Not all right-sided hearts are the same—the importance of identifying the correct diagnosis

Abstract

Scimitar syndrome is characterized by an anomalous venous return with the characteristic chest roentgenogram (CxR) appearance of the anomalous vein draining into the inferior vena cava (IVC). This appears as a curvilinear opacity paralleling the right border of the heart resembling a curved sword or Scimitar. A 27-year-old white woman with a reported history of dextrocardia was admitted after a drug overdose. Examination demonstrated an obtunded woman with tachycardia and right sided heart sounds. Her CxR revealed a right sided heart image with two curvilinear opacities in the retrocardiac area. Chest computed tomography (CT) demonstrated that these opacities join to represent an anomalous vein draining into IVC. Furthermore, an anomalous systemic artery arising from the abdominal aorta was seen to supply the right lower lobe. The patient was eventually diagnosed with Scimitar syndrome. This syndrome affects 1-3 in 100,000 live births while nearly half of the patients remain asymptomatic with some initially being misdiagnosed as dextrocardia, such as in our case. Correctly diagnosing these patients is of paramount importance as some can develop severe pulmonary hypertension and right ventricular failure. In turn, close ongoing echocardiographic monitoring can help identify those that may benefit from surgical interventions to prevent them from developing these complications.

Variants in myelin regulatory factor (MYRF) cause autosomal dominant and syndromic nanophthalmos in humans and retinal degeneration in mice

“…Four affected individuals have reported dextrocardia, a very uncommon finding in the general population [38]. Scimitar syndrome, an anomalous venous return syndrome associated with MYRF mutations [33], may be misdiagnosed as isolated dextrocardia [67]. As such, dextrocardia in these individuals may represent a milder form of the cardiac anomalies present in syndromic patients carrying MYRF loss of function variants.…”