RESUMEN
BACKGROUND: Aortic stenosis (AS) causes significant disturbances in left ventricular (LV) and left atrial (LA) function irrespective of the extent of myocardial hypertrophy which associates the increased afterload. We hypothesize that aortic valve replacement (AVR) and removal of LV outflow tract obstruction should result in LA size and function recovery, even partial, and were set to study this in a group of patients with AVR for AS. METHODS: Peak atrial longitudinal strain (PALS) was evaluated in 43 patients with severe isolated AS and normal EF (56.6 ± 3.8%) and no obstructive coronary artery disease candidates for AVR, pre-operatively and then 40 days and 3 months after surgery. Results were compared with those from 34 age- and gender-matched healthy controls. RESULTS: LVEF remained unchanged and LV mass regressed after AVR. Global PALS was reduced pre-operatively and increased 40 days after surgery (p=0.002) and showed only a slight further increase at 3 months follow-up (p<0.0001). Indexed LA volume was increased before surgery, but significantly fell 40 days after surgery (p<0.0001) and showed only a slight further reduction after 3 months (p<0.0001). Trans-aortic mean gradient change after surgery was the only independent predictor of the recovery of LA size and function. CONCLUSIONS: AVR reverses LA abnormalities and regains normal atrial function, a behavior which is directly related to the severity of pre-operative LV outflow tract obstruction. Early identification of LA size enlargement and functional disturbances might contribute to better patient's recruitment for AVR.
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Estenosis de la Válvula Aórtica/diagnóstico , Función del Atrio Izquierdo/fisiología , Atrios Cardíacos/patología , Implantación de Prótesis de Válvulas Cardíacas/métodos , Cuidados Posoperatorios/métodos , Índice de Severidad de la Enfermedad , Anciano , Anciano de 80 o más Años , Estenosis de la Válvula Aórtica/fisiopatología , Estenosis de la Válvula Aórtica/cirugía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Recuperación de la Función/fisiologíaRESUMEN
BACKGROUND: In patients with chronic mitral regurgitation (MR), undergoing surgical mitral valve repair, current Guidelines only recommend standard echocardiographic indices i.e. left ventricular (LV) ejection fraction (EF), and LV end-systolic and end-diastolic diameters as preoperative variables. However LV EF is often preserved until advanced stages of the valve disease. Aim of this study was to evaluate changes in LV systolic longitudinal function, 3 months after mitral valve repair in patients with chronic degenerative MR and normal preoperative EF. METHODS: We measured M-mode mitral lateral annulus systolic excursion (MAPSE) and Tissue Doppler (TD) peak systolic annular velocity (S(m)) in 31 patients with moderate to severe MR and normal EF (59.9 ± 4.7%) candidates for mitral valve repair, preoperatively and 3 months after surgery. RESULTS: After mitral valve repair, S(m) increased from 7.8 ± 1.4 to 9.6 ± 2.2 cm/s (p<0.0001) and MAPSE increased from 1.33 ± 0.26 to 1.55 ± 0.25 cm (p=0.0013). EF decreased from 59.9 ± 4.7 to 51.3 ± 5.9% (p<0.0001). As expected, LV diameters and volumes, wall thicknesses, midwall fractional shortening (mFS), and left atrial (LA) size were all reduced after surgery. CONCLUSIONS: This study suggests that assessment of LV long axis systolic velocity and amplitude of excursion by echocardiography is more sensitive than simple determination of EF for revealing the beneficial impact of MR surgery on overall systolic function.
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Insuficiencia de la Válvula Mitral/diagnóstico por imagen , Insuficiencia de la Válvula Mitral/cirugía , Válvula Mitral/diagnóstico por imagen , Válvula Mitral/cirugía , Recuperación de la Función/fisiología , Función Ventricular Izquierda/fisiología , Estudios de Seguimiento , Humanos , Estudios Longitudinales , Válvula Mitral/fisiopatología , Insuficiencia de la Válvula Mitral/fisiopatología , UltrasonografíaRESUMEN
INTRODUCTION: We sought to evaluate the behavior of C2 values and their correlation with acute rejection episodes and cyclosporine (CyA) side effects in heart transplant patients whose immunosuppressive therapy, was monitored with C0 trough levels. METHODS: Sixty stable patients who had received heart transplants from 3 months to 60 months prior were randomly observed from September 2001 to June 2004. Four area under the concentration-time curves (AUC) were performed on each patient, a total of 240 AUC curves. RESULTS: Regarding the variability of CyA absorption, two groups of patients were distinguished: group A, "constant absorbers," namely, low variability (<15%) of CyA absorption; group B, "inconstant absorbers" patients with higher (>15%) variability of absorption. Group B patients showed more acute rejection episodes (41%) than group A (19%). CyA side effects were more serious in patients with higher variability of absorption: systemic hypertension, neurological disorders, hyperlipidemia, and gum hyperplasia; Group B patients who developed CyA side effects showed higher maximum and mean C2 levels (P < .05) than group A patients. No differences were found with regard to renal dysfunction between the two groups: all patients showed a mean increase of serum creatinine by at least 50% compared to the baseline value. CONCLUSION: Higher C2 levels were not sufficient to predict acute rejection compared to lower but constants, C2 levels. Patients with inconstant absorption were more often overexposed to CyA than underexposed, developing more side effects than patients with lower variability of absorption. Monitoring CyA therapy with C0 and C2 may prevent over- or underexposure to the drug.
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Ciclosporina/farmacocinética , Trasplante de Corazón/inmunología , Administración Oral , Área Bajo la Curva , Ciclosporina/sangre , Ciclosporina/uso terapéutico , Diabetes Mellitus Tipo 1/sangre , Monitoreo de Drogas/métodos , Femenino , Estudios de Seguimiento , Humanos , Inmunosupresores/sangre , Inmunosupresores/farmacocinética , Inmunosupresores/uso terapéutico , Absorción Intestinal , Masculino , Persona de Mediana Edad , Factores de TiempoRESUMEN
Patients (n = 103) were studied before heart transplantation with regard to smoking habits by means of a clinical interview, and 81 were submitted to Minnesota Multiphasic Personality Inventory (MMPI). After a mean time of 50.8 +/- 24.2 months from transplant, they were once again interviewed to ascertain their smoking habits after intervention. Nonsmokers (35 of 103) were still nonabusers. Of the remaining 68 patients who ceased smoking before heart transplant, 12 (17.6%) had returned to tobacco abuse. Dividing these 68 patients into two groups based upon the length of smoking cessation before heart transplant (less than 1 year: short term [ST] more than 1 year: long term [LT]), we noticed that the ST group showed a much greater rate of reabuse (8 of 20, 40%) than the LT group (4 of 48, 8.3%, P =.006). Analyzing six scales of MMPI, we found a statistically different score for self-control ability (scale K) in ST and LT smokers compared to nonsmokers (45.5 and 45.5 vs 51.2, P =.026), and for difficult adaptation (scale Ma) in ST compared both to LT smokers and nonsmokers (ST 57, LT 50.5, NS 47.6; P =.042 LT vs ST, P =.0005 ST vs NS). We concluded that patients who have recently decided to stop smoking and show after MMPI compilation a score of >50 for K and <50 for Ma scale have a higher risk of reabuse and need a greater effort by the transplant team to reinforce their will to stop smoking.
Asunto(s)
Trasplante de Corazón/fisiología , MMPI , Fumar/efectos adversos , Estudios de Seguimiento , Trasplante de Corazón/psicología , Humanos , Factores de Riesgo , Fumar/psicología , Factores de TiempoRESUMEN
BACKGROUND: Composite cardiac binding consists of wrapping the heart with a synthetic membrane and a pericardial interposition. The goal of the present study was to apply composite cardiac binding to a canine model of heart failure. METHODS: Twenty dogs were randomized to 2 groups: untreated heart failure (group 1, n = 13) and heart failure pretreated by composite cardiac binding (group 2, n = 7). They received a total dose of 1 mg x kg(-1) of intracoronary doxorubicin over 4 weeks. Hemodynamic data were obtained at weeks 0, 7, and 12. All animals were followed up with weekly echocardiography for 12 weeks. RESULTS: Survival in group 1 was 54% and in group 2 was 100% at week 12 (p = 0.0438). Left ventricular end-diastolic pressure increased by 153% in group 1 and by 59% in group 2 (p = 0.0395) at week 12. Ejection fraction decreased by 27% in group 1 and by 19% in group 2 (p = 0.4401) at week 12. CONCLUSIONS: Composite cardiac binding significantly prolongs survival and attenuates left ventricular dilatation and the increase in left ventricular end-diastolic pressure associated to chronic heart failure. Further evaluation in established heart failure is needed. Composite cardiac binding may be used for the prevention of recurrent dilatation following reduction ventriculoplasty.
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Cardiomiopatía Dilatada/cirugía , Cardiomioplastia/métodos , Pericardio/trasplante , Animales , Cardiomiopatía Dilatada/fisiopatología , Modelos Animales de Enfermedad , Perros , Estudios de Evaluación como Asunto , Hemodinámica , Masculino , Distribución Aleatoria , Volumen Sistólico , Trasplante Autólogo , Función Ventricular IzquierdaRESUMEN
Ruptured sinus of Valsalva aneurysm is a rare cardiac abnormality. Early surgical repair is indicated to prevent complications such as heart failure, infective endocarditis, arrhythmias, and thromboembolic events. The authors report an unusual case of recurrent right atrial thrombus after the surgical repair and closure of ruptured sinus of Valsalva aneurysm.
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Rotura de la Aorta/complicaciones , Rotura de la Aorta/cirugía , Trombosis Coronaria/etiología , Atrios Cardíacos/cirugía , Seno Aórtico/cirugía , Adulto , Rotura de la Aorta/diagnóstico por imagen , Trombosis Coronaria/diagnóstico por imagen , Trombosis Coronaria/terapia , Atrios Cardíacos/diagnóstico por imagen , Humanos , Masculino , Recurrencia , Seno Aórtico/diagnóstico por imagen , UltrasonografíaRESUMEN
Anomalous origin of the right coronary artery (ARCA) from the main pulmonary artery (MPA) is a rare congenital anomaly, with only 18 reported cases in the pediatric age group. More than half of these had associated cardiac anomalies that masked the presence of ARCA. Conversely, in many patients with ARCA as an isolated anomaly, the diagnosis has been missed during lifetime. The only patient with an isolated ARCA who was diagnosed in infancy presented with congestive heart failure. Asymptomatic infants with ARCA from the MPA have not been previously reported. Three additional cases, two infants and a child with ARCA from the MPA, are reported in this paper. The diagnostic dilemmas and the prognosis are discussed and management is recommended.
Asunto(s)
Anomalías de los Vasos Coronarios , Arteria Pulmonar/anomalías , Preescolar , Angiografía Coronaria , Anomalías de los Vasos Coronarios/diagnóstico , Anomalías de los Vasos Coronarios/cirugía , Ecocardiografía , Ecocardiografía Doppler en Color , Electrocardiografía , Femenino , Estudios de Seguimiento , Humanos , Lactante , Masculino , Factores de TiempoRESUMEN
BACKGROUND: Cardiomyoplasty is a potential therapy for heart failure. Its benefits are attributed to systolic augmentation (dynamic cardiomyoplasty) and prevention of cardiac dilatation (static cardiomyoplasty). To evaluate the static component, we used an artificial membrane for cardiac binding in a canine model of heart failure. METHODS: Intracoronary doxorubicin was administered weekly for 4 weeks to induce heart failure in 10 dogs, each of which was assigned to one of two treatment groups: (1) no treatment, or (2) cardiac binding. Hemodynamic data were obtained at operation and at 7 weeks after operation. Echocardiography was performed weekly. RESULTS: Left ventricular end-diastolic pressure and diameter, and right ventricular end-diastolic diameter increased in group 1 (from 9.6 +/- 6.1 to 19.6 +/- 2.3 mm Hg, p = 0.009; from 3.9 +/- 0.4 to 5 +/- 0.3 cm, p = 0.0013; and from 1.6 +/- 0.2 to 1.9 +/- 0.3 cm, p = 0.0036, respectively). Ejection fraction fell in group 1 from 0.60 +/- 0.10 to 0.40 +/- 0.04 (p = 0.0009) and in group 2 from 0.56 +/- 0.02 to 0.40 +/- 0.04 (p = 0.0001), but the difference between groups was not significant. CONCLUSION: Cardiac binding reduces the ventricular dilatation associated with heart failure without exacerbating left ventricular dysfunction.
Asunto(s)
Gasto Cardíaco Bajo/cirugía , Cardiomioplastia/métodos , Membranas Artificiales , Animales , Antibióticos Antineoplásicos , Gasto Cardíaco Bajo/inducido químicamente , Gasto Cardíaco Bajo/fisiopatología , Modelos Animales de Enfermedad , Perros , Doxorrubicina , Hemodinámica , Masculino , Factores de Tiempo , Función Ventricular IzquierdaRESUMEN
Prolonged pleural effusion after congenital heart surgery results in extended hospitalization. Pleural drainage was evaluated in 39 consecutive patients undergoing repair of tetralogy of Fallot, to identify risk factors for persistent pleural effusion. Duration and amount of drainage was examined by the Kaplan-Meier method and risk factors were evaluated by univariable and multivariable analyses. Median time of pleural drainage was 6.1 days, range 3 to 42 days. Duration of pleural drainage correlated with length of hospital stay (p < 0.0001). Postrepair right atrial pressure (p = 0.018) and preoperative hemoglobin (p = 0.035) were risk factors for persistent drainage. The presence of a previous right thoracotomy reduced drainage duration (p = 0.034). Prolonged mechanical ventilation increased the average daily volume of effusion (p < 0.0001). In conclusion, prolonged pleural effusion is an important morbidity factor after repair of tetralogy of Fallot. Bilateral chest tube insertion is indicated in patients with high preoperative hemoglobin and elevated postrepair right atrial pressure. Right thoracotomy is the preferred surgical approach when a preliminary palliative shunt is required.
Asunto(s)
Procedimientos Quirúrgicos Cardíacos/efectos adversos , Drenaje/métodos , Derrame Pleural/cirugía , Complicaciones Posoperatorias/cirugía , Tetralogía de Fallot/cirugía , Adolescente , Adulto , Tubos Torácicos , Niño , Preescolar , Estudios de Seguimiento , Humanos , Lactante , Tiempo de Internación , Derrame Pleural/etiología , Estudios Retrospectivos , Factores de RiesgoRESUMEN
End-stage heart disease is a major health care issue and it represents one of the most costly diseases. Several experimental heart failure models have been developed; however, a single model is not widely accepted as representative of clinical heart failure. The doxorubicin-induced cardiomyopathy model was used in the current study to address two issues: 1) to define a standardized dose regimen of intracoronary doxorubicin infusion; and 2) to establish a method of determining the onset and time course of heart failure. Twenty dogs underwent placement of an intracoronary catheter. A total dose of 1 mg/kg of intracoronary doxorubicin was infused. Hemodynamics were obtained at weeks 0, 7, and 12. Echocardiography was performed weekly. Right and left ventricular biopsy specimens were examined at weeks 0 and 12. Survival after doxorubicin-induced cardiomyopathy was 60% at week 12. The development of heart failure was demonstrated by a significant decrease in left ventricular ejection fraction and cardiac index and a significant increase in left ventricular end-diastolic pressure and volume. The leukocyte count, hemoglobin, and hematocrit decreased significantly. Histologic changes of both the right and left ventricular myocardial biopsy specimens included myocellular hypertrophy, loss of myofibrillar material, and vacuolization. Intracoronary doxorubicin reliably produced an experimental model of accelerated heart failure that developed over the course of 12 weeks. Echocardiographic monitoring allowed a close surveillance of heart failure development. This model may be useful to evaluate the efficacy of cardiomyoplasty, mechanical assist devices, transplantation, and reduction ventriculoplasty.
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Gasto Cardíaco Bajo/inducido químicamente , Cardiomiopatías/inducido químicamente , Doxorrubicina/toxicidad , Animales , Transporte Biológico , Modelos Animales de Enfermedad , Perros , Relación Dosis-Respuesta a Droga , Ecocardiografía , Hemodinámica/efectos de los fármacos , Infusiones Intravenosas , Masculino , Monitoreo Fisiológico/métodos , Oxígeno/farmacocinética , Tasa de SupervivenciaRESUMEN
Latissimus dorsi muscle (LDM) transformation following chronic stimulation is the critical requirement for its use in cardiac assist procedures. In order to identify one or two molecular markers that can be used to effectively monitor the LDM transformation, the modulation in the expression of creatine kinase (CK) and phospholamban (PLB) genes by semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR) was examined. Continuous in situ stimulation of left LDM was performed in four dogs for a period of 10 weeks after a vascular delay period of 2 weeks following surgery. For RT-PCR, gene-specific radiolabeled primers and equal amounts of cDNA synthesized from total RNA extracted from the LDM biopsies obtained at 4, 7, and 10 weeks of stimulation were used. A 2.6-fold increase in creatine kinase (brain type) (CK-B) mRNA was observed at transformed LDM compared to the control (P = 0.004) following 10 weeks of stimulation. On the contrary, a 30% decline was observed in creatine kinase (muscle type) (CK-M) mRNA level. An increase up to eight-fold was also observed in PLB mRNA in stimulated LDM compared to the contralateral muscle (P = 0.002). The PLB mRNA level in transformed LDM reached plateau and became comparable to that of normal heart after 7 weeks of stimulation. However, a sustained increase in CK-B mRNA level was observed until 10 weeks of stimulation. The level of beta-actin mRNA used as control remained the same in both stimulated and control samples. Thus the increase in CK-B and PLB mRNA and downregulation of CK-M mRNA in transformed LDM, demonstrated here by RT-PCR, indicate a switch from anaerobic to aerobic potential of transformed LDM along with a change towards slow-twitch phenotype and provide valuable markers to monitor the effectiveness of muscle transformation in cardiomyoplasty.
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Adenosina Trifosfatasas/metabolismo , Proteínas de Unión al Calcio/metabolismo , Creatina Quinasa/metabolismo , Músculo Esquelético/metabolismo , Actinas/metabolismo , Adenosina Trifosfatasas/genética , Animales , Biopsia , Creatina Quinasa/genética , Perros , Activación Enzimática , Músculo Esquelético/fisiología , Reacción en Cadena de la Polimerasa/métodos , ARN Mensajero/análisis , Factores de TiempoRESUMEN
The possible modulation by the endothelium of the contractile responses to sympathetic nerve stimulation was examined in isolated superfused human saphenous vein. Contractile response curves for transmural nerve stimulation and noradrenaline were higher in endothelium-denuded than in intact human saphenous vein rings. In vessels with endothelium, transmural nerve stimulation- and noradrenaline-induced contractions were unaffected by the cyclooxygenase inhibitor, indomethacin (10 microM), but were potentiated by the nitric oxide (NO) synthase inhibitor, L-N omega-nitro-L-arginine (L-NNA, 3 microM) even when combined with D-arginine (0.3 mM), but not with L-arginine (0.3 mM). As in the case of noradrenaline, contractile responses to 5-HT, but not to KCI, were enhanced by endothelium removal, L-NNA or L-NNA plus D-arginine, but were unaffected by L-NNA plus L-arginine. The guanylyl cyclase inhibitor, methylene blue (10 microM), potentiated both transmural nerve stimulation- and noradrenaline-induced contractions in endothelium intact rings, whereas it enhanced, although to a lesser degree, only the neurally evoked contractions in endothelium-denuded human saphenous vein. In the vessels without endothelium L-NNA failed to affect the vasoconstriction induced by both transmural nerve stimulation and noradrenaline. Our results suggest that at least two inhibitory factors are involved in modulating the sympathetic vasoconstriction in the human saphenous vein: (1) at a postjunctional level, NO, the release of which from endothelial cells is probably stimulated by the activation of specific receptors, and (2) at a prejunctional level, an unidentified vasodilator agent, which is unmasked by the removal of the endothelium layer and which is probably co-released along with noradrenaline, and which acts through the guanylyl cyclase pathway.
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Óxido Nítrico/farmacología , Vena Safena/efectos de los fármacos , Sistema Nervioso Simpático/fisiología , Vasoconstricción/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Humanos , Norepinefrina/farmacología , Vena Safena/fisiología , Serotonina/farmacologíaRESUMEN
In order to evaluate the effects of potassium cristalloid cardioplegic solutions (CPS) on the endothelial morphology, human saphenous veins were studied by scanning electron microscopy after exposure to three CPS named MKP (magnesium-potassium-procaine cardioplegia), LK (low-potassium cardioplegia), and HKA (high-potassium-albumin cardioplegia) and to their main components. Vein rings, selected from the saphenous veins sampled for graft harvesting in 63 patients undergoing aorto-coronary bypass surgery, were exposed for 30, 60, and 120 minutes to the following buffered solutions: Krebs bicarbonate (as control); MKP cardioplegia; KCl (16.0 mmol/L); MgCl2(2).6H2O (16.0 mmol/L); Procaine (0.05 mmol/L); NaCl (92.5 mmol/L); LK cardioplegia; KCl (10.0 mmol/L); Mannitol (74.3 mmol/L); Glucose (27.7 mmol/L); HKA cardioplegia; KCl (30 mmol/L). Severe endothelial lesions, consisting of diffuse disendothelialization and diffuse signs of endothelial suffering, were induced by KCl (30 and 16 mmol/L) after 60-120 min, and by MKP cardioplegia and KCl (10 mmol/L) after 120 min. Moderate endothelial lesions, characterised by diffuse endothelial surface changes and focal cellular loss, were induced by KCl (30 and 16 mmol/L) after 30 min, MKP cardioplegia and KCl (10 mmol) 30-60 min, LK cardioplegia, HKA cardioplegia, and MgCl2.6H2O after 120 min. Slight endothelial lesions, consisting of diffuse endothelial bulging, or absence of significant endothelial changes, were found in samples otherwise treated. Our findings showed a significant damaging effect of CPS on the human saphenous vein endothelium in-vitro. The endothelial lesions seemed related to the presence of potassium and magnesium, and to prolongation of the time of exposure to the cardioplegic solutions.(ABSTRACT TRUNCATED AT 250 WORDS)
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Soluciones Cardiopléjicas/farmacología , Endotelio Vascular/efectos de los fármacos , Endotelio Vascular/ultraestructura , Soluciones Cardiopléjicas/efectos adversos , Femenino , Humanos , Técnicas In Vitro , Masculino , Microscopía Electrónica de Rastreo , Persona de Mediana Edad , Potasio/efectos adversos , Potasio/farmacología , Vena SafenaRESUMEN
OBJECTIVE: To determine whether cardiac transplantation improves the natural history of infants with hypoplastic left-heart syndrome and to examine differences in outcome as a function of the pretransplant period. DESIGN: Retrospective cohort study. Historical, clinical, and laboratory data were collected during the pretransplant period, the in-hospital period, and for up to 6 years following transplantation. Data were analyzed using the product-limit estimate and the log rank test. SETTING: A tertiary, acute care, university teaching hospital. PATIENTS: All 111 infants with hypoplastic left-heart syndrome who entered and completed a protocol leading to transplantation from November 19, 1985, to December 31, 1991. Infants who died while waiting for transplantation were included. INTERVENTION: Orthotopic cardiac allotransplantation. MAIN OUTCOME MEASURES: Pretransplant waiting mortality and its influence on posttransplant survival, operative (in-hospital or within 30 postoperative days in discharged patients) and intermediate-term mortality (5 years), and reoperation rates for cardiac surgery. RESULTS: Transplantation procedures were performed in 84 infants (76%; 95% confidence interval [CI], 66% to 83%) ranging in age from 3 hours to 151 days. Twenty-seven infants registered for transplantation died while awaiting a donor heart. Operative mortality was 13% (CI, 7% to 23%), and 69 patients were late survivors (62% [CI, 52% to 71%] of the study group and 82% [CI, 72% to 89%] of the transplant recipients). Overall 5-year actuarial survival was 61% (CI, 52% to 70%). Transplant recipients had a 5-year survival of 81% (CI, 71% to 88%). Freedom from reoperation was 89% (CI, 76% to 95%) at 5 years. CONCLUSIONS: Cardiac transplantation for hypoplastic left-heart syndrome has a significant positive impact on the natural history of this uniformly lethal lesion.
Asunto(s)
Cardiopatías Congénitas/mortalidad , Cardiopatías Congénitas/cirugía , Trasplante de Corazón , Estudios de Cohortes , Femenino , Trasplante de Corazón/mortalidad , Humanos , Lactante , Recién Nacido , Masculino , Cuidados Preoperatorios , Estudios Retrospectivos , Análisis de Supervivencia , Factores de Tiempo , Obtención de Tejidos y ÓrganosRESUMEN
1. The specific type(s) of voltage-sensitive calcium channels (VSCCs) involved in sympathetic neurotransmission have not yet been characterized in human vascular tissues. We therefore examined the functional role of the N- and L-type VSCCs in human saphenous veins. 2. Contractile response curves for transmural nerve stimulation (TNS) and for exogenously administered noradrenaline (NA) were obtained in superfused saphenous vein rings. The contractions induced by TNS, but not by NA, were inhibited by 1 microM tetrodotoxin and by 10 microM guanethidine. Both responses were substantially reduced by 1 microM phentolamine, indicating that the contractions evoked by TNS were mediated by endogenous NA released from noradrenergic nerves. 3. In the presence of 2 microM omega-conotoxin GVIA (omega Conus Geographus toxin, fraction VI A; omega-CgTx), a polypeptide with specific inhibitory activity on N- and L-type calcium channels, the neurally evoked contractions were almost completely abolished. In contrast, the responses induced by exogenous NA were not affected by the neurotoxin, thus providing evidence of the exclusive presynaptic action of omega-CgTx. 4. In the presence of the calcium antagonist verapamil (10 microM), which selectively blocks L-type VSCCs, the contractions induced by both TNS and NA were diminished to the same extent, suggesting that the organic calcium blocker is active only at the postjunctional level. 5. It is concluded that N-type calcium channels are the main pathway of calcium entry controlling the functional responses induced by activating sympathetic nerves; the role of L-type channels appears to be limited to the postjunctional level, modulating smooth muscle contractions.
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Canales de Calcio/fisiología , Músculo Liso Vascular/fisiología , Sistema Nervioso Simpático/fisiología , Adulto , Bloqueadores de los Canales de Calcio/farmacología , Canales de Calcio/efectos de los fármacos , Estimulación Eléctrica , Electrofisiología , Guanetidina/farmacología , Humanos , Técnicas In Vitro , Masculino , Persona de Mediana Edad , Contracción Muscular/efectos de los fármacos , Músculo Liso Vascular/efectos de los fármacos , Músculo Liso Vascular/inervación , Norepinefrina/antagonistas & inhibidores , Norepinefrina/farmacología , Péptidos/farmacología , Receptores Presinapticos/efectos de los fármacos , Vena Safena/efectos de los fármacos , Vena Safena/inervación , Vena Safena/fisiología , Sistema Nervioso Simpático/efectos de los fármacos , Transmisión Sináptica/efectos de los fármacos , Transmisión Sináptica/fisiología , Tetrodotoxina/farmacología , Verapamilo/farmacología , omega-Conotoxina GVIARESUMEN
There is a rapid growth of interest in heart transplantation therapy during early infancy. From 10% to 25% of the infants who are listed for transplantation annually have died while awaiting a donor heart. There has been no significant trend in this variable. Since November 1985, 140 consecutive orthotopic transplantation procedures were performed in 139 infants who were from 3 hours to 12 months of age. Indications for transplantation included hypoplastic left heart syndrome (63%), other complex structural anomalies (29%), myopathy (6.5%), and tumors (1.5%). Most recipients had ductus-dependent circulation and received continuous infusion of prostaglandin E1. Heart donors were usually victims of trauma, sudden infant death, or birth asphyxia. A donor-recipient weight ratio of 4.0 or less was found to be acceptable. The amount of time the graft underwent cold ischemia, ranged from 64 to 576 minutes. The procurement process was facilitated by a single dose of cold crystalloid cardioplegic solution and cold immersion transport. Profound hypothermic circulatory arrest was used for graft implantation. One hundred twenty-four (89%) recipients survived transplantation and were discharged from the hospital. There were 9 late deaths, which resulted in an 83% overall survival. The 5-year actuarial survival is 80%. The survival among newborn recipients (n = 60) at 5 years is 84%. Chronic immunomodulation was cyclosporine-based and steroid-free. Surveillance was noninvasive and relied heavily on echocardiography, electrocardiography, and clinical intuition. There was one documented late lethal infection, tumor was not encountered, and coronary occlusive disease was known to exist in only one long-term survivor. We concluded that transplantation results in excellent life quality and is a highly effective and durable therapy when applied during early infancy.
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Cardiopatías Congénitas/cirugía , Trasplante de Corazón/mortalidad , Análisis Actuarial , Femenino , Rechazo de Injerto/epidemiología , Rechazo de Injerto/prevención & control , Trasplante de Corazón/métodos , Humanos , Terapia de Inmunosupresión/métodos , Inmunosupresores/uso terapéutico , Lactante , Recién Nacido , Masculino , Tasa de Supervivencia , Factores de Tiempo , Obtención de Tejidos y ÓrganosRESUMEN
Early age at cardiac transplantation may favor successful engrafting with minimal chronic immunosuppression. Fifty-two newborns underwent orthotopic heart transplantation; 47 (90%) survived the operation, and 44 (85%) were late survivors. Actuarial survival was 92% at 1 month, 86% at 1 year, and 84% at 5 years. Forty-four infants who survived 12 weeks and the corresponding 100 rejection episodes were analyzed. Mean follow-up was 2.2 years. The mean number of rejections per year of follow-up was 1.2. No episodes of rejection were identified in six patients. Seven patients had a late rejection episode more than 1 year after transplantation, and only one had a late rejection episode after 2 years. Neonatal cardiac transplantation is effective and durable therapy for uncorrectable heart disease. Intermediate-term results are excellent. Severe rejection is uncommon, and few episodes occur after 1 year of follow-up.
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Rechazo de Injerto , Trasplante de Corazón , Recién Nacido , Azatioprina/administración & dosificación , Azatioprina/uso terapéutico , Causas de Muerte , Intervalos de Confianza , Ciclosporina/administración & dosificación , Ciclosporina/uso terapéutico , Femenino , Estudios de Seguimiento , Cardiopatías Congénitas/cirugía , Trasplante de Corazón/métodos , Humanos , Terapia de Inmunosupresión , Incidencia , Masculino , Tasa de Supervivencia , Factores de TiempoRESUMEN
Double-outlet left ventricle is conventionally repaired with an intraventricular tunnel or with an extracardiac conduit when pulmonary stenosis is present. We report a 4-month-old female infant whose surgical correction of double-outlet left ventricle and subpulmonic stenosis was accomplished by pulmonary arterial translocation to the blind right ventricular infundibulum. This approach provided excellent hemodynamic repair without the use of an extracardiac conduit.
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Ventrículo Derecho con Doble Salida/cirugía , Arteria Pulmonar/cirugía , Ventrículo Derecho con Doble Salida/diagnóstico por imagen , Ventrículo Derecho con Doble Salida/fisiopatología , Femenino , Ventrículos Cardíacos/cirugía , Hemodinámica , Humanos , Lactante , Métodos , RadiografíaRESUMEN
Cardioplegic solution administration into the vein graft is an established method to ensure cardioplegic distribution beyond coronary artery stenoses. The ultrastructural demonstration of severe endothelial damage after cardioplegic exposure suggests that intravenous cardioplegic administration can contribute to early and late graft thrombosis. The direct effect on human saphenous vein contractility of three cardioplegic solutions and their components was compared. A solution with 30 mmol/L K+ and 82 mmol/L Na+ produced intense venoconstriction. Lowering the potassium level to 10 mmol/L and increasing the sodium level to 92 mmol/L reduced its vasoconstricting action. A third solution with 16 mmol/L K+, 16 mmol/L Mg2+, and lidocaine caused venodilatation. Analysis of the single component effects showed that high potassium level, low sodium level, and the addition of lidocaine produced concentration-dependent vasoconstriction. High magnesium concentration resulted in vasodilatation. The present data suggest that cardioplegic solution composition may cause marked vasomotor effects on saphenous vein and thus influence its endothelial integrity. In the search for an "ideal solution" to the cardioplegic controversy, a venoconstrictor infusate should be avoided to improve patency rates of coronary artery bypass grafts.
Asunto(s)
Soluciones Cardiopléjicas/farmacología , Vena Safena/efectos de los fármacos , Vasoconstricción/efectos de los fármacos , Humanos , Técnicas In Vitro , Lidocaína/farmacología , Magnesio/farmacología , Potasio/farmacología , Vena Safena/fisiología , Sodio/farmacología , TemperaturaRESUMEN
From January 1981 to January 1991, 40 patients underwent operation for acute ascending aorta dissection (AAD, 14 patients), chronic ascending aorta dissection (CAD, 9 patients) or aortic ectasia (AE, 17 patients), with simultaneous aortic valve replacement in 30 cases (75%). Average age was 54 years with a 3:1 M/F ratio. In 20 cases (50%) a composite graft bearing a mechanical bileaflet valve was inserted with coronary artery reattachment (Bentall operation). In 16 cases (40%) the ascending aorta was replaced by a woven dacron graft alone (7 cases) or associated with aortic valve substitution (7 cases) or resuspension (2 cases). In 1 case (2.5%) a sutureless ring graft replacement of ascending aorta was carried out and 3 patients (7.5%) underwent aortoplasty with aortic valve substitution. Postoperative mortality rate was 21% for AAD group, 11% for CAD group and 6% for AE group. Non-fatal postoperative complications developed in 36% of AAD patients and in 78% and 29% of CAD and AE patients respectively. These complications occurred in 45% of patients who underwent Bentall operation, in 44% of those who underwent ascending aorta replacement associated with aortic substitution or resuspension, and in 14% of those operated of simple ascending aorta replacement. Average follow-up was 41.6 months (range 1.7-107.4 months). During this period 5 deaths occurred for a long-term mortality rate of 14.2%. Out of 30 survivors 21 (70%) underwent CT-study to evaluate the natural course of the false channel and the risk of redissection or late aneurysm formation.(ABSTRACT TRUNCATED AT 250 WORDS)