Sinus bradycardia, junctional rhythm, and low-rate atrial fibrillation in Short QT syndrome during 20 years of follow-up: three faces of the same genetic problem.

We describe the case of an asymptomatic girl with sinus bradycardia and short QT interval at birth, junctional bradycardia in infancy requiring single-chamber pacemaker, atrial fibrillation in adolescence, and V141M mutation in the KCNQ1 gene. Atrial fibrillation recurred and became unresponsive to electrical or anti-arrhythmic therapy. During 20 years of follow-up, a progressive evolution from sinus node dysfunction to low-rate atrial fibrillation was observed.