Casimir operators of the exceptional group F4F_4: the chain B4⊂F4⊂D13B_4\subset F_4\subset D_{13}

Expressions are given for the Casimir operators of the exceptional group $F_4$ in a concise form similar to that used for the classical groups. The chain $B_4\subset F_4\subset D_{13}$ is used to label the generators of $F_4$ in terms of the adjoint and spinor representations of $B_4$ and to express the 26-dimensional representation of $F_4$ in terms of the defining representation of $D_{13}$. Casimir operators of any degree are obtained and it is shown that a basis consists of the operators of degree 2, 6, 8 and 12

Adults with congenital heart defects--clinical spectrum and surgical management

Two hundred adults who underwent surgery for congenital heart disease at our institution within a four year period were the basis for this report. Clinical data was obtained, i.e. demographic details, past medical history, physical findings, EKGs, echocardiograms, catheterization and angiography material as well as the New York Heart Association (NYHA) class. Intraoperative findings, perioperative management, complications and morbidity and mortality were assessed. After discharge the patients were followed on an outpatient basis. Again the clinical findings, laboratory results and NYHA class were recorded. Age ranged from 16 to 75 years (mean = 38). There were 114 females and 86 males. 178 patients had primary surgical correction, 18 were reoperated after prior correction and 4 underwent palliation. Eighty-three percent of the patients were symptomatic preoperatively. Seventeen percent were diagnosed per chance, for example by a preemployment physical examination, without a prior history of heart disease. The patients were grouped according to related diagnoses (Table 1). Among the 130 patients with left to right shunts, 112 had an atrial septal defect, 7 a ventricular septal defect, 5 a persistent ductus arteriosus, and 6 partial anomalous pulmonary venous return. Atrial flutter or fibrillation occurred in approximately 10% of all patients with atrial septal defects. It was terminated either by rapid overdrive pacing or DC cardioversion. Postoperatively the patients with pulmonary hypertension were monitored invasively with arterial lines and thermodilution catheters. Therapy consisted of alkalization, hyperventilation and sedation. There was only one postoperative death in this patient group due to marked pulmonary hypertension (1/130 = 0.8%). Nineteen adults had obstruction to right or left ventricular outflow. Surgery included valvotomy, infundibulectomy and valve replacement by homograft or mechanical valve. One patient with multiple previous surgeries expired due to bleeding (3%). Thirteen patients had coarctation. All of them were hypertensive, some on medication. Surgery consisted of aortic patchplasty or interposition of a graft. There was no mortality. Perioperative antihypertensive therapy was necessary in most patients and consisted of nifedipin, nitroprussid or propanolol intravenously. Upon follow up 11 patients became normotensive, 8 of these without the need for medication. Fifteen cyanotic patients underwent 11 corrective and 4 shunt procedures (3 with tricuspid atresia, 10 with Tetralogy of Fallot and 2 with complex cyanotic heart disease. Three died due to low cardiac output or dysrhythmias (20%). The survivors improved their clinical status markedly. Seven adults with Ebstein's disease had valve reconstruction and/or ASD closure. Five had recurrent supraventricular tachycardia, 2 paradoxical emboli with neurological symptoms and 4 out of 7 had decreased exercise tolerance. One patient died postoperatively because of dysrhythmias (14%). Sixteen patients had a variety of defects, i.e. status post Rastelli operation and conduit obstruction, status post Tetralogy of Fallot with pulmonary valvar disease, corrected transposition with left AV valve insufficiency, congenital mitral valve disease and double aortic arch, no deaths. The overall operative mortality was 6/200 = 3%. the late mortality was 4/200 = 2%. The morbidity included 7 reoperations due to bleeding. Five patients needed short-term hemodialysis. One patient developed hemiplegia and two patients had permanent decrease of their left ventricular function. The mean length of follow up was 21 months. The clinical status improved from a NYHA class mean of 2.1 +/- 0.9 to 1.2 +/- 0.45 (p < 0.001). In Germany significant numbers of adults with operated and unoperated congenital heart disease do exist. Detection of these patients can be difficult due to inconspicuous murmurs or stable clinical status