Atrial tachyarrhythmia in adult congenital heart disease

Figure 2 Electrocardiograms from a patient with a Mustard procedure. A: Sinus rhythm with 1^st degree heart block. Patient feeling well; B: Intra-atrial reentry tachycardia with 2:1 ventricular conduction, alternate p-waves not seen as overlapping with QRS complexes. Patient complaining palpitations initially. Within 3 h unable to lie flat, requiring oxygen for desaturation and with pulmonary edema on chest X-ray. Note incorrect automated diagnosis of sinus tachycardia.