Scimitar Syndrome


The scimitar syndrome is a complex malformation of the heart, lungs, and blood vessels. The main feature of this malformation is the anomalous drainage of the pulmonary veins into the inferior vena cava.

Scimitar syndrome represents a combination of pulmonary hypoplasia and partial anomalous pulmonary venous return (PAPVR) which can be noted on CXR and can be documented angiographically. Classically, there is displacement of the cardiac silhouette to the right; a small right lung; with a prominent curved (‘scimitar’) vein draining the right lung to the inferior vena cava (IVC). The majority of cases are manifest on the right side.

  • Scimitar: The English word scimitar refers to a single-edged backsword or sabre with a curved blade. Probably adapted from the Italian word scimitarra in the 16th century. The term was used for all curved ‘Oriental’ blades as distinct from the straight, double-edged European swords of the time.
  • Pulmonary hypoplasia (PH): deficient or incomplete development of parts of the lung.
  • Partial anomalous pulmonary venous return (PAPVR): rare congenital cardiovascular condition in which some of the pulmonary veins, but not all, drain into the systemic circulation rather than in the left atrium. [aka partial anomalous pulmonary venous connection (PAPVC)]


1836 –  English pathologist George Cooper published an “account of a case which fell under my own notice, of transposition of the heart, and imperfect development of the right lung, while the vessels and viscera of the abdomen retained their usual relative situations.” In 1833, Cooper had performed an autopsy on a 10-month-old girl and described right pulmonary hypoplasia, partial right pulmonary arterial supply from the aorta, and partial right lung venous drainage to the inferior vena cava.

1836 –  Raoul Chassinat (1807-1891) accurately defined the anatomy of the anomalous venous return [Legend: in French]

1912 – The pathology of this disease was described in detail by EA Park. He reported the postmortem observation of an anomalous pulmonary venous drainage of the right lung into the diaphragmatic portion of the inferior vena cava in three infant patients 

1949 – Dotter et al made the first clinical diagnosis of the anomaly. used the “newly developed technique of venous angiography”, angiocardiography and cardiac catheterization to define the anomalous vessel course In the first published report of the radiographic findings of the “un-named syndrome”, Dotter described the anomaly as

Curving downward through the right lower lung field was a band-like shadow which widened gradually as it descended, paralleling the right cardiac border.

Dotter, 1949: 32

1956 – Halasz et al were the first to actually use the word ‘‘scimitar’’ as a description in their analysis of three cases of anomalous pulmonary venous return to the inferior vena cava. They analysed the clinical, radiographic, circulatory/pulmonary function, and anatomic features in a total of 21 cases.

Radiographic Findings. In the plain films the most striking appearance, which should at once suggest the diagnosis, was that of a dagger or scimitar-shaped vascular density more or less parallel to the right cardiac border, but tending to deviate laterally into the lung field near its tapering upper end (Fig 1, 11, 20)

Halasz. 1956
Halasz Scimitar syndrome 1956
The scimitar-shaped anomalous vein (arrows) is more or less parallel to the right border of the enlarged and dextroposed heart. Halasz. 1956

1960Neill et al defined the pathophysiology, clinical findings and familial occurrence and defined two clinically distinct groups of patients. The first groups included sick infants with complications of severe pulmonary hypertension; and the second group compromised typically asymptomatic adults usually incidentally diagnosed following CXR performed for other reasons. Neil termed the condition ‘scimitar syndrome’

Associated Persons

Alternative names
  • pulmonary venolobar syndrome
  • hypogenetic lung syndrome

Scimitar syndrome CXR vein with scimitar 001
Scimitar syndrome CXR vein with scimitar 002


the names behind the name

BA MA (Oxon) MBChB (Edin) FACEM FFSEM. Emergency physician, Sir Charles Gairdner Hospital.  Passion for rugby; medical history; medical education; and asynchronous learning #FOAMed evangelist. Co-founder and CTO of Life in the Fast lane | Eponyms | Books | Twitter |

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