Inmaculada Sánchez Pérez

Una forma rara de cardiopatía cianosante por obstrucción supravalvular tricuspídea en el lactante

Presentamos el caso de un lactante de 2 meses con cianosis desde el primer dia de vida. El diagnostico de sospecha inicial fue displasia tricuspidea, con shunt derecha- izquierda a traves de una comunicacion interauricular. Fue necesario llegar al acto quirurgico para objetivar un «bolson» de tejido supratricuspideo adherido al septo interauricular bajo, que dificultaba el llenado del ventriculo derecho. Tras su reseccion se evidencio el aspecto macroscopico normal de la valvula tricuspide. La histologia fue compatible con tejido fibromixoide. Se discuten la etiopatogenia y posibilidades diagnosticas de este hallazgo inhabitual.

Unusual cyanosing heart defect due to supravalvular tricuspid obstruction in an infant

We present a case involving a rare form of cyanotic congenital heart disease in a 2-month-old neonate. The initial diagnosis was thought to be tricuspid dysplasia with right-to-left shunting through an interatrial communication. However, surgery showed the presence of a pedunculated mass that prolapsed into the tricuspid valve orifice, thereby causing severe obstruction to right ventricular filling. This mass was attached to the lower part of the atrial septum. Pathological examination showed fibrotic myxoid tissue. After the mass was resected surgically, the tricuspid valve appeared normal. We comment on the pathogenesis and the differential diagnosis of this rare entity.

Value of the “Standing Test” in the Diagnosis and Evaluation of Beta-blocker Therapy Response in Long QT Syndrome

INTRODUCTION AND OBJECTIVES Patients with congenital long QT syndrome (LQTS) have an abnormal QT adaptation to sudden changes in heart rate provoked by standing. The present study sought to evaluate the standing test in a cohort of LQTS patients and to assess if this QT maladaptation phenomenon is ameliorated by beta-blocker therapy. METHODS Electrographic assessments were performed at baseline and immediately after standing in 36 LQTS patients (6 LQT1 [17%], 20 LQT2 [56%], 3 LQT7 [8%], 7 unidentified-genotype patients [19%]) and 41 controls. The corrected QT interval (QTc) was measured at baseline (QTcsupine) and immediately after standing (QTcstanding); the QTc change from baseline (ΔQTc) was calculated as QTcstanding - QTcsupine. The test was repeated in 26 patients receiving beta-blocker therapy. RESULTS Both QTcstanding and ΔQTc were significantly higher in the LQTS group than in controls (QTcstanding, 528 ± 46ms vs 420 ± 15ms, P < .0001; ΔQTc, 78 ± 40ms vs 8 ± 13ms, P < .0001). No significant differences were noted between LQT1 and LQT2 patients. Typical ST-T wave patterns appeared after standing in LQTS patients. Receiver operating characteristic curves of QTcstanding and ΔQTc showed a significant increase in diagnostic value compared with the QTcsupine (area under the curve for both, 0.99 vs 0.85; P < .001). Beta-blockers attenuated the response to standing in LQTS patients (QTcstanding, 440 ± 32ms, P < .0001; ΔQTc, 14 ± 16ms, P < .0001). CONCLUSIONS Evaluation of the QTc after the simple maneuver of standing shows a high diagnostic performance and could be important for monitoring the effects of beta-blocker therapy in LQTS patients.