RESUMEN
UNLABELLED: This study was performed to determine the secretion pattern and prognostic value of A-type (ANP) and B-type (BNP) natriuretic peptide in patients undergoing cardiac surgical procedures. We measured ANP and BNP in patients undergoing coronary artery bypass grafting (CABG) with (n = 28) or without (n = 32) ventricular dysfunction and in patients undergoing mitral (n = 21) or aortic (n = 24) valve replacement, respectively. Postoperative mortality was recorded up to 730 days after operation. ANP, but not BNP, concentrations were closely associated with volume reloading of the heart after aortic cross-clamp in all patients. The secretion pattern of BNP during surgery was much less uniform. BNP, but not ANP, concentrations correlated with aortic cross-clamp time (r(2) = 0.32; P = 0.006) and postoperative troponin I concentrations (r(2) = 0.22; P = 0.0009) in bypass patients, and preoperative BNP increases were associated with a more frequent postoperative (2-yr) mortality in these patients. Markedly increased preoperative BNP concentrations in mitral (3-fold) and aortic (14-fold) valve disease patients did not further increase during cardiopulmonary surgery. The data suggest that ANP is primarily influenced by intravascular volume reloading of the heart after cross-clamp, whereas the secretion of BNP is related to other factors, such as duration of ischemia and long-term left ventricular pressure and/or excessive intravascular volume. BNP, but not ANP, was shown to be a mortality risk predictor in patients undergoing CABG. IMPLICATIONS: A-type natriuretic peptide is primarily influenced by volume reloading of the heart after cross-clamp, whereas the secretion of B-type natriuretic peptide (BNP) is related to the duration of ischemia and long-term left ventricular pressure and/or volume overload. Preoperative BNP, but not postoperative BNP, concentrations predict long-term outcome after coronary artery bypass grafting.
Asunto(s)
Factor Natriurético Atrial/sangre , Procedimientos Quirúrgicos Cardíacos/efectos adversos , Péptido Natriurético Encefálico/sangre , Anciano , Anestesia General , Biomarcadores , Procedimientos Quirúrgicos Cardíacos/mortalidad , Puente de Arteria Coronaria/efectos adversos , Puente de Arteria Coronaria/mortalidad , Enfermedad Coronaria/complicaciones , Enfermedad Coronaria/cirugía , Femenino , Implantación de Prótesis de Válvulas Cardíacas/efectos adversos , Implantación de Prótesis de Válvulas Cardíacas/mortalidad , Humanos , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/mortalidad , Pronóstico , Estudios Prospectivos , Troponina I/sangre , Función Ventricular IzquierdaRESUMEN
HYPOTHESIS: To evaluate the effects of high thoracic epidural anesthesia (TEA) on global and regional myocardial function and on perioperative coronary risk in patients undergoing coronary artery bypass grafting. DESIGN, SETTING, AND PATIENTS: Prospective and randomized clinical trial blinded for the primary outcome measure of 73 patients scheduled for coronary artery bypass grafting who had a left ventricular ejection fraction of 50% or more conducted from February 1, 2000, through August 31, 2000, at University Hospital, Münster, Germany. INTERVENTIONS: Of 73 randomized patients, 37 were control subjects (who received general anesthesia only) and 36 were in the group who received general anesthesia and high TEA. MAIN OUTCOME MEASURES: The primary outcome measure was regional left ventricular function after myocardial revascularization, assessed by transesophageal echocardiography. We further determined the plasma concentrations of cardiac troponin I and atrial and brain natriuretic peptides. Secondary outcome measures were postoperative complications recorded to 14 days and mortality recorded to 720 days. RESULTS: High TEA was effective in all patients of this group, the somatosensory block extended from T1 through T7 vertebrae. Regional left ventricular function was significantly improved (mean [SD] global wall motion index, 0.74 [0.18] vs 0.38 [0.16]; P<.05), and cardiac troponin I concentrations were reduced by 72% (mean [SD], 5.7 [1.5] vs 1.6 [0.7] ng/mL, P<.05) in patients with high TEA. Natriuretic peptide concentrations peaked during reperfusion (atrial natriuretic peptide) and 24 hours after reperfusion (brain natriuretic peptide). High TEA reduced the mean (SD) peak concentrations of atrial natriuretic peptide by 54% (211 [63] vs 98 [33] ng/mL, P =.03) and brain natriuretic peptide by 43% (189 [39] vs 108 [21] ng/mL, P =.01). One of 36 patients who received high TEA and 3 of 37 controls died. CONCLUSIONS: Reversible cardiac sympathectomy by high TEA improves regional left ventricular function and reduces postoperative ischemia after coronary artery bypass grafting. These effects of high TEA may improve the long-term outcome after myocardial revascularization.
Asunto(s)
Anestesia Epidural/métodos , Puente de Arteria Coronaria , Simpatectomía/métodos , Disfunción Ventricular Izquierda/cirugía , Factor Natriurético Atrial/sangre , Distribución de Chi-Cuadrado , Ecocardiografía Transesofágica , Femenino , Humanos , Masculino , Persona de Mediana Edad , Péptido Natriurético Encefálico/sangre , Estudios Prospectivos , Resultado del Tratamiento , Troponina I/sangre , Disfunción Ventricular Izquierda/diagnóstico por imagenRESUMEN
During fetoscopic interventions, intraesophageal placement of intravascular ultrasound (US) catheters for fetal hemodynamic monitoring may result in esophageal injury in very small fetuses. Moreover, conventional fetal imaging by the transvaginal or transabdominal routes may be impossible in some high-risk pregnancies. The purpose of our study in sheep was to assess the potential of a phased-array intravascular US catheter for intra-amniotic fetal echocardiography. The catheter was percutaneously inserted into the amniotic cavity in seven pregnant ewes at between 78 to 98 days of gestation and permitted high-quality 2-D imaging of the fetal heart and multimodal Doppler assessment of fetal cardiovascular flows. Fetoscopic examination of intra-amniotic contents after intra-amniotic imaging was finished did not display any injury to intra-amniotic contents. The intra-amniotic imaging approach may provide an effective alternative in humans for monitoring during fetoscopic interventions, and to assess fetal anatomy and hemodynamics in high-risk pregnancies when sufficient images cannot be obtained by conventional routes.
Asunto(s)
Líquido Amniótico/diagnóstico por imagen , Ecocardiografía Doppler/métodos , Corazón Fetal/diagnóstico por imagen , Ultrasonografía Intervencional/métodos , Ultrasonografía Prenatal/métodos , Animales , Cateterismo/instrumentación , Modelos Animales , Ovinos , Ultrasonografía Intervencional/instrumentaciónRESUMEN
BACKGROUND: In patients undergoing colonoscopy, naloxone has vasodilative properties. However, it remains unclear whether this effect is mediated by central or peripheral mechanisms. The aim of this study was to investigate whether these effects are mediated by an effect of naloxone on the central nervous system. METHODS: Twenty dogs were chronically instrumented for measurement of hemodynamic parameters. Splanchnic blood flow was determined using colored microspheres. Transthoracic echocardiographic examinations were performed to measure cardiac output. In each animal, two experiments were performed in a random order: experiment 1 was determination of splanchnic blood flow before and 5 min after intravenous administration of naloxone (63 microg/kg), and experiment 2 was determination of splanchnic blood flow before and 5 min after administration of naloxone methiodide (63 microg/kg), which does not cross the blood-brain barrier. RESULTS: Naloxone, but not naloxone methiodide, significantly increased blood flow to the stomach (from 0.41 +/- 0.022 to 0.9 +/- 0.016# ml x g (-1) x min(-1) with naloxone), jejunum (from 0.31 +/- 0.024 to 0.83 +/- 0.083# ml x g(-1) x min(-1) with naloxone), colon (from 0.41 +/- 0.057 to 0.68 +/- 0.008# ml x g(-1) x min(-1) with naloxone), spleen (from 1.45 +/- 0.21 to 2.13 +/- 0.25# ml x g(-1) x min(-1) with naloxone), pancreas (from 0.97 +/- 0.021 to 1.25 +/- 0.005# ml x g(-1) x min(-1) with naloxone), and kidneys (from 3.24 +/- 0.108 to 5.31 +/- 0.26# ml x g(-1) x min(-1) with naloxone), without altering cardiac output or arterial blood pressure in conscious dogs. There were no differences in the hemodynamics or cardiac output between the two experiments. Data are presented as mean +/- SD. CONCLUSIONS: The increased splanchnic perfusion after naloxone is not caused by direct peripheral vascular effects or increased cardiac output. Indirect vasodilative effects on splanchnic vessels mediated by actions of naloxone on the central nervous system account for the increased gastrointestinal perfusion after naloxone in dogs.