ABSTRACT
In patients with "sloped" appearance of the Doppler signal across a ventricular septal defect (VSD), the peak Doppler velocity seems to overestimate the catheterization-derived peak-to-peak gradient, resulting in underestimation of right-sided heart pressures. In 11 patients with sloped Doppler signals across the VSD, ventricular pressure tracings were compared with simultaneous recordings of the Doppler signal. The average peak Doppler gradient (40.2 +/- 19.2 mm Hg) overestimated the catheterization-derived peak-to-peak gradient (20.2 +/- 13.6 mm Hg) significantly (P < or =.001). Doppler mean gradient (20.2 +/- 11.3 mm Hg; P = ns) and end-systolic gradient (17.0 +/- 12.5 mm Hg; P < or =.05) were closer estimates of the catheterization peak-to-peak gradient. All Doppler gradients showed good correlation to the catheterization peak-to-peak gradient with r2 values of 0.77, 0.73, and 0.91. We conclude that Doppler mean or end-systolic gradients should be used for calculation of right-sided heart pressures in this patient population.
Subject(s)
Echocardiography, Doppler/methods , Heart Septal Defects, Ventricular/diagnostic imaging , Cardiac Catheterization , Child, Preschool , Electrocardiography , Heart Septal Defects, Ventricular/physiopathology , Humans , Infant , Middle Aged , Signal Processing, Computer-Assisted , Systole , Ventricular Function, Right , Ventricular PressureABSTRACT
Several techniques have been developed to retrieve catheter and guide wire fragments that have embolized to the heart and pulmonary vasculature. In most instances, retrieval of the embolized fragments is performed soon after the event has occurred. In this report, we summarize our experience with the removal of these fragments in 3 children after a significant amount of time had elapsed since the time of embolization. The embolized catheter and guide wire fragments were removed without any complications. We also describe the techniques used for their removal, and the problems encountered during the removal of these "old" foreign bodies.
Subject(s)
Catheters, Indwelling/adverse effects , Foreign Bodies/surgery , Heart Atria , Pulmonary Artery , Adolescent , Child, Preschool , Echocardiography , Female , Foreign Bodies/complications , Foreign Bodies/diagnosis , Heart Diseases/diagnosis , Heart Diseases/etiology , Heart Diseases/surgery , Humans , Infant , Pulmonary Embolism/diagnosis , Pulmonary Embolism/etiology , Pulmonary Embolism/surgery , Tomography, X-Ray ComputedABSTRACT
The object of this study was to determine, if possible, the mode of inheritance of the susceptibility to multiple sclerosis (MS). It was known that no single-gene model could fit the observations, so oligogenic models (models involving a small number of genes) were sought. Oligogenic hypotheses were tested against the available population data for MS until a reasonable level of agreement was found. The best-fitting simple hypothesis was this: MS occurs only in people who are homozygous for a recessive gene and carry a dominant X gene, and then only with reduced penetrance. The dangerous allele m- at the autosomal locus appears to be fairly uniformly distributed across England, Ireland and Canada, occurring in 10-30% of the gene pool. There are large variations in the frequency of the allele s- at the X-locus, ranging from 10% up to 72% of the gene pool. The penetrance varies significantly with geographical location, but nowhere approaches unity, so that the environmental factors are of great importance. The hypothesis explains the broad features of the population pattern of the occurrence of MS and it gives an outstanding fit to the best available data on MS in relatives. The result may assist attempts to map the genetic data on MS, opens the way for a reassessment of the attempts to identify the environmental factors, and it makes possible the completion of nonempirical risk tables for various countries. Similar techniques may be applied to other disorders with a genetic component in their aetiology.
