Atrial tachyarrhythmia in adult congenital heart disease

Figure 1 Electrocardiograms from a patient with an interatrial lateral tunnel Fontan for double inlet left ventricle. Patient has an epicardial DDI pacemaker for management of postoperative complete heart block. A: Atrio-ventricular sequentially paced rhythm. Patient feeling well; B: Grouped beating with V paced beats and intermittent p-waves. Underlying intra-atrial reentry tachycardia with AV Wenkebach demonstrated on device tracing (not shown). Patient complaining palpitations.