RESUMO
OBJECTIVE: To investigate the incidence and risk factors of pressure injury (PI) development after ventricular assist device (VAD) or total artificial heart (TAH) surgery. METHODS: The investigator reviewed all VAD-TAH surgeries performed between 2010 and 2018 in a large academic health system. The PIs were reported by case incidence, patient incidence, and incidence density for each of the respective 1,000 patient days during the study period. Statistics on four different VAD-TAH devices were assessed; variables significant in bivariate analysis were entered into a stepwise logistic regression model to identify significant predictors of PI. RESULTS: The sample included 292 independent VAD-TAH surgeries among 265 patients. Thirty-two patients developed 45 PIs. The PI incidence was 11% (32/292), with a PI incidence per patient of 12% (32/265). Incidence density was 10 per 1,000 patient days (1%) for 2010-2012, 12 per 1,000 patient days (1.2%) for 2013-2015, and 10 per 920 patient days (1.1%) for 2016-2018. Logistic regression revealed that significant predictor variables for PI were age, mechanical ventilation time, and preoperative Braden Scale score. The mean time to PI was 23 days after admission and over 14 days after surgery, indicating a low rate of intraoperative and ICU-associated PI. CONCLUSIONS: The incidence of PI was lower than anticipated given historic rates. Potential mechanisms by which these patients were protected from PI are discussed. Prospective studies to further investigate significant risk factors and effective prevention measures are warranted.
Assuntos
Procedimentos Cirúrgicos Cardíacos/efeitos adversos , Previsões/métodos , Coração Artificial/estatística & dados numéricos , Úlcera por Pressão/classificação , Adulto , Procedimentos Cirúrgicos Cardíacos/métodos , Estudos de Coortes , Feminino , Coração Auxiliar/normas , Coração Auxiliar/estatística & dados numéricos , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Úlcera por Pressão/epidemiologia , Estudos Retrospectivos , Fatores de RiscoRESUMO
The Virtual Mock Loop (VML) is a mathematical model designed to simulate mechanism of the human cardiovascular system interacting with mechanical circulatory support devices. Here, we aimed to mimic the hemodynamic performance of Cleveland Clinic's self-regulating continuous-flow total artificial heart (CFTAH) via VML and evaluate the accuracy of the VML compared with an in vivo acute animal study. The VML reproduced 124 hemodynamic conditions from three acute in vivo experiments in calves. Systemic/pulmonary vascular resistances, pump rotational speed, pulsatility, and pulse rate were set for the VML from in vivo data. We compared outputs (pump flow, left and right pump pressure rises, and atrial pressure difference) between the two systems. The pump performance curves all fell in the designed range. There was a strong correlation between the VML and the in vivo study in the left pump flow (r2 = 0.84) and pressure rise (r2 = 0.80), and a moderate correlation in right pressure rise (r2 = 0.52) and atrial pressure difference (r2 = 0.59). Although there is room for improvement in simulating right-sided pump performance of self-regulating CFTAH, the VML acceptably simulated the hemodynamics observed in an in vivo study. These results indicate that pump flow and pressure rise can be estimated from vascular resistances and pump settings.
Assuntos
Coração Artificial/estatística & dados numéricos , Modelos Cardiovasculares , Animais , Bovinos , MasculinoRESUMO
OBJECTIVES: The purpose of this study was to describe pre- and postoperative data from the EUROMACS registry with regard to indications, for and survival and complication rates of patients with primary continuous flow and pulsatile biventricular long-term assist devices (BiVADs) versus total artificial hearts (TAHs) or left ventricular assist devices (LVADs) + short-term right ventricular assist device (RVAD) implants. METHODS: We investigated patients who received implants between 1 January 2011 and 21 October 2017. Clinical baseline information about comorbidities, laboratory results, medical and device therapies and echocardiographic, haemodynamic and right ventricle (RV) parameters were evaluated along with the rates of deaths and complications. RESULTS: A total of 413 of 3282 patients (12.5%) needed a biventricular pump. We investigated 37 long-term BiVADs, 342 LVAD + short-term RVAD implants and 34 TAHs. Minor differences were found in the baseline characteristics of our population, which had an overall high morbidity profile. The 1-year survival rate was 55% for patients with a continuous flow BiVAD; 52% for patients with an LVAD + short-term RVAD; 37% for patients with pulsatile BiVADs; and 36% for patients with a TAH. No statistical difference was observed among the groups. Over 50% of patients with BiVAD support were classified as INTERMACS profiles 1 and 2. The percent of patients with ambulatory heart failure (INTERMACS 4â7) undergoing BiVAD implants was modest at <15%. No patients with a pulsatile BiVAD (n = 15) or a TAH (n = 34) were implanted as destination therapy, but 27% of the patients with continuous flow BiVADs (n = 6) and 23% of the patients with LVAD + short-term RVAD (n = 342) were implanted as 'destination'. The adverse events profile remained high, with no significant difference among pump types. The right ventricular stroke work index and right heart failure scores indicated poor RV function in all groups. After 3 months of LVAD + short-term RVAD support, 46.7% still required ongoing support, and only 18.5% were weaned from RVAD support; 33.1% died. CONCLUSIONS: The mortality rate after BiVAD support was high. Survival rates and adverse events were statistically not different among the investigated groups. In the future, composite study end points examining quality of life and adverse events beyond survival may help in shared decision-making prior to general mechanical circulatory support, particularly in patients with BiVAD implants.
Assuntos
Procedimentos Cirúrgicos Cardíacos , Coração Artificial , Adulto , Procedimentos Cirúrgicos Cardíacos/efeitos adversos , Procedimentos Cirúrgicos Cardíacos/instrumentação , Procedimentos Cirúrgicos Cardíacos/mortalidade , Procedimentos Cirúrgicos Cardíacos/estatística & dados numéricos , Comorbidade , Feminino , Insuficiência Cardíaca/epidemiologia , Insuficiência Cardíaca/mortalidade , Insuficiência Cardíaca/cirurgia , Coração Artificial/efeitos adversos , Coração Artificial/estatística & dados numéricos , Coração Auxiliar/efeitos adversos , Coração Auxiliar/estatística & dados numéricos , Hemodinâmica/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias , Falha de Prótese , Sistema de Registros , Estudos Retrospectivos , Disfunção Ventricular/epidemiologia , Disfunção Ventricular/mortalidade , Disfunção Ventricular/cirurgiaRESUMO
BACKGROUND: Data are limited on clinical outcomes in patients awaiting heart transplant (HT) with total artificial heart (TAH) infections. METHODS: We retrospectively reviewed all TAH recipients at our center. TAH infection was classified as definite if a microorganism was isolated in cultures from the exit site or deep tissues around the TAH; as probable in patients without surgical or microbiologic evidence of infection but no other explanation for persistent or recurrent bloodstream infection (BSI); or possible in patients with clinical suspicion and radiographic findings suggestive of TAH infection, but without surgical intervention or microbiologic evidence. RESULTS: From 2012 to 2015, a total of 13 patients received a TAH, with a median age at implantation of 52 years (range: 28-60). TAH infection occurred in nine patients (seven definite, one probable, one possible) a median of 41 days after implant (range: 17-475). The majority of TAH infections were caused by Staphylococcus species. Seven of nine patients underwent HT (four had pre-HT mediastinal washout, and five had positive HT operative cultures). Three patients had an active BSI caused by the same pathogen causing TAH infection at the time of HT, with one developing a post-HT BSI with the same bacteria. No patient developed post-HT surgical site infection caused by the TAH infection pathogen. No deaths among HT recipients were attributed to infection. CONCLUSION: TAH infection is frequently associated with BSI and mediastinitis and Staphylococcus was the most common pathogen. A multimodal approach of appropriate pre- and post-HT antimicrobial therapy, surgical drainage, and heart transplantation with radical mediastinal debridement was successful in curing infection.
Assuntos
Transplante de Coração/efeitos adversos , Coração Artificial/microbiologia , Avaliação de Resultados da Assistência ao Paciente , Infecção da Ferida Cirúrgica/microbiologia , Adulto , Desbridamento , Feminino , Insuficiência Cardíaca/prevenção & controle , Transplante de Coração/estatística & dados numéricos , Coração Artificial/estatística & dados numéricos , Humanos , Masculino , Mediastinite/epidemiologia , Mediastinite/microbiologia , Pessoa de Meia-Idade , Estudos Retrospectivos , Infecções Estafilocócicas/sangue , Infecções Estafilocócicas/epidemiologia , Infecções Estafilocócicas/microbiologia , Staphylococcus/isolamento & purificação , Infecção da Ferida Cirúrgica/epidemiologia , Fatores de TempoRESUMO
OBJECTIVES: To describe the characteristics of patients who undergo withdrawal of total artificial heart support and to explore the ethical aspects of withdrawing this life-sustaining treatment. PATIENTS AND METHODS: We retrospectively reviewed the medical records of all adult recipients of a total artificial heart at Mayo Clinic from the program's inception in 2007 through June 30, 2015. Management of other life-sustaining therapies, approach to end-of-life decision making, engagement of ethics and palliative care consultation, and causes of death were analyzed. RESULTS: Of 47 total artificial heart recipients, 14 patients or their surrogates (30%) requested withdrawal of total artificial heart support. No request was denied by treatment teams. All 14 patients were supported with at least 1 other life-sustaining therapy. Only 1 patient was able to participate in decision making. CONCLUSION: It is widely held to be ethically permissible to withdraw a life-sustaining treatment when the treatment no longer meets the patient's health care-related goals (ie, the burdens outweigh the benefits). These data suggest that some patients, surrogates, physicians, and other care providers believe that this principle extends to the withdrawal of total artificial heart support.
Assuntos
Coração Artificial/ética , Cuidados para Prolongar a Vida/ética , Insuficiência de Múltiplos Órgãos/mortalidade , Suspensão de Tratamento/ética , Adulto , Diretivas Antecipadas/ética , Diretivas Antecipadas/estatística & dados numéricos , Idoso , Causas de Morte , Tomada de Decisões/ética , Análise Ética , Feminino , Coração Artificial/efeitos adversos , Coração Artificial/estatística & dados numéricos , Humanos , Masculino , Futilidade Médica/ética , Pessoa de Meia-Idade , Avaliação de Resultados em Cuidados de Saúde/estatística & dados numéricos , Procurador , Estudos Retrospectivos , Análise de SobrevidaRESUMO
BACKGROUND: Mechanical circulatory support (MCS) is the standard therapy for the management of acute or chronic end-stage heart failure. We report on our two-center experience with MCS therapy. METHODS: Between January 2000 and December 2012, 116 adult patients (mean age 56.8 ± 9.9 years, range: 31 to 76 years) were primarily supported on temporary or long-term ventricular assist devices (VADs) or total artificial hearts (TAHs) at our institutions. Temporary extracorporeal radial VAD support was established in 50 patients (43.1%) (Group A) whereas 66 (56.8%) patients received long-term paracorporeal and intracorporeal VAD or TAH (Group B). LVAD support was established in 63 patients (54.3%), with BVAD/TAH support in 29 (25%). A temporary CentriMag was the only device adopted as an isolated RVAD support, being placed in 24 patients (20.6%). RESULTS: In Group A, the overall mean support time was 10.2 ± 6.6 days (range: 3 to 43 days) and the overall success rate was 55.1% (27 patients). The mean LVAD support time was 357 ± 352.3 days (range: 1 to 902 days) in Group B and 98 ± 82.6 days (range: 8 to 832 days) in BVAD/TAH patients, with success rates of 72.5% (37 patients) and 46.6% (seven patients), respectively. The heart transplantation (Htx) rate for both groups combined was 25.8% (n = 30). The overall one- and five-year survival rates after Htx were 73.3% and 60%, respectively. CONCLUSIONS: When a decision to treat with VAD or TAH is made early, either modality can be used as an alternative to Htx, affording comparable early to mid-term outcomes.
Assuntos
Insuficiência Cardíaca/terapia , Coração Artificial , Coração Auxiliar , Adulto , Idoso , Feminino , Insuficiência Cardíaca/mortalidade , Transplante de Coração , Coração Artificial/estatística & dados numéricos , Coração Auxiliar/estatística & dados numéricos , Humanos , Masculino , Pessoa de Meia-Idade , Taxa de Sobrevida , Fatores de Tempo , Resultado do TratamentoRESUMO
Left ventricular assist devices (LVADs) and total artificial hearts (TAHs) are surgically implanted as permanent treatment of unrecoverable heart failure. Both LVADs and TAHs are durable mechanical circulatory support (MCS) devices that can prolong patient survival but also alter end-of-life trajectory. The permissibility of discontinuing assisted circulation is controversial because device deactivation is a life-ending intervention. Durable MCS is intended to successfully replace native physiological functions in heart disease. We posit that the presence of new lethal pathophysiology (ie, a self-perpetuating cascade of abnormal physiological processes causing death) is a central element in evaluating the permissibility of deactivating an LVAD or a TAH. Consensual discontinuation of durable MCS is equivalent with allowing natural death when there is an onset of new lethal pathophysiology that is unrelated to the physiological functions replaced by an LVAD or a TAH. Examples of such lethal conditions include irreversible coma, circulatory shock, overwhelming infections, multiple organ failure, refractory hypoxia, or catastrophic device failure. In all other situations, deactivating the LVAD/TAH is itself the lethal pathophysiology and the proximate cause of death. We postulate that the onset of new lethal pathophysiology is the determinant factor in judging the permissibility of the life-ending discontinuation of a durable MCS.
Assuntos
Insuficiência Cardíaca/terapia , Coração Auxiliar/estatística & dados numéricos , Assistência Terminal/ética , Disfunção Ventricular Esquerda/terapia , Suspensão de Tratamento/ética , Tomada de Decisões , Remoção de Dispositivo/ética , Coração Artificial/estatística & dados numéricos , Coração Auxiliar/ética , Humanos , Unidades de Terapia Intensiva , Suicídio Assistido/éticaRESUMO
The prevalence of heart failure is increasing, and the prognosis of end-stage heart failure remains dismal. The gold-standard therapy in end-stage heart failure remains cardiac transplantation at the present time, but there is a great excess of eligible candidates compared with the number of donor organs. Advances in mechanical support, the development of the left ventricular assist device (LVAD), and the total artificial heart has reduced mortality and morbidity in patients awaiting transplantation, and LVADs are now approved as an strategy for destination therapy. Miniaturization, increased device durability, and complete implantability may render LVADs an option in earlier stages of heart failure, as a bridge to myocardial recovery or even as a viable alternative to transplantation. Alternative strategies under investigation are cell therapy and xenotransplantation. In the present article, current and potential future therapeutic options in end-stage heart failure are reviewed.
Assuntos
Insuficiência Cardíaca/terapia , Transplante de Coração/métodos , Coração Artificial , Rejeição de Enxerto/patologia , Rejeição de Enxerto/prevenção & controle , Insuficiência Cardíaca/epidemiologia , Transplante de Coração/mortalidade , Transplante de Coração/tendências , Coração Artificial/normas , Coração Artificial/estatística & dados numéricos , Coração Artificial/tendências , Coração Auxiliar/normas , Coração Auxiliar/tendências , Humanos , Terapia de Imunossupressão/efeitos adversos , Terapia de Imunossupressão/métodos , Masculino , Pessoa de Meia-Idade , Seleção de Pacientes , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/prevenção & controle , Prevalência , Doadores de TecidosRESUMO
End-stage congestive heart failure remains the leading cause of death in the United States. Despite advances in medical treatment, it also remains the most common reason for admission to the hospital. The gold standard of treatment for the failing heart, orthotopic heart transplantation, is limited by a shortage of donor hearts. There are also a significant number of patients who are not transplant candidates due to comorbid conditions and/or inability to tolerate immunosuppressive therapy. To meet the need for this latter group, the medical field has embraced ventricular assist device (VAD) therapy to extend survival and improve quality-of-life for the end-stage cardiac patient. This therapy, however, has been currently limited to the failing left ventricle and is still fraught with complications that limit long-term and widespread use. The total artificial heart, as currently available with two devices, is rapidly becoming the treatment of choice for biventricular failure.
Assuntos
Insuficiência Cardíaca/terapia , Coração Artificial/estatística & dados numéricos , Coração Artificial/normas , Implantação de Prótese/métodos , Insuficiência Cardíaca/fisiopatologia , Ventrículos do Coração/fisiopatologia , Ventrículos do Coração/cirurgia , Humanos , Desenho de Prótese , Resultado do TratamentoAssuntos
Coração Artificial , Animais , Ásia , Cães , Oxigenação por Membrana Extracorpórea , Insuficiência Cardíaca/epidemiologia , Insuficiência Cardíaca/terapia , Coração Artificial/economia , Coração Artificial/estatística & dados numéricos , Coração Artificial/tendências , Coração Auxiliar , Humanos , Balão Intra-AórticoRESUMO
Artificial heart or heart transplantation are required for the treatment of profound heart failure. Total artificial heart (TAH) and ventricular assist system (VAS) were developed from late 1950s and 2 extracorporeal pneumatic Japanese VASs (Toyobo VAS and Zeon VAS) were introduced to clinical field from 1980. Now, over 850 patients were applied several types of VASs including Japanese VASs. And 80% of heart transplant recipients were supported by VASs for 714 days (mean). Small size implantable left VAS (LVAS) are required and several types of non-pulsatile pump, including 2 Japanese made centrifugal pumps, are under clinical trials. And destination therapy by using implantable pulsatile LVAS for end-stage heart failure patients has been started in United States and is performed in United States and Europe. In near future, artificial heart and heart transplantation will be selected according to the conditions of the patients with profound heart failure.
Assuntos
Coração Artificial , Adolescente , Adulto , Procedimentos Cirúrgicos Cardíacos/métodos , Cardiomiopatias/cirurgia , Criança , Estudos de Avaliação como Assunto , Feminino , Insuficiência Cardíaca/cirurgia , Transplante de Coração/estatística & dados numéricos , Coração Artificial/normas , Coração Artificial/estatística & dados numéricos , Coração Auxiliar , Humanos , Masculino , Pessoa de Meia-Idade , Desenho de PróteseRESUMO
Japan has a long history of research and development of the artificial heart since Atsumi began studying artificial hearts at the University of Tokyo in 1959. Since that time, the University of Tokyo group has been developing different types of artificial hearts, as well as materials, blood pumps, driving mechanisms, and control methods. Other than the University of Tokyo, there are 12 institutes involved in artificial heart research and development in Japan. As for artificial heart clinical application in Japan, four devices were approved by the government; two are domestic, two are imported. Between 1980 and 2004, 697 cases of clinical application of a ventricular assist device (VAD) have been performed, including in 38 pediatric patients under 18 years. Recently, clinical use of percutaneous cardiopulmonary support has been increasing with 600 to 800 cases being performed every year, including in 40 to 60 patients under age 20 years. Although the requirement for clinical use of pediatric VADs is increasing, there is no device, domestic or imported, currently used in Japan; therefore, there is an urgent need for development of a pediatric VAD.
Assuntos
Coração Artificial/tendências , Coração Auxiliar/tendências , Pesquisa/tendências , Animais , Materiais Biocompatíveis , Desenho de Equipamento , Transplante de Coração/estatística & dados numéricos , Coração Artificial/história , Coração Artificial/estatística & dados numéricos , Coração Auxiliar/história , Coração Auxiliar/estatística & dados numéricos , História do Século XX , História do Século XXI , Humanos , Japão , Teste de Materiais , Modelos Biológicos , Pesquisa/históriaRESUMO
Heart transplants have been decreasing globally due to the lack of available donor hearts. As a result, the increased use of artificial hearts is anticipated as an alternative therapy. Although biocompatibility issues, such as thrombus formation/thromboembolism and infection, are still the main cause of mortality associated with artificial hearts, more than 20 different types are now clinically available after a half-century of development and experimental trials. These devices range from extracorporeal pneumatic to implantable battery-powered artificial hearts. The early development of artificial hearts logically focused on volumetric pump designs incorporating functions similar to the natural heart. Today, development has shifted toward designs that are significantly different from the natural heart. These pumps utilize axial or centrifugal flow allowing for a much simpler design, which is smaller in size and has very few moving parts. With rapid advances in technology, this new generation of artificial heart pumps is beginning to emerge as an alternative to heart transplants.
Assuntos
Coração Artificial , Transplante de Coração , Coração Artificial/estatística & dados numéricos , HumanosRESUMO
BACKGROUND: The SynCardia CardioWest total artificial heart (CardioWest TAH) is a biventricular, orthotopic, pneumatic, pulsatile blood pump driven by an external console. For each ventricle, the length of the blood-flow path is shorter and the inflow and outflow valves are larger than in any other bridge-to-transplant device, resulting in greater blood flow at smaller pre-load. Such a device should be optimal for bridging transplant candidates who have biventricular failure and for whom all other therapies have failed. METHODS: From January 1, 1993, to April 1, 2002, we prospectively studied 62 consecutive CardioWest TAH implant recipients to document safety and efficacy in bridge to transplantation. We used multisystem monitoring and multidrug therapy for anti-coagulation in 58 patients starting September 1, 1994. RESULTS: Before implantation, patients were critically ill with biventricular heart failure. Mortality in this group from the time of implantation until transplantation was 23%. Causes of death during device support included multi-organ failure (6), sepsis (3), and valve entrapment (2). Forty-eight patients underwent transplantation (77%). Forty-two survived to hospital discharge (68% of the total, 88% of those undergoing transplantation). Adverse events included bleeding (20%), device malfunction (5%), fit complications (3%), mediastinal infections (5%), visceral embolus (1.6%), and stroke during support (1.6%). The linearized stroke rate was 0.068 events per patient-year. CONCLUSIONS: Sixty-eight percent of critically ill transplant candidates for whom medical therapy failed were bridged to transplantation with the CardioWest TAH and survived long-term. Most deaths that occurred during device support were related to pre-implant problems. Infection and stroke were rare events. Therefore, we recommend the CardioWest TAH as the biventricular bridge-to-transplant device of choice.
Assuntos
Insuficiência Cardíaca/terapia , Transplante de Coração , Coração Artificial , Adolescente , Adulto , Idoso , Anticoagulantes/uso terapêutico , Falha de Equipamento , Feminino , Insuficiência Cardíaca/mortalidade , Coração Artificial/estatística & dados numéricos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos ProspectivosRESUMO
In October of 2002, a workshop was held as part of the Canadian Cardiovascular Congress in Edmonton, Canada, entitled "Under-Utilization of Mechanical Circulatory Support in Canada. Why and What Can Be Done?" The workshop examined various issues related to the use of mechanical circulatory support devices in the Canadian context. Representatives from all Canadian centers with active mechanical circulatory support programs were invited to participate and participants included surgeons and cardiologists, as well as other affiliated health professionals. Opinions were solicited from the workshop participants and a series of recommendations were formulated.
Assuntos
Circulação Assistida/estatística & dados numéricos , Insuficiência Cardíaca/cirurgia , Coração Artificial/estatística & dados numéricos , Canadá , Diretrizes para o Planejamento em Saúde , Coração Auxiliar/estatística & dados numéricos , Humanos , Estados UnidosRESUMO
Left ventricular assist devices (LVADs) and artificial hearts are improving. These devices can prolong a patient's life while on a heart transplant list. More exciting, mechanical assistance may provide an opportunity for a damaged heart to recover some function. Still, despite the promise, the use of these devices raises some difficult cost-benefit and ethical questions.
Assuntos
Insuficiência Cardíaca/mortalidade , Insuficiência Cardíaca/terapia , Coração Artificial/estatística & dados numéricos , Coração Auxiliar/estatística & dados numéricos , Disfunção Ventricular Esquerda/mortalidade , Disfunção Ventricular Esquerda/terapia , Feminino , Insuficiência Cardíaca/diagnóstico , Humanos , Masculino , Seleção de Pacientes , Ensaios Clínicos Controlados Aleatórios como Assunto , Medição de Risco , Sensibilidade e Especificidade , Índice de Gravidade de Doença , Taxa de Sobrevida , Resultado do Tratamento , Disfunção Ventricular Esquerda/diagnósticoRESUMO
Undulation pump total artificial heart (UPTAH) is a unique total artificial heart implant (TAH) using an undulation pump that is a continuous blood flow pump. To evaluate the autonomic nerve function mediating the circulation system, we analyzed the hemodynamic parameters during animal experiments with UPTAH using the non-linear mathematical analyzing technique, including chaos and fractal theory. Adult female goats were used for the implantation of UPTAH. The natural heart was replaced with UPTAH under extra-corporal circulation. The conductance- and arterial pressure-based control method (1/R control) was applied on the 5th to 7th post-operative day as the influences of the cardiopulmonary bypass circulation were diagnosed to be terminated. Hemodynamic parameters were recorded on the data recorder, and non-linear mathematical analysis was performed. For the quantitative evaluation of the strange attractor, which was the characteristics of the deterministic chaos, the fractal dimension analysis was carried out. As a result, hemodynamic parameters fluctuated on the time axis and showed fractal characteristics, which were thought to be the characteristics of the deterministic chaos. The reconstructed attractor of the hemodynamics showed various behaviors according to changes in the situation of the goats. These results suggest that non-linear dynamical analysis might be useful in monitoring the circulatory regulatory system in artificial heart circulation.
Assuntos
Coração Artificial/estatística & dados numéricos , Hemodinâmica/fisiologia , Dinâmica não Linear , Animais , Feminino , CabrasRESUMO
The CardioWest total artificial heart (TAH), formerly known as the Jarvik-7 and then the Symbion heart, is the only TAH in current clinical use. A new study, approved by the Food and Drug Administration (FDA), was initiated in 1993 with the goal of approving this pump for commercial release. Since then, 145 CardioWest TAHs have been implanted, including 37 pumps in 36 patients at our center. Our 36 patients were studied prospectively according to the investigational device exemption protocol approved by the FDA. Clinical and hemodynamic data obtained upon patients' entry into the study identified this group as mortally ill. After receiving a CardioWest TAH, 29 of the 36 patients (81%) survived to heart transplantation, and 26 (72% of the total group and 90% of the transplant recipients) have survived for up to 7 years (average, 24 months). Multicomponent anticoagulation, based on readily available tests, and the intrinsic properties of the TAH have resulted in a low linearized stroke rate of 0.48 event per patient-year. There have been no device-related mediastinal infections. In dying patients with nonexistent or severely compromised biventricular function, the CardioWest TAH has proved safe and effective, allowing a 72% survival rate for an average of 24 months.