Objective: To define occurrence, lesions and clinical characteristics of grown-up congenital heart (GUCH) patients who develop atrial flutter (AFL).
Design: All GUCH patients who presented as inpatients or outpatients with documented sustained AFL between 1996 and 1998 were studied prospectively. Retrospective review of case notes for basic data relating to underlying anomaly, prior surgery and age at onset of AFL, enquiry into events before the first attack. Clinical state was assessed by Ability Index before AFL and at last visit.
Setting: Designated quaternary service for GUC in a tertiary referral centre.
Results: From October 1996 to April 1998, 100 consecutive patients (49 female) aged 17-77 (mean 35) years, who presented to the GUCH Unit at Royal Brompton Hospital with a sustained attack of AEL documented by a 12 lead electrocardiogram were studied. Four basic cardiac anomalies accounted for 75% patients: one ventricle (26), atrial septal defect (ASD) (19), transposition of great arteries (TGA) (17) and Tetralogy of Fallot (13). AFL occurred occasionally in small ventricular septal defect (VSD), congenital corrected TGA (CC-TGA), pulmonary stenosis and pulmonary atresia with or without VSD. 86/100 patients had undergone cardiac surgery: Fontan 19 (22%), reconstruction of right ventricular outflow tract 17 (20%), closure of ASD 15 (17%), Mustard for TGA 13 (15%), and other palliative surgery 22 (26%). AFL occurred in 'natural history' (unoperated) in 14 (14%) mostly in CC-TGA, ASD and Fallot. Age at first attack was 6-64 (mean 28) years with the first attack occurring at younger age after Mustard (22+/-7 years) and Fontan (24+/-7), than in un-operated ASD (46+/-13) and CCTGA (31+/-10). Haemodynamic abnormalities from anatomical causes were present in 62/74 (84%) patients who had undergone reparative surgery and included venous pathway obstruction, pulmonary regurgitation and pulmonary hypertension. Additional factors which could have precipitated AFL in prone patients were present in 63. New symptoms appeared in 96 patients with the first attack of AFL. Ability Index prior to onset in 90 patients who have been followed-up for more than 1 year since the first onset was 1 in 52, 2 in 31, 3 in 6 and 4 in 1 patients. At the last visit (mean time from the first onset 6.6+/-4.7 years), only 9 patients remained with Ability Index 1, 43 in 2, 20 in 3 and 18 in 4 despite return to sinus rhythm.
Conclusion: One ventricle heart, ASD, transposition of great arteries and Tetrology of Fallot are the most common underlying anomalies in GUCH patients who develop AFL. It is less commonly seen in unoperated patients. When occurs AFL compromises patients' activities and deteriorates the clinical condition. Residual or developed haemodynamic abnormalities and precipitating factor are often present in this patients, hence full investigation and close follow up are necessary once AFL develops.