Coronary echocardiography in tetralogy of fallot: diagnostic accuracy, resource utilization and surgical implications over 13 years.

OBJECTIVES: This study sought to determine the diagnostic accuracy and impact of the systematic use of coronary echocardiography in a large group of preoperative patients with tetralogy of Fallot (TOF).

BACKGROUND: Accurate preoperative identification of an anomalous coronary artery crossing the right ventricular outflow tract (RVOT) in patients with TOF is important to prevent coronary injury during surgical repair.

METHODS: A retrospective review identified 598 patients with TOF between 1983 to 1995 who underwent an echocardiogram at <2 years old before complete surgical repair. Associated diagnoses included pulmonary stenosis (n = 433), pulmonary atresia (n = 121), common atrioventricular canal (n = 17), absent pulmonary valve syndrome (n = 24) and aortopulmonary window (n = 3).

RESULTS: Based on intraoperative findings, 32 patients (5.4%) were found to have a major coronary artery crossing the RVOT. The use and diagnostic performance of coronary echocardiography increased over time, while the number of patients undergoing preoperative cardiac catheterization declined. During the most recent study period (1991 to 1995, n = 274), 97% of patients underwent coronary echocardiography yielding a sensitivity of 82%, specificity of 99% and accuracy of 98.5%. Of the 18 patients with TOF and pulmonary stenosis who had abnormal coronary arteries during this period, only 6 (33%) required an extracardiac conduit as part of their complete repair.

CONCLUSIONS: Coronary echocardiography is an accurate noninvasive tool to delineate coronary anatomy in infants with TOF before complete repair. Routine preoperative cardiac catheterization solely for diagnosis of coronary anatomy is not necessary. The use of an extracardiac conduit can be avoided in the majority of patients with TOF and pulmonary stenosis who have a major coronary artery crossing the RVOT.