Paul H. Heintzen

Dimensions of the great arteries, semilunar valve roots, and right ventricular outflow tract during growth: Normative angiocardiographic data

SummarySystolic and diastolic diameters of the right and left pulmonary arteries (RPAD, LPAD), descending thoracic aorta (DTAD), right ventricular infundibulum (RVID), and pulmonary and aortic valve roots at the proximal, commissural and distal levels were estimated from angiocardiograms in 24 infants, children, and adolescents without heart disease, and correlated with body surface area (BSA), stroke volume (SV), cardiac output (CO), and ventricular volumes.The relationships between cardiovascular diameters and BSA were better expressed by a power function than by the other functions tried. We obtained different exponents for pulmonary and aortic valve annuli and the more distally measured great arteries (RPAD, LPAD, and DTAD), suggesting different growth patterns. The right ventricular infundibular shortening fraction (RVISF) was weakly correlated with BSA (r=-0.328), and the values obtained indicated constancy during normal growth. There was a direct proportional relationship between the pulmonary valve annulus diameter and the cube root of the right ventricular volume (r=0.952), as well as between SV and cross-sections of the right pulmonary artery (RPAC;r=0.916), left pulmonary artery (LPAC;r=0.878) and descending thoracic aorta (r=0.962). RPAC and LPAC were strongly correlated (r=0.940), the RPAC being significantly larger than the LPAC.

Left and right ventricular adaptation to right ventricular overload before and after surgical repair of tetralogy of Fallot

On the basis of angiographic projections, left (n = 43) and right (n = 56) ventricular volume data were obtained in patients with tetralogy of Fallot before and after surgical repair. The postoperative patients were divided into 3 groups according to the degree of an additional volume load secondary to a residual ventricular septal defect or pulmonary insufficiency, or both. The decreased left ventricular ejection fraction (p less than 0.01) in preoperative tetralogy of Fallot in the presence of a normal sized left ventricle suggests depressed global myocardial function, which is not improved after surgical repair, even if excellent results are achieved. A certain functional reserve, however, seems to be preserved, since the ejection fraction did not decrease further with increasing additional volume loads. Similar enlargement of the right ventricle secondary to comparable degrees of pulmonary insufficiency and residual ventricular septal defect indicates similar effects of additional diastolic and systolic filling on right ventricular function in patients with tetralogy of Fallot after surgical repair. Even in patients with excellent surgical results, such as those without significant right ventricular outflow tract obstruction and additional volume load, right ventricular pump function is depressed, the ejection fraction being significantly (p less than 0.01) lower than normal. The further decrease of global myocardial function with increasing volume load suggests a loss of functional reserve. Attempts to minimize right ventricular volume load after surgical repair seem advisable.

On-line processing of the video-image for left ventricular volume determination

Abstract Biplane videoangiocardiograms of the left ventricle are stored on a video-disc recorder and replayed onto a TV monitor in a stop-action mode. The ventricular contours are successively traced with a light pen and stored on a scan converter (TEKTRONIX 4501) by means of a specially designed sweep-stop unblanc unit. The scan converter reads out the stored information automatically. During each horizontal scan, up to four counters are triggered by the heart boundary pulses. Information corresponding to each line of the contour which is stored in the buffer is read into a Control Data 1700 computer by means of a coding and counting unit in real time and stored in an array. Playback of the stored information onto a storage scope allows a visual check of the circumscribed image. The computer utilizing both images calculates the cross-section area obtained from each line pair of video-information by an elliptical fit. A three-dimensional summation of all volume slices together with the appropriate calibration factors results in a computer displayed volume. Programs are available which allow a simultaneous or successive evaluation of the biplane video-information with the additional possibility to correct different amplifications of the heart in both planes by a “blow up” procedure in the latter program.

Automated Video-Angiocardiographic Image Analysis

This paper describes a hardware-software system for handling the two main groups of cardiological data: a) physiological variables such as voltages, pressures, etc., and b) morphological data, derived from x-ray images or angiocardiograms, such as dimensions, areas, or volumes. We will concentrate in particular on some aspects of automated image processing–i. e., the analysis of the size, shape, and contraction pattern of the ventricles from video-angiocardiograms.

Computerized video-image preprocessing with applications to cardio-angiographic roentgen-image series

We report on the enhancement of video-angiocardiographic image-series by digital preprocessing methods including a newly developed technique of interframe subtraction recording as well as computerized image subtraction, integration, and nonlinear representation techniques. Background suppression and noise reduction obtained through these processes applied to roentgen images from animal experiments are demonstrated. Image-series handling and storage are simplified by combining a new method of digitally formatted videotape recording with conventional digital storage of selected image data in the periphery of a minicomputer system.

Value of image enhancement and injection of contrast medium for right ventricular volume determination by two-dimensional echocardiography in congenital heart disease

To determine factors that influence the accuracy of echocardiographically estimated right ventricular volume and to improve the echocardiographic input information by applying image enhancement techniques, quantitative contrast echocardiography (4-chamber view) and biplane angiocardiography were performed in 23 children during routine diagnostic cardiac catheterization. Volumes calculated on the basis of unprocessed and processed echocardiographic cross sections (area-length method and sphere model) underestimated angiocardiographic volumes significantly (p less than 0.01), and more so in end-diastole (50.6%) than in end-systole (35.9%). Thus, ejection fraction was significantly (p less than 0.01) underestimated; mean values were 0.48 +/- 0.12 and 0.60 +/- 0.08, respectively. The best comparison between echocardiography and angiocardiography at end-diastole was achieved with the sphere model using image enhancement techniques and injection of contrast media, where y = 0.54x - 6.8, r = 0.97, sy.x = 7.3. Correlations, however, in which unprocessed echocardiograms were used showed only slightly less good correlations. With the 6 image-enhancement techniques, a more homogeneous structure of the image and a more distinct outline of the internal surface was achieved. The statistical error improved only slightly. The echocardiographic 4-chamber view allows right ventricular volume determination with an acceptable accuracy. Its underestimation is related to inadequate visualization of trabeculations and mainly to the models used. Application of image enhancement techniques allows easier outlining of the internal cavity surface. The advantage gained by the combination of contrast infection and image enhancement techniques does not warrant the routine central injection of available contrast material.

The genesis of the normally split first heart sound

Abstract 1. 1. The intensity distribution along the anterior chest wall, timing, respiratory and poststraining variations of the physiologically split first heart sound, especially in the medium-high frequency range, has been investigated by means of multiple-filter phonocardiography in children who were 2 to 12 years of age. 2. 2. In 60 children from 2 to 12 years of age the first main component of the split first heart sound has on an average, its maximum intensity at the apex, where it is of greater amplitude than the second main group of vibrations. 3. 3. The second component of the split first heart sound has its point of maximum intensity (especially in the medium-high-frequency band) at the fourth left intercostal space and is the dominating vibration along the left sternal border in each age group. 4. 4. The reversal of the intensity relationship between both major components of the split first heart sound from the left sternal border to the apex is a constant feature in the whole group of children included in this study. 5. 5. The average time interval from the Q wave to the beginning of the first main component of the split first heart sound is 53.4 ± 0.33 msec. (S.D. 6.4 msec.); and to the onset of the second main component the interval is 75.2 ± 0.42 msec. (S.D. 7.8 msec.). 6. 6. Both main components of the split first heart sound are normally separated by no more than 21.5 ± 0.23 msec. (S.D. = 4.1 msec.). Therefore, in about 95 per cent of all normal children the splitting interval is shorter than 30 msec. 7. 7. The intensity of both components of the normally split first heart sound as well as the splitting interval increase with age. 8. 8. During inspiration the first component of the split first heart sound decreases in intensity, whereas the second component increases, if respiratory variations of sound conduction (transmission) can be eliminated. 9. 9. During the poststraining period of the Valsalva maneuver the second component of the split first heart sound reaches its maximum amplitude immediately after the release of pressure, whereas the initial group of vibrations is at first small and increases with some delay. 10. 10. The respiratory and poststraining variations of both splitting components reflect the different hemodynamic events of the left and right sides of the heart. 11. 11. The intensity distribution, timing, respiratory and poststraining behavior of the first component of the normally split first heart sound are in accordance with the concept of left-sided (mitral) origin of the vibration, whereas the corresponding data for the second main component of the normally split first heart sound leave no doubt that this vibration is, at least in the 2 to 12-year age group studied, of tricuspid and not of aortic origin.

A new device for slow progressive narrowing of vessels

SummaryThe purpose of this work was to develop a device which allows slow progressive banding of a great artery in infants within 4 to 5 weeks. Employed was the hygroscopic casein ameroid. When brought in contact with fluids, an ameroid cylinder expands characteristically. An early phase of fast expansion proceeds gradually to a phase of slow growth. Size, shape, and encasement of ameroid as well as temperature and type of surrounding fluid modify but do not alter the typical pattern of expansion. The developed constrictor (weight: 5.8 kg, length: 18 mm, diameter: 12 mm) includes a stainless steel socket containing an ameroid cylinder (length: 8.5 mm, diameter: 8 mm). The expanding ameroid pushes a piston with a concave extension (makrolon) a maximum of 2 mm against the artery, which is fixed to the metal housing by a teflon band (width: 4 mm, thickness: 0.5 mm). The band runs in 2 fitting grooves on the metal housing to which it is fixed by a metal ring with a precisely manufactured internal thread allowing exact tightening and loosening of the band around the artery.Utilization of inert materials like teflon, makrolon, and stainless steel warrents experimental and possibly clinical application of the developed small constrictor.

Catheter evaluation of left ventricular shape and function 1 or more years after anatomic correction of transposition of the great arteries

Twenty-eight children were reinvestigated by cardiac catheterization and angiography greater than 1 year after anatomic correction of transposition of the great arteries (TGA). Seventeen patients with simple TGA underwent banding of the pulmonary trunk plus or minus systemic to pulmonary artery shunt to prepare the left ventricle for anatomic correction. In addition to TGA, 10 of the remaining 11 patients had a large ventricular septal defect and 1 had an aorticopulmonary window. They required no preparation of the left ventricle. Age at repair ranged from 2 to 120 months (mean 26). Catheterization 12 to 48 months after anatomic repair revealed a left ventricular end-diastolic pressure of 4 to 14 mm Hg (mean 9.5 +/- 2.5 [+/- standard deviation]). Ejection fraction ranged from 52 to 75% (mean 66 +/- 8). Frame-by-frame computer-assisted analysis of left ventricular (LV) contraction and relaxation was performed in 14 patients and compared with normal left ventriculograms. Shape index, derived as 4 pi X cavity area/perimeter2 X 100, was measured in 24 patients and showed a mean index of 89 +/- 3% at end-diastole and 79 +/- 8% at end-systole. A control group had a mean diastolic index of 86 +/- 6% and mean systolic index of 73 +/- 8%. It is concluded that LV shape after anatomic correction tends to be more globular than normal and changes little during systole. LV ejection fraction and end-diastolic pressure are normal.

Left ventricular muscle volume in children and young adults

SummaryA computer-assisted method of estimating left ventricular muscle volume and its clinical application in 193 children and young adults is described. Wall thickness was measured at the lower half of the left cardiac border in the angiographic posteroanterior projection of the left ventricle, where only three points are marked when the left ventricular contour is traced. The intra- and interobserver reproducibility of the wall thickness were both within 1 mm. The individual beat-to-beat variability was 0.6 mm, 10% of the mean thickness.In normal left ventricles, the ratio between ventricular muscle volume and end-diastolic volume, the muscle volume index (MVI), was independent of body surface area, being 1.01+0.14 (mean±SD,n=28). MVI was normal in ventricles which were volume loaded secondary to a ventricular septal defect (n=9) or ductus arteriosus (n=11). It was significantly increased in aortic coarctation (1.66±0.44,n=24,P<0.001) and in valvar aortic stenosis (1.34±0.31,n=21,P<0.01). In tetralogy of Fallot (n=34) MVI was normal. MVI was significantly reduced in the case of pressure and possibly volume-underloaded left ventricles of simple transposition of the great arteries (TGA) (0.53±0.15,n=15) at the age of one year, compared to normal (P<0.001) and to the mean in TGA shortly after birth (P<0.05). However, it increased (P<0.001) to normal after banding of the pulmonary artery in TGA.