Qualitative radionuclide angiocardiography in the diagnosis of corrected transposition

Scintigraphic imaging of a case of congenitally corrected transposition of the great vessels and an adult case of single atrium and single ventricle

We report on the clinical utility of radionuclide angiography and gated blood pool single emission computed tomography (gated blood pool SPECT) in two patients having congenital heart disease. Both conventional equilibrium radionuclide angiography and gated blood pool SPECT demonstrated the connection of the great vessels with both ventricles in a 15-year-old male patient with a congenitally corrected transposition of the great vessels. In particular, the latter procedure could provide very useful information about the ventricular morphology and inversion which is important for diagnosing this disorder. The second case is an extremely rare 42-year-old female patient with a single atrium and single ventricle. She underwent first-pass and multiple gated blood pool angiography from the anterior, right and left oblique views. The combination of these scintigraphic techniques revealed an insufficiency in anatomical correlations among the single atrium, atrioventricular valve, single ventricle and the great vessels in addition to the connection of superior vena cava with the single atrium, and the atrioventricular valve. Thus, conventional equilibrated angiography from multiple views and gated blood pool SPECT seems to be very reliable not only for anatomical evaluation but also for clinical course observation in patients with complicated congenital heart disease.

Radionuclide angiographic evaluation of ventricular function in isolated congenitally corrected transposition of the great arteries

Eight asymptomatic patients (mean age 19 years, range 7 to 32) with congenitally corrected transposition of the great arteries (CCTGA) underwent equilibrium gated radionuclide angiocardiography at rest and during supine bicycle exercise to assess systemic (morphologic right) and pulmonary (morphologic left) ventricular function. Five patients had normal intracardiac hemodynamic values, 2 had trivial atrioventricular valve regurgitation and 1 patient had trivial pulmonary ventricular outflow tract obstruction. Average exercise duration was 11 +/- 1 minute, with limitation due only to fatigue. At peak exercise, heart rate increased 225% and systolic blood pressure 152% over the rest value. Pulmonary ventricular ejection fraction at rest was 51 +/- 3% (mean +/- standard error of the mean); it did not change significantly at peak stress, 53 +/- 2%. Systemic ventricular ejection fraction was 48 +/- 4% at rest and increased to 64 +/- 4% at peak exercise (p less than 0.01). Count-based volume changes for the pulmonary chamber showed no significant change in end-diastolic or systolic counts at peak exercise (109 +/- 8% and 106 +/- 9% of rest value, respectively). However, end-diastolic counts decreased 13% (87 +/- 3% of rest value) and end-systolic counts 34% (62 +/- 7% of rest value) at peak exercise in the systemic ventricle. These data suggest normal systemic and impaired pulmonary ventricular function in patients with congenitally corrected transposition of the great arteries unaccompanied by significant associated lesions. These findings have important clinical implications in the setting of complex congenital heart disease in patients in whom a morphologic right ventricle functions as the systemic pumping chamber. Despite the pulmonary ventricular dysfunction, symptoms were not apparent at rest or during exercise.

The clinical features and diagnosis of a discordant atrioventricular connexion

Seventy-three patients were studied with a discordant atrioventricular connexion (ages 3 months to 46 years). In 58 the diagnosis was proved by angiography and in the other 15 at necropsy. Forty-eight had usual atrial arrangement and 25 mirror-image atria. Fifty-two patients had ventriculo-arterial discordance, 13 double outlet right ventricle, 4 ventriculoarterial concordance, 3 single outlet of the heart and 1 double outlet left ventricle. Nine with ventriculoarterial discordance had no other associated defects. The spatial relationship of the ventricles was variable, but in usual atrial arrangement the morphologically left ventricle tended to be on the right, and in mirror-image arrangement to the left of the morphologically right ventricle. The spatial relationship between the arterial valves was also variable, but in ventriculoarterial discordance and double outlet right ventricle the aortic valve was anterior and either to the right or left of the pulmonary valve in all but 3 cases. There is no typical clinical picture for these malformations. Symptoms depend upon the associated anomalies or the presence of atrioventricular dissociation. The diagnosis of a discordant atrioventricular connexion is best achieved by the echocardiographic and haemodynamic studies, but the electrocardiogram, chest radiograph and nuclear medicine studies may suggest its presence. Most patients are asymptomatic and progress normally to adult life. Only the symptomatic patients require surgical correction. Postoperative follow-up in the survivors is excellent, only 2 of 14 patients dying after surgery.