Hemodynamic evaluation before and after balloon atrial septostomy in patients with transposition of the great arteries using pulsed Doppler echocardiography

In nine patients with transposition of the great arteries, hemodynamic changes after the initial balloon atrial septostomy (BAS) were investigated using pulsed Doppler echocardiography and cardiac catheterization. Patients consisted of five males and four females, who ranged in age from zero to 82 days (median, one day). All but one who had ventricular septal defect had no associated cardiac anomalies other than patent ductus arteriosus. Prostaglandin E1 was administered before and after BAS to four patients who had hypoxemia. At cardiac catheterization, right and left atrial pressures and arterial oxygen partial pressure were measured. Using pulsed Doppler echocardiography, the time-velocity curve was recorded at the tricuspid and mitral valves, pulmonary artery, ascending aorta and interatrial septum. The maximum diastolic velocity was measured from the tricuspid and mitral valve time-velocity curves. The product of the time-velocity integral and heart rate was measured from the time-velocity recordings at the pulmonary artery and ascending aorta. The duration of the left-to-right shunt at the foramen ovale was measured and was normalized by corresponding R-R intervals on the electrocardiogram. After BAS, left atrial pressures and pressure gradients between both atria decreased significantly (p less than 0.01). Arterial oxygen partial pressure increased from 24.4 +/- 7.2 to 40.4 +/- 6.0 mmHg (p less than 0.01). The maximum flow velocity at the tricuspid valve increased significantly (p less than 0.01), but that at the mitral valve showed no significant change after BAS. The velocity time integral of the aorta increased significantly (p less than 0.01), but that of the pulmonary artery did not.(ABSTRACT TRUNCATED AT 250 WORDS)