Thomas P. Caudell

Echocardiographic ventricular shape analysis in congenital heart disease with right ventricular volume or pressure overload

In this 2-dimensional (2-D) echocardiographic study, a computerized Fourier analysis technique refined from one that allows quantification of changes in septal shapes in normal fetuses, newborns and infants allowed analysis of left ventricular (LV) shapes in 14 patients with right ventricular (RV) volume overload (atrial septal defects), 5 with volume and pressure overload (total anomalous pulmonary venous connection), and 10 with pressure overload (complete transposition of the great arteries [TGA] with intact ventricular septum). Diastolic shape factors in the 3 groups were significantly different from those of normal subjects (p less than 0.01). Highest diastolic values were found in patients with TGA (mean 4.59 +/- 1.28). Systolic shape factors were similar in patients with atrial septal defect and normal subjects. Significant differences existed between normal subjects and patients with total anomalous pulmonary venous connection, with the greatest differences in systolic shape factor being 5.61 for TGA vs 1.87 (p less than 0.005) for normal subjects. Shape factor correlated well with hemodynamic data for RV/LV systolic pressure ratios (r = 0.93, p less than 0.001) for normalized interventricular pressure differences (r = -0.95, p less than 0.001). The lower the normalized systolic pressure difference or the higher the RV/LV ratio, the more the septum encroached into the LV cavity. Significant but weaker correlations were noted for values during diastole. Quantitative application of Fourier shape factor analysis to LV shapes allows numerical expression of visually interpreted distortions over a wide range of geometric alterations.

A Non-Contact Method For Surface Profile Measurement And Angular Deflection Monitoring Using A Scanning Laser Beam

A method for measuring the surface profile of a reflecting surface is presented. The technique involves comparing, in the time domain, a surface reflected laser beam to a reference beam. The comparison is made by alternately scanning both beams across an optical detector and measuring their phase relationship electronically. From this information and by scanning along a line, the surface profile in a plane can be determined. The accuracy of the method falls between mechanical contact techniques and more sophisticated interferometric schemes. Precision of microns with dynamic range of millimeters or more can be achieved. A brief theoretical analysis is presented as well as the result of several experimental tests. This method can be useful in such applications as measuring the profile of the human cornea and other delicate materials where non-contact is obligatory and in determining the surface contour of optical components or of any other reflecting surface. Precise monitoring of angular deflection is also possible with this technique.

On the origin of oscillations in a solar diameter observed through the Earth's atmosphere: A terrestrial atmospheric or a solar phenomenon

Interpretations of current and past results from ground-based solar diameter measurements, as well as the planning of scientific programs for the 1980s, are strongly dependent on the perceived level of the degrading effects of the Earths atmosphere. One of the more effective approaches has been to design the observing program and the subsequent data analysis such that the solar diameter measurements themselves could provide an evaluation of atmospheric effects. Many important results have been obtained in studies of this type and these results are collected here to help in appraising the current situation. This evidence all points in one direction: the Earths atmosphere, while complicating the design of observational programs, is not the source of the oscillations observed in solar diameter measurements. Further, this same evidence indicates that the Earths atmosphere will not pose any serious limitations in ground-based solar diameter studies during the 1980s.

QUANTITATIVE TWO-DIMENSIONAL (2D) ECHO STUDY OF LEFT VENTRICULAR (LV) SHAPE IN NORMAL NEWBORNS (NB) - EARLY (EC) VS LATE (LC) UMBILICAL CORD CLAMPING

Using a computerized method which quantitatively analyzes overall LV shape and distortion, we recently reported a study in which fetuses and NB had flattening of the septal portion of the LV which tended toward roundness during infancy. Our present study evaluates effects of EC (≤5 sec; n=6), and late (LC)(3 min; n=7) cord clamping on LV shape in NB. Vaginal delivery was accomplished with all infants kept at the same level. NB were studied serially at <.5 hr and at 10-48 hrs. Mean gestational age (EC=39.5 ±.37 wks; LC=39.6±.55) (mean±SD), weight (EC=3.22 ±.3 kg; LC=3.21±.40), and Apgar scores (>8 EC and LC)(all p=ns) were recorded. Mean venous hematocrit for EC was 47±.03%, and for LC was 59±5% (p<.02). Diastolic (d) and systolic (s) 2D standard short axis frames were evaluated. Shape factor (SF) from this method for a circle = 1; for an indented ellipse = 7. Serial LC diastolic septal LV shape distortion was significantly greater than for EC (SFd LC at .5 hour = 5.08±.86 vs SFd EC at .5H=2.91 ±.68, p<.001; SFd LC 10-48 hour = 4.25±.65 vs SFd EC 2.45±.48, p<.01). In systole, LV shapes were all rounder, but SFs in LC was significantly higher than in EC at <.5 hour (3.15 ±.45 vs 2.15±.43, p<.05). Systolic SF data were similar at 10-48 hours (EC=2.15 ±.40; LC=2.3±.48). Placental transfusion significantly alters and distorts LV shape.