[Transvenous pacemaker implantation for sick sinus syndrome with mirror-image dextrocardia]

A case of sick sinus syndrome with mirror-image dextrocardia which was associated with bilateral superior vena cava and an absent inferior vena cava with azygos continuation is reported. A 45-year-old woman was referred to our hospital with the chief complaints of dizziness and palpitation. The electrocardiogram showed a atrial fibrillation with a 4-second period of asystole. A permanent endocardial bipolar demand pacemaker was inserted through the left superior vena cava. Since anomaly of venous system is commonly associated with mirror-image dextrocardia, the angiogram is necessary prior to permanent pacemaker implantation.