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1.
Heart Lung Circ ; 31(10): 1309-1314, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36109293

RESUMO

Brian F. Buxton, one of Australia's greatest cardiac surgeons, died in May 2022, aged 82 years. In June 2022, a memorial celebration of Brian's life was held in Melbourne, Australia, attended by 550 colleagues and friends from many walks of life-not only "medical people" but also friends involved in Brian's sailing and hiking activities. This Special Article includes an introduction from Professor Jayme Bennetts, President of the Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS), an abridged version of a memorial address by Professor James Tatoulis and contributions from two other long-term professional colleagues and personal friends of Buxton, Professor Jaishankar Raman and Professor Franklin Rosenfeldt, founding editor of Heart, Lung and Circulation. Buxton was an outstanding and pioneering surgeon, clinical leader, and good friend to many. The Brian F. Buxton Cardiac and Thoracic Aortic Surgery Unit in Melbourne, Australia, is now so named in honour of his outstanding achievements and as a legacy. Vale Brian F. Buxton.


Assuntos
Cirurgia Torácica , Procedimentos Cirúrgicos Torácicos , Austrália , Humanos , Nova Zelândia
2.
Heart Lung Circ ; 29(2): 188-195, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31668616

RESUMO

Heart failure (HF) is one of the most common causes of death in Western society. Recent results underscore the utility of coenzyme Q10 (CoQ10) addition to standard medications in order to reduce mortality and to improve quality of life and functional capacity in chronic heart failure (CHF). The rationale for CoQ10 supplementation in CHF is two-fold. One is the well-known role of CoQ10 in myocardial bioenergetics, and the second is its antioxidant property. Redox balance is also improved by oral supplementation of CoQ10, and this effect contributes to enhanced endothelium-dependent relaxation. Previous reports have shown that CoQ10 concentration is decreased in myocardial tissue in CHF and by statin therapy, and the greater the CoQ10 deficiency the more severe is the cardiocirculatory impairment. In patients with CHF and hypercholesterolaemia being treated with statins, the combination of CoQ10 with a statin may be useful for two reasons: decreasing skeletal muscle injury and improving myocardial function. Ubiquinol, the active reduced form of CoQ10, presents higher bioavailability than the oxidised form ubiquinone, and should be the preferred form to be added to a statin. The combination ezetimibe/simvastatin may have advantages over single statins. Since ezetimibe reduces absorption of cholesterol and does not affect CoQ10 synthesis in the liver, the impact of this combination on CoQ10 tissue levels will be much less than that of high dose statin monotherapy at any target low density lipoprotein-cholesterol (LDL-C) level to be reached. This consideration makes the ezetimibe/statin combination the ideal LDL-lowering agent to be combined with ubiquinol in CHF patients. However, particular caution is advisable with the use of strategies of extreme lowering of cholesterol that may negatively impact on myocardial function. All in all there is a strong case for considering co-administration of ubiquinol with statin therapy in patients with depressed or borderline myocardial function.


Assuntos
Metabolismo Energético/efeitos dos fármacos , Insuficiência Cardíaca , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Miocárdio , Ubiquinona/análogos & derivados , Doença Crônica , Ezetimiba/uso terapêutico , Insuficiência Cardíaca/tratamento farmacológico , Insuficiência Cardíaca/metabolismo , Insuficiência Cardíaca/patologia , Humanos , Hipercolesterolemia/tratamento farmacológico , Hipercolesterolemia/metabolismo , Hipercolesterolemia/patologia , Miocárdio/metabolismo , Miocárdio/patologia , Ubiquinona/uso terapêutico
3.
Heart Lung Circ ; 29(2): 295-300, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30827856

RESUMO

BACKGROUND: Measurements of organ flow and perfusion during cardiopulmonary bypass suggest that perfusion of the splanchnic bed can be impaired by non-pulsatile flow. We postulated that non-pulsatile flow from centrifugal ventricular assist devices might also compromise splanchnic blood flow and cause bowel ischaemia especially in the period of circulatory instability early post-implant. The aim of the present studies was to compare the incidence of gastrointestinal (GI) complications in patients having a non-pulsatile device with the incidence in those having a pulsatile device. METHODS: In a pilot study, the initial 12 patients who received the Ventrassist (Ventracor, Sydney, NSW, Australia) centrifugal, non-pulsatile device during the period from June 2003 to September 2005 at the Alfred Hospital, Melbourne were compared with 11 patients who received a Thoratec (Thoratec, Pleasanton, CA, USA), pulsatile, positive displacement device and the incidence was recorded of GI complications requiring an intervention either surgical, endoscopic or by interventional radiology. This was followed by a larger (full) study of a second cohort of similar ventricular assist device (VAD) patients from January 1992 until December 2012 comparing 53 patients having non-pulsatile devices and 110 having pulsatile devices. RESULTS: In the pilot study, the overall incidence of complications in the non-pulsatile group (67%) was almost double that in the pulsatile group (36%) but the difference was not statistically significant (p = 0.15) because of the small number (n = 23) of participants. In the full study, all GI complications with either device occurred within the first 3 weeks post-implant. In the non-pulsatile patients, there was a higher incidence of GI bleeding, 23% vs 4% (p = 0.002), endoscopies, 24% vs 12% (p = 0.049). More patients with a non-pulsatile flow device had delayed absorption of nasogastric feeds than their pulsatile counterparts, 35% vs 7% (p < 0.0001). Patients with a non-pulsatile flow device had a higher overall rate of gastrointestinal complications than patients had with a pulsatile flow device, 56% vs 20% (p < 0.0001). After correcting for the other predictors, the odds of developing a gastrointestinal complication in the pulsatile group was significantly lower (odds ratio 0.07) than in the non-pulsatile device group (p < 0.0001). CONCLUSIONS: We conclude that the use of non-pulsatile centrifugal VADs compared with pulsatile positive displacement VADs is associated with a higher incidence of both haemorrhagic and ischaemic complications in the gastro-intestinal system especially in the very early post-implant period. Whether these complications could be reduced in centrifugal devices by increasing their pulsatility is not clear and merits further research.


Assuntos
Hemorragia Gastrointestinal , Insuficiência Cardíaca , Coração Auxiliar/efeitos adversos , Adulto , Idoso , Feminino , Hemorragia Gastrointestinal/epidemiologia , Hemorragia Gastrointestinal/etiologia , Insuficiência Cardíaca/epidemiologia , Insuficiência Cardíaca/terapia , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Fluxo Pulsátil , Fatores de Tempo
4.
Heart Lung Circ ; 28(8): 1267-1276, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30075944

RESUMO

BACKGROUND: Coronary artery bypass grafting (CABG) performed early after acute myocardial infarction (AMI) carries a high risk of mortality. By avoiding cardioplegic arrest and aortic cross-clamping, on-pump beating heart CABG (ONBEAT) may benefit patients requiring urgent or emergency revascularisation in the setting of AMI. We evaluated the early and long-term outcomes of ONBEAT versus conventional CABG (ONSTOP) utilising the ANZSCTS National Cardiac Surgery Database. METHODS: Between 2001 and 2015, 5,851 patients underwent non-elective on-pump CABG within 7 days of AMI. Of these, 77 patients (1.3%) underwent ONBEAT and 5774 (98.7%) underwent ONSTOP surgery. Propensity-score matching (with a 1:2 matching ratio) was performed for risk adjustment. Survival data were obtained from the National Death Index. RESULTS: Before matching, the unadjusted 30-day mortality was ONBEAT: 9/77 (11.7%) vs. ONSTOP: 256/5,774 (4.4%), p<0.001. Preoperative factors independently associated with the ONBEAT were: septuagenarian age, peripheral vascular disease, redo surgery, cardiogenic shock, emergency surgery and single-vessel disease. After propensity-score matching, 30-day mortality was similar (ONBEAT: 9/77 (11.7%) vs. ONSTOP: 16/154 (10.4%), p=0.85), as was the rate of major adverse cardiac and cerebrovascular events (ONBEAT: 17/77 (22.1%) vs. ONSTOP: 38/154 (24.7%), p=0.84). ONBEAT patients received fewer distal anastomoses and were more likely to have incomplete revascularisation (ONBEAT: 15/77 (19.5%) vs. ONSTOP: 15/154, (9.7%), p=0.03). Despite this, 12-year survival was comparable (ONBEAT: 64.8% (95% CI 39.4-82.4%) vs. ONSTOP: 63.6% (95% CI 50.5, 74.3%), p=0.89). CONCLUSIONS: ONBEAT can be performed safely in high-risk patients requiring CABG early after AMI with similar short and long-term survival compared to ONSTOP.


Assuntos
Ponte de Artéria Coronária , Bases de Dados Factuais , Parada Cardíaca Induzida , Infarto do Miocárdio , Choque Cardiogênico , Idoso , Idoso de 80 Anos ou mais , Intervalo Livre de Doença , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/mortalidade , Infarto do Miocárdio/fisiopatologia , Infarto do Miocárdio/cirurgia , Estudos Retrospectivos , Choque Cardiogênico/mortalidade , Choque Cardiogênico/fisiopatologia , Choque Cardiogênico/cirurgia , Taxa de Sobrevida , Fatores de Tempo
5.
Heart Lung Circ ; 27(6): 760-762, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28882495

RESUMO

BACKGROUND: The aim of this study was to define the status of preoperative zinc levels in patients with heart disease presenting for cardiac surgery and to identify any predictors for and any clinical consequences of low zinc levels. METHODS: Adult patients presenting for elective surgery, either coronary artery bypass graft surgery and/or valve replacement, provided a fasting blood sample on the day of admission for surgery. Plasma and erythrocyte zinc levels were analysed and the levels correlated with the patient's characteristics and clinical outcomes. RESULTS: Of 56 patients 53% (n=30) had abnormally low plasma zinc levels (<12µmol/L) and 5.5% (n=3) had abnormally low erythrocyte zinc levels (<160µmol/L), indicative of deficiency. There were significant associations between lower plasma zinc levels and the presence of hypertension (p=0.02), hypercholesteraemia (p=0.02) and higher body mass index (BMI) (p=0.034) but no effect on major postoperative clinical outcomes. CONCLUSIONS: This small study shows that zinc deficiency is common in cardiac surgery patients, especially in the presence of hypertension, hypercholesterolaemia or obesity. The effects of zinc deficiency in cardiac surgery need to be further investigated.


Assuntos
Procedimentos Cirúrgicos Cardíacos , Procedimentos Cirúrgicos Eletivos , Cardiopatias/cirurgia , Zinco/deficiência , Idoso , Terapias Complementares , Feminino , Seguimentos , Cardiopatias/sangue , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Risco , Zinco/sangue
6.
J Card Fail ; 22(7): 548-59, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27002943

RESUMO

BACKGROUND: The mechanisms for cognitive impairment in heart failure (HF) are unclear. We investigated the relative contributions of cerebral blood flow velocity (BFV), oxidative stress, and inflammation to HF-associated cognitive impairment. METHODS AND RESULTS: Thirty-six HF patients (≥60 years) and 40 healthy controls (68 ± 7 vs 67 ± 5 years, P > .05; 69% vs 50% male, P > .05) completed the Cognitive Drug Research computerized assessment battery and Stroop tasks. Common carotid (CCA) and middle cerebral arterial BFV were obtained by transcranial Doppler. Blood samples were collected for oxidant (diacron-reactive oxygen metabolites; F2-isoprostanes), antioxidant (coenzyme Q10; CoQ10), and inflammatory markers (high-sensitivity C-reactive protein). Compared with controls, patients exhibited impaired attention (Cognitive Drug Research's Power of Attention domain, congruent Stroop) and executive function (incongruent Stroop). Multiple regression modeling showed that CCA-BFV and CoQ10 but not group predicted performance on attention and executive function. Additionally, in HF patients, CCA-BFV and CoQ10 (ß = -0.34 vs ß = -0.35) were significant predictors of attention, and CCA-BFV (ß = -0.34) was a predictor of executive function. CONCLUSIONS: Power of Attention and executive function is impaired in older HF patients, and reduced CCA-BFV and CoQ10 are associated with worse cognition. Interventions addressing these mechanisms may improve cognition in older HF patients.


Assuntos
Circulação Cerebrovascular/fisiologia , Transtornos Cognitivos/fisiopatologia , Cognição/fisiologia , Insuficiência Cardíaca/fisiopatologia , Inflamação/fisiopatologia , Estresse Oxidativo/fisiologia , Idoso , Velocidade do Fluxo Sanguíneo , Proteína C-Reativa , Transtornos Cognitivos/diagnóstico , Transtornos Cognitivos/etiologia , Feminino , Insuficiência Cardíaca/complicações , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Ubiquinona/fisiologia
7.
Artif Organs ; 39(8): 681-90, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26146861

RESUMO

This study in five large greyhound dogs implanted with a VentrAssist left ventricular assist device focused on identification of the precise site and physiological changes induced by or underlying the complication of left ventricular suction. Pressure sensors were placed in left and right atria, proximal and distal left ventricle, and proximal aorta while dual perivascular and tubing ultrasonic flow meters measured blood flow in the aortic root and pump outlet cannula. When suction occurred, end-systolic pressure gradients between proximal and distal regions of the left ventricle on the order of 40-160 mm Hg indicated an occlusive process of variable intensity in the distal ventricle. A variable negative flow difference between end systole and end diastole (0.5-3.4 L/min) was observed. This was presumably mediated by variable apposition of the free and septal walls of the ventricle at the pump inlet cannula orifice which lasted approximately 100 ms. This apposition, by inducing an end-systolic flow deficit, terminated the suction process by relieving the imbalance between pump requirement and delivery from the right ventricle. Immediately preceding this event, however, unnaturally low end-systolic pressures occurred in the left atrium and proximal left ventricle which in four dogs lasted for 80-120 ms. In one dog, however, this collapse progressed to a new level and remained at approximately -5 mm Hg across four heart beats at which point suction was relieved by manual reduction in pump speed. Because these pressures were associated with a pulmonary capillary wedge pressure of -5 mm Hg as well, they indicate total collapse of the entire pulmonary venous system, left atrium, and left ventricle which persisted until pump flow requirement was relieved by reducing pump speed. We suggest that this collapse caused the whole vascular region from pulmonary capillaries to distal left ventricle to behave as a Starling resistance which further reduced right ventricular output thus contributing to a major reduction in pump flow. We contend that similar complications of manual speed control also occur in the human subject and remain a major unsolved problem in the clinical management of patients implanted with rotary blood pumps.


Assuntos
Coração Auxiliar/efeitos adversos , Hemodinâmica , Falha de Prótese , Disfunção Ventricular Esquerda/etiologia , Função Ventricular Esquerda , Animais , Modelos Animais de Doenças , Cães , Modelos Cardiovasculares , Desenho de Prótese , Volume Sistólico , Fatores de Tempo , Transdutores de Pressão , Resistência Vascular , Disfunção Ventricular Esquerda/diagnóstico , Disfunção Ventricular Esquerda/fisiopatologia , Pressão Ventricular
8.
Prostate ; 74(5): 458-68, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24442790

RESUMO

BACKGROUND: Irreversible electroporation (IRE) delivers brief electric pulses to attain non-thermal focal ablation that spares vasculature and other sensitive systems. It is a promising prostate cancer treatment due to sparing of the tissues associated with morbidity risk from conventional therapies. IRE effects depend on electric field strength and tissue properties. These characteristics are organ-dependent, affecting IRE treatment outcomes. This study characterizes the relevant properties to improve treatment planning and outcome predictions for IRE prostate cancer treatment. METHODS: Clinically relevant IRE pulse protocols were delivered to a healthy canine and two human cancerous prostates while measuring electrical parameters to determine tissue characteristics for predictive treatment simulations. Prostates were resected 5 hr, 3 weeks, and 4 weeks post-IRE. Lesions were correlated with numerical simulations to determine an effective prostate lethal IRE electric field threshold. RESULTS: Lesions were produced in all subjects. Tissue electrical conductivity increased from 0.284 to 0.927 S/m due to IRE pulses. Numerical simulations show an average effective prostate electric field threshold of 1072 ± 119 V/cm, significantly higher than previously characterized tissues. Histological findings in the human cases show instances of complete tissue necrosis centrally with variable tissue effects beyond the margin. CONCLUSIONS: Preliminary experimental IRE trials safely ablated healthy canine and cancerous human prostates, as examined in the short- and medium-term. IRE-relevant prostate properties are now experimentally and numerically defined. Importantly, the electric field required to kill healthy prostate tissue is substantially higher than previously characterized tissues. These findings can be applied to optimize IRE prostate cancer treatment protocols.


Assuntos
Eletroquimioterapia/métodos , Próstata/fisiopatologia , Neoplasias da Próstata/terapia , Animais , Simulação por Computador , Cães , Condutividade Elétrica , Humanos , Masculino , Modelos Biológicos , Próstata/patologia , Neoplasias da Próstata/patologia , Neoplasias da Próstata/fisiopatologia
9.
J Paediatr Child Health ; 50(10): E63-7, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20626583

RESUMO

BACKGROUND: Cardiac opioid peptides have been identified to exert important adaptive metabolic signalling for cardioprotection against ischaemia or hypoxia-related injury. AIMS: To determine myocardial methionine-enkephalin content in children with hypoxemic congenital heart defects and to correlate myocardial content of methionine-enkephalin with the extent of arterial oxygen desaturation. METHODS: Children (n= 20, median age of 16 months), undergoing cardiac surgical repair (tetralogy of Fallot, 17/20), were included in this study. Arterial oxygen saturation was measured on admission. Myocardial samples obtained during surgery were assayed via radioimmunochemistry for methionine-enkephalin content. RESULTS: Greater methionine-enkephalin content was measured in the right ventricles of the patients suffering from recent cyanotic spells compared with those with no recent spells (cyanotic spells: 2418 ± 844 pg/g wet weight tissue, n= 6; no spells: 1175 ± 189 pg/g wet weight tissue, n= 14, P= 0.04). An inverse correlation was evident between the arterial oxygen saturation and myocardial methionine-enkephalin content. CONCLUSION: Myocardial methionine-enkephalin levels increase with the severity of hypoxic stress in congenital cardiac disease and may play an important adaptive role in countering adrenergic over-activity and related excess demand on myocardial metabolic capacity.


Assuntos
Procedimentos Cirúrgicos Cardíacos/métodos , Encefalina Metionina/metabolismo , Cardiopatias Congênitas/cirurgia , Hipóxia/diagnóstico , Consumo de Oxigênio/fisiologia , Biomarcadores/análise , Biomarcadores/metabolismo , Gasometria , Procedimentos Cirúrgicos Cardíacos/mortalidade , Criança , Pré-Escolar , Estudos de Coortes , Encefalina Metionina/análise , Feminino , Seguimentos , Cardiopatias Congênitas/diagnóstico , Cardiopatias Congênitas/mortalidade , Humanos , Hipóxia/congênito , Lactente , Masculino , Miocárdio/metabolismo , Oximetria , Valor Preditivo dos Testes , Estudos Prospectivos , Medição de Risco , Taxa de Sobrevida , Resultado do Tratamento
10.
Heart Lung Circ ; 23(1): 88-90, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23957942

RESUMO

Despite increasing use of donation after cardiac death (DCD) and encouraging results for non-cardiac transplants, DCD cardiac transplantation has not been widely adopted because, (1) the DCD heart sustains warm ischaemic injury during the death process and (2) conventional static cold storage significantly adds to the ischaemic injury. We have developed a simple system for perfusion of the DCD heart with cold crystalloid solution using gravity-feed that can reduce ischaemic injury and potentially render the heart suitable for transplantation. This report describes the first application of this technique to a human DCD heart with good functional metabolic recovery over 12h on an ex vivo rig.


Assuntos
Coração , Soluções Isotônicas/farmacologia , Preservação de Órgãos/métodos , Doadores de Tecidos , Soluções Cristaloides , Morte , Transplante de Coração , Humanos , Masculino , Isquemia Miocárdica/prevenção & controle , Fatores de Tempo
11.
Heart Lung Circ ; 23(10): 978-80, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24996389

RESUMO

BACKGROUND: Vitamin D deficiency is one of the most common chronic medical conditions in the world and also prevalent in Australia. A growing body of evidence suggests that low vitamin D also has adverse effects on cardiovascular health, including coronary risk factors and adverse cardiovascular outcomes such as myocardial infarction, cardiac failure and stroke. There is some evidence suggesting that a greater proportion of people with cardiovascular disease have low vitamin D compared to the general population. We examined the prevalence of vitamin D deficiency and insufficiency in elective cardiothoracic surgical patients presenting to the Alfred Hospital in Melbourne, Australia and compared this to recent Victorian statistics for people of the same age group. METHODS: Consecutive adult elective cardiothoracic surgical patients listed for either coronary artery bypass graft surgery or heart valve repair or replacement surgery attending The Alfred Hospital, Melbourne between July 2011 and October 2012 were invited to participate. This ensured that patients were enrolled over all four seasons. Fasting serum samples were taken on the day of surgery, immediately after admission. Eighty volunteers participated in the study. Of the group, 40% were due to have coronary artery bypass graft surgery, 35% valve surgery and 25% a combination of the two; 74% reported having hypertension, 69% hyperlipidaemia, 26% diabetes and 39% had a BMI >30 kg/m(2). RESULTS: Test results revealed that 92.5% of patients had Vitamin D levels < 75 nmol/L, 67.5% had levels < 60 nmol/L, 52.5% had levels between 30-59 nmol/L and 15% had levels < 30 nmol/L. Inadequate vitamin D levels were found in 80% of obese patients (BMI > 30 kg/m(2)) compared to 59% of non-obese patients. CONCLUSIONS: Based on our small screening study, a substantial proportion of elective cardiothoracic surgical patients have less than optimal serum vitamin D3 levels prior to surgery. We found two-thirds of patients had serum vitamin D levels below 60 nmol/L, placing them at higher risk of falls. This finding is of concern as these patients would have received multiple consultations with various medical practitioners prior to hospital admission and yet their inadequate vitamin D status remained. Failing to identify patients with low vitamin D and correcting it with supplementation places older adults at unnecessary risk, especially of falls, which are associated with a high risk of mortality. In an ageing population with CVD, vitamin D status needs to be assessed and any inadequacy corrected. Whether low vitamin D status prior to cardiac surgery affects post-surgery outcomes, is another issue which deserves future investigation.


Assuntos
Procedimentos Cirúrgicos Cardíacos , Colecalciferol/sangue , Deficiência de Vitamina D/epidemiologia , Idoso , Austrália/epidemiologia , Anuloplastia da Valva Cardíaca , Ponte de Artéria Coronária , Diabetes Mellitus/epidemiologia , Feminino , Implante de Prótese de Valva Cardíaca , Humanos , Hiperlipidemias/epidemiologia , Hipertensão/epidemiologia , Masculino , Pessoa de Meia-Idade , Obesidade/epidemiologia , Prevalência , Deficiência de Vitamina D/sangue
12.
Heart Lung Circ ; 23(3): 234-41, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24268488

RESUMO

BACKGROUND: Ventricular assist device (VAD) implantation has become an effective option for patients with severe heart failure. However, device-related infections remain a significant problem. The aim of this study was to describe the incidence and microbiological aetiology of bacteraemia in patients with VADs, and to assess the impact of bacteraemia on clinical outcomes. METHODS: A retrospective study was conducted of patients having VAD implantation at the Alfred Hospital (Melbourne, Australia) from October 1990 to July 2009. Medical records and microbiology databases were reviewed. Patients who were supported with a VAD for 72h or more were evaluated for demographic data, VAD type, the occurrence of bacteraemia and clinical outcomes. RESULTS: During the 19-year period, 135 VAD patients (89 Thoratec PVAD, 10 Novacor, and 36 Ventrassist) supported for a total duration of 17,304 (median 74) support days were included. Sixty-one patients (45%) developed VAD-associated bacteraemia, an incidence of 5.6 episodes per 1000 support days. The incidence of bacteraemia per 1000 days of support was similar for the three devices used: Thoratec PVAD, Novacor and Ventrassist VADs (7.8±0.8, 5.2±1.5 and 3.4±0.5, respectively, p=0.74). Staphylococcus aureus was the most common pathogen (25%). The rates of death on device, survival to transplant, recovery with explant and outcomes after transplantation, including 30-day mortality, median survival time and incidence of cerebrovascular accidents were not significantly impacted upon by bacteraemia. CONCLUSIONS: Bacteraemia is common in VAD patients. However, the incidence of VAD-associated bacteraemia is independent of device type and with aggressive antimicrobial therapy; clinical outcomes need not be affected by the bacteraemia.


Assuntos
Antibacterianos/administração & dosagem , Bacteriemia , Coração Auxiliar/efeitos adversos , Prontuários Médicos , Infecções Estafilocócicas , Staphylococcus aureus , Adolescente , Adulto , Idoso , Bacteriemia/tratamento farmacológico , Bacteriemia/etiologia , Bacteriemia/mortalidade , Intervalo Livre de Doença , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/etiologia , Infecções Estafilocócicas/mortalidade , Taxa de Sobrevida
13.
Heart Lung Circ ; 22(11): 895-902, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23948287

RESUMO

Phrenic nerve injury is a well-recognised complication of cardiac surgery that can lead to disabling effects from diaphragmatic dysfunction, especially in children and patients with a history of chronic obstructive airway disease. Various mechanisms of injury have been recognised including hypothermia, mechanical trauma and possibly ischaemia. A clear understanding of these mechanisms is important in order to modify surgical techniques to prevent this serious complication of cardiac surgery.


Assuntos
Procedimentos Cirúrgicos Cardíacos/efeitos adversos , Traumatismos dos Nervos Periféricos/prevenção & controle , Nervo Frênico/lesões , Adolescente , Criança , Pré-Escolar , Humanos , Traumatismos dos Nervos Periféricos/etiologia , Traumatismos dos Nervos Periféricos/patologia
14.
Heart Lung Circ ; 22(8): 627-33, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23465653

RESUMO

INTRODUCTION: Multiple agents have been investigated to prevent atrial fibrillation (AF) after cardiac surgery. Several studies have investigated the use of ß-blockers such as metoprolol or amiodarone with promising results. We aimed to investigate perioperative pharmacologic prophylaxis against AF using metoprolol, and amiodarone in combination with metoprolol. METHODS: We conducted a prospective, randomised, single-blind, controlled pilot study in patients undergoing elective cardiac surgery. Subjects were randomised pre-operatively to one of three treatment groups: standard therapy (control) or metoprolol (5 mg IV over 5 min on commencement of bypass then 5 mg IV qid for 24h then 25-50 mg tds orally until discharge) or amiodarone (300 mg over 1h starting shortly after the commencement of bypass, then 900 mg over 24h then 400 mg orally tds until discharge) plus metoprolol as above. Patients had ECG monitoring for the occurrence of AF for six days or until discharge. RESULTS: Two hundred and fifteen patients were enrolled. Between-group differences in AF in an intention-to-treat analysis were not significant: control 34% (23-45%), metoprolol 35% (24-46%), combined 22% (12-33%) (p = 0.21). However 87 patients (40%) did not receive the assigned treatment mainly due to side effects, especially bradycardia. The remaining 128 patients were analysed on a per-protocol basis with the overall difference between the three groups bordering on significance: control 34% (23-45%), metoprolol 26% (9-43%), combined 11% (0-23%) (p = 0.06). Logistic regression analysis, correcting for age and gender, was used to separate the individual effects of metoprolol and amiodarone in the presence of metoprolol which showed that compared to control there was a significant effect of metroprolol on AF incidence (O.R. 0.31 (0.10-0.99), p = 0.048) but not of amiodarone (O.R. 0.97 (0.19-5.02), p = 0.97). CONCLUSIONS: (1) Perioperative metoprolol but not amiodarone itself in combination with metoprolol is associated with a significant reduction in postoperative AF. (2) Perioperative administration of metoprolol and combination of metoprolol with amiodarone is associated with a high incidence of side effects, especially bradycardia. (3) Further studies are indicated to confirm these preliminary findings but in the meantime it would not be unreasonable to implement the use of perioperative metoprolol for routine prophylaxis of AF.


Assuntos
Antiarrítmicos/administração & dosagem , Fibrilação Atrial/prevenção & controle , Procedimentos Cirúrgicos Cardíacos/efeitos adversos , Metoprolol/administração & dosagem , Complicações Pós-Operatórias/prevenção & controle , Administração Oral , Idoso , Amiodarona/administração & dosagem , Amiodarona/efeitos adversos , Antiarrítmicos/efeitos adversos , Fibrilação Atrial/etiologia , Fibrilação Atrial/fisiopatologia , Eletrocardiografia , Feminino , Humanos , Masculino , Metoprolol/efeitos adversos , Pessoa de Meia-Idade , Assistência Perioperatória , Projetos Piloto , Complicações Pós-Operatórias/fisiopatologia , Estudos Prospectivos , Fatores de Tempo
15.
Artif Organs ; 36(5): E125-37, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22489771

RESUMO

Numerical models, able to simulate the response of the human cardiovascular system (CVS) in the presence of an implantable rotary blood pump (IRBP), have been widely used as a predictive tool to investigate the interaction between the CVS and the IRBP under various operating conditions. The present study investigates the effect of alterations in the model parameter values, that is, cardiac contractility, systemic vascular resistance, and total blood volume on the efficiency of rotary pump assistance, using an optimized dynamic heart-pump interaction model previously developed in our laboratory based on animal experimental measurements obtained from five canines. The effect of mean pump speed and the circulatory perturbations on left and right ventricular pressure volume loops, mean aortic pressure, mean cardiac output, pump assistance ratio, and pump flow pulsatility from both the greyhound experiments and model simulations are demonstrated. Furthermore, the applicability of some of the previously proposed control parameters, that is, pulsatility index (PI), gradient of PI with respect to pump speed, pump differential pressure, and aortic pressure are discussed based on our observations from experimental and simulation results. It was found that previously proposed control strategies were not able to perform well under highly varying circulatory conditions. Among these, control algorithms which rely on the left ventricular filling pressure appear to be the most robust as they emulate the Frank-Starling mechanism of the heart.


Assuntos
Volume Sanguíneo , Coração Auxiliar , Modelos Cardiovasculares , Contração Miocárdica , Resistência Vascular , Algoritmos , Animais , Simulação por Computador , Cães , Insuficiência Cardíaca/terapia , Humanos , Pressão , Fluxo Pulsátil
16.
Artif Organs ; 36(5): E110-24, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22489799

RESUMO

A heart-pump interaction model has been developed based on animal experimental measurements obtained with a rotary blood pump in situ. Five canine experiments were performed to investigate the interaction between the cardiovascular system and the implantable rotary blood pump over a wide range of operating conditions, including variations in cardiac contractility and heart rate, systemic vascular resistance (SVR), and total blood volume (V(total) ). It was observed in our experiments that SVR decreased with increasing mean pump speed under the healthy condition, but was relatively constant during the speed ramp study under reduced cardiac contractility conditions. Furthermore, we also found a significant increase in pulmonary vascular resistance with increasing mean pump speed and decreasing total blood volume, despite a relatively constant SVR. Least squares parameter estimation methods were utilized to fit a subset of model parameters in order to achieve better agreement with the experimental data and to evaluate the robustness and validity of the model under various operating conditions. The fitted model produced reasonable agreement with the experimental measurements, both in terms of mean values and steady-state waveforms. In addition, all the optimized parameters were within physiological limits.


Assuntos
Volume Sanguíneo , Frequência Cardíaca , Coração Auxiliar , Modelos Cardiovasculares , Contração Miocárdica , Resistência Vascular , Agonistas de Receptores Adrenérgicos alfa 1/farmacologia , Antagonistas de Receptores Adrenérgicos beta 1/farmacologia , Animais , Cães , Insuficiência Cardíaca/terapia , Humanos , Análise dos Mínimos Quadrados , Metaraminol/farmacologia , Metoprolol/farmacologia , Nitroprussiato/farmacologia , Substitutos do Plasma , Poligelina , Vasodilatadores/farmacologia
17.
Heart Lung Circ ; 21(5): 255-9, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22386614

RESUMO

BACKGROUND: Little is known about the outcome of cardiac surgery in patients with a prior history of malignancy. Our aim was to investigate in our unit the population of patients with a known malignancy and compare their outcomes to a matched population without malignancy. METHODS: We identified all patients who underwent cardiac surgery at the Alfred Hospital between February 2002 and December 2009 with malignancy. Cases were matched to 216 controls based on age, gender, major medical comorbidities and type of surgery. A univariate analysis was performed with Fishers exact test and χ(2) test. RESULTS: 83/4474 patients were identified with malignancy. Sixty-four (77%) were male. Mean age of the patients with malignancy was 66.7 years, and 67.4 in the control group. 68.7% had a solid organ tumour, and 31.3% had a haematological malignancy. There were no significant between-group differences in hospital or 30-day mortality. However, there were significantly higher rates of transfusion (79.5% vs 49%, p<0.0001), reintubation (8.4% vs 0.9%, p=0.0009), pneumonia (14.5% vs 6%, p=0.035), septicaemia (8.4% vs 1.9%, p=0.018), arrhythmias (42.2% vs. 33.8%, p=0.047) and anticoagulant complications (7.2% vs 0%, p=0.008) in patients with malignancies. CONCLUSION: Patients who present for cardiac surgery having had prior treatment for cancer are at particular risk for complications. However, these patients can be operated upon with acceptable risk. There is no difference in the short term mortality. Therefore, for selected patients who are undergoing curative treatment for their malignancy, or are in remission, cardiac surgery is not contraindicated.


Assuntos
Procedimentos Cirúrgicos Cardíacos/efeitos adversos , Complicações Intraoperatórias/epidemiologia , Neoplasias/complicações , Complicações Pós-Operatórias/epidemiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Procedimentos Cirúrgicos Cardíacos/mortalidade , Procedimentos Cirúrgicos Cardíacos/estatística & dados numéricos , Distribuição de Qui-Quadrado , Feminino , Hospitalização , Humanos , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Neoplasias/mortalidade , Medição de Risco/métodos , Estatística como Assunto , Estatísticas não Paramétricas , Vitória , Adulto Jovem
18.
Heart Lung Circ ; 21(1): 1-11, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21937275

RESUMO

Traditionally, patients presenting with symptoms of coronary artery disease (CAD) were managed medically. If medical treatment proved unsuccessful, patients were referred for coronary artery bypass surgery (CABG). However, in recent years, increasing numbers of patients have received percutaneous coronary intervention (PCI), usually a coronary stent, for primary treatment. PCI is attractive because it is minimally invasive, has proven success in the immediate treatment of acute myocardial infarction and is well-accepted for poor surgical candidates in selected cases. However, evidence from emerging and ongoing clinical trials and registries suggests that compared to PCI, CABG offers superior long-term prognostic benefits in many, if not most, patients with significant CAD. We present an analysis of recent evidence showing that patients with complex atherosclerotic lesions, multivessel disease, left main stem disease, left ventricular dysfunction and diabetes mellitus derive more benefit from surgical revascularisation than from PCI. We conclude that PCI should be restricted to patient groups where superiority or equivalence to CABG has been demonstrated and that the decision-making process in allocating treatment should be made by a multidisciplinary team to ensure that every patient receives balanced advice and therapy that is most effective in the long term.


Assuntos
Angioplastia Coronária com Balão , Ponte de Artéria Coronária , Doença da Artéria Coronariana/terapia , Tratamento Farmacológico/métodos , Angioplastia Coronária com Balão/efeitos adversos , Angioplastia Coronária com Balão/métodos , Contraindicações , Ponte de Artéria Coronária/métodos , Doença da Artéria Coronariana/complicações , Doença da Artéria Coronariana/diagnóstico , Doença da Artéria Coronariana/patologia , Vasos Coronários/patologia , Diabetes Mellitus Tipo 2/complicações , Gerenciamento Clínico , Humanos , Avaliação de Resultados em Cuidados de Saúde , Seleção de Pacientes , Prognóstico , Ensaios Clínicos Controlados Aleatórios como Assunto , Medição de Risco , Índice de Gravidade de Doença , Stents , Tempo , Disfunção Ventricular Esquerda/complicações
19.
BMC Complement Altern Med ; 11: 20, 2011 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-21385466

RESUMO

BACKGROUND: Preoperative anxiety and physical unfitness have been shown to have adverse effects on recovery from cardiac surgery. This study involving cardiac surgery patients was primarily aimed at assessing the feasibility of delivering physical conditioning and stress reduction programs within the public hospital setting. Secondary aims were to evaluate the effect of these programs on quality of life (QOL), rates of postoperative atrial fibrillation (AF) and length of stay (LOS) in hospital. METHODS: Elective patients scheduled for coronary artery bypass graft and/or valve surgery at a public hospital in Melbourne, Australia were enrolled. Patients were randomized to receive either holistic therapy (HT) or usual care (UC). HT consisted of a series of light physical exercise sessions together with a mental stress reduction program administered in an outpatient setting for the first two weeks after placement on the waiting list for surgery. A self-administered SF-36 questionnaire was used to measure QOL and hospital records to collect data on LOS and rate of postoperative AF. RESULTS: The study population comprised 117 patients of whom 60 received HT and 57 received UC. Both programs were able to be delivered within the hospital setting but ongoing therapy beyond the two week duration of the program was not carried out due to long waiting periods and insufficient resources. HT, as delivered in this study, compared to UC did not result in significant changes in QOL, LOS or AF incidence. CONCLUSIONS: Preoperative holistic therapy can be delivered in the hospital setting, although two weeks is insufficient to provide benefits beyond usual care on QOL, LOS or postoperative AF. Further research is now required to determine whether a similar program of longer duration, or targeted to high risk patients can provide measurable benefits. TRIAL REGISTRATION: This trial was conducted as part of a larger study and according to the principles contained in the CONSORT statement 2001.


Assuntos
Procedimentos Cirúrgicos Cardíacos/psicologia , Terapia por Exercício , Saúde Holística , Terapias Mente-Corpo , Aptidão Física , Cuidados Pré-Operatórios/métodos , Estresse Psicológico/terapia , Idoso , Fibrilação Atrial/etiologia , Fibrilação Atrial/terapia , Ponte de Artéria Coronária , Estudos de Avaliação como Assunto , Feminino , Cardiopatias/cirurgia , Valvas Cardíacas/cirurgia , Humanos , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Avaliação de Resultados em Cuidados de Saúde , Complicações Pós-Operatórias/terapia , Qualidade de Vida , Padrão de Cuidado , Inquéritos e Questionários
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