Children with repaired tetralogy of Fallot, double-outlet right ventricle, or truncus arteriosus who underwent CMR and echocardiography within a 4-week interval were retrospectively studied. From the four-chamber view, indexed RV lateral wall length, indexed RV end-diastolic perimeter length, and indexed RV end-diastolic area (RVEDAi), were measured. Results were compared with CMR indexed RV volume. The sensitivity and specifity of echocardiographic threshold values predicting RV volumes < 170 mL/m2 were determined.
Fifty-one children (mean age, 12.7 卤 3.5 years; 25 male, 26 female) were reviewed. RVEDAi was correlated with CMR indexed RV volume (r聽= 0.60, P < .0001). Indexed RV end-diastolic perimeter length and indexed RV lateral wall length were not correlated with CMR. RVEDAi < 20 cm2/m2 had 100%specificity to predict indexed RV volume 鈮?170 mL/m2 (area under the curve, 0.79), reducing the need for CMR in 15 of 51 patients (29%). A threshold RVEDAi of 22 cm2/m2 would reduce the need for CMR in 21 of 51 patients (41%) at the expense of one false-negative result. The coefficients of variation were 14.7%for intraobserver variability and 9.6%for interobserver variability.
The specificity of echocardiography-measured RVEDAi can be set to predict RV volumes below a 170 mL/m2 threshold in 100%of cases. This may reduce the need for CMR to determine RV volumes in 鈮?5%of patients with congenital heart disease, potentially reducing patient burden and costs.