Scimitar syndrome

Role of computed tomography in adult congenital heart disease: A review

Due to advances in cardiac surgery, perioperative care and transcatheter interventions, the majority of infants with congenital heart disease (CHD) now survive and reach adulthood. Transthoracic Echocardiography (TTE) is considered the primary imaging modality in evaluation of patients with CHD. However, in adults it can be limited due to several reasons. Although cardiac magnetic resonance (CMR) is extremely useful in evaluating cardiac morphology and function, it is not widely available, takes a long time to obtain images, and cannot be done in severely ill patients or patients that have claustrophobia. Due to high spatial and temporal resolution, isotropic imaging fast imaging and wide availability, multidetector computed tomography (MDCT) has emerged as an excellent alternative modality in the evaluation of adult congenital heart disease (ACHD). It can be performed on patients with hardware and those with claustrophobia, due to shorter image acquisition time. In this article, the commonly encountered congenital heart disorders in adults are reviewed, whether incidentally discovered on a computed tomography (CT), on a CT done to evaluate sequela of unknown CHD, or known treated CHD. To appropriately perform and evaluate CT imaging for postoperative correction or palliation congenital heart disease in adults, the imager should know the detailed cardiac anatomy, details of the operative technique used, and be familiar with the common short and long term post-operative complications.

Scimitar Syndrome: Late Presentation and Conservative Management

Partial anomalous pulmonary venous return (PAPVR) is a rare congenital malformation. The infracardiac variant with the right lobe of the lung draining to the inferior vena cava (IVC) is called Scimitar syndrome. The infantile subtype presents before one year of age and the adult variant is also usually diagnosed in childhood.

A 70-year-old woman presented with worsening shortness of breath. An echocardiogram suggested severe pulmonary hypertension that was confirmed by right heart catheterization. A computed tomography (CT) without contrast revealed an anomalous vein from the right upper lobe suggestive of Scimitar syndrome. The patient did not have any other associated congenital heart defects (CHD) (incomplete Scimitar syndrome). A surgical treatment approach was avoided due to the incomplete nature of the Scimitar syndrome.

Incomplete Scimitar syndrome may present later and with less severity than the typical Scimitar syndrome with left to right shunting occurring only in the lung and may be managed nonsurgically.

Scimitar syndrome associated with partial anomalous pulmonary venous draining into superior vena cava

Scimitar syndrome is a rare congenital cardiopulmonary malformation characterized by hypoplasia of the right lung and drainage of the right pulmonary veins into the vena cava inferior. It may also be associated with cardiac dextroversion and anomalies of the tracheobronchial system, cardiovascular system, and diaphragm. Some cases are asymptomatic with others diagnosed in early-childhood period with pulmonary hypoplasia and other associated malformations. We present here a patient whose venous return of the middle and lower lobes of the right lung is into the superior vena cava, which is a very unusual finding for this disorder.

Eponym. Scimitar syndrome

Scimitar syndrome is a rare congenital anomaly, characterized by partial or complete anomalous pulmonary venous drainage of the right or left lung into the inferior vena cava. The syndrome is commonly associated with hypoplasia of the right lung, pulmonary sequestration, persisting left superior vena cava, and dextroposition of the heart. The pathogenesis of the syndrome is unclear, but it seems to originate from a basic developmental disorder of the entire lung bud early in embryogenesis. Two main forms of scimitar syndrome have been described. Signs and symptoms can start during infancy (infantile form) or beyond (childhood/adult form). The infantile form generally presents within the first 2 months of life with tachypnea, recurrent pneumonia, failure to thrive, and signs of heart failure. The diagnosis of scimitar syndrome is usually made based on the characteristic chest X-ray films and can be confirmed by angiography; however, it is now done mostly by transthoracic or transesophageal echocardiography, noninvasive computed tomography, or magnetic resonance angiography. Fetal echocardiography using three-dimensional power Doppler imaging permits prenatal diagnosis. Most frequently, patients are asymptomatic in the absence of associated abnormalities and can be followed conservatively. For patients with congestive heart failure, repeated pneumonia, or pulmonary-to-systemic blood flow ratios greater than 1.5 and pulmonary hypertension, it is important to reroute the anomalous right pulmonary veins and repair the associated cardiac defects in order to avoid progression to right ventricular failure. The triad of respiratory distress, right lung hypoplasia, and dextroposition of the heart should alert the clinician to think of scimitar syndrome.

Scimitar Syndrome: Experience with 6 Patients

Scimitar syndrome is a rare congenital anomaly characterized by anomalous pulmonary venous drainage to the inferior vena cava, causing a left-to-right shunt. Six patients with scimitar syndrome were diagnosed in our hospital between 2002 and 2008. There were 4 girls and 2 boys; 4 < 5 kg in weight, 2 < 8 kg in weight. Scimitar syndrome was suspected in 5 cases because of dextroversion, and diagnosed by color Doppler echocardiography in all 6 when a scimitar vein was detected entering the inferior vena cava. Computed tomography confirmed the diagnosis in all patients. Two patients had horseshoe lung, 2 had a unilobar right lung, 1 had a hypoplastic right lung, and 1 had a hypoplastic right lower lobe. Three patients had severe pulmonary arterial hypertension, 2 had moderate pulmonary arterial hypertension, and one had normal pulmonary arterial pressure. All patients had lower respiratory tract infections, volume loss of the right lung, a normal or hyperinflated left lung, dextroversion of the heart, and scimitar arteries from the descending aorta. Pneumonectomy was performed in 3 patients, lobectomy in 1, ligation of anomalous vessels in 1, and 1 died before surgery.

Pre- and postoperative evaluation of congenital heart disease in children and adults with 64-section CT

Although echocardiography is the imaging method of choice for diagnostic, preoperative, and postoperative evaluation of congenital heart disease, computed tomography (CT) is a helpful complementary imaging modality, particularly for postoperative evaluation. A thorough understanding of the normal anatomy and the morphologic features of congenital heart diseases is a prerequisite for choosing the optimal CT technique and achieving an accurate diagnosis. Furthermore, a close collaboration with a cardiologist with special training and expertise in congenital heart diseases is required. A sequential segmental approach should be used in evaluating morphologic features, especially during the review of CT images obtained in patients with rare congenital cardiac defects and in postoperative adult patients. To accurately document and interpret the altered flow conditions in patients with congenital heart disease, knowledge of the wide spectrum of surgical procedures and familiarity with the dedicated protocols for performing 64-section CT are needed.

Scimitar syndrome; an unusual congenital abnormality occasionally seen in adults

Scimitar syndrome a very rare and variable congenital disorder characterized by an anomalous connection of the pulmonary vein with the IVC. The syndrome is mostly seen in very early infancy, but was now recognized in a 46-year-old woman, who was referred to the outpatient clinic of the department of cardiology with complaints of dizziness. Contrast enhanced computer tomography (CT) showed dextroposition of the heart and a large right pulmonary vein joined the inferior vena cava (IVC) just above the level of the diaphragm. The typical features of the syndrome are discussed.