Corrected transposition of the great arteries without associated defects in adult patients: clinical profile and follow up.

OBJECTIVE: To assess the clinical course of adult patients with corrected transposition of the great arteries without associated anomalies.
DESIGN: All patients with corrected transposition of the great arteries without associated anomalies were reviewed with complete clinical and echocardiographic assessment. The complications were evaluated in each decade.
SETTING: Tertiary centre with a specific unit dealing with "grown-up" adolescent and adult congenital heart disease, designated as a quaternary centre and a general hospital with a referral centre for "grown-up" congenital heart disease. PATIENTS: 18 patients (nine male and nine female) aged 16-61 years followed for 1-30 years (mean 10 years).
RESULTS: There were no deaths. Six patients had a worsening ability index during follow up. Complications were: (a) complete heart block in seven, three of whom required pacemaker insertion; (b) significant left atrioventricular valve regurgitation in 50%, appearing only in the third decade (12%), with increasing frequency thereafter. Infective endocarditis was responsible for increasing left atrioventricular valve regurgitation in only one patient; (c) supraventricular arrhythmia appeared in the fifth decade, and occurred in all patients over the age of 60 years. One patient aged 61 had recurrent sustained ventricular tachycardia; and (d) congestive heart failure developed only after 50 years in 66%. One patient had severe left atrioventricular valve regurgitation; the function of the systemic ventricle was only moderately reduced in the other three. Three of the nine women had seven uneventful pregnancies.
CONCLUSIONS: Patients with corrected transposition of the great arteries without associated defects may remain undiagnosed until adult life. Symptoms occur rarely before the fourth and fifth decades, when rhythm disturbance, left atrioventricular valve regurgitation, and moderately impaired systemic ventricular function cause congestive cardiac failure. The role of pacemaker insertion or surgery for left atrioventricular valve regurgitation needs further assessment.