We describe the case of a 29-year-old man with complete heart block after aortic and mitral valve surgery for bacterial endocarditis. Prior to pacemaker implantation, the patient had sinus bradycardia with third degree atrioventricular (AV) block. During testing of the atrial lead, the patient manifested intact AV conduction with a constant PR interval, which was robust up to 120 beats/min. This case represents a dramatic example of unexpected, improved AV conduction, perhaps a result of loss of Phase IV block.