Effect of atrioventricular synchrony on stroke volume during ventricular tachycardia in man.

The hemodynamic consequences of atrioventricular (AV) synchrony during ventricular tachycardia were evaluated during cardiac electrophysiologic testing. The relationship between stroke volume and the AV interval was investigated on a beat-by-beat basis in six patients during induced monomorphic ventricular tachycardia. Stroke volume was calculated either (1) in the right ventricle using impedance catheter method (four patients) or (2) in the left ventricle using Doppler measurement of aortic blood velocity (two patients). The impedance catheter method underestimated stroke volume by a factor of 4.2 +/- 2.4 compared with the thermodilution cardiac output method. However, there was a highly linear relationship between both methods for computing stroke volume (r greater than 0.9). Five patients had complete AV dissociation during ventricular tachycardia, and different AV intervals spanned the entire tachycardia cycle lengths. Largest stroke volumes were associated with optimal AV intervals within 120 and 230 msec, resulting in a 97 +/- 59% increase in stroke volume over ventricular tachycardia cycles not associated with atrial activity. Customized atrial pacing during ventricular tachycardia may provide a valuable means for artificially establishing the hemodynamically optimal AV interval and eliminating the ventricular tachycardia cycles not preceded by atrial activity.     

Orbital compartment syndrome as the first manifestation of SLE

Clinical Rheumatology - The occurrence of orbital compartment syndrome is a rare and unusual complication of systemic lupus erythematosus (SLE). Patients will present with symptoms of ocular pain...     

Does periconceptional multivitamin use reduce the risk of neural tube defects associated with other birth defects? Data from two population-based case-control studies

The role of periconceptional folic acid in the prevention of neural tube defects (NTDs) is well established. However, it is not clear whether a protective effect exists for the subset of nonsyndromic NTD with other “unrelated” major structural birth defects (NTD-multiples). This question is important to investigate because of shared pathogenetic mechanisms between NTD and other types of birth defects, and because of the epidemiologic differences that have been shown between NTD-multiples and NTD-singles. We analyzed data from two population-based case-control studies of NTDs, Atlanta 1968–1980, and California 1989–1991, to assess whether periconceptional multivitamin use reduces the risk of NTD-multiples. Maternal vitamin histories were assessed for 47 and 65 NTD-multiples cases and 3,029 and 539 control babies in Atlanta, and California, respectively. There was a substantial risk reduction associated with periconceptional multivitamin use (−3 to +3 months) for NTD-multiples (pooled odds ratio = 0.36, 95% C.I. 0.18–0.72) that persisted after adjustment for maternal race/ethnicity and education. Also, no specific types of NTDs or NTDs with specific defects explained the risk reduction with vitamin use. These data suggest that multivitamins reduce the risk of nonsyndromic NTD cases associated with other major birth defects. The implication of this finding for the role of vitamins in the prevention of non-NTD birth defects should be further explored. © 1996 Wiley-Liss, Inc.     

Cultural conflicts and problem behaviors of Latino adolescents in home and school environments

This empirical study examines the behavioral sequelae of acculturation strains among Latino adolescents in home ans school settings. Two theoretically derived hypotheses are tested. First, low acculturation Latinos experiencing strains associated wsith rapid cultural and language transitions will have more behavior problems reported by their parents and teachers. Second, highly acculturated Latinos reporting more acculturation strains. associated with perceptions of prejudical treatment and internalization of inority status will have more behavior problems reported by aprents and teachers. The data were taken from the self-reports of 2,360 adolescents in the greater Miami (Florida) area, ans their teacher ans parent reports. problem behaviors were measured using the Child Behavior Checklist and the Teacher Report Form. Strain measures included language conflicts, acculturation conflicts, perceived discrimination, and perception of a closed society. Results indicated general confirmation of both hypotheses. Among immigrant adolescents only language confilicts were associated with reported behavior problems reported by teachers and parents. Among the U.S. born, language conficts, perceived discrimination, and perceptions ofa closed society were associated with behavior problems reported by teachers but not by parents. The central finding is that both immigrant and nonimmigrant Latino adolescents are likely to experience a variety of acculturative strains in the school setting that may affect role performance and lower educational aspirations.     

Penetrating trauma to the carotid vessels

Over a 13 year period extending between April 1975 and June 1988, 510 neck injuries were treated at the American University of Beirut Medical Center; the carotid vessels were involved in 48 patients, resulting in 53 carotid injuries. The mean age of the patients was 25.3 years and shrapnel injuries were the commonest (45.8%), followed by bullet wounds (33%). Thirty-nine patients had a laceration and five had complete disruption of the carotid vessels and only three presented in coma. Shock was present in 14 patients, of whom five had a neurological deficit. In six the injured vessels were ligated, three of them were external carotid arteries. Nine patients were not initially operated on. Six of them had a chronic arterio-venous fistula and three were in coma. The remainder underwent surgical repair. Nine patients died, giving an overall mortality rate of 18.8%. Four of these died because of multisystem failure, thus giving a 10.4% mortality rate for the isolated carotid injury. There was definite improvement in the repaired group, but the haemodynamic status seemed to significantly affect the mortality rate (P less than 0.01). Follow-up of surviving patients has revealed five with persistent neurological deficits in the repaired group (33 patients), and four patients with a chronic arterio-venous fistula. Two patients had a false aneurysm. Carotid artery injury seems to have a good prognosis if repaired promptly within 3 h.     

The Stoppa approach for acetabular fracture

Objective

Acetabular fractures pose a great surgical challenge for orthopedic trauma surgeons. We believe that the Stoppa approach with an iliac window extension, previously described as a modified Stoppa approach is adequate for the majority of acetabular fractures excluding those with predominant posterior wall involvement. In this paper we will present our experience in using the Stoppa approach, its indications, preparations, the detailed surgical approach, complications and the different tips used in this relatively modern approach.

Indications

All simple and combined fracture types that involve the anterior column of the pelvis including the quadrilateral plate.

Contraindications

Posterior wall or extensive posterior column involvement. Transverse and T-fractures with mainly posterior displacement.

Surgical technique

Suprapubic, intrapelvic approach, extending from the symphysis pubis anteriorly to the sacroiliac joint posteriorly. Superficial landmarks are identical to the Pfannenstiel approach, the rectus abdominis muscles are longitudinally dissected, the symphysis pubis is exposed and a sub-periosteal deep surgical dissection is carried out along the anterior column and the quadrilateral plate, and posteriorly toward the greater sciatic notch and the sacroiliac joint.

Results

In a 5-year review of 60 acetabular fractures that underwent open reduction and internal fixation using the modified Stoppa approach, there were 36% anterior column fractures, 28% both-column fractures, the rest being anterior column with posterior hemi transverse fractures, transverse and T-fractures. Any extension of the fracture to the iliac wing necessitated an additional lateral window (93% of cases). In cases with posterior displacement, an additional approach was utilized to address a posterior wall fracture. All fractures healed within 12?weeks. Mean Merle d’Aubigné score was 15.22. Postoperative radiological evaluation revealed anatomical reduction in 54% of the patients, satisfactory in 43%, and unsatisfactory in 3% of the patients. Overall there were 15?minor and major complications