A number of years ago, this journal reported a young woman with advanced congenital first-degree atrioventricular (AV) block.1 Review of the literature at that time failed to uncover a comparable case. We have recently studied the same patient with His bundle electrocardiography and atrial pacing. To the best of our knowledge, no other account of the electrophysiology of this type of congenital conduction defect has been published.
A 23-year-old woman was admitted to Georgetown University Hospital for gynecologic surgery (tubovarian abscess). At the age of 1 year, an electrocardiogram revealed advanced first-degree AV block.1 No other heart disease was suspected until the age of 10 years when a diagnosis of atrial septal defect was entertained. A year later, surgical repair of a small ostium secundum defect was accomplished at the Mayo Clinic using the well technique. Both preoperative and postoperative exercise tolerance were normal, including response