RESUMO
BACKGROUND: Resilience is associated with a positive and resource-oriented perspective. Therefore, it seems especially attractive for health promotion and prevention. In recent years, interventions to foster resilience have been increasingly developed, which train resilience factors and are mainly conducted in a face to face group format. OBJECTIVE: The question is raised what potential internet-based interventions (i-interventions) that train resilience factors have for health promotion and prevention. MATERIAL AND METHODS: Based on a narrative overview, the possibilities for iinterventions that train resilience factors for health promotion and prevention are investigated and the state of research is described. RESULTS: The effects of the iinterventions presented here, which aim at fostering resilience, on measures of mental health and well-being are heterogeneous and vary between low to high effects. Stronger evidence for the efficacy of these measures exists for more general iinterventions that also train resilience factors but are conceptualized for the prevention of specific disorders, such as depression or for stress reduction. DISCUSSION: Given the heterogeneous nature of intervention contents, theoretical foundations and therapeutic methods used, the heterogeneity of the evidence is discussed. In addition, perspectives for the further development of resource-oriented resilience interventions are outlined.
Assuntos
Promoção da Saúde , Internet , Transtornos Mentais , Serviços de Saúde Mental , Promoção da Saúde/métodos , Humanos , Transtornos Mentais/prevenção & controle , Saúde Mental , Serviços de Saúde Mental/normasRESUMO
BACKGROUND: Atherosclerotic coronary arteries are prone to constriction but the underlying causes are incompletely understood. We tested the hypothesis that endothelin-1 (ET-1), a potent vasoconstrictor, contributes to the heightened tone of atherosclerotic human coronary arteries. METHODS AND RESULTS: In 8 patients with coronary artery disease (CAD) and 8 patients with angiographically smooth coronary arteries (normal), we infused BQ-123, an antagonist of the ET(A) receptor, into a major coronary artery (infused artery) at 40 nmol/min for 60 minutes. The infused artery in the CAD patients contained a >50% stenosis. Using quantitative angiography, we compared the dilation of the infused artery with another, noninfused coronary artery. To estimate the magnitude of the contribution of ET-1 to coronary tone, we compared the dilation to BQ-123 with that elicited by intracoronary nitroglycerin (200 microgram). BQ-123 induced significant dilation in the normal arteries (7.3% at 60 minutes, P<0.001 versus noninfused arteries) and a greater dilation in the CAD arteries (16.3% at 60 minutes, P<0.001 versus infused normal arteries). The dilation at stenoses was particularly pronounced (21.6% at 60 minutes, P<0.001 versus infused CAD arteries). Compared with the dilation from nitroglycerin, ET-1 contributed to 39% of the coronary tone in normal arteries, 74% of tone in CAD arteries, and 106% of tone at stenoses (P<0.01). CONCLUSIONS: ET-1 accounts for nearly all the resting tone in atherosclerotic coronary arteries, especially at stenoses. Inhibitors of ET-1, by relieving constriction, may significantly lessen the hemodynamic significance of coronary stenoses and thereby reduce myocardial ischemia.
Assuntos
Doença da Artéria Coronariana/fisiopatologia , Vasos Coronários/fisiopatologia , Endotelina-1/fisiologia , Vasoconstrição/fisiologia , Circulação Coronária/efeitos dos fármacos , Vasos Coronários/efeitos dos fármacos , Vasos Coronários/patologia , Antagonistas dos Receptores de Endotelina , Humanos , Pessoa de Meia-Idade , Análise Multivariada , Nitroglicerina/farmacologia , Peptídeos Cíclicos/farmacologia , Receptor de Endotelina A , Vasoconstrição/efeitos dos fármacos , Vasodilatadores/farmacologiaRESUMO
BACKGROUND: Short- and long-term outcomes after prosthetic mitral valve replacement (MVR) in children aged <5 years are ill-defined and generally perceived as poor. The experience of the Pediatric Cardiac Care Consortium (45 centers, 1982 to 1999) was reviewed. METHODS AND RESULTS: MVR was performed 176 times on 139 patients. Median follow-up was 6.2 years (range 0 to 20 years, 96% complete). Age at initial MVR was 1.9+/-1.4 years. Complications after initial MVR included heart block requiring pacemaker (16%), endocarditis (6%), thrombosis (3%), and stroke (2%). Patient survival was as follows: 1 year, 79%; 5 years, 75%; and 10 years, 74%. The majority of deaths occurred early after initial MVR, with little late attrition despite repeat MVR and chronic anticoagulation. Among survivors, the 5-year freedom from reoperation was 81%. Age-adjusted multivariable predictors of death include the presence of complete atrioventricular canal (hazard ratio 4.76, 95% CI 1.59 to 14.30), Shone's syndrome (hazard ratio 3.68, 95% CI 1.14 to 11.89), and increased ratio of prosthetic valve size to patient weight (relative risk 1.77 per mm/kg increment, 95% CI 1.06 to 2.97). Age- and diagnosis-adjusted prosthetic size/weight ratios predicted a 1-year survival of 91% for size/weight ratio 2, 79% for size/weight ratio 3, 61% for size/weight ratio 4, and 37% for size/weight ratio 5. CONCLUSIONS: Early mortality after MVR can be predicted on the basis of diagnosis and the size/weight ratio. Late mortality is low. These data can assist in choosing between MVR and alternative palliative strategies.
Assuntos
Doenças das Valvas Cardíacas/cirurgia , Implante de Prótese de Valva Cardíaca/mortalidade , Valva Mitral/cirurgia , Adolescente , Peso Corporal , Criança , Pré-Escolar , Estudos de Coortes , Bases de Dados Factuais , Feminino , Seguimentos , Humanos , Lactente , Recém-Nascido , Masculino , Complicações Pós-Operatórias , Reoperação/estatística & dados numéricos , Fatores de Risco , Taxa de Sobrevida , Resultado do TratamentoRESUMO
Sinus of Valsalva aneurysm is a rare complication of bacterial endocarditis in infancy and childhood. This report describes an infant with congenital aortic stenosis who developed bacterial endocarditis after abdominal surgery and placement of indwelling central venous catheters for long-term parenteral nutrition. Bacterial endocarditis in this infant was complicated by the development of an aneurysm of the left sinus of Valsalva. Surgical intervention was necessary because of gradual expansion of the aneurysm with compression of the adjacent right pulmonary artery and descending aorta. Two-dimensional and Doppler echocardiography proved useful for the initial diagnosis and serial follow-up of this unusual disorder and for its successful surgical management.
Assuntos
Aneurisma Aórtico/complicações , Ecocardiografia/métodos , Endocardite Bacteriana/complicações , Seio Aórtico , Aneurisma Aórtico/diagnóstico , Aneurisma Aórtico/cirurgia , Endocardite Bacteriana/diagnóstico , Endocardite Bacteriana/cirurgia , Feminino , Humanos , Recém-NascidoRESUMO
To assess the long-term results of left ventricular outflow tract reconstruction utilizing an apical left ventricular to aortic valved (porcine) conduit the clinical and hemodynamic data were reviewed from 24 patients who had placement of an apico-aortic conduit. Eighteen of the patients are asymptomatic and taking no cardiac medications. Three patients were reoperated on, one patient 1.5 years after his original operation for subacute bacterial endocarditis and two patients 3 to 4 years after their original operation for severe conduit valve insufficiency. None of the patients is taking anticoagulants and no thromboembolic events have occurred. Postoperative catheterization has been performed 1 to 1.5 years (mean 1.2) after repair in 15 of 21 patients. The rest left ventricular outflow tract gradient has decreased from 102.5 +/- 20 mm Hg preoperatively to 14.8 +/- 9.9 mm Hg postoperatively (probability [p] less than 0.001). Some degree of conduit obstruction was demonstrated by catheter passage in 11 of the 15 patients. In these 11 patients, the obstruction occurred at three distant sites: at the egress of the left ventricle in 9, at the porcine valve in 5 and at the aortic to conduit junction in 1. Isometric exercise in five and supine bicycle exercise in six patients increased the left ventricular outflow tract gradient by 2.5 +/- 1.1 and 20.8 +/- 11.8 mm Hg, respectively, despite an increase in cardiac index of 1 +/- 0.3 and 3.7 +/- 0.4 liters/min per m2, respectively. The data suggest that a left ventricular to aortic conduit is an effective form of therapy for severe left ventricular outflow tract obstruction.
Assuntos
Aorta , Estenose da Valva Aórtica/cirurgia , Prótese Vascular , Próteses Valvulares Cardíacas , Adolescente , Adulto , Estenose da Valva Aórtica/fisiopatologia , Cateterismo Cardíaco , Débito Cardíaco , Criança , Pré-Escolar , Teste de Esforço , Seguimentos , Ventrículos do Coração/cirurgia , Hemodinâmica , Humanos , Consumo de Oxigênio , Complicações Pós-Operatórias/diagnóstico , Complicações Pós-Operatórias/fisiopatologiaRESUMO
To assess the influence of surgical technique on the need for reoperation after coarctation repair in infancy, follow-up data were analyzed for 125 consecutive infants (less than 12 months) who underwent repair of coarctation of the aorta by subclavian angioplasty or resection and end to end anastomosis. Sixty-three infants underwent coarctation repair by resection between 1960 and 1980, and 62 underwent subclavian angioplasty between 1977 and 1985. The mean age (+/- SEM) at operation for infants with subclavian flap angioplasty was 1.54 +/- 0.93 months and for infants with resection was 2.70 +/- 0.93 months (p = 0.02). There was no difference between the groups in patient weight at initial repair or the proportion of patients with complex anatomy or aortic arch hypoplasia. Follow-up duration for the subclavian flap group was 2.55 +/- 0.51 years (range 0.3 to 8.2), and for the resection group was 7.97 +/- 3.61 years (range 0.6 to 21). Indication for reoperation was the presence of a coarctation gradient at rest of 40 mm Hg or greater and arm hypertension. Reoperation was required in 5 patients in the subclavian flap group and 12 patients in the resection group. The mean reoperation rate after subclavian flap repair was 0.0356 reoperations per patient-year, and after resection was 0.0342 reoperations per patient-year (p = 0.94). To determine an individual's risk of requiring reoperation from these group measures, a reoperation risk model was developed. The risk of reoperation by the fifth postoperative year was found to be 16.3% after subclavian flap repair and 15.7% after resection.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Angioplastia com Balão/normas , Coartação Aórtica/cirurgia , Artéria Subclávia/cirurgia , Coartação Aórtica/terapia , Seguimentos , Humanos , Lactente , Recém-Nascido , Reoperação , Estudos Retrospectivos , Retalhos Cirúrgicos , Fatores de TempoRESUMO
Pulmonary artery banding has become an infrequently used surgical technique. However, if a band was developed that could be relieved without the need for open heart surgery, it is likely that pulmonary artery banding would be used more frequently in the management of infants with congenital heart disease. Such a pulmonary artery band was placed in seven 1 week old mongrel puppies by using a loop of an absorbable suture material (Vicryl). One dog died at 2 months as a result of right ventricular failure. The remaining six dogs underwent cardiac catheterization and pulmonary balloon angioplasty at 6 months of age. After measuring pulmonary artery, right ventricular and aortic pressures and performing a right ventricular angiogram, balloon angioplasty of the band site was performed. A 20 mm balloon angioplasty catheter (Medi-Tech) was used in all dogs. Balloon angioplasty decreased right ventricular pressure from 101 +/- 19 to 42 +/- 3 mm Hg (p less than 0.05) and right ventricular systolic outflow tract gradient from 59 +/- 14 to 7 +/- 2 mm Hg (p less than 0.03), and increased the size of the band site from 8.7 +/- 0.03 to 14.9 +/- 0.5 mm (p less than 0.01). All dogs were recatheterized 2 months after angioplasty and were then killed for pathologic evaluation. At follow-up catheterization, right ventricular pressure, right ventricular outflow tract gradient and pulmonary artery size at the band site remained at the values obtained immediately after angioplasty. Postmortem examination demonstrated that there was no evidence of pulmonary artery damage. Although these studies are preliminary, they suggest that a reversible pulmonary artery band can be performed.
Assuntos
Artéria Pulmonar/cirurgia , Suturas , Angioplastia com Balão , Animais , Constrição , Cães , Comunicação Interventricular/terapia , Cuidados Paliativos/métodos , Poliglactina 910RESUMO
The effects of a continuous intravenous infusion of prostaglandin E1 (PGE1) on mean arterial pressure (MAP), sodium and water balance, and plasma renin activity (PRA) were examined in 10 conscious dogs maintained on a 70 to 75 mEq/day sodium intake. In a crossover pattern, each dog received 6 days of intravenous PGE1 (0.1 micrograms/kg/min) and 6 days of intravenous diluent. When compared to diluent, intravenous PGE1 resulted in a mild sustained rise in MAP. By Day 6 the intravenous PGE1, MAP had increased from 98 +/- 4 to 112 +/- 5 mm Hg (mean +/- SE) (p less than 0.04). Concurrent with the MAP increase, PRA increased from 0.6 +/- 0.2 to 3.1 +/- 0.7 ng angiotensin I (AI)/ml/hr (p less than 0.03). To assess the role of the renin-angiotensin system in the maintenance of the systemic hypertension. AI converting-enzyme inhibitor was given to four dogs on Day 6 of both intravenous PGE1 and diluent. Only when the dogs were receiving PGE1 did the administration of converting-enzyme inhibitor result in a significant decrease in MAP (-19 +/- 5 mm Hg). In addition to increasing arterial pressure, the chronic infusion of PGE1 also produced changes in salt and water balance. When compared to diluent, PGE1 resulted in a twofold increase in both water intake and urine output, an increase in urinary sodium excretion (from 72 +/- 3 to 84 +/- 6 mEq/day, p less than 0.05, on Day 1), and a decrease in urine osmolality (from 942 +/- 82 to 586 +/- 61 mOsmol/kg H2O/day, p less than 0.05, on Day 1).(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Hipertensão/fisiopatologia , Poliúria/fisiopatologia , Prostaglandinas E/farmacologia , Sede , Alprostadil , Animais , Pressão Sanguínea/efeitos dos fármacos , Débito Cardíaco/efeitos dos fármacos , Cães , Ingestão de Líquidos/efeitos dos fármacos , Hipertensão/induzido quimicamente , Infusões Parenterais , Poliúria/induzido quimicamente , Potássio/sangue , Potássio/urina , Prostaglandinas E/administração & dosagem , Renina/sangue , Sódio/sangue , Sódio/urina , Sede/fisiologia , Micção/efeitos dos fármacosRESUMO
We studied the effectiveness of a computer program based on a mathematic model of warfarin dynamics in assisting with the initial phases of anticoagulation. In retrospective evaluations the program was successful in predicting prothrombin complex activity (PCA) responses for three different groups of subjects, indicating that the model is a good representation of the physiologic system. In a prospective evaluation of the program a computer-assisted group of 10 patients was compared with a control of 10 patients who did not receive computer assistance. Because of the program's very conservative upper limits for warfarin dosage in the first few days of therapy, the computer-assisted patient require slightly more time (6 days), on the average, to first reach PCA values in the 20% to 30% therapeutic range than did the control patients (4.8 days). After the desired PCA had been achieved, however, the computer-assisted group remained within the therapeutic range for 83% of the time compared to only 60% for the control group. This difference was due primarily to much less overanticoagulation of the computer-assisted patients than of the controls.
Assuntos
Coagulação Sanguínea/efeitos dos fármacos , Computadores , Modelos Biológicos , Varfarina/farmacologia , Estudos de Avaliação como Assunto , Humanos , Estudos Prospectivos , Estudos Retrospectivos , Varfarina/administração & dosagemRESUMO
After obtaining samples at open heart surgery, serum and right atrial digoxin concentrations were measured in 25 children by a nonspecific, direct radioimmunoassay method (NS) and by a specific method in which digoxin was separated from its metabolites by HPLC before radioimmunoassay was applied to the digoxin fraction (S). Digoxin was detectable by S assay (sensitivity 0.1 ng/g) in 16 heart specimens and 22 serum samples. The mean and range of the S/NS ratio was 0.74 (0.23 to 2.63) for serum and 0.81 (0.068 to 1.38) for atrial tissue. By NS assay the mean and range of the atrial/serum ratio was 78.1 (2.4 to 340, n = 21) and by S assay the corresponding values were 100 (10.7 to 318, n = 15). A multiple linear regression indicated that 72.5% of the variance of the heart digoxin concentrations measured by S assay were accounted for by the variables height, body weight, daily digoxin dose before operation, plasma digoxin concentration by S assay, and BUN.
Assuntos
Cromatografia Líquida de Alta Pressão , Digoxina/análise , Miocárdio/análise , Radioimunoensaio , Adolescente , Análise de Variância , Nitrogênio da Ureia Sanguínea , Estatura , Peso Corporal , Procedimentos Cirúrgicos Cardíacos , Criança , Pré-Escolar , Digoxina/administração & dosagem , Digoxina/sangue , Feminino , Átrios do Coração/análise , Humanos , Lactente , Masculino , Pré-MedicaçãoRESUMO
We have documented seven B cell lymphomas over a six-month period in 132 (5.3%) kidney and heart allograft recipients immunosuppressed with cyclosporine, azathioprine, and prednisone (triple therapy). This is a significant increase (P less than 0.0001) over the number of such tumors seen by us previously. Only 2 lymphomas had occurred in 669 cadaver and 29 living-related kidney allografts treated with azathioprine and prednisone alone (0.3%). In 160 cadaver kidney recipients treated with cyclosporine and prednisone there have been no lymphomas. Similarly in 14 living-related kidney recipients who were transplanted since the introduction of triple therapy for cadaver grafts, but continued to receive only azathioprine and prednisone, no lymphomas occurred. There seemed to be a clear relationship between this increase and the use of triple therapy. This led us to examine other possible contributing factors. A case control study has not shown any other factor that differs in patients in whom lymphomas developed. We have only been able to demonstrate Epstein Barr virus nuclear antigen in the cells of one tumor. Four of these 7 tumors were monoclonal, one polyclonal, and two indeterminate. All patients had their immunosuppression withdrawn and six received intravenous acyclovir. Three patients have shown some response but four patients died. Triple therapy is being used by many centers to reduce the level of cyclosporine toxicity. We wish to sound a note of caution that this may result in an increased incidence of posttransplant lymphomas.
Assuntos
Imunossupressores/efeitos adversos , Leucemia Linfocítica Crônica de Células B/induzido quimicamente , Complicações Pós-Operatórias/etiologia , Adulto , Idoso , Azatioprina/efeitos adversos , Linfócitos B , Ciclosporinas/efeitos adversos , Quimioterapia Combinada , Feminino , Rejeição de Enxerto/efeitos dos fármacos , Transplante de Coração , Humanos , Transplante de Rim , Leucemia Linfocítica Crônica de Células B/epidemiologia , Leucemia Linfocítica Crônica de Células B/mortalidade , Masculino , Pessoa de Meia-Idade , Prednisona/efeitos adversos , Conglomerados Espaço-Temporais , Viroses/etiologiaRESUMO
Nuclear medicine technologists routinely use flood phantoms containing 5 to 10 mCi (185-370 MBq) of Tc-99m to perform quality assurance tests on scintillation cameras. This paper presents the results of a study that measured the radiation exposure received by three individuals from a Tc-99m flood phantom during the daily performance of flood-field uniformity tests on three scintillation cameras. The extrapolated annual personnel exposure to the anterior trunk and the back of the hand were 172 mR and 220 mR, respectively. Additional measurements indicate that personnel performing these tests with a 10-mCi Co-57 flood disk source or a 200-muCi point source would receive approximately 25% and 1%, respectively, of the exposure from a 10-mCi Tc-99m flood phantom. These exposure levels should be considered when evaluating personnel radiation exposure in a nuclear medicine clinic.
Assuntos
Pessoal Técnico de Saúde , Monitoramento de Radiação/normas , Cintilografia/normas , Radioisótopos de Cobalto , Dosimetria Fotográfica , Humanos , Controle de Qualidade , TecnécioRESUMO
Epicardial and left ventricular endocardial activation were assessed in 5 patients (aged 4 months to 9.5 years) with endocardial cushion defect (ECD) during surgical repair. Epicardial activation was recorded from 40 to 47 sites over the epicardium; left ventricular endocardial activation was measured at 3 sites immediately after institution of cardiopulmonary bypass. Compared with the reported activation sequence in normal hearts, the pattern of excitation in hearts of patients with ECD was abnormal; epicardial excitation began at the left ventricular diaphragmatic surface and spread laterally and anteriorly over the anterobasal left ventricle. It then merged with right ventricular wavefronts ending along the right ventricular anterior atrioventricular groove and outflow tract. Left ventricular endocardial activation also occurred earliest in the diaphragmatic segment of the left ventricle with later wavefronts recorded laterally and anteriorly. This study demonstrates, for the first time in human subjects, correlation between left ventricular epicardial and endocardial activation in patients with ECD. The data indicate that earliest endocardial and epicardial activation occurs at the left ventricular diaphragmatic segments of the heart, and are consistent with the known posterior and inferior displacement of the specialized atrioventricular conduction system in patients with ECD.
Assuntos
Comunicação Atrioventricular/fisiopatologia , Defeitos dos Septos Cardíacos/fisiopatologia , Coração/fisiopatologia , Criança , Pré-Escolar , Eletrocardiografia , Eletrofisiologia , Endocárdio/fisiopatologia , Feminino , Sistema de Condução Cardíaco/fisiopatologia , Humanos , Lactente , MasculinoRESUMO
Intravascular hemolysis was present in 5 of 16 children who underwent porcine valve replacement. Each patient had an abnormal blood smear pattern and reticulocytosis and one or more biochemical changes indicative of hemolysis. In all five patients, the porcine valve was calcified. Cardiac catheterization demonstrated severe mitral stenosis and minimal mitral insufficiency in each of the patients with intravascular hemolysis. The presence of hemolysis is indicative of valve dysfunction.
Assuntos
Bioprótese , Calcinose , Próteses Valvulares Cardíacas/efeitos adversos , Hemólise , Valva Mitral , Adolescente , Animais , Cateterismo Cardíaco , Criança , Pré-Escolar , Eritrócitos/fisiopatologia , Humanos , Lactente , Insuficiência da Valva Mitral/diagnóstico , Estenose da Valva Mitral/diagnóstico , Reticulócitos/fisiopatologia , SuínosRESUMO
To determine long-term postoperative results in patients with double-chamber right ventricle and ventricular septal defect, 20 patients who had survived complete repair between 1959 and 1966 were recalled and studied. An interview, physical examination, electrocardiogram and chest x-ray were performed in all 20 patients, a treadmill exercise test in 16, 24-hour Holter monitor recording in 7 and postoperative cardiac catheterization in 8. Mean age at repair was 14 years and at follow-up evaluation 33 years. There were no late deaths. At a mean follow-up of 19 years, 17 patients were in New York Heart Association functional class I, 1 patient was in class II and 2 patients were in class III. Reoperation was performed in 2 patients (10%), and at present only 1 patient (5%) is considered to have hemodynamically significant cardiac compromise. Aortic regurgitation, not present in any patient preoperatively, developed in 5 patients (25%). Mild residual right ventricular outflow obstruction was present in 2 (10%) and the murmur of a hemodynamically insignificant residual ventricular septal defect or tricuspid regurgitation was present in 5 patients (25%). One patient (5%) had cardiomegaly (cardiothoracic ratio greater than 0.55). The frequency of infective endocarditis in the postoperative follow-up period was 1 per 388 patient-years. Thus, 20 years after repair of double-chamber right ventricle, mild residua and sequelae are common, but serious cardiac compromise is infrequent.
Assuntos
Comunicação Interventricular/cirurgia , Ventrículos do Coração/anormalidades , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Seguimentos , Cardiopatias/diagnóstico , Cardiopatias/etiologia , Doenças das Valvas Cardíacas/diagnóstico , Ventrículos do Coração/cirurgia , Humanos , Masculino , Complicações Pós-Operatórias , Prognóstico , Reoperação , Fatores de TempoRESUMO
To examine the excitation of the double chamber right ventricle and the possibility that it results from a displaced, hypertrophied moderator band, seven patients with double chamber right ventricle were studied. All seven had pre- and postoperative electrocardiograms. Intraoperative right ventricular epicardial maps were obtained in three; right ventricular endocardial activation maps performed at postoperative catheterization were obtained in four. In the three patients studied at operation the breakthrough point of right ventricular epicardial activation was demonstrated in a normal inferior location well below the obstructing muscle band. Two patients with right bundle branch block after operation and two others with only right ventricular conduction delay on postoperative electrocardiogram demonstrated high normal right ventricular time with prolongation of activation in the right ventricular outflow or inflow region, or both, suggesting only peripheral injury. These data suggest that activation of the double chamber right ventricle is similar to that of the normal heart. In addition, the observed normal activation sequence militates against the hypothesis that the moderator band is the obstructing bundle.
Assuntos
Cardiopatias Congênitas/fisiopatologia , Adolescente , Adulto , Fascículo Atrioventricular/fisiopatologia , Cateterismo Cardíaco , Criança , Pré-Escolar , Eletrocardiografia , Eletrofisiologia , Cardiopatias Congênitas/patologia , Cardiopatias Congênitas/cirurgia , Ventrículos do Coração , Humanos , Cuidados Intraoperatórios , Cuidados Pós-OperatóriosRESUMO
Aortic valvotomy for critical aortic stenosis in infancy has had a high mortality. To determine the factors that influence survival, we reviewed the cases of 24 infants who underwent aortic valvotomy in the first 6 months of life (mean 4 1/2 weeks) for aortic stenosis from 1978 to 1984. Cardiopulmonary bypass was used in all patients. Operative mortality was 21% (5/24), four of the five deaths occurring from low cardiac output. Analysis of preoperative factors affecting survival versus nonsurvival revealed that low ejection fraction (60% +/- 17% in survivors versus 36% +/- 2% in nonsurvivors), high left ventricular end-diastolic pressure (16 +/- 7 mm Hg in survivors versus 30 +/- 14 mm Hg in nonsurvivors), and presence of endocardial fibroelastosis (25% in survivors versus 100% in nonsurvivors) all were predictive of a poor outcome, although the small sample size indicated caution in interpreting results. Factors that did not appear to influence survival included peak systolic gradient (79 +/- 30 mm Hg in survivors versus 60 +/- 15 mm Hg in nonsurvivors) and left ventricular end-diastolic volume (37 +/- 17 cm3/m2 in survivors versus 36 +/- 7 cm3/m2 in nonsurvivors). Four patients with a left ventricular end-diastolic volume below 26 cm3/m2 survived. Postoperative gradients averaged 25 +/- 21 mm Hg at 3.4 +/- 2 years' follow-up in nine recatheterized patients. Ejection fraction of these patients increased from 45% +/- 10% to 70% +/- 11% and left ventricular end-diastolic volume increased from 37 +/- 17 to 58 +/- 5 cm3/m2. Two of 17 patients have required apical-aortic conduits; all other patients are asymptomatic. We conclude that infants with critical aortic stenosis benefit from valvotomy even with impaired left ventricular function and severely reduced left ventricular dimensions and many have nearly normal hemodynamics on late follow-up.
Assuntos
Estenose da Valva Aórtica/cirurgia , Cardiopatias Congênitas/cirurgia , Fatores Etários , Estenose da Valva Aórtica/congênito , Estenose da Valva Aórtica/mortalidade , Pressão Sanguínea , Volume Sanguíneo , Ponte Cardiopulmonar , Cineangiografia , Fibroelastose Endocárdica/cirurgia , Feminino , Seguimentos , Cardiopatias Congênitas/mortalidade , Humanos , Lactente , Recém-Nascido , Masculino , Prognóstico , Volume SistólicoRESUMO
This study tests the hypothesis that the efficacy of cardioplegic solution depends upon its chemical constituents rather than on its temperature alone. A standard preparation of right heart bypass in the dog was utilized. Left ventricular function curves were inscribed before and after 1 hour of aortic cross-clamping. No deterioration in function was observed in nonischemic control hearts or in hearts protected with cardioplegic solution consisting of potassium chloride (25 mEq. per liter) and mannitol (12.5 Gm. per liter in 5 percent dextrose and 0.2 percent saline at either 4 degrees C or 28 degrees C. Severe myocardial depression was observed in hearts rendered ischemic for 1 hour at 28 degrees C. without protection and also in hearts perfused with 5 percent dextrose and 0.2 percent saline at 28 degrees C. without the potassium chloride and mannitol. The evidence from this study indicates that cardioplegic solution exerts a protective effect beyond that which is afforded by hypothermia.
Assuntos
Parada Cardíaca Induzida/métodos , Hipotermia Induzida/métodos , Soluções , Animais , Ponte Cardiopulmonar , Circulação Coronária , Cães , Estudos de Avaliação como Assunto , Glucose , Cloreto de Sódio , TemperaturaRESUMO
The myocardial protection achieved by blood cardioplegia was compared to that achieved by crystalloid cardioplegia in a randomized prospective series of patients having coronary bypass operations. Group BCP (n = 15) was protected with 10 degrees C blood containing potassium, 30 mEq/L; Group KCP (n = 9) by an electrolyte solution at 4 degrees C with mannitol, 25 gm/L, and potassium, 26 mEq/L, and group MgKCP (n = 9) by an electrolyte solution at 4 degrees C containing magnesium, 30 Meq/L, and potassium, 19.6 mEq/L. The three groups were comparable in regard to age, sex, preoperative left ventricular function, symptoms, propranolol use, previous myocardial infarction, number of vessels bypassed, and duration of ischemic arrest. In each patient cardiac output, left ventricular end-diastolic pressure (LVEDP), and maximum contractile element velocity (Vpm) were recorded before and after the ischemic period. All operations were performed in an identical manner with one continuous period of aortic cross-clamping averaging 52.9 minutes. No significant alterations in myocardial function were observed after ischemia within the BCP or KCP groups. However, patients receiving MgKCP had significant (p = 0.02) depression in Vpm from 2.86 +/- 7.8 to 2.04 +/- 3.6 second-1 and increase (p < 0.05) in LVEDP from 9.4 +/- 2.2 to 13.4 +/- 5.2 mm Hg. Analysis of variance between groups showed that Vpm decreased significantly (p < 0.05) and LVEDP increased significantly (p < 0.05) in the MgKCP group by comparison to the BCP group. Patients receiving BCP experienced spontaneous defibrillation more frequently (p < 0.02) and received nitroprusside postoperatively more often (p < 0.05) than patients in the other two groups. From these results we conclude that blood cardioplegia provides excellent protection during myocardial ischemia, probably better than one of the two crystalloid solutions tested but no better than the other crystalloid solution. Because the three solutions differed from one another in several respects, no conclusion can be reached about the efficacy of any one ingredient.
Assuntos
Antiarrítmicos/farmacologia , Ponte de Artéria Coronária , Parada Cardíaca Induzida/métodos , Magnésio/farmacologia , Contração Miocárdica/efeitos dos fármacos , Potássio/farmacologia , Adulto , Sangue , Débito Cardíaco/efeitos dos fármacos , Feminino , Hemodinâmica/efeitos dos fármacos , Humanos , Hipotermia Induzida , Masculino , Pessoa de Meia-Idade , Distribuição Aleatória , SoluçõesRESUMO
The effects of adding 500 mg. of methylprednisolone to each liter of cardioplegic solution were studied in patients undergoing coronary artery bypass grafts. Patients were randomly assigned to control (12 patients) or steroid-treated groups (10 patients). The cardioplegic solution was identical in the two groups except for the added methylprednisolone. Contractile element velocity (VCE and left ventricular end-diastolic pressure (LVEDP) were recorded immediately before and after perfusion in the operating room. There were no differences between the two groups with respect to these two variables or the postoperative courses. Thus this study fails to demonstrate a beneficial effect of methylprednisolone when added to cardioplegic solutions.