Use of ECGs in ACHD Evaluation Identification of sinus bradycardia or junctional rhythm in patients at risk of sinus node dysfunction (especially after the Mustard, Senning, Glenn, or Fontan procedure) Identification of clinically inapparent intra-atrial re-entry tachycardia in patients who have had atriotomy Identification of atrioventricular block in patients at risk for progression of atrioventricular conduction system disease (especially CCTGA) Evaluation of rhythm in patients with pacemakers Measurement of QRS duration in patients after repair of TOF and as part of CRT evaluation Preoperatively to compare with postoperative ECGs in patients undergoing heart surgery and noncardiac surgery Postoperatively to identify arrhythmias (eg, atrial ectopic tachycardia, atrial flutter, AF, junctional ectopic tachycardia, atrioventricular block) Diagnosis of Wolff-Parkinson-White Syndrome in patients with Ebstein anomaly Initial evaluation of suspected acute coronary syndromes ACHD indicates adult congenital heart disease; AF, atrial fibrillation; CCTGA, congenitally corrected transposition of the great arteries; CRT, cardiac resynchronization therapy; ECG, electrocardiogram; and TOF, tetralogy of Fallot. Table 8. Circumstances Where CMR, CCT, TEE, and/or Cardiac Catheterization May be Superior to TTE Assessment of RV size and function in repaired TOF, systemic right ventricles, and other conditions associated with RV volume and pressure Identification of anomalous pulmonary venous connectionsS3.4.4-16 Serial assessment of thoracic aortic aneurysms, especially when the dilation might extend beyond the echocardiographic windowsS3.4.4-7 Accurate assessment of PA pressure and pulmonary vascular resistance Assessment for recoarctation of the aorta Sinus venosus defects Vascular rings Evaluation of coronary anomalies Quantification of valvular regurgitation CCT indicates cardiac computed tomography; CMR, cardiovascular magnetic resonance; PA, pulmonary artery; RV, right ventricular; TEE, transesophageal echocardiography; and TOF, tetralogy of Fallot. 