**3. Classification**

186 Congenital Heart Disease – Selected Aspects

In the normal heart, the coronary arteries arise from the upper half of sinuses, close to the sinotubular junction in most of cases (Muriago et al., 1997). A connection above the level of the sinotubular junction is possible. The coronary orifices are not always located in the centre of aortic sinuses. The left coronary ostium may lie near the junction between the left and right aortic sinuses, whereas the right ostium may lie near the junction between the right and the non-coronary aortic sinuses (Muriago et al., 1997). The discrimination between a common variant and an anomalous origin from an unusual site within the appropriate sinus is often difficult. It is inappropriate to use the notation of left and right aortic sinuses when there is an anomalous aortic origin of one of the coronary arteries. The categorisation proposed by the working group of Leiden (Gittenberger-de Groot et al., 1983) is based on the view by an observer positioned in the sinus farthest from the pulmonary trunk. The sinus at the right hand of the observer is named sinus 1 and gives rise to the right coronary artery in the normal heart, whereas the sinus at the left hand is named sinus 2 and normally gives rise to the left coronary artery. Another classification is used in this review with the two sinuses adjacent to the pulmonary trunk called respectively appropriate sinus and opposite sinus. The origin of mistakes that occur in the literature is often due to the confused interpretation describing the relationships of the ectopic coronary arteries with the adjacent structures, mainly the great vessels. The schematic representation, often cited, with a cross-section view of the aortic and pulmonary valves is erroneous. Indeed, the aortic and pulmonary annuluses are not in the same plane and the latter is more superior. Therefore, it is easy to understand that the initial path of the RCA is facing the subpulmonary infundibulum and not the pulmonary trunk (figure 2). According to the position and the

Fig. 2. Volume-rendered computed tomography image of the heart with the normal origin of the right coronary artery (white circle) marked. AO: aorta, LV: left ventricle, PT: pulmonary

**RV**

**SPI**

**PT**

**LV**

trunk, RA: right atrium, RV: right ventricle, SPI: subpulmonary infundibulum.

**RA**

**AO**

So far, no consensus exists to define and classify easily the wide spectrum of the congenital coronary artery abnormalities (Angelini, 2002). Numerous, sometimes long or complex, descriptions have been presented in the literature (Angelini 2007, Dodge-Khatami et al., 2000, Jacobs & Mavroudis, 2010, Rigatelli et al., 2009, Roberts, 1986). We propose, in this review focused on the proximal anomalous connections of the coronary arteries, a simplified classification with 8 types (table 2). This classification is based on an anatomical view with the contribution of postmortem data (Frescura et al., 1998) and recent imaging modalities. By definition, the abnormalities involve the orifices of the LCA and RCA, and their branches. Different types of ANOCOR may be observed in the same patient. Diagnosis of ANOCOR is sometimes uncertain, especially in cases of an incomplete or poor-quality imaging. We consider that an accurate anatomical diagnosis should be the first step when an ANOCOR is suspected.


Table 2. Simplified classification of proximal anomalous connections of the coronary arteries.

Proximal Anomalous Connections of Coronary Arteries in Adults 189

Fig. 4. Angiographic view showing an anomalous connection of the left main coronary

An anomalous orifice of a coronary artery is usually linked with an ectopic ostium. Nevertheless, in rare postmortem observations (Frescura et al., 1998), a valve-like stenosis has been described with a ridge, consequence of an aortic wall fold that is in contact with an ostium in right position. Recently, a LMCA originated from the left sinus in the usual site, but with a slit-like orifice due to a tangential initial course associated with a short intramural segment, has been described (Angelini et al., 2010). An ectopic origin of a coronary artery in the appropriate sinus remains possible, but the limit between a true abnormality and a common variant may be tenuous, such as a connection in the lower half of the sinus, or near

ANOCOR from the non-coronary sinus proved by surgical or postmortem examination were previously described as exceptional. Nevertheless, a higher frequency of the latter is

A high take-off from the aorta at least 10 mm above the sinotubular junction is generally considered as an anomalous connection (Hlavacek et al., 2010). However, the height of takeoff judged to represent the abnormality is based on few solid data. Indeed, a level of 4 mm has been reported in a postmortem study (Frescura et al., 1998). Therefore, the criteria to determine an anomalous aortic origin above the sinotubular junction should be redefined with the contribution of non-invasive imaging. Usually, the ectopic vessel continues to arise

artery (arrow head) with the proximal right coronary artery (arrow).

**3.3 Anomalous connection with the appropriate sinus (type III)** 

the commissural junction between the left and right cusps.

noticed in recent studies using tomographic imaging.

above the appropriate sinus (figure 5).

**3.4 Anomalous connection with the non-coronary sinus (type IV)** 

**3.5 Anomalous connection above the sinotubular junction (type V)** 
