Disease summary: The Bland-White-Garland syndrome (BWGS) is an extremely rare congenital cardiac abnormality [28]. This syndrome was first mentioned in 1886, but the full anatomy and clinical symptoms were first described by Bland, White and Garland in 1933 [5, 6]. Within this syndrome, the left coronary artery (LCA) has an unexpected anomalous origin from the pulmonary artery instead of the aorta. Blood flow in the coronary system follows the direction of pressure gradient and takes the path of lowest resistance [14,15]. In patients with BWGS, blood flows from the normal origin of the (often enlarged and dilatated) right coronary artery (RCA) through myocardial coronary collateral vessels to the LCA and low-pressure system of the pulmonary artery system [15,25]. After the drop of pulmonary vascular resistance in the first months of life, the majority of the blood drains to the pulmonary arteries, causing a "coronary steal" phenomenon, a left-to-right shunt and ultimately leads to an abnormal left ventricular perfusion [35]. This may lead to myocardial ischaemia and infarction, left ventricular dysfunction, mitral insufficiency and regurgitation, congestive heart failure and finally to sudden cardiac death [35,47]. BWGS occurs between 0.26 % and 0.46 % of patients with congenital heart disease and appears once in 300,000 births [3,22]. It is usually seen as an isolated cardiac abnormality, but in about 5 % of cases, it appears in coexistence with other cardiac abnormalities like patent ductus arteriosus (PDA), atrial septal defect (ASD), ventricular septal defect (VSD) with or without mitral stenosis, tetralogy of Fallot, pulmonary stenosis, coarctation of the aorta or transposition of the great vessels [1,4,8,10,15,34,35,43,45,48]. Symptoms usually become clinically apparent shortly after the neonatal period [15]. Vascular resistance is equal in right (pulmonary artery) and left (aorta) system during foetal period. This condition allows the myocardium supplied by the anomalous artery to remain well perfused. Promotive at this stage of development, there is an identical oxygen content in the pulmonary artery in comparison to the aorta. For this reason, this coronary anomaly is well tolerated in foetal and early neonatal life [4,35,38]. These conditions lead to an antegrade flow in anomalous LCA as well as in normal RCA [35]. In consequence, coronary collateral growth is not especially promoted before birth [38]. When pulmonary arterial pressure decreases physiologically after birth, the antegrade LCA flow diminishes and reverses. Moreover, the antegrade LCA is filled with deoxygenated mixed venous blood [4]. Subsequent, this coronary steal phenomenon leads to ventricular (anterolateral) myocardial ischaemia and in further consequence to mitral valve papillary muscle dysfunction [15,35]. Clinical presentation of BWGS may vary but primarily goes along with symptoms of heart failure like angina-like symptoms, severe dyspnoea, tachypnoea, cyanosis, wheezing, pallor, dizziness, profuse sweating, signs of decreased peripheral perfusion, syncope and pulmonary oedema or malignant arrhythmias [13,15,17,40,47]. In children, a failure to thrive, a smaller stature, diaphoresis while drinking and feeding, reduced exercise tolerance or poor weight gain may occur [15,51]. Two types of BWGS can be differed [25,35]. The infant type applies to patients without collateral vessels. Regarding differential diagnosis in this age, dilatated cardiomyopathy of differing genesis should be considered [35]. In contrast, the adult type occurs in patients with well-established collateral vessels and possible coronary ostial stenosis. These collaterals between RCA and LCA were formed during childhood due to ischaemic stimulation. They are essential and the only way to survive beyond infancy without surgery. Despite formation of these collaterals, adult patients develop a chronic left ventricular subendocardial ischaemia over the years, with high risk of lethal ventricular arrhythmias [35]. Asymptomatic patients with BWGS presenting in adulthood are rare [21,24,28,29,44,50,51]. They must have a well-developed coronary collateral circulation with retrograde perfusion of the left ventricle from the RCA [28,38]. An ostial stenosis of the LCA or persistence of elevated pulmonary resistance might limit the steal and increasing myocardial perfusion pressure. At least the degree of collaterals determines the moment of medical consultation due to beginning cardiac decompensation [15]. Nevertheless, adult BWGS patients without performed surgical correction are at high risk for sudden death. Typical is a precipitation by exercise at an average age of 35 years in untreated patients with BWGS [25,38,50]. The definitive treatment option for BWGS is cardiac surgery [49,51]. Untreated, 90 % of patients with BWGS die within the first year of life [35,47]. In case of early diagnosis and prompt surgical intervention, patients with BWGS may achieve adulthood. This applies also for asymptomatic patients [25]. There is one case report of an 88-year-old woman with BWGS, but, due to severe cardiac impairment, this expectation of life remains a rarity in this disease [42]. Supportive and conservative measures consist of typical pharmacotherapy of congestive heart failure (e.g., diuretics, ß-blockers and in acute failure: inotropes) [12,18,44]. [ABSTRACT FROM AUTHOR]