Alison Hayes

Antegrade diastolic pulmonary arterial flow as a marker of right ventricular restriction after complete repair of pulmonary atresia with intact septum and critical pulmonary valvar stenosis

In order to examine right ventricular diastolic function after complete correction of pulmonary atresia with intact ventricular septum and critical pulmonary valvar stenosis, we undertook a prospective analysis of seven patients who had previously undergone successful repair. Comparison was with age and sex-matched controls. The relationship between antegrade pulmonary arterial diastolic flow and other indices of right ventricular dysfunction were compared. The ratio of the velocity of early rapid filling to that of atrial systolic flow was no different from normal, but the deceleration of early rapid filling showed significant shortening with inspiration in patients, but not in control subjects. All patients, but none of the controls, demonstrated significant antegrade diastolic pulmonary arterial flow during late diastole. Despite “normal” ratios ofvelocity of early rapid filling to systolic atrial flow, patients after complete correction of pulmonary atresia with intact ventricular septum and critical pulmonary stenosis have abnormal right ventricular diastolic function typical of a restrictive physiology. This presumably reflects incomplete adaptation due to the presence of endomyocardial fibrosis.

Determinants of hemodynamic results of balloon dilation of aortic recoarctation

Between October 1982 and May 1990, balloon dilation of aortic recoarctation was attempted in 27 patients. In 1 case dilation was not performed owing to suspected aortic perforation. The remaining 26 patients had 30 procedures. The age at the first dilation ranged between 2.6 months and 18.3 years. After dilation, systolic gradient decreased from 49 +/- 17 mm Hg to 20 +/- 17 mm Hg (p less than 0.001). A reduction of gradient to less than or equal to 20 mm Hg occurred after the first dilation in 17 of 26 (65%) patients. Residual gradients between 25 and 80 mm Hg were present in the remaining 9 patients. During follow-up of 2 months to 6.7 years, 5 of 17 patients with a good initial result developed further recoarctation (2 had successful redilation, 2 had reoperation, and 1 is awaiting repeat dilation). Of 9 patients with gradients greater than 20 mm Hg after the first dilation, 1 had successful redilation and 3 had reoperation. The remaining 5 patients are being managed conservatively. 2 patients developed aneurysms after dilation (1 immediately and the other at 2 months). In all, 15 patients (58%) had a good, and 11 (42%) a poor late hemodynamic result. Aortic diameters at different levels of the aortic arch and at the reconstructed isthmus (normalized to the aorta at the level of the diaphragm) were significantly higher in the group with a good late result than in that with a poor one. Balloon/aortic diameter ratio at diaphragm level also had a significant influence on the late results.

Double-outlet right ventricle: morphologic demonstration using nuclear magnetic resonance imaging.

Sixteen patients with double-outlet right ventricle, aged 1 week to 29 years (median 5 months), were studied with a 1.5 tesla nuclear magnetic resonance (NMR) imaging scanner. Two-dimensional echocardiography was performed in all patients. Thirteen patients underwent angiography, including nine who underwent subsequent surgical correction. Three patients underwent postmortem examination. Small children and infants were scanned inside a 32 cm diameter proton head coil. Multiple 5 mm thick sections separated by 0.5 mm and gated to the patients electrocardiogram were acquired with a spin-echo sequence and an echo time of 30 ms. A combination of standard and oblique imaging planes was used. Imaging times were less than 90 min. The NMR images were technically unsuitable in one patient because of excessive motion artifact. In the remaining patients, the diagnosis of double outlet right ventricle was confirmed and correlated with surgical and postmortem findings. The NMR images were particularly valuable in demonstrating the interrelations between the great arteries and the anatomy of the outlet septum and the spatial relations between the ventricular septal defect and the great arteries. Although the atrioventricular (AV) valves were not consistently demonstrated, NMR imaging in two patients identified abnormalities of the mitral valve that were not seen with two-dimensional echocardiography. In one patient who had a superoinferior arrangement of the ventricles, NMR imaging was the most useful imaging technique for demonstrating the anatomy. In patients with double-outlet right ventricle, NMR imaging can provide clinically relevant and accurate morphologic information that may contribute to future improvement in patient management.

An unusual cause of cyanosis after the modified Fontan procedure—closure of venous communications between the coronary sinus and left atrium by transcatheter techniques

Communication of the coronary sinus with the left atrium is an unusual anomaly. Two cases of tricuspid atresia are described where systemic desaturation developed following a modified Fontan procedure. In both, investigation demonstrated a communication between the coronary sinus and the left atrium. Transcatheter closure of these communications was achieved with a ductal device in one case and coil embolization in the other. Following occlusion and elimination of the right-to-left shunt, both patients became fully saturated in room air.

Evaluation of pulmonary artery anatomy using magnetic resonance: The importance of multiplanar and oblique imaging

SummaryPulmonary artery anatomy was studied in 36 patients (age range 12 days to 12.83 years, mean 2.9 years) with right ventricular outflow tract obstruction over a 3-year period using a 1.5 Tesla Magnetic Resonance system. Gated spin-echo sequences were obtained in each patient. Image planes used were straight and oblique transverse, oblique coronal, and oblique sagittal. The studies were analyzed retrospectively and comparative angiographic, surgical, and postmortem data was available in all cases. As previously noted with other imaging modalities, multiple views and oblique cuts were found to increase significantly the quality and accuracy of the information acquired. In 12 of the 15 patients who had axial and coronal imaging of both branch pulmonary arteries, the pulmonary arteries were unequivocally demonstrated to at least the first hilar branch. However, early in our experience we missed a number of branch stenoses that developed following surgical anastomoses. These mistakes were caused by inadequate or inappropriate slice acquisition. Magnetic resonance is an important technique for imaging pulmonary arteries. Careful use of the appropriate imaging planes is essential for accurate demonstration of the anatomy.