Wu Mei-Hwan, Wang Jou-Kou, Lin Jiunn-Lee, Lin Ming-Tai, Chiu Sheun-Nan, Chen Chun-An
Department of Pediatrics, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei, Taiwan.
Heart Rhythm. 2008 Feb;5(2):224-9. doi: 10.1016/j.hrthm.2007.10.010. Epub 2007 Oct 7.
Twin AV nodes and resulting supraventricular tachycardia (SVT) have been described in right atrial isomerism (RAI).
We sought to analyze the long-term outcome of patients with RAI with a focus on rhythm disturbances.
Retrospective study of 257 patients (152 male and 105 female, 1,171 patient-years) with RAI diagnosed between 1980 and 2005.
SVT in 68 patients (26%) occurred at various ages from the prenatal period to 15 years and was only significantly associated with balanced ventricles (P = .009). Cardioversion was achieved in by verapamil in 6 of 6 cases (100%), adenosine in 18 of 21 cases (88%) and propranolol in 10 of 12 cases (83%). Electrocardiographic evidence of twin AV nodes, as shown by 2 discrete non-pre-excited QRS complexes, was found in 28 of 44 (64%) patients with more than 2 electrocardiograms, and was more frequent in those with balanced ventricles rather than a dominant ventricle and would increase risk of SVT. Recurrence of SVT was documented in 27 (40%) patients 1 day to 4.5 years after the first episode. However, the occurrence or recurrence of SVT was not associated with increased all-cause or surgical mortality or sudden death. Successful catheter ablation of ventriculoatrial pathways with junctional ectopic tachycardia at radiofrequency energy delivery was obtained in 5 of 6 patients.
This study showed that twin AV nodes in RAI patients could be disclosed by serial electrocardiograms and that SVT, most likely a twin node tachycardia, was common and tended to recur but could be managed by ablation or medication.
