Presentamos el caso de una mujer de 28 años, diagnosticada de prolapso de la válvula mitral con insuficiencia mitral moderada que ingresó en la unidad para monitorización del ritmo cardíaco al presentar arritmias ventriculares con el hallazgo de QTc prolongado sin causa conocida. Durante su ingreso mostró, sin embargo, predominancia de la bradicardia sinusal, marcapasos errante y en ocasiones taquicardias supraventriculares. La observación de los trastornos del ritmo, las malformaciones esqueléticas, similares a las presentes en un familiar directo y el diagnóstico de cardiopatía estructural nos hizo pensar en la presencia de un síndrome mendeliano que englobara estos hallazgos. Esto facilitó el diagnóstico del síndrome de Holt-Oram.

Holt-Oram syndrome is an autosomal dominant disease due to a genetic mutation at chromosome 12q. It is characterized by malformations of the upper extremities and congenital heart disease, which may be familial or present in an isolated individual. Malformation of the upper extremities range from the scarcely noticeable, such as hypoplasia of a finger/digital hypoplasia to severe hypoplasia or lack of arms. The most common cardiac abnormality is atrial septal defect although other structural alterations have been described, as well as different types of arrhythmias, especially atrioventricular conduction abnormalities for wich electrostimulation with a permanent pacemaker is sometimes required.

We present the case of a 28-year-old woman, diagnosed with mitral valve prolapse and moderate mitral insufficiency. On presentig ventricular arrhythmia with prolonged QTc with no known cause, she was admitted to the intensive care unit for cardiac rhythm monitoring. While in hospital, however, she showed predominance of sinus bradycardia, erratic pacemaker and occasional supraventricular tachycardias. The observation of rhythmic alterations, skeletal malformations, similar to those of a direct relative and the diagnosis of structural heart disease led to the suspicion of a Mendelian syndrome which would include these findings. These observations lead to the diagnosis of Holt-Oram syndrome.