ABSTRACT
Twin AV nodes is a very rare condition found exclusively in a subset of patients with cardiac involvement from heterotaxy syndrome. Nearly all patients who suffer from recurrent tachycardia related to this problem will have equally complex structural heart disease that requires surgical intervention, and failure to control tachycardia can greatly complicate perioperative management and recovery. Catheter ablation of one AV node is a potential solution in problematic cases. Although it remains a rare entity and ablation experience is still quite limited, it is nonetheless a brilliant example of the instructive link between embryologic development and cardiac arrhythmias. Improved recognition of this condition is resulting in expanded clinical material that will hopefully fill in the many remaining blanks in our understanding. Twin node tachycardia, and heterotaxy in general, still have a lot to teach us.
