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Intravascular stents have recently been used to treat vascular stenoses in congenital heart disease. Size limitations, however, may preclude their use in certain situations. We describe the successful relief of right ventricular to pulmonary artery conduit stenosis in an adult patient late after repair of truncus arteriosus using a larger, self-expanding wall stent.

An 8-year-old girl presented with linear scleroderma, no evidence of systemic disease, and a negative antinuclear antibody (ANA) test. Over the next 12 months, she functioned normally. However, over the subsequent 5 months, she developed dyspnea, progressive pulmonary hypertension, a positive ANA test, and died 17 months after presentation. At autopsy, diffuse pulmonary interstitial fibrosis, small pulmonary arterial fibroplasia, tricuspid and mitral valve subendocardial fibrosis, and distal esophageal fibrosis were seen. Contrary to suggestions in the rheumatology literature, childhood linear scleroderma, even when ANA negative at presentation, may progress to fatal systemic sclerosis.

In 1978 Choussat and Fontan established ten criteria, which should be fulfilled to achieve a successful outcome in Fontan operation. Recent data suggest that while some of these ten criteria need not be necessarrily be fulfilled, new criteria should be added. These include 1. good diastolic function, 2. normal or only slightly increased ventricular mass, and 3. absence of systemic outflow obstruction. In addition the morphology of the single ventricle may be important as long-term results in patients with single ventricle of right ventricular morphology may be worse than results in patients with single ventricle of left ventricular morphology. Ventricular size and pump function can be assessed by cardiac catherization, echocardiography or magnetic resonance imaging. Estimation of ejection fraction under stress by nuclear angiography may be indicated. Diastolic function can be examined using Doppler echocardiography or nuclear angiography. Myocardial mass may be assessed by echocardiography or magnetic resonance imaging. Normal reference values for different parameters of systolic and diastolic function are listed in the enclosed tables. Patients scheduled for a Fontan operation should have an ejection fraction less than 50%. Patients with borderline ejection fraction should be examined by echocardiography to determine the end-systolic wall stress, a parameter of ventricular contraction, which is independent of pre- and afterload. As afterload may decrease after a Fontan operation some patients with reduced ejection fraction but normal end-systolic wall stress may still be suitable candidates for Fontan operation.(ABSTRACT TRUNCATED AT 250 WORDS)

The room temperature Gd3+ EPR spectrum in SrF2 containing Ce3+ as a second dopant exhibits three types of symmetry sites: cubic, trigonal, and tetragonal. Relative intensities of the spectra from these sites have been determined as a function of the Ce3+ codopant level in crystals having nominally 0.1 molar % of Gd3+. At low Ce3+ concentrations (< 0.1 molar %), the tetragonal‐to‐trigonal intensity ratio is 1.85 ± 0.25, with the cubic site intensity accounting for less than one tenth of the total observed intensity. At higher Ce3+ concentrations (up to 0.8 molar %), the cubic site intensity grows and the intensity of both axial sites decreases. This increase of cubic intensity is at variance with the generally accepted model of nonlocalized cubic compensation of the Gd3+, and a phenomenological explanation based on a local cubic phase in which rare earth ions are essentially surrounded with interstitial compensating fluorines is presented.

The effects on the nuclear magnetic resonance line shape of a polycrystalline sample resulting from combined axially symmetric electric quadrupole and anisotropic shift interactions have been calculated through the second order. The line shape of the central transition of the resonance has been shown to change smoothly from that characteristic of quadrupole effects (inverse field dependence) to that characteristic of anisotropic shift effects (direct field dependence) as the magnetic field strength is increased. Methods are given for determining the magnetic shift parameters---both isotropic and anisotropic (axial)---and the electric quadrupole coupling from line shape and shift measurements. An illustration of these methods is given, based on experimental measurements of the ${\mathrm{Al}}^{27}$ spectrum in polycrystalline Pr${\mathrm{Al}}_{2}$.

Current interest in the arterial switch operation for simple transposition of the great arteries (TGA) has led us to evaluate our latest patients who have undergone intra-atrial repair. Right ventricular function and overall results were compared in 32 patients who had undergone the Senning procedure between 1978 and 1983 and 26 patients who had undergone Mustard repair between 1971 and 1978). Deep hypothermia and circulatory arrest were used in all Senning operations and in 18 of 26 Mustard procedures. Cardiac catheterization was performed an average of 1 year after surgery in all patients. Postoperative right ventricular ejection fraction (EF) was below normal (less than 0.49) in 16 of 32 patients who underwent the Senning procedure and averaged 0.48 +/- 0.09. In the patients in this group with abnormal right ventricular EFs after repair there was a fall in the value after surgery (0.51 to 0.40, p less than .001), while in those with normal right ventricular EFs after repair there was no change (0.57 to 0.55, NS). All 32 patients who underwent the Senning procedure were compared with 26 patients who underwent the Mustard operation (13 treated between 1971 and 1974 and 13 treated between 1975 and 1978). An older age at surgery (12 +/- 7 vs 6 +/- 8 months, p less than .006) and a lower preoperative right ventricular EF (0.46 +/- 0.09 vs 0.54 +/- 0.08, p less than .007) characterized the Mustard vs the Senning group.(ABSTRACT TRUNCATED AT 250 WORDS)

Left ventricular wall stress and contractile function were determined by echocardiographic methods in 11 patients studied 0.7 to 13.8 years (mean +/- standard error of the mean = 5.6 +/- 1.2 years) after undergoing the Rastelli operation for transposition of the great arteries associated with ventricular septal defect and left ventricular outflow tract obstruction. Age at operation ranged from 4.6 to 11.3 years (mean +/- standard error of the mean = 7.4 +/- 0.7 years). Data were compared with data of 24 normal subjects of similar age and heart rate. Left ventricular end-diastolic dimension and end-diastolic volume were significantly higher than normal, averaging 134% +/- 8% of normal dimension (p less than 0.004) and 106 +/- 13 ml/m2 versus a normal volume of 60 +/- 3 ml/m2) (p less than 0.007). In addition left ventricular wall mass was 215 +/- 40 gm/m2 versus a normal value of 72 + 6 gm/m2 (p less than 0.004). Both meridional and circumferential end-systolic and peak systolic stress values were not significantly different between normal subjects and Rastelli patients. Estimates of ventricular pump function including shortening fraction, rate-corrected velocity of circumferential fiber shortening, and ejection fraction were all depressed when compared with normal values. Velocity of fiber shortening, evaluated as a function of end-systolic stress, demonstrated abnormal contractile function in eight of 11 (73%) patients. These data indicate that left ventricular function is usually abnormal and residual left ventricular dilation and wall hypertrophy remain despite successful use of the Rastelli operation for repair in patients with transposition of the great arteries, ventricular septal defect, and left ventricular outflow tract obstruction.

The effect of a similar degree of "respiratory" and "metabolic" acidosis was studied in seven isolated in vitro human pectinate muscles and eight ventricular muscle bundles. Either "respiratory" or "metabolic" acidosis (from 7.36 plus or minus 0.03 to 7.01 plus or minus 0.02 and 6.98 plus or minus 0.03, respectively) depressed in vitro contractility in human atrial or ventricular muscle to a similar extent. Previous contradictory responses of myocardial tissue to alterations in pH appear to be the result of species differences.

Rabbit hearts were excised and perfused with blood pumped through a cannula placed in the aortic root. A fluid-filled balloon-tipped catheter was positioned in the left ventricle for the measurement of left ventricular pressure and dP/dt. Total coronary vascular resistance (CVR) was calculated by dividing the coronary perfusion pressure by the rate of coronary blood flow. Following stabilization, coronary blood flow was held at a constant rate. Compared to control hearts, endotoxin (E. coli) added directly to the blood perfusate (6 mg/80 ml of circulating blood) had no effect on CVR or left ventricular dP/dt. In contrast, changing the perfusate to blood obtained from rabbits previously given endotoxin (LD100; 6 mg/kg IV) resulted in significantly higher CVR, without depression of left ventricular dP/dt. This increase in CVR was observed not only when the endotoxemic donor rabbits were hypotensive at the time the blood was obtained (4-6 hours following endotoxin administration), but also when the endotoxemic donors remained normotensive (blood withdrawn 30 minutes following endotoxin administration). A pathologic increase in CVR might contribute to the myocardial ischemia and contractile dysfunction observed in endotoxin shock.

This report presents our experience with producing a stable chronic hypoxemia preparation in the dog without the disadvantages of prosthetic graft insertion or sacrifice of pulmonary tissue. In 28 adult dogs, the intrapericardial inferior vena cava and the area of junction of the right and left inferior pulmonary veins were exposed through a right thoracotomy. The cava was clamped at the diaphragm and at the right atrium, divided at the atrial clamp, and quickly anastomosed to the inferior pulmonary veins. The mean arterial O2 tension (PaO2) decreased from 83.2 +/- 1.6 mmHg preoperatively in mechanically ventilated (room air) animals to 35.3 +/- 1.5 mmHg postoperatively in awake animals spontaneously breathing room air (P less than 0.001). There was persistent depression of the PaO2 (49.1 +/- 1.8 mmHg) and elevation of the hematocrit (64.8 +/- 2.0%) in six animals tested at 18.5 mo postoperatively. Shunt patency without significant stenosis was confirmed in each animal at autopsy. This method attains predictable and persistent hypoxemia and polycythemia and is simple to perform. It may be useful in studying various aspects of ventricular function and ventricular histological and biochemical changes with chronic cyanosis.

Left ventricular wall stress and contractile function were determined by echocardiographic methods in 23 patients with tricuspid atresia after palliation only (group 1), in 19 patients after Fontan repair (group 2), and in 24 age-matched normal subjects. End-diastolic dimension was increased above normal in both groups with tricuspid atresia (group 1 [mean +/- SEM] 141 +/- 4%, group 2 129 +/- 5% of normal; both p less than .001) but were not different from each other. Left ventricular end-diastolic volume and wall mass also were increased above normal in both groups (group 1, 126 +/- 9 ml/m2 and 194 +/- 19 g/m2, respectively, p less than .001 and p less than .004; group 2, 80 +/- 7 ml/m2 and 128 +/- 10 g/m2, p less than .02 and p less than .001), and group 2 patients showed significantly lower values than group 1 patients (p less than .001 and p less than .004). Meridional end-systolic stress was increased above normal in both groups with tricuspid atresia but was not different between groups (normal, 43 +/- 3 g/cm2; group 1, 56 +/- 54 g/cm2, p less than .02; group 2, 59 +/- 7 g/cm2, p less than .001). Contractile function estimated by rate-corrected circumferential fiber shortening velocity was abnormal in nine of 23 (39%) group 1 patients and in five of 19 (26%) group 2 patients (percentages not different from each other by nonparametric testing). Contractile function was depressed in one of 11 group 1 patients under 5 years old and in eight of 12 over 5.3 years old.(ABSTRACT TRUNCATED AT 250 WORDS)

The surgical experience with total anomalous pulmonary venous connection (TAPVC) at the Venderbilt Hospital between the years 1969 and 1979 was reviewed. Twenty-five patients with TAPVC were studied. All but one patient presented at less than 1 year of age, and 11 patients were operated upon in the first 2 weeks of life. Operative mortality rate was 20% (5/25). Four of the five deaths were in critically ill neonates requiring preoperative ventilatory support. All operative deaths were in patients with pulmonary venous obstruction. All operative survivors have been followed for a mean 4.5 years (6 months to 10 years). There have been no late deaths or cases of symptomatic pulmonary venous obstruction. All children have had normal growth patterns. Ten patients have been recatheterized. Pulmonary artery systolic pressure, which was markedly elevated prior to operation, fell to normal levels after operation. Ventricular function has been evaluated by quantitative angiocardiography in nine patients before and after operation. Left ventricular size and function were markedly depressed preoperatively and rose to normal levels in postoperative survivors. Left atrial maximal volume was found to be 94% of normal values. These data support the contention that preoperative pulmonary venous obstruction is the single risk factor predicting higher risk of operative death. The presence of severe depression of left ventricular size and function preoperatively does not predict a higher operative risk, and postoperative survivors can expect normal ventricular function.

Disappointing results with pulmonary artery banding and subsequent correction led to the decision in 1977 that all infants presenting to our hospital with atrioventricular (AV) canal and evidence of severe heart failure, lack of growth, or pulmonary hypertension should have early operative correction. Since that time 24 consecutive infants have undergone repair. All had refractory heart failure. Average age at operation was 18 weeks (3 to 38) and average weight was 4.3 kg (2.3 to 6.4). Only four patients were older than 6 months of age at operation. Preoperative peak pulmonary artery pressure was 81 +/- 3.3 mm Hg, which was equal to systemic arterial pressure in all cases. Mean pulmonary-to-systemic resistance ratio was 0.28 +/- 0.05. five patients had moderate mitral regurgitation and five had a ductus arteriosus. Three had significant associated malformations. Profound hypothermia and circulatory arrest were utilized in all patients. Common AV valve tissue was divided and valvular integrity was ensured by resuspension to a single Dacron patch which closed both the atrial and ventricular defects. Operative death occurred in two patients (8%) both with associated defects (one with total anomalous pulmonary venous connection and the other with coarctation). One late death occurred in a patient with associated partial anomalous pulmonary venous connection, and one patient has had a pacemaker implanted. Survivors have been followed for 7 to 60 months. All patients are growing at an increased rate postoperatively. All cardiac medications have been discontinued in 16 of 21 patients. Operative repair of complete atrioventricular canal can be performed in infancy with low operative and late death rates and will relieve signs and symptoms of heart failure and allow more normal growth and development. On the basis of this experience, it appears unnecessary to delay operative correction with the known increased risk of the development of pulmonary hypertension.

This article describes the determination of small systemic ventricular volume by quantitative cineangiocardiography in two patients with congenitally corrected transposition of great arteries, Ebstein's malformation of the systemic atrioventricular valve, and ventricular septal defect. A subjectively small systemic ventricle and an Ebstein-like abnormality of the systemic atrioventricular valve have been described previously in association with congenitally corrected transposition, but in vivo quantification of ventricular size and pump function has not been reported. An initial palliative rather than a totally corrective procedure is probably desirable in patients with this combination of findings. Ventricular volume calculations may prove useful as an aid in selection of operation in this setting.

When a thin oxide (30 A) is sandwiched between two metal electrodes to form a junction and a small dc bias is applied, a current due to tunneling electrons is observed. Electrons near the Fermi level in one metal tunnel through the oxide potential barrier into empty states above the Fermi level in the second metal. For voltages small compared to the barrier height, this tunneling is essentially elastic and the current varies nearly linearly with the voltage.1 More careful examination of the I-V curve by means of the function d2I/dV2 shows that additional channels for tunneling, which parallel the elastic current, become available at certain characteristic voltages. These inelastic electron tunneling (IET) channels produce increases in the conductance dI/dV of the order of 1%. The onset of each new channel occurs when the tunneling electron has sufficient energy to cause excitation of a molecular vibrational mode at the interface or within the metal oxide and still emerge above the Fermi level in the second metal. These characteristic voltages V correspond to the vibrational frequencies ν of molecules contained in the junction, i.e., eV = hν.

The assessment of ventricular function has contributed to the current surgical evaluation and surgical treatment of congenital heart defects, but many issues remain unresolved. The challenge of assessing ventricular function after surgical repair of congenital heart defects includes not only the general problem of distinguishing adverse loading conditions from myocardial failure but also more unique problems of right heart function and developmental differences in ventricular function. The possibility and significance of diastolic dysfunction are essentially unexplored and contingent upon our better understanding of the determinants of diastolic indices. Many of the technologies and methods are currently available and there is the beginning of a move toward better designed clinical trials and analysis of results. The assessment of ventricular function will become increasingly important as surgical techniques are improved and we are left with the more difficult choices between competing approaches.

The antiferromagnetic transition temperature of chromium‐rich V‐Cr alloys has been investigated by means of the extinction of the 51V and 53Cr NMR signals at the transition temperature in these alloys. Measurements on both natural and isotopically enriched 53Cr chromium yield TN=39.0±0.5°C, in excellent agreement with neutron diffraction results. TN decreases roughly linearly with V content, falling below 4.2°K at 3.4% V. In all cases, the resonance intensity follows the empirical behavior, I=I0 tanh K(1‐TN/T), where K ≈ 15. At temperatures well above TN, the linewidth and second moment of the 53Cr resonance are appreciably larger than the calculated values based solely on nuclear dipolar broadening. These results might be attributed to the persistence of a very small electronic moment in the paramagnetic state.

The preparation, calibration, and use of forsterite as an EPR field marker and intensity reference are described. Measurements of field separations and relative line heights at room temperature for the manganese hyperfine lines in forsterite are reported.

The Knight shifts were measured with a Varian Model V-4200B wide-line nuclear magnetic resonance spectrometer. The intervals between the centers of the nuclear resonance in the metal and in the diamagnetic reference sample were measured using the dispersion mode of the NMR signal. In the dispersion mode. the location of the resonance center is insensitive to the position of the noise baseline of the recorded trace. A summary of the relevant Knight shift data for K/sup 39/, ln/sup 115/, and Y/sup 89/ is tabulated. (B.O.G.)