associated with a better outcome while a baseline LVEF ≤ 25 % was associated with a worse outcome. A high recovery rate (96 %) was observed in patients obtaining combination therapy with beta-blocker, angiotensin-converting enzyme (ACE) inhibitors/angiotensin-receptor-blockers (ARBs) and bromocriptine. Increased serum levels of Cathepsin D, the enzyme that generates 16 kDa Prolactin, miR-146a, a direct target of 16 kDa Prolactin, N-terminal-pro-brain-natriuretic peptide (NT-proBNP) and asymmetric dimethylarginine (ADMA) emerged as biomarkers for PPCM. In conclusion, low baseline LVEF is a predictor for poor outcome while pregnancy-induced hypertensive disorders are associated with a better outcome in this European PPCM cohort. The high recovery rate in this collective is associated with a treatment concept using beta-blockers, ACE inhibitors/ARBs and bromocriptine. Increased levels of Cathepsin D activity, miR-146a and ADMA in serum of PPCM patients support the pathophysiological role of 16 kDa Prolactin for PPCM and may be used as a specific diagnostic marker profile.


Assuntos
Cardiomiopatias/tratamento farmacológico , Cardiomiopatias/fisiopatologia , Gerenciamento Clínico , Período Periparto , Fenótipo , Sistema de Registros , Adulto , Anti-Hipertensivos/uso terapêutico , Bromocriptina/uso terapêutico , Cardiomiopatias/epidemiologia , Estudos de Coortes , Quimioterapia Combinada , Feminino , Seguimentos , Alemanha/epidemiologia , Humanos , Estresse Oxidativo/fisiologia , Gravidez , Estudos Prospectivos , Volume Sistólico/fisiologia , Resultado do Tratamento
13.
Glob Heart ; 16(1): 29, 2021 04 27.
Artigo em Inglês | MEDLINE | ID: mdl-34040942

RESUMO

The current COVID-19 pandemic has challenged health systems and communities globally. As such, several countries have embarked on national COVID-19 vaccination programmes in order to curb spread of the disease. However, at present, there isn't yet enough dosages to enable vaccination of the general population. Different vaccine prioritization strategies are thus being implemented in different communities in order to permit for a systematic vaccination of individuals. Here, on behalf of the World Heart Federation, we emphasize the need for individuals with Cardiovascular disease to be prioritized in national vaccine prioritization programmes as these are high risk individuals.


Assuntos
Vacinas contra COVID-19 , Doenças Cardiovasculares/complicações , Prioridades em Saúde , Vacinas contra COVID-19/provisão & distribuição , Comorbidade , Saúde Global , Humanos , Sociedades Médicas
14.
Clin Res Cardiol ; 110(8): 1259-1269, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33555408

RESUMO

INTRODUCTION: Peripartum cardiomyopathy (PPCM) is an important cause of pregnancy-associated heart failure worldwide. Although a significant number of women recover their left ventricular (LV) function within 12 months, some remain with persistently reduced systolic function. METHODS: Knowledge gaps exist on predictors of myocardial recovery in PPCM. N-terminal pro-brain natriuretic peptide (NT-proBNP) is the only clinically established biomarker with diagnostic value in PPCM. We aimed to establish whether NT-proBNP could serve as a predictor of LV recovery in PPCM, as measured by LV end-diastolic volume (LVEDD) and LV ejection fraction (LVEF). RESULTS: This study of 35 women with PPCM (mean age 30.0 ± 5.9 years) had a median NT-proBNP of 834.7 pg/ml (IQR 571.2-1840.5) at baseline. Within the first year of follow-up, 51.4% of the cohort recovered their LV dimensions (LVEDD < 55 mm) and systolic function (LVEF > 50%). Women without LV recovery presented with higher NT-proBNP at baseline. Multivariable regression analyses demonstrated that NT-proBNP of ≥ 900 pg/ml at the time of diagnosis was predictive of failure to recover LVEDD (OR 0.22, 95% CI 0.05-0.95, P = 0.043) or LVEF (OR 0.20 [95% CI 0.04-0.89], p = 0.035) at follow-up. CONCLUSIONS: We have demonstrated that NT-proBNP has a prognostic value in predicting LV recovery of patients with PPCM. Patients with NT-proBNP of ≥ 900 pg/ml were less likely to show any improvement in LVEF or LVEDD. Our findings have implications for clinical practice as patients with higher NT-proBNP might require more aggressive therapy and more intensive follow-up. Point-of-care NT-proBNP for diagnosis and risk stratification warrants further investigation.


Assuntos
Cardiomiopatias/sangue , Peptídeo Natriurético Encefálico/sangue , Fragmentos de Peptídeos/sangue , Período Periparto , Adulto , Biomarcadores/sangue , Cardiomiopatias/fisiopatologia , Diástole , Feminino , Humanos , Valor Preditivo dos Testes , Gravidez , Prognóstico , Volume Sistólico , Sístole
15.
J Interv Cardiol ; 23(1): 70-7, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20015160

RESUMO

BACKGROUND: HIV patients on protease inhibitors have greater risk of acute coronary syndromes (ACS) but little is known about treatment-naïve patients. METHODS AND RESULTS: Authors conducted a prospective single-center study from Soweto, South Africa, comparing the clinical and angiographic features of treatment-naïve HIV positive and negative patients with ACS. Between March 2004 and February 2008, 30 consecutive treatment-naïve HIV patients with ACS were compared to the next HIV-negative patient as a 1:1 control. HIV patients were younger (43 +/- 7 vs. 54 +/- 13, P = 0.004) and, besides smoking (73% vs. 33%, P = 0.002), had fewer risk factors than the control group with less hypertension (23% vs. 77%, P = 0.0001), diabetes (3% vs. 23%, P = 0.05), LDL hyperlipidemia (2.2 +/- 0.9 vs. 3.0 +/- 1.2, P = 0.006), and other coronary risk factors (7% vs. 53%, P = 0.0001). HDL was lower in the HIV group (0.8 +/- 0.3 vs. 1.1 +/- 0.4, P = 0.001). Atherosclerotic burden was lower in the HIV group with more normal infarct-related arteries (47% vs. 13%, P = 0.005) but a higher degree of large thrombus burden (43% vs. 17%, P = 0.02). Stents were used to a similar degree in HIV and control patients (30% vs. 37%, P = 0.78) with more target lesion revascularization in the HIV group (56% vs. 0%, P = 0.008). CONCLUSION: Treatment-naïve HIV patients with ACS are younger and have fewer traditional risk factors than HIV-negative patients. HIV patients have less atherosclerotic but higher thrombotic burden which may imply a prothrombotic state in the pathogenesis of ACS in these patients.


Assuntos
Síndrome Coronariana Aguda/epidemiologia , Terapia Antirretroviral de Alta Atividade , População Negra , Infecções por HIV/fisiopatologia , Síndrome Coronariana Aguda/diagnóstico , Síndrome Coronariana Aguda/diagnóstico por imagem , Adulto , Fatores Etários , Fármacos Anti-HIV/uso terapêutico , Estudos de Casos e Controles , LDL-Colesterol , Intervalos de Confiança , Angiografia Coronária , Diabetes Mellitus , Feminino , Infecções por HIV/tratamento farmacológico , HIV-1 , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Razão de Chances , Estudos Prospectivos , Inibidores de Proteases/uso terapêutico , Fumar/efeitos adversos , África do Sul/epidemiologia , Estatística como Assunto , Ultrassonografia
16.
S Afr Med J ; 110(8b): 13057, 2020 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-32880257

RESUMO

Heart failure with a reduced ejection fraction (HFrEF) is a condition frequently encountered by healthcare professionals and, in order to achieve the best outcomes for patients, needs to be managed optimally. This guideline document is based on the European Society of Cardiology Guidelines for the treatment of acute and chronic heart failure published in 2016, and summarises what is considered the best current management of patients with the condition. It provides information on the definition, diagnosis and epidemiology of HFrEF in the African context. The best evidence-based treatments for HFrEF are discussed, including established therapies (beta-blockers, ACE-i/ARBs, mineralocorticoid receptor antagonists (MRAs), diuretics) that form the cornerstone of heart failure management as well as therapies that have only recently entered clinical use (angiotensin receptor-neprilysin inhibitor (ARNI), sodium/glucose cotransporter-2 (SGLT2) inhibitors). Guidance is offered in terms of more invasive therapies (revascularisation, implantable cardioverter defibrillators (ICDs) and cardiac resynchronisation therapy (CRT) by implantation of a biventricular pacemaker with (CRT-D) or without (CRT-P) an ICD, left ventricular assist device (LVAD) use and heart transplantation) in order to ensure efficient use of these expensive treatment modalities in a resource-limited environment. Furthermore, additional therapies (digoxin, hydralazine and nitrates, ivabradine, iron supplementation) are discussed and advice is provided on general preventive strategies (vaccinations). Sections to discuss conditions that are particularly prevalent in sub-Saharan Africa (HIV-associated cardiomyopathy (CMO), peripartum CMO, rheumatic heart disease, atrial fibrillation) have been added to further improve clinical care for these commonly encountered disease processes. You are encouraged to read the complete 2016 ESC Heart Failure guideline: Ponikowski P, Voors AA, Anker SD, et al.; on behalf of the European Society of Cardiology. 2016 ESC guidelines for the diagnosis and treatment of acute and chronic heart failure. Eur Heart J 2016,37:2129-2200.


Assuntos
Fármacos Cardiovasculares/uso terapêutico , Insuficiência Cardíaca/terapia , Doença Aguda , Fármacos Cardiovasculares/farmacologia , Doença Crônica , Desfibriladores Implantáveis , Insuficiência Cardíaca/fisiopatologia , Transplante de Coração , Coração Auxiliar , Humanos , Marca-Passo Artificial , África do Sul
17.
Int J Cardiol ; 276: 177-184, 2019 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-30497895

RESUMO

BACKGROUND: Peripartum cardiomyopathy (PPCM) is an important cause of pregnancy-associated heart failure, which appears in previously healthy women towards the end of pregnancy or within five months following delivery. Although the ECG is widely used in clinical practice, its prognostic value has not been established in PPCM. METHODS: We analysed 12-lead ECGs of patients with PPCM, taken at index presentation and follow-up visits at 6 and 12 months. Poor outcome was determined by the composite endpoint of death, readmission, NYHA functional class III/IV or left ventricular ejection fraction (LVEF) of ≤35% at follow-up. RESULTS: This cohort of 66 patients had a median age of 28.59 (IQR 25.43-32.19). The median LVEF at presentation (33%, IQR 25-40) improved significantly at follow-up (LVEF 49%, IQR 38-55, P < 0.001 at 6 months; 52% IQR 38-57, P = 0.001 at 12 months). Poor outcome occurred in 27.91% at 6 months and 41.18% at 1 year. Whereas sinus tachycardia at baseline was an independent predictor of poor outcome at 12 months (OR 6.56, 95% CI 1.17-20.41, P = 0.030), sinus arrhythmia was associated with event free survival (log rank P = 0.013). T wave inversion was associated with an LVEF ≤35% at presentation (P = 0.038), but did not predict poor outcome. A prolonged QTc interval at presentation (found in almost half of the cohort) was an independent predictor of poor outcome at 6 months (OR 6.34, 95% CI 1.06-37.80, P = 0.043). CONCLUSION(S): A prolonged QTc and sinus tachycardia at baseline were independent predictors of poor outcome in PPCM at 6 months and 1 year respectively.


Assuntos
Cardiomiopatias/fisiopatologia , Eletrocardiografia/métodos , Período Periparto/fisiologia , Complicações Cardiovasculares na Gravidez/fisiopatologia , Adulto , Cardiomiopatias/diagnóstico por imagem , Cardiomiopatias/epidemiologia , Estudos de Coortes , Feminino , Seguimentos , Insuficiência Cardíaca/diagnóstico por imagem , Insuficiência Cardíaca/epidemiologia , Insuficiência Cardíaca/fisiopatologia , Humanos , Gravidez , Complicações Cardiovasculares na Gravidez/diagnóstico por imagem , Complicações Cardiovasculares na Gravidez/epidemiologia , Prognóstico , Método Simples-Cego , África do Sul/epidemiologia
18.
Cardiovasc J Afr ; 29(5): 289-295, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30059130

RESUMO

OBJECTIVE: To document maternal and foetal morbidity and mortality in anticoagulated, pregnant patients with mechanical heart valves until 42 days postpartum. METHODS: In a tertiary single-centre, prospective cohort, 178 consecutive patients at the cardiac-obstetric clinic were screened for warfarin use between 1 July 2010 and 31 December 2015. Of 33 pregnancies identified, 29 were included. Patients received intravenous unfractionated heparin from six to 12 weeks' gestation and peripartum, and warfarin from 12 to 36 weeks. Maternal outcomes including death, major haemorrhage and thrombosis, and foetal outcomes were documented. RESULTS: There were two maternal deaths, five returns to theatre post-delivery, eight patients transfused, six major haemorrhages, one case of infective endocarditis and three ischaemic strokes. Ten pregnancies had poor foetal outcomes (six miscarriages, three terminations, one early neonatal death). Twenty patients required more than 30 days' hospitalisation, and 15 required three or more admissions. HIV positivity was associated with surgical delivery (p = 0.0017). CONCLUSION: Complication rates were high despite centralised care.


Assuntos
Anticoagulantes/efeitos adversos , Implante de Prótese de Valva Cardíaca , Heparina/efeitos adversos , Hemorragia Pós-Parto/induzido quimicamente , Complicações Cardiovasculares na Gravidez/induzido quimicamente , Varfarina/efeitos adversos , Aborto Espontâneo/induzido quimicamente , Adulto , Anticoagulantes/administração & dosagem , Feminino , Mortalidade Fetal , Idade Gestacional , Infecções por HIV/tratamento farmacológico , Infecções por HIV/mortalidade , Próteses Valvulares Cardíacas , Implante de Prótese de Valva Cardíaca/efeitos adversos , Implante de Prótese de Valva Cardíaca/instrumentação , Heparina/administração & dosagem , Humanos , Nascido Vivo , Mortalidade Materna , Hemorragia Pós-Parto/diagnóstico , Hemorragia Pós-Parto/mortalidade , Hemorragia Pós-Parto/terapia , Período Pós-Parto , Gravidez , Complicações Cardiovasculares na Gravidez/diagnóstico , Complicações Cardiovasculares na Gravidez/mortalidade , Complicações Cardiovasculares na Gravidez/terapia , Complicações Infecciosas na Gravidez/tratamento farmacológico , Complicações Infecciosas na Gravidez/mortalidade , Prognóstico , Estudos Prospectivos , Medição de Risco , Fatores de Risco , África do Sul , Fatores de Tempo , Varfarina/administração & dosagem , Adulto Jovem
19.
S Afr Med J ; 108(9): 702-704, 2018 08 28.
Artigo em Inglês | MEDLINE | ID: mdl-30182888

RESUMO

Twelve years after cardiologists and cardiac surgeons from all over the world issued the 'Drakensberg Declaration on the Control of Rheumatic Fever and Rheumatic Heart Disease in Africa', calling on the world community to address the prevention and treatment of rheumatic heart disease (RHD) through improving living conditions, to develop pilot programmes at selected sites for control of rheumatic fever and RHD, and to periodically review progress made and challenges that remain, RHD still accounts for a major proportion of cardiovascular diseases in children and young adults in low- and middle-income countries, where more than 80% of the world population live. Globally equal in prevalence to human immunodeficiency virus infection, RHD affects 33 million people worldwide. Prevention efforts have been important but have failed to eradicate the disease. At the present time, the only effective treatment for symptomatic RHD is open heart surgery, yet that life-saving cardiac surgery is woefully absent in many endemic regions. In this declaration, we propose a framework structure to create a co-ordinated and transparent international alliance to address this inequality.


Assuntos
Procedimentos Cirúrgicos Cardíacos/estatística & dados numéricos , Acessibilidade aos Serviços de Saúde , Febre Reumática/complicações , Cardiopatia Reumática/cirurgia , Criança , Saúde Global , Humanos , Prevalência , Febre Reumática/epidemiologia , Cardiopatia Reumática/epidemiologia , África do Sul/epidemiologia , Resultado do Tratamento , Adulto Jovem
20.
S Afr Med J ; 107(10): 892-899, 2017 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-29022535

RESUMO

BACKGROUND: Pulmonary hypertension (PH) is a potent cause of heart failure and has been little investigated in the African setting. OBJECTIVE: To investigate the effects of gender on the clinical presentation, echocardiographic features and outcomes of patients with PH in Douala, Cameroon. METHODS: A prospective cohort study was conducted from March 2012 to December 2013 as part of the Pan African Pulmonary Hypertension Cohort study. PH was diagnosed by echocardiography and defined as a right ventricular systolic pressure >35 mmHg in the absence of acute right heart failure. Patients were followed up for a maximum of 12 months for primary endpoint mortality. RESULTS: In total, 130 patients with PH were recruited; 71 (54.6%) were women. The median age was 59.2 years for men and 58.3 years for women (p=0.76). Active smoking and alcohol use were more frequent in men than women (both p<0.001), but women had greater exposure to indoor cooking fumes than men (p<0.001). Previous tuberculosis infection (11.3% v. 1.7%) and S3 gallop rhythm (30.9% v. 11.9%) were more common in women (both p<0.03). Women had a significantly higher mean systolic blood pressure (134 mmHg v. 125 mmHg; p=0.04) and pulse pressure (53.8 mmHg v. 44.9 mmHg; p=0.01) and a lower mean haemoglobin concentration (10.4 g/dL v. 12.4 g/dL; p<0.05) compared with men. Echocardiographic left ventricular (LV) systolic dysfunction was more frequent in men: mean LV ejection fraction 42.6% v. 51.5% (p=0.01) and mean fractional shortening 21.4% v. 28.6% (p=0.01). The overall mortality rate was 20.3%, and rates were similar in the two groups (Kaplan-Meier log rank 1.1; p=0.30). CONCLUSIONS: Despite differences in baseline characteristics including cardiovascular risk factors, mortality rates on follow-up were similar in men and women in this study. However, these different baseline characteristics probably suggest differences in the pathogenesis of PH in men and women in our setting that need further investigation.

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