Long QT syndrome diagnosed in two sisters with propionic acidemia: a case report.

Propionic acidemia (PA) is a rare autosomal recessive metabolic disorder caused by deficiency of the mitochondrial enzyme propionyl-CoA carboxylase (PCC). This disorder mostly progresses with episodes of metabolic acidosis. Cardiomyopathy is among the cardiac complications known to occur during metabolic decompensation episodes. However, several recent papers emphasized the association of PA and long QT syndrome (LQTS) which may lead to extremely serious and fatal consequences. In this report, we describe two sisters with PA who have prolonged QT duration that were incidentally detected in an outpatient setting. LQTS was verified by electrocardiogram, stress test and 24 h rhythm holter monitoring. By this report, we want to emphasize the importance of early diagnosis of LQTS in asymptomatic patients with PA to prevent fatal complications.