Quadricuspid aortic valve: a report of 12 cases and a review of the literature.

Quadricuspid aortic valve (QAV) is rare and its diagnosis, clinical course, and management are less well defined relative to other aortic valve abnormalities. Advances in diagnostic imaging, notably in ultrasound, have increased clinical awareness of this anomaly and prompted this review of our experience with 12 new patients and a compilation of previously reported patients to further characterize this condition.