Surgical management of tetralogy of Fallot in the first year of life.

BACKGROUND: The surgical approach to tetralogy of Fallot (TOF) continues to evolve and now many centers favor early repair for TOF. METHODS: Our experience includes 82 consecutive patients less than 1 year old with TOF (n = 74) and TOF with pulmonary atresia (n = 8) who were operated on between January 1992 and March 1998. Mean age at repair was 5.2 +/- 1.2 months and mean weight was 4.5 +/- 0.4 kg. Seven patients (anomalous left anterior descending artery [n = 1], pulmonary atresia with hypoplastic pulmonary arteries [n = 6]), underwent palliative procedures in the neonatal period followed by complete repair. Forty-nine patients (59%) were symptomatic (severe cyanosis or hypoxic spells), and 33 patients (41%) were asymptomatic. A combined transatrial-transpulmonary approach was employed in 28 patients (34%), and transannular patch or conduit for reconstruction of the right ventricular outflow tract (RVOT) was required in 54 patients (66%). The mean Nakata index was 160 +/- 25 mm2/m2. RESULTS: There were no hospital deaths. Mean post-repair peak right ventricular/systemic pressure ratio was 0.48 +/- 0.1. There were no late deaths or reoperations during a mean follow-up of 23 +/- 5 months. All patients are currently asymptomatic and in New York Heart Association class 1. Postoperative evaluation by two-dimensional and Doppler echocardiography or cardiac catheterization showed minimal pulmonary artery stenosis with a mean pressure gradient of 15 +/- 6 mm Hg across the RVOT. CONCLUSIONS: Our experience suggests that early repair of TOF can yield excellent results and initial palliation does not preclude early complete repair.

Surgical treatment of right ventricular myxoma in infancy.

Myxomas are the most common of all primary cardiac tumors in adults. They are extremely rare in infancy. We report on a 5-month-old infant who was admitted in a state of cardiogenic shock. Echocardiography showed a right ventricular myxoma completely occluding the right ventricular outflow tract. prompt surgical removal of the tumor resulted in a excellent outcome.

Abnormal coronary perfusion in experimental scorpion envenomation.

Perfusion defects and left ventricular dilation after experimental scorpion envenomation were evaluated in five dogs. Left Left ventricular dilation was observed in three dogs and right ventricular dilation in one other, in scans immediately after envenomation. Perfusion defects were inferred from scans in four dogs. The data are strongly suggestive of coronary hypoperfusion, and the mechanics of abnormal coronary flow after scorpion envenomation are discussed.

Effect of endogenous digoxin-like substances on the interpretation of high concentrations of digoxin in children.

The objective of this study was to assess the effect of endogenous digoxin-like substances on the interpretation of excessive concentrations of digoxin in children. After the development of a high-pressure liquid chromatography (HPLC) method for digoxin in our laboratories, we analyzed sera of children in whom the fluorescence polarization immunoassay identified potentially toxic concentrations of the glycoside (greater than 3 nmol/L; 2.3 ng/ml). Sixteen of them were receiving long-term digoxin therapy, and one had an accidental overdose. The immunoassay yielded significantly higher concentrations (4.1 +/- 1.2 nmol/L; 3.2 +/- 0.9 ng/ml) than the HPLC method (3.3 +/- 1.6 nmol/L; 2.6 +/- 1.2 ng/ml; p less than 0.01). In five cases (30%) these differences were clinically significant because administration of digoxin had been discontinued in the presence of true digoxin concentrations within the therapeutic range and the lack of clinical toxic effects. These data suggest that therapeutic drug monitoring using immunoassays of digoxin may be too inaccurate to detect potential toxic effects, and that much more weight should be focused on clinical monitoring. The HPLC method for assay of digoxin is extremely meticulous and will not become clinically available; therefore the development of better immunoassays should be encouraged.