RESUMO
Increasing complexity and new highly differentiated therapeutic procedures in cardiology result in a need for additional training beyond cardiology board certification. The German Cardiac Society therefore developed a variety of certifications of educational curricula and definition of specialized centers. Standardization and structuring in education and patient treatment, as defined by certifications may be helpful; however, introduction of certification can have serious consequences for hospital structure, the side effects of which may impair quality of treatment for individual patients. The current article discusses these issues against the background of the following questions: how is quality defined? How do certifications interfere with patient care on a nationwide level, how do they influence responsibilities and teamwork? Are there conflicts of interests by designing certifications and how good are the organizational structures? Finally, suggestions are made on what has to be considered when designing certifications. Certifications should acknowledge all cardiologists, irrespective of their position in the level of care. There should be a coherent unified concept synchronizing all certifications and administration needs to be transparent and well structured.
Assuntos
Cardiologia , Certificação , Cardiologia/normas , HumanosRESUMO
Extracorporeal cardiopulmonary resuscitation (eCPR) may be considered as a rescue attempt for highly selected patients with refractory cardiac arrest and potentially reversible etiology. Currently there are no randomized, controlled studies on eCPR, and valid predictors of benefit and outcome which might guide the indication for eCPR are lacking. Currently selection criteria and procedures differ across hospitals and standardized algorithms are lacking. Based on expert opinion, the present consensus statement provides a proposal for a standardized treatment algorithm for eCPR.
Assuntos
Reanimação Cardiopulmonar/métodos , Parada Cardíaca/terapia , Algoritmos , Consenso , Oxigenação por Membrana Extracorpórea/métodos , HumanosRESUMO
Indications for TF-TAVI (transfemoral transcatheter aortic valve implantation) are rapidly changing according to increasing evidence from randomized controlled trials. Present trials document the non-inferiority or even superiority of TF-TAVI in intermediate-risk patients (STS-Score 4-8%) as well as in low-risk patients (STS-Score < 4%). However, risk scores exhibit limitations and, as a single criterion, are unable to establish an appropriate indication of TF-TAVI vs transapical TAVI vs SAVR (surgical aortic valve replacement). The ESC (European Society of Cardiology)/EACTS (European Association for Cardio-Thoracic Surgery) guidelines 2017 and the German DGK (Deutsche Gesellschaft für Kardiologie)/DGTHG (Deutsche Gesellschaft für Thorax-, Herz- und Gefäßchirurgie) commentary 2018 offer a framework for the selection of the best therapeutic method, but the individual decision is left to the discretion of the heart teams. An interdisciplinary TAVI consensus group of interventional cardiologists of the ALKK (Arbeitsgemeinschaft Leitende Kardiologische Krankenhausärzte e.V.) and cardiac surgeons has developed a detailed consensus on the indications for TF-TAVI to provide an up-to-date, evidence-based, comprehensive decision matrix for daily practice. The matrix of indication criteria includes age, risk scores, contraindications against SAVR (e.g., porcelain aorta), cardiovascular criteria pro TAVI, additional criteria pro TAVI (e.g., frailty, comorbidities, organ dysfunction), contraindications against TAVI (e.g., endocarditis) and cardiovascular criteria pro SAVR (e.g., bicuspid valve anatomy). This interdisciplinary consensus may provide orientation to heart teams for individual TAVI-indication decisions. Future adaptations according to evolving medical evidence are to be expected. Interdisciplinary consensus on indications for transfemoral transcatheter aortic valve implantation (TF-TAVI).
Assuntos
Estenose da Valva Aórtica/cirurgia , Substituição da Valva Aórtica Transcateter/métodos , Consenso , Artéria Femoral , Humanos , Seleção de Pacientes , Ensaios Clínicos Controlados Aleatórios como AssuntoRESUMO
BACKGROUND: Regulation of the fibrinolytic balance between plasminogen activators and inhibitors is modulated by the renin-angiotensin system. Thus, alterations in the renin-angiotensin system by ACE inhibitors probably result in modification of the fibrinolytic system. We examined the effect of a short-term treatment with the ACE inhibitor enalapril in 47 patients with severe coronary artery disease requiring coronary artery bypass grafting (CABG). METHODS: Patients received either 20 mg/d enalapril or placebo for 6 days. Tissue-type plasminogen activator (TPA), plasminogen activator inhibitor-1 (PAI-1), plasmin-a2-antiplasmin-complex (PAP) and D-dimers were measured initially and after treatment. RESULTS: In the enalapril group PAI-1 levels were significantly reduced after treatment (11.9 +/- 2.3 U/ml vs. 17.1 +/- 3.0 U/l; P < 0.05). In the placebo group PAP levels were significantly higher ( P < 0.05) after treatment compared to initial values. No differences could be detected between the study groups with regard to TPA and D-dimers. CONCLUSION: Although PAI-1 activity levels are reduced after short-term treatment with ACE inhibitors in patients with stable angina pectoris while TPA antigen is unaffected, treatment with ACE inhibitors does not lead to a marked change in plasmin activation.
Assuntos
Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Ponte de Artéria Coronária , Doença da Artéria Coronariana/tratamento farmacológico , Doença da Artéria Coronariana/cirurgia , Enalapril/uso terapêutico , Fibrinólise/efeitos dos fármacos , Adulto , Idoso , Biomarcadores/sangue , Ponte de Artéria Coronária/efeitos adversos , Doença da Artéria Coronariana/sangue , Trombose Coronária/sangue , Trombose Coronária/etiologia , Trombose Coronária/prevenção & controle , Método Duplo-Cego , Feminino , Produtos de Degradação da Fibrina e do Fibrinogênio/metabolismo , Fibrinolisina/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Inibidor 1 de Ativador de Plasminogênio/sangue , Estudos Prospectivos , Sistema Renina-Angiotensina/efeitos dos fármacos , Índice de Gravidade de Doença , Ativador de Plasminogênio Tecidual/sangue , Resultado do Tratamento , alfa 2-Antiplasmina/metabolismoRESUMO
The use of anticoagulants is associated with an increased risk of bleeding and nevertheless bleeding complications can be lifethreatening. The focus is on bleeding under direct oral anticoagulants (DOAC) because antidotes and specific measures are lacking for some DOACs. Furthermore, routinely carried out clotting tests cannot be used to determine the degree of anticoagulation under DOACs. Therefore, it becomes difficult to determine whether the coagulation inhibition effect is present. This article presents the treatment of hemorrhage in patients with DOACs in the intensive care unit. Further, the indications for DOACS and details of administration and monitoring are presented.
Assuntos
Anticoagulantes , Cuidados Críticos , Hemorragia , Administração Oral , Anticoagulantes/efeitos adversos , Coagulação Sanguínea , Hemorragia/induzido quimicamente , HumanosRESUMO
Extracorporeal cardiopulmonary resuscitation (eCPR) may be considered as a rescue attempt for highly selected patients with refractory cardiac arrest and potentially reversible etiology. Currently there are no randomized, controlled studies on eCPR, and valid predictors of benefit and outcome which might guide the indication for eCPR are lacking. Currently selection criteria and procedures differ across hospitals and standardized algorithms are lacking. Based on expert opinion, the present consensus statement provides a proposal for a standardized treatment algorithm for eCPR.
Assuntos
Reanimação Cardiopulmonar , Oxigenação por Membrana Extracorpórea , Parada Cardíaca , Consenso , Parada Cardíaca/terapia , Humanos , Seleção de PacientesRESUMO
Many patients under oral anticoagulation therapy need percutaneous or surgical interventions/operations. For vitamin K antagonists (VKA), there are recommendations regarding preoperative or postoperative administration. Management of the new oral anticoagulants (NOAC) was supposed to be easier - but some aspects must be considered. Due to the different pharmacokinetic profiles of substances such as dabigatran, rivaroxaban, apixaban, and edoxaban, different recommendations are given.Upon periprocedural management, thromboembolic risk has to be considered in patients treated with NOACs. NOACS have a pharmacokinetic advantage in terms of a rapid onset and rapid elimination via the liver and kidneys. Impaired renal function results in extended half-life of NOACs considerably.Surgical procedures under NOACS can be scheduled at the beginning of next dosing interval or omitted in low/minimal bleeding risk patients, so that only 2-3 NOAC doses are not administered. In patients with moderate and high risk of bleeding, there should be a NOAC break of 24-48 h prior to surgery in order to allow a corresponding decay of the active metabolite. In patients with low/intermediate risk for thromboembolism, no bridging is necessary if the "unprotected" time (NOAC break) is less than 4-5-(7) days. In patients at high risk of thromboembolism, individual consideration must be taken regarding bridging or extended NOAC break. Whether NOACs can be dispensed or bridging is necessary in these patients must be clarified in randomized trials for periprocedural management of NOACs patients.
Assuntos
Anticorpos Monoclonais Humanizados/efeitos adversos , Anticorpos Monoclonais Humanizados/uso terapêutico , Anticoagulantes/efeitos adversos , Anticoagulantes/uso terapêutico , Perda Sanguínea Cirúrgica/prevenção & controle , Procedimentos Cirúrgicos Operatórios , Tromboembolia/sangue , Tromboembolia/prevenção & controle , Administração Oral , Anticorpos Monoclonais Humanizados/farmacocinética , Anticoagulantes/farmacocinética , Perda Sanguínea Cirúrgica/fisiopatologia , Dabigatrana/efeitos adversos , Dabigatrana/farmacocinética , Dabigatrana/uso terapêutico , Interações Medicamentosas , Meia-Vida , Humanos , Pirazóis/efeitos adversos , Pirazóis/farmacocinética , Pirazóis/uso terapêutico , Piridinas/efeitos adversos , Piridinas/farmacocinética , Piridinas/uso terapêutico , Piridonas/efeitos adversos , Piridonas/farmacocinética , Piridonas/uso terapêutico , Rivaroxabana/efeitos adversos , Rivaroxabana/farmacocinética , Rivaroxabana/uso terapêutico , Tiazóis/efeitos adversos , Tiazóis/farmacocinética , Tiazóis/uso terapêutico , Vitamina K/antagonistas & inibidoresRESUMO
OBJECTIVES: The purpose of the study was to evaluate the cardiopulmonary exercise capacity and ventilatory function in adults with atrial septal defect (ASD) preoperatively and 4 months and 10 years postoperatively. BACKGROUND: Only few data are available on cardiopulmonary exercise tolerance after ASD closure, but detailed knowledge might be helpful for indication for defect closure in certain patients. METHODS: The study was performed in adult patients (mean [+/-SD] age at operation 39.9 +/- 11.5 years; left-right shunt 9.6 +/- 5.6 liters/min; pulmonary/systemic flow ratio 2.8 +/- 1.2; mean pulmonary artery pressure 18.2 +/- 6.2 mm Hg). Cardiopulmonary exercise testing was performed with a bicycle ergometer. We determined peak oxygen uptake, anaerobic threshold, performance at anaerobic threshold and maximal performance in relation to these variables in a normal group. Ventilatory function at rest was expressed by vital capacity, maximal voluntary ventilation and forced expiratory volume in 1 s. RESULTS: Preoperatively, ventilatory function at rest was only moderately reduced to approximately 75% to 85%. Four months postoperatively we found no significant improvement, but 10 years postoperatively ventilatory function at rest was normalized. Preoperative cardiopulmonary exercise capacity was markedly reduced to 50% to 60%; early postoperatively it was only slightly higher, but late postoperatively exercise capacity significantly improved and was completely normalized. CONCLUSIONS: Although preoperative cardiopulmonary capacity in adult patients with nonrestrictive ASD was significantly decreased, some improvement was seen at 4 months postoperatively, with complete restitution to normal at 10 years after shunt closure.
Assuntos
Tolerância ao Exercício/fisiologia , Comunicação Interatrial/fisiopatologia , Comunicação Interatrial/cirurgia , Adulto , Cateterismo Cardíaco , Teste de Esforço , Feminino , Seguimentos , Comunicação Interatrial/diagnóstico , Humanos , Masculino , Cuidados Pré-Operatórios , Ventilação Pulmonar/fisiologia , Fatores de TempoRESUMO
OBJECTIVES: We sought to examine whether the disturbed fibrinolytic system in patients with an acute coronary syndrome is associated with a reduced endothelial fibrinolytic capacity. BACKGROUND: Intracoronary thrombus formation is a frequent finding in acute coronary syndromes. Systemic alterations of coagulation and fibrinolysis are known to occur, but possible disturbances of endothelial fibrinolytic function have not been investigated. METHODS: We compared 42 patients with an acute coronary syndrome (acute myocardial infarction in 11 and unstable angina pectoris in 31) with 25 patients with stable angina. Venous blood was sampled serially for determination of markers of the fibrinolytic system and of hypercoagulability from admission to day 10. An occlusion test to determine the maximal endothelial tissue-type plasminogen activator (t-PA) release was also performed. RESULTS: Both on day 0 and day 10, patients with an acute coronary syndrome had a marked elevation of t-PA mass concentration (mean value +/- SEM 14.4 +/- 1.6 [day 0], 18.9 +/- 2.5 ng/ml [day 10]) and of plasminogen activator inhibitor (PAI) (9.4 +/- 2.2 [day 0], 11.3 +/- 2.6 AU/liter [day 10], p < 0.05 vs. patients with stable angina). There was also a hypercoagulative state with elevated thrombin activity and increased D-dimers (p < 0.05 vs. patients with stable angina). Maximal endothelial t-PA release was initially reduced (p < 0.05 vs. patients with stable angina) to 2.3 +/- 0.9 ng/ml, but levels recovered during follow-up to 4.4 +/- 1.4 ng/ml (vs. 5.7 +/- 1.5 ng/ml in patients with stable angina). CONCLUSIONS: Despite the known prolonged systemic alteration of fibrinolysis in acute coronary syndromes, endothelial fibrinolytic capacity is reduced only during the acute phase and becomes normalized during follow-up, and thus is linked more to intravascular thrombus formation than to steady state levels of markers of the fibrinolytic system.
Assuntos
Angina Instável/metabolismo , Endotélio Vascular/metabolismo , Fibrinólise , Infarto do Miocárdio/metabolismo , Ativador de Plasminogênio Tecidual/metabolismo , Antitrombina III/metabolismo , Fibrinogênio/metabolismo , Humanos , Peptídeo Hidrolases/metabolismo , Plasminogênio/metabolismo , Estudos Prospectivos , Fatores de Tempo , alfa 2-Antiplasmina/metabolismoRESUMO
The endothelin peptide family consists of the 21 amino acid isoforms endothelin-1, endothelin-2, endothelin-3, and sarafotoxin (a snake venom). Endothelin-1 has been isolated from the supernatant of endothelial cells and has subsequently been shown to be the most potent vasoconstrictor known to date and to be positively inotropic. This review summarizes some of the current literature pertaining to circulatory and myocardial effects of endothelins. Exogenously administered endothelin-1 has been demonstrated to increase peripheral resistance and blood pressure in a dose-dependent manner. However, during the first minutes of intravenous administration endothelins also decrease peripheral resistance and blood pressure, presumably due to the release of vasodilatory compounds such as nitric oxide, prostacyclin, and atrial natriuretic peptide. Endothelins appear to be involved in the pathogenesis of salt-dependent and renovascular animal models of experimental hypertension. Although endothelins appear to contribute to basal vascular tone, the role of endothelins in the pathophysiology of human hypertension remains unclear. In addition, a role has been suggested for endothelins in specific vascular lesions and inflammatory conditions (e.g., restenosis after coronary angioplasty, atherosclerotic coronary lesions, acute myocardial infarction, and vasculitis, glomerulonephritis). Endothelins are positively inotropic peptides in cardiac myocyte and papillary muscle preparations. They have also been demonstrated to induce hypertrophy of cardiac myocyte and may play an important role in ventricular processes that lead to chronic cardiac failure. The pathophysiological relevance of the endothelin system in human disease states is elucidated using selective (ET[A]) and nonselective (ET[A/B]) inhibitors of the endothelin receptors.
Assuntos
Circulação Sanguínea/efeitos dos fármacos , Endotelinas/farmacologia , Contração Miocárdica/efeitos dos fármacos , Miocárdio/metabolismo , Animais , Endotelinas/genética , HumanosRESUMO
The effect of graded ischaemic injury on post-ischaemic myocardium was examined in rat hearts after three 4 min periods of asphyxia. Systolic function under steady state conditions and during isovolumic beats, the content of high energy phosphates and glycogen, and myocardial material properties were determined. Severity of the oxygen deficiency was varied by manipulating myocardial oxygen demand (MVO2) either by rapid atrial pacing or by vagal stimulation. After 20 min of post-asphyxial recovery, steady state haemodynamics were almost normal. In the high MVO2 group (atrial pacing) the dp/dtmax was reduced to 90%(NS). The isovolumic indices of function were decreased in all post-asphyxial groups. This was most pronounced in the high MVO2 group, with a reduction in peak left ventricular systolic pressure to 85.7 (SEM 3.4)% and a decrease in peak left ventricular systolic stress to 82.3(3.9)% (p less than 0.01). The post-asphyxial myocardial performance recovered better in the low MVO2 group (vagal stimulation). Material properties were altered only in the high MVO2 group. The decreased content of ATP and glycogen were comparable in all post-asphyxial groups. A phosphocreatine overshoot phenomenon was most marked in the high MVO2 group: 11.4(2.8) mumol.g-1 v 4.7(0.9) mumol.g-1 (control), p less than 0.01. The results indicate that post-ischaemic contractile dysfunction of reversibly injured is not closely related to the previous O2 deficit or to the functional impairment. We also obtained no correlation between ATP content and material properties in modestly injured post-ischaemic myocardium.
Assuntos
Doença das Coronárias/fisiopatologia , Metabolismo Energético , Coração/fisiopatologia , Hipóxia/fisiopatologia , Miocárdio/metabolismo , Animais , Hipóxia/metabolismo , Masculino , Consumo de Oxigênio , Ratos , Ratos Endogâmicos , Fatores de TempoRESUMO
The action of inosine (2.5, 5, or 10 mg.kg-1.min-1 iv) was investigated in open chest rats (n = 46) and guinea pigs (n = 16). Left ventricular and aortic pressures, dP/dtmax, and stroke volume were measured. Additionally, isovolumic peak pressure and peak dP/dtmax were measured during short occlusions of the aorta for assessing myocardial performance independent of circulatory changes. In rats inosine caused a dose dependent decrease in dP/dtmax (-5%, -21%, -40% of preinfusion values), heart rate (-7%, -23%, -55%), and mean aortic pressure. Additionally, a subgroup of seven rats was paced at their initial preinfusion heart rate, but independently from the heart rate there was a reduction in dP/dtmax (-15%). The isovolumic measurements confirmed the negative inotropic effect of inosine in rats. Peak dP/dtmax was reduced to 85% of preinfusion values with a dose of 2.5 mg.kg-1 min-1 (to 70% of preinfusion values with 10 mg.kg-1.min-1). Similarly, the maximum isovolumic pressure for a defined filling volume was decreased by 30 mmHg (at 350 microliter; 5 mg.kg-1.min-1; p less than 0.05). The mean aortic pressure decreased with 2.5 mg.kg-1.min-1 inosine indicating vasodilative properties. In contrast to the significant effects in rats even 10 mg.kg-1.min-1 inosine did not have an effect on heart rate, mean aortic pressure, or dP/dtmax in guinea pigs. The isovolumic peak left ventricular pressure in guinea pigs was also unchanged after inosine infusion. Thus the haemodynamic effects of inosine were species dependent.
Assuntos
Hemodinâmica/efeitos dos fármacos , Inosina/farmacologia , Contração Miocárdica/efeitos dos fármacos , Animais , Pressão Sanguínea/efeitos dos fármacos , Depressão Química , Relação Dose-Resposta a Droga , Cobaias , Frequência Cardíaca/efeitos dos fármacos , Masculino , Ratos , Ratos EndogâmicosRESUMO
OBJECTIVE: To investigate the effects of moderate prolonged and of maximum short-term positive inotropic stimulation of postischemic myocardium as a function of the severity of stunning. METHODS: Stunned isolated rat hearts (n = 116) after 30 min and 45 min of ischemia were stimulated with dopamine to raise systolic function (double product) back to control levels. In the isovolumetrically beating hearts, left ventricular developed pressure, double product, dp/dtmax, coronary flow, and myocardial oxygen consumption were determined during steady-state conditions. After maximum stimulation the contractile reserve was examined. Measurements of adenine nucleotides (n = 47) and electron microscopy (n = 9) were made. RESULTS: 30 min ischemia resulted in moderate postischemic dysfunction (LVP 81 +/- 3%; P < 0.05). After 45 min ischemia, function was more severely reduced (LVP 66 +/- 5%; P < 0.01). Coronary flow tended to be lower after ischemia. Myocardial oxygen consumption was not reduced in parallel with the dysfunction. Adenine nucleotides were gradually reduced after ischemia (ATP: 2.5 +/- 0.2 and 1.2 +/- 0.1 vs. 4.2 +/- 0.2 mumol/gww; P < 0.01). Contractile reserve also decreased in relation to the previous ischemic injury (after 45 min ischemia max. LVP 105 +/- 10% vs. max. LVP 152 +/- 8% in controls, P < 0.01). Prolonged stimulation did not result in further reduction in adenine nucleotides and function. CONCLUSIONS: Contractile reserve is decreased in postischemic myocardium in parallel with the previous ischemic burden. Depending on the degree of contractile dysfunction a disturbed function-flow-oxygen consumption relation is present. Prolonged stimulation of stunned myocardium with dopamine back to the control level of function has no harmful short-term effects, indicating sufficient mitochondrial energy generation.
Assuntos
Dopamina/farmacologia , Contração Miocárdica/efeitos dos fármacos , Miocárdio Atordoado/fisiopatologia , Consumo de Oxigênio/efeitos dos fármacos , Trifosfato de Adenosina/metabolismo , Animais , Circulação Coronária , Ventrículos do Coração/ultraestrutura , Masculino , Microscopia Eletrônica , Miocárdio Atordoado/metabolismo , Miocárdio Atordoado/patologia , Perfusão , Ratos , Ratos Wistar , Estimulação Química , Fatores de TempoRESUMO
OBJECTIVE: Severely hypertrophied myocardium was described to have a reduced tolerance towards ischemia. For non-hypertrophied hearts inconclusive findings on the Ca(2+)-responsiveness are reported. Information sensitivity to reversible ischemia and on postischemic Ca(2+)-responsiveness of hearts with clinically common moderate hypertrophy is lacking. Thus, the responsiveness of hypertrophied and normal postischemic myocardium to positive inotropic stimulation should be investigated in the present study. METHODS AND RESULTS: Hearts from spontaneously hypertensive rats (SHR, 4 months old) with significant LV-hypertrophy (+ 50%) and hearts from normotensive 4 months old Wistar rats were investigated using an isovolumic beating isolated heart model (8 hearts/each of the 8 groups). Functional recovery after 30 min of no-flow ischemia was 78 +/- 1% and 77 +/- 3% of preischemic control data in hypertrophied and non-hypertrophied hearts assessed as developed left ventricular pressure (non-ischemic controls: 95 +/- 2% in hypertrophied and 93 +/- 3% in non-hypertrophied controls). Maximum short-term stimulation with Ca2+ revealed a decreased peak left ventricular pressure of 124 +/- 4% in hypertrophied and 120 +/- 5% in non-hypertrophied postischemic hearts, as compared with non-ischemic controls 138 +/- 3% and 157 +/- 5%, respectively ( p < 0.01). A maximum dose of dopamine stimulated hypertrophied and non-hypertrophied postischemic hearts comparable to Ca2+. Analysing the dose-response curve for Ca(2+)-stimulation, the sensitivity expressed as fraction of the maximum was identical in non-ischemic and postischemic myocardium of hypertrophied and non-hypertrophied ventricles in spite of the reduced peak values. CONCLUSION: The findings demonstrate that after moderate reversible ischemia the steady-state function is similarly decreased in hypertrophied and non-hypertrophied postischemic myocardium. The maximum response to Ca2+ is significantly reduced in both types of myocardium, while the Ca2+ sensitivity is unchanged. Identical results after maximum dopamine stimulation as after Ca2+ indicate that the releasibility of Ca2+ and the beta-adrenoceptors are not the critical causes for the postischemic dysfunction in hypertrophied or non-hypertrophied myocardium.
Assuntos
Cálcio/farmacologia , Cardiomegalia/fisiopatologia , Dopamina/farmacologia , Contração Miocárdica/efeitos dos fármacos , Miocárdio Atordoado/fisiopatologia , Análise de Variância , Animais , Relação Dose-Resposta a Droga , Hemodinâmica/efeitos dos fármacos , Técnicas In Vitro , Masculino , Isquemia Miocárdica/fisiopatologia , Perfusão , Ratos , Ratos Endogâmicos SHR , Ratos Wistar , Estimulação Química , Pressão Ventricular/efeitos dos fármacosRESUMO
-In vivo studies could not detect a positive inotropy of endothelin (ET)-1 as described in in vitro experiments. ET-induced direct positive inotropy, which seems to be mediated by ETB receptors, may be antagonized in vivo by an indirect cardiodepressive effect owing to an ET-induced coronary vasoconstriction via ETA receptors. This study compares the effects of a dose of 1 nmol/kg ET-1 alone on myocardial contractility and myocardial energy metabolism with the effects of 1 nmol/kg ET-1 after pretreatment with 5 mg/kg molsidomine or with 100 microg/kg of the ETA receptor antagonist BQ 610. We investigated the effects of ET-1 versus saline controls in open-chest rats. In addition to measurements in the intact circulation, myocardial function was examined by isovolumic registrations independent of peripheral vascular effects. We also studied the effect of ET-1 on myocardial high-energy phosphates. Pretreatment with molsidomine and BQ 610 attenuated the ET-induced reduction of cardiac output (ET-1: -62%; molsidomine+ET-1: -47%; BQ 610+ET-1: -27% different from controls). After a transient initial vasodilation, ET-1 raised total peripheral resistance (ET-1: +190%; molsidomine+ET-1: +171%; BQ 610+ET-1: +89%). BQ 610 was more effective in preventing ET-induced vasoconstriction. The increase of isovolumic peak first derivative of left ventricular pressure (ET-1: -2%; molsidomine+ET-1: +16%; BQ 610+ET-1: +19%) after pretreatment with molsidomine or BQ 610 indicates that these drugs unmask the positive inotropy of ET-1. ET-induced myocardial ischemia was abolished by molsidomine and BQ 610. Pretreatment with molsidomine or blockade of ETA receptors by BQ 610 can unmask the positive inotropy of ET-1 by preventing ET-induced myocardial ischemia. The positive inotropic effect of ET-1 seems to be mediated by ETB receptors.
Assuntos
Endotelina-1/farmacologia , Coração/efeitos dos fármacos , Molsidomina/farmacologia , Contração Miocárdica/efeitos dos fármacos , Oligopeptídeos/farmacologia , Vasodilatadores/farmacologia , Animais , Circulação Coronária/efeitos dos fármacos , Interpretação Estatística de Dados , Interações Medicamentosas , Metabolismo Energético , Hemodinâmica/efeitos dos fármacos , Masculino , Miocárdio/metabolismo , Fosfatos/metabolismo , RatosRESUMO
Acute myocardial infarction is associated with profound alterations in the plasma lipoprotein profile. The mechanism of these alterations is not clear, and both cholesterol biosynthesis up- and downregulation could possibly be a consequence of acute myocardial infarction. We determined plasma lipids, lipoproteins, apolipoproteins, and lathosterol-which is regarded as an estimate of whole body cholesterol biosynthesis in humans-concentrations in 34 patients (age 68+/-10 years, 24 male, 10 female) admitted to our hospital with acute MI and with onset of symptoms within the last 12 h. Samples were taken immediately after admission to the hospital, and 1, 2, and 10 days after admission. On the first day after admission there was a decrease in total cholesterol (C) by 14.1%, (P = 0.01), in LDL-C by 14.4% (P = 0.03), in HDL-C by 9.3% (NS), and in triglycerides by 19.5% (NS). Apolipoprotein B100 was reduced by 18.3% (P = 0.008), and apolipoprotein AI by 12.3% (NS). The lathosterol/cholesterol ratio was increased by 23.1% after 1 day, and by 28.7% after 2 days (P = 0.05). After 10 days, all variables except the apolipoproteins had essentially returned to baseline values. In conclusion, the changes in the plasma lipid profile after acute myocardial infarction are associated with a profound increase of whole body cholesterol biosynthesis as judged by the lathosterol/cholesterol ratio. These changes may possibly enhance the delivery of cholesterol to cells involved in tissue repair mechanisms after acute myocardial infarction.
Assuntos
Reação de Fase Aguda/sangue , Colesterol/biossíntese , Infarto do Miocárdio/sangue , Regulação para Cima , Idoso , Angioplastia Coronária com Balão , Apolipoproteínas/sangue , Biomarcadores/sangue , Proteína C-Reativa/metabolismo , Colesterol/sangue , Creatina Quinase/sangue , Feminino , Seguimentos , Humanos , Isomerismo , Lipídeos/sangue , Lipoproteínas/sangue , Masculino , Infarto do Miocárdio/terapia , Prognóstico , Terapia Trombolítica , Regulação para Cima/fisiologiaRESUMO
BACKGROUND: In acute coronary syndromes, marked alterations of coagulation and fibrinolysis have been observed, but no data are available concerning a possible relation to coronary stenosis morphology. METHODS: Thirty one patients with unstable angina pectoris were included. Culprit stenosis morphology judged from coronary angiography was graded using the modified ACC/AHA classification. Molecular and functional markers of hemostasis and fibrinolysis were determined from venous plasma samples obtained at admission. RESULTS: Patients with unstable angina pectoris had a moderate procoagulant state, especially a contact phase activation compared with age-matched controls (factor XII 93.9 +/- 5.6 vs 112.8 +/- 5.4%; P < 0.05; high molecular weight kininogen 55.3 +/- 5.4 vs 86.1 +/- 6.5%; P < 0.01). Thrombin-antithrombin (TAT) was not significantly elevated (7.6 +/- 1.9 vs 4.0 +/- 0.5 microg/l). Elevated plasminogen activator mass concentration (16.6 +/- 2.1 vs 5.4 +/- 0.6 ng/ml; P < 0.01) and plasminogen activator inhibitor (PAI) activity (9.9 +/- 3.0 vs 5.6 +/- 3.0 AU/ml; P < 0.05) indicated an alteration of the fibrinolysis. Complexity of coronary stenosis was positively correlated with tissue-type plasminogen activator (TPA) mass concentration (P < 0.01) and PAI activity (P < 0.05). No association was found to markers of a hypercoagulative state. CONCLUSION: These findings indicate a relation between alterations of the fibrinolytic system and coronary morphology, whereas the acute changes of coagulation occur independently of culprit stenosis complexity.
Assuntos
Angina Instável/sangue , Angina Instável/diagnóstico por imagem , Doença das Coronárias/diagnóstico por imagem , Fator XII/análise , Cininogênios/sangue , Inibidor 1 de Ativador de Plasminogênio/sangue , Adulto , Idoso , Angina Instável/fisiopatologia , Biomarcadores/análise , Angiografia Coronária , Doença das Coronárias/sangue , Doença das Coronárias/fisiopatologia , Feminino , Fibrinólise/fisiologia , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Valores de Referência , Sensibilidade e EspecificidadeRESUMO
Several alterations of the coagulation, of the fibrinolysis and of inflammation are known in patients with acute coronary syndromes. To extent current knowledge of the pathophysiology and to optimize therapeutical strategies, the new molecular markers can be used in clinical studies. Furthermore, several studies were undertaken to assess the prognostic value of activation markers of these systems for patients with unstable angina pectoris and acute myocardial infarction with or without thrombolytic therapy. The majority of studies focussed on markers of thrombin activation, fibrinogen, fibrin degradation products and t-PA and its main inhibitor PAI-1. While there are stimulating results from larger studies, the value for prognosis for the individual patient still is limited by the overlap of patients with good versus a poor outcome.
Assuntos
Doença das Coronárias , Fibrinólise , Doença Aguda , Animais , Biomarcadores , Coagulação Sanguínea , Humanos , Valor Preditivo dos TestesRESUMO
Patients with acute coronary syndromes (ACS) frequently present with signs of disturbed fibrinolysis. The present study investigates the correlation of alterations in the fibrinolytic system and the amount of myocardial damage characterized by troponin release. In 85 patients with ACS markers of plasmin activation, plasminogen activator system and troponin T (TnT) were measured initially and after 48 h. Patients with TnT release (> or = 0.01 microg/l) at admission had higher TPA levels than those without release (10.2+/-0.7 ng/ml vs. 7.6+/-0.5 ng/ml; p <0.01). Additionally, patients with positive TnT had higher D-dimer levels initially (457+/-39 ng/ml vs. 316+/-22 ng/ml; p <0.01) and 48 h later (451+/-42 ng/ml vs. 275+/-37 ng/ml; p <0.01). The association of myocardial damage with a prothrombotic state and an enhanced fibrinolysis may explain the high prognostic value of troponin measurements in respect to future coronary events.
Assuntos
Doença das Coronárias/sangue , Fibrinólise/fisiologia , Troponina T/metabolismo , Doença Aguda , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/sangue , Estudos de Casos e Controles , Doença das Coronárias/diagnóstico , Feminino , Produtos de Degradação da Fibrina e do Fibrinogênio/metabolismo , Fibrinolisina/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Miocárdio/metabolismo , Miocárdio/patologia , Plasminogênio/metabolismo , Prognóstico , Trombofilia/sangue , Trombofilia/complicações , Ativador de Plasminogênio Tecidual/sangue , Troponina T/sangue , Troponina T/fisiologiaRESUMO
The negative inotropic effect of nearly all antiarrhythmic drugs is one of the major drawbacks in antiarrhythmic therapy. This is particularly important in patients with reduced left ventricular function. In the clinical setting, different compounds have been described to depress cardiac function to a variable extent. The results are not uniform. In an experimental model, the hemodynamic effects of different drugs in the intact circulation as well as under isovolumic conditions in vivo after short cross-clamping of the aorta were tested. The results indicate that all antiarrhythmic compounds with the exception of class III drugs have a similar negative inotropic action on the heart muscle. However, the drugs have different effects on peripheral resistance, thus influencing cardiac afterload. These differences seem to be responsible for the different hemodynamic effects of the drugs observed clinically.