Studies on the Use of "Prophylactic" Intrathecal Amethopterin in Childhood Leukemia

Central nervous system infiltration was studied in a group of 47 childrenwith acute leukemia. CNS involvement was found to occur more frequentlyand appear more rapidly in patients who presented with elevated peripheralWBC counts. CNS infiltration not suspected clinically was identified by spinalfluid examination in a significant minority of children at the time of theinitial diagnosis of leukemia, indicating that lumbar puncture should be aroutine part of the initial evaluation of patients with acute leukemia. Intrathecal amethopterin administered "prophylactically" at the time of initialdiagnosis of leukemia did not prevent or decrease the frequency of occurrenceof CNS infiltration. However, it did delay the onset of CNS involvement in patients with elevated WBC counts. Intrathecal amethopterin administered before the onset of CNS infiltration appears to be useful in delaying morbidityresulting from CNS involvement in children who present with elevated peripheral WBC counts.

Submitted on July 21, 1969 Revised on January 27, 1970 Accepted on February 10, 1970     

Electron Microscopy of the Red Cells in Erythropoietic Porphyria

With the aid of electron microscopy two different red cell lines have beenidentified in erythropoietic porphyria. A normal red cell series has been foundin association with hemoglobin containing normoblastic nuclei and ferritinladen reticulocytes. The abnormal line presumably represents the porphyrincontaining cells. A possible explanation to account for the abnormality inheme synthesis has been proposed.

Submitted on February 24, 1964 Accepted on April 17, 1964     

Use of an Autologous Blood Recovery System during Emergency Pericardiocentesis in the Electrophysiology Laboratory

Introduction: Emergency pericardiocentesis during electrophysiology procedures is often associated with significant aspiration of pericardial blood, requiring transfusion. We sought to assess the feasibility of urgent use of an autologous blood recovery system in the electrophysiology laboratory to autotransfuse blood aspirated from the pericardium.
Methods and Results: We retrospectively analyzed Mayo Clinic electrophysiology records for patients who had ablation procedure-related pericardial effusions requiring emergency pericardial drainage during an 8-month period. An autologous blood recovery system was used during pericardiocentesis to separate and clean packed red blood cells from the pericardial aspirate. These cells were returned acutely to the patient intravenously. The procedural safety, aspirated and autotransfused volumes, and efficacy of this approach were evaluated. During the study period, nine patients underwent pericardial drainage with autotransfusion using a cell-salvage instrument during electrophysiology procedures. The mean aspirated volume was 1,078 mL, with a mean autotransfused volume of 390 mL. For four patients, all with aspirated volumes of 1,100 mL or less, autotransfusion alone was sufficient to maintain hemodynamic stability and avoid allogeneic transfusion. One patient required surgical intervention because of ongoing pericardial bleeding. The ablation procedure was completed after aspiration in two patients. No procedural complications related to the use of the cell-salvage system occurred. 
Conclusion: Autologous blood recovery during pericardiocentesis is safe, convenient, and feasible. With early use it may decrease or eliminate the need for allogeneic blood transfusion and, in selected cases, may permit completion of the ablation procedure.     

Factors Predisposing to the Development of Atrial Fibrillation

Atrial fibrillation (AF) is in most patients (approximately 70%) associated with organic heart disease including valvular heart disease, coronary artery disease, hypertension, hypertrophic cardiomyopathy, dilated cardiomyopathy, and congenital heart disease, mostly atrial septal defect in adults. In many chronic conditions, determining whether AF is the result or is unrelated to the underlying heart disease, remains unclear. The list of possible etiologies also include cardiac amyloidosis, hemochromatosis and endomyocardial fibrosis. Other heart diseases, such as mitral valve prolapse (without mitral regurgitation), calcifications of the mitral annulus, atrial myxoma, pheochomocytoma, and idiopathic dilated right atrium may present with AF. Atrial fibrillation may occur in the absence of detectable organic heart disease, the so-called “lone AF”, in about 30% of cases. The term “idiopathic AF” implies the absence of any detectable etiology including hyperthyroidism, chronic obstructive lung disease, overt sinus node dysfunction, and overt or concealed preexcitation (Wolff-Parkinson-White syndrome), only to mention a few of other uncommon causes of AF. The autonomous nervous system may contribute to the occurrence of AF in some patients. AF occurs commonly. In patients with valvular heart disease, AF is common, particularly when the mitral valve is involved. The occurrence of AF is unrelated to the severity of mitral stenosis or mitral regurgitation but is more common in patients with enlarged left atrium and congestive heart failure. In patients with coronary artery disease, AF occurs predominantly in older patients, males, and patients with left ventricular dysfunction. Important predictive factors of AF include hypertension, left ventricular hypertrophy and diabetes. The risk of the development of AF, in an individual patient, is often difficult to assess. Increasing age, presence of valvular heart disease, and congestive heart failure increase the risk of atrial fibrillation.