**8.1 Echocardiography**

Transthoracic echocardiography (TTE) is not commonly used to examine the coronary arteries. The parasternal short-axis plane, with the help of the colour flow mapping, is the best view for an echographic visualization of the coronary origins (Frommelt et al., 2003). Nevertheless, the ability of the TTE to identify the coronary origins with confidence becomes less easy with age and increase in the body mass. Transoesophageal

The intramural segment of the ectopic has an abnormal shape (figure 18), resulting from a shared media with the aorta and a probably incomplete growth of the ectopic vessel in the aortic wall. The cross section is more or less oblong. The lateral compression is defined as a smaller area than that possessed by a circle of the same circumference. This parameter is

quantified with the asymmetric ratio of the smallest to the largest diameter <1.0.

**A B**

Fig. 18. Intravascular ultrasound images showing the intramural segment (A) and the extramural segment (B) of an ectopic right coronary artery connected with the left sinus.

angina may occur during IVUS manoeuvres.

**8. Non-invasive imaging modalities** 

**8.1 Echocardiography** 

Despite first promising results, the IVUS imaging tool has several limits. Non selective canulation of the vessel may disrupt the procedure. The possibility of artefacts has been pointed out, as well as the decreasing in the precision of measurements, due to the tangential orientation of the vessel (Angelini & Flamm, 2007). Moreover, ST-T changes and

Selective coronary angiography does not always assure the diagnosis of ANOCOR, particularly to identify accurately the origin of the RCA from the left sinus, or to delineate the initial course of an ectopic vessel. Over the last decade, the multislice tomographic imaging made dramatically breakthroughs, so much that the electrocardiography-gated multidetector coronary CT angiography has become the method of choice for evaluation of known or suspected ANOCOR (Sundaram et al., 2010). Tomographic reconstructed images provide useful supplemental information with volumetric views allowing an analysis of ANOCOR in 3-D spatial orientation (Gharib et al., 2008, Manghat et al., 2005). However,

Transthoracic echocardiography (TTE) is not commonly used to examine the coronary arteries. The parasternal short-axis plane, with the help of the colour flow mapping, is the best view for an echographic visualization of the coronary origins (Frommelt et al., 2003). Nevertheless, the ability of the TTE to identify the coronary origins with confidence becomes less easy with age and increase in the body mass. Transoesophageal

other non-invasive methods have been used to diagnose or evaluate ANOCOR.

**7.3 Lateral compression** 

echocardiography (TEE) may improve the imaging quality (figure 19) but not necessarily the diagnostic ability. Several studies have reported the echocardiographic prevalence of ANOCOR particularly in paediatric populations or young adults. An anomalous connection with the opposite sinus was found in 4 cases (0.2%) in a series of 2388 children or adolescents referred for innocent murmurs or functional assessments (Davis et al., 2001), and in 3 cases (0.09%) in 3504 (mean age, 30 years) asymptomatic athletes (Zeppilli et al., 1998). In the latter study a clear visualization of both ostia was obtained in 90% of cases. Therefore, the echographic prevalence is lower than those reported with selective coronary angiography and tomographic imaging techniques. The limited discriminating power of TTE to distinguish some ANOCOR may explain this discrepancy. TTE lacks reliability to identify a small RCA or CX coronary artery with an ectopic origin. Besides, an ectopic vessel with preaortic course crosses very closely the appropriate sinus, and thus may pretend a normal origin. Nevertheless, in young adults or in patients with a satisfactory acoustic window, several echographic characteristics must be known (Cohen et al., 2010). An abnormal diastolic colour flow between the aorta and the pulmonary trunk is often the first identification of an ANOCOR with a preaortic course. However, only the first millimetres of the ectopic vessel are visualized, and, often, the TTE is inconclusive in ruling out some ectopic paths. Thus, a suspected retroinfundibular or preaortic course with TTE should be always confirmed with other imaging modalities. In addition, TTE is not able to describe the shape of an ectopic orifice and to measure a possible ostial narrowing. TEE may identify some high take-off above the sinotubular junction with the long-axis view. Echographic diagnosis of anomalous origin of the LCA from the pulmonary trunk is mainly based on indirect features with a dilation of the RCA and a multiple collateral flow through the interventricular septum. In practice, the management of an ANOCOR should never be discussed with only echocardiographic imaging in adult patient.

Fig. 19. Short-axis transoesphageal echocardiographic view showing an ectopic circumflex coronary artery (arrows) coursing between the aorta (AO) and the left atrium (LA) with a retroaortic course.

Proximal Anomalous Connections of Coronary Arteries in Adults 209

In addition, selective canulation of ectopic vessel was not possible in 3 cases, and the ectopic artery was not identified in 1 case. MR angiography depicted correctly all ANOCOR, and in 13 patients (62%) a preaortic course, which passes between the aorta and right ventricular outflow tract, was affirmed. MR angiography seems to be an accurate tool as primary investigation in symptomatic young patients. In older population, due to a higher

In comparison with aforementioned non-invasive tools imaging, multidetector CT angiography has the major advantage of a better spatial resolution. Despite, the need of administration of contrast media and the use of ionizing radiation, the CT angiography is becoming for most practioners the preferred test in adult patients with known or suspected ANOCOR. The impressive 3-D ability of CT angiography to identify unambiguously the origin and the ectopic course of an ANOCOR (figure 21) explain easily its wide use. However, it must be remembered that the production of consistent and reliable imaging is one thing, and that the correct interpretation of the latter is another thing. In ACC/AHA 2008 guidelines for adults with congenital heart disease, CT and MR angiography are recognized useful as the initial screening method in centers with expertise in such imaging

prevalence of the coronary artery disease, the CT angiography is generally preferred.

Fig. 21. Three-dimensional volume-rendered reconstruction of computed tomography showing an ectopic origin of the left main coronary artery (white arrow) arising from the right coronary artery with an ectopic course coursing on the subpulmonary infundibulum. CX: circumflex coronary artery, LAD: left anterior descending coronary artery, RCA: right

**SPI**

**RCA LAD** 

**CX** 

Numerous studies, often with small populations, have described the interest of CT angiography in the ANOCOR field. Some of them have been already mentioned above

coronary artery, SPI: subpulmonary infundibulum.

**8.3 Multidetector computed tomography angiography** 

(Warnes et al. 2008).

### **8.2 Magnetic resonance angiography**

Magnetic resonance (MR) angiography is a non invasive imaging technique that does not expose to ionizing radiation and to potentially nephrotoxic contrast media. Cardiac MR angiography allows 3-D reconstruction of the heart and can identify the origin of coronary arteries (figure 20). The relationships with neighbouring structures are well visualized. Nonetheless, due to insufficient spatial resolution and cardiac movements, this imaging technique fails sometimes to describe accurately the anatomy of the ectopic course of the ANOCOR, especially the orifice and the visualization of a lateral compression in the aortic wall. Otherwise, MR angiography is a less available technique in comparison to the CT angiography, and identifies not as good the degree of atherosclerotic associated lesions. Nevertheless, coronary MR angiography remains an attractive option in young population to avoid ionizing radiation. Several studies have shown the feasibility of coronary MR angiography to identify ANOCOR. In a selected population of 19 patients with known ANOCOR by a previous selective coronary angiography, sensitivity and sensibility for detecting anomalous origins and ectopic courses were 100% with MR angiography (Post et al., 1995). Delineation of the ectopic course was erroneous in 3 of 19 patients (16%) with the conventional coronary angiography. The hypothesis that MR angiography may be useful in the identification of ANOCOR was confirmed in 12 of 14 patients (86%) with a known anomaly (Mc Connell et al., 1995). A series of 21 patients with known or suspected ANOCOR (9 LMCA or LAD coronary arteries, 6 CX coronary arteries and 6 RCA) underwent a MR angiography (Bunce et al., 2003). All patients had undergone a selective coronary angiography but in 11 patients (52%) the proximal course was uncertain.

Fig. 20. Volume-rendered magnetic resonance angiography showing a normal origin of the left main coronary artery (arrow) dividing into left anterior descending coronary artery (white arrow head) and circumflex coronary artery (black arrow head). AO: aorta, PT: pulmonary trunk.

Magnetic resonance (MR) angiography is a non invasive imaging technique that does not expose to ionizing radiation and to potentially nephrotoxic contrast media. Cardiac MR angiography allows 3-D reconstruction of the heart and can identify the origin of coronary arteries (figure 20). The relationships with neighbouring structures are well visualized. Nonetheless, due to insufficient spatial resolution and cardiac movements, this imaging technique fails sometimes to describe accurately the anatomy of the ectopic course of the ANOCOR, especially the orifice and the visualization of a lateral compression in the aortic wall. Otherwise, MR angiography is a less available technique in comparison to the CT angiography, and identifies not as good the degree of atherosclerotic associated lesions. Nevertheless, coronary MR angiography remains an attractive option in young population to avoid ionizing radiation. Several studies have shown the feasibility of coronary MR angiography to identify ANOCOR. In a selected population of 19 patients with known ANOCOR by a previous selective coronary angiography, sensitivity and sensibility for detecting anomalous origins and ectopic courses were 100% with MR angiography (Post et al., 1995). Delineation of the ectopic course was erroneous in 3 of 19 patients (16%) with the conventional coronary angiography. The hypothesis that MR angiography may be useful in the identification of ANOCOR was confirmed in 12 of 14 patients (86%) with a known anomaly (Mc Connell et al., 1995). A series of 21 patients with known or suspected ANOCOR (9 LMCA or LAD coronary arteries, 6 CX coronary arteries and 6 RCA) underwent a MR angiography (Bunce et al., 2003). All patients had undergone a selective coronary angiography but in 11 patients (52%) the proximal course was uncertain.

Fig. 20. Volume-rendered magnetic resonance angiography showing a normal origin of the left main coronary artery (arrow) dividing into left anterior descending coronary artery (white arrow head) and circumflex coronary artery (black arrow head). AO: aorta, PT:

**AO**

**PT**

**8.2 Magnetic resonance angiography** 

pulmonary trunk.

In addition, selective canulation of ectopic vessel was not possible in 3 cases, and the ectopic artery was not identified in 1 case. MR angiography depicted correctly all ANOCOR, and in 13 patients (62%) a preaortic course, which passes between the aorta and right ventricular outflow tract, was affirmed. MR angiography seems to be an accurate tool as primary investigation in symptomatic young patients. In older population, due to a higher prevalence of the coronary artery disease, the CT angiography is generally preferred.

### **8.3 Multidetector computed tomography angiography**

In comparison with aforementioned non-invasive tools imaging, multidetector CT angiography has the major advantage of a better spatial resolution. Despite, the need of administration of contrast media and the use of ionizing radiation, the CT angiography is becoming for most practioners the preferred test in adult patients with known or suspected ANOCOR. The impressive 3-D ability of CT angiography to identify unambiguously the origin and the ectopic course of an ANOCOR (figure 21) explain easily its wide use. However, it must be remembered that the production of consistent and reliable imaging is one thing, and that the correct interpretation of the latter is another thing. In ACC/AHA 2008 guidelines for adults with congenital heart disease, CT and MR angiography are recognized useful as the initial screening method in centers with expertise in such imaging (Warnes et al. 2008).

Fig. 21. Three-dimensional volume-rendered reconstruction of computed tomography showing an ectopic origin of the left main coronary artery (white arrow) arising from the right coronary artery with an ectopic course coursing on the subpulmonary infundibulum. CX: circumflex coronary artery, LAD: left anterior descending coronary artery, RCA: right coronary artery, SPI: subpulmonary infundibulum.

Numerous studies, often with small populations, have described the interest of CT angiography in the ANOCOR field. Some of them have been already mentioned above

Proximal Anomalous Connections of Coronary Arteries in Adults 211

ANOCOR with a significant CAD is common. Sudden ANOCOR-related death is rare in such patients. Some ANOCOR may also be identified late in patients referred for evaluation of various atypical symptoms. In young populations, the latter can lead also to the diagnosis of ANOCOR. Nevertheless, serious symptoms usually related to exertion, are possible. Last but not least, a sudden death related to a high risk ANOCOR may be the first event in the life of a young patient. Fortunately, only a small subgroup of ANOCOR, including mainly anomalies with an intramural segment and anomalous connections with the pulmonary artery, may entail life-threatening adverse events. In patients with significant acquired heart disease, relationships between the coronary abnormality and clinical status should be made clear as far as possible. The clinical presentations of anomalous origins from the pulmonary

Analysis of necropsy cases has been crucial to highlight the lethal risk of some ANOCOR (Frescura et al. 1998, Kragel & Williams, 1988). In a postmortem series of 242 congenital abnormalities of coronary arteries, 49 anomalous connections of the LCA and 52 anomalous connections of the RCA with the opposite sinus were identified (Virmani et al., 2001). Sudden death was observed in 57% of LCA abnormalities and 25% of RCA abnormalities. Most of them had a preaortic course. The profile of the patients suffered from sudden death is often typical: young age, frequent intensive exercise, and non systematic premonitory symptoms. In a necropsy study of 150 consecutive sudden deaths occurring in a population ≤ 35-year old, 16 sudden deaths related to non-atherosclerotic coronary disease were identified (Corrado et al., 1992). Three (19%) of them were ANOCOR (11, 22 and 29 year-old patients). Sudden death occurred during effort. In a series of 27 ANOCOR (23 LMCA and 4 RCA from the opposite sinus) identified at autopsy in young athletes, sudden death occurred during intense exertion in 25 cases or immediately after in 2 cases (Basso, et al. 2000). In 126 nontraumatic sudden deaths collected during a 25-year autopsy study of military recruits, there were 21 (17%) ANOCOR, all LCA originated from the opposite sinus, with a preaortic course (Eckart et al. 2004). Thus, sudden death, especially during exercise, is a fairly common mode of revealing high-risk ANOCOR in young populations. Some sudden cardiac arrests may survive up to hospitalization with public education and emergency care systems. The individual incidence of sudden death in asymptomatic patients with high risk

All usual cardiac symptoms are possible, i.e. angina, chest pain, dyspnea, syncopes, palpitations. In autopsy studies mentioned above, prodromal symptoms before sudden death were noted in up to 56% of patients (Eckart et al., 2004) but often underestimated or hidden owning to the patient profile (athlete or military). In another study, only 55% of patients had no cardiac history (Basso et al., 2000). Syncope and chest pain, exercise-related almost without exception, are the most frequent symptoms However, it must be remembered that the population studied was subjected to extreme exercise, unusual for a general population. In the latter, symptoms leading to the diagnosis of ANOCOR are variable and sometimes no such typical with chest discomfort or palpitations. Obviously, stable angina and acute coronary syndromes are possible if a significant CAD is associated. In a retrospective study, 301 anomalous origin from the opposite sinus were identified among

artery differ from that of anomalous origins form the aorta.

**9.1 Sudden deaths** 

ANOCOR remains unknown.

**9.2 Other symptoms** 

(Fujimoto et al, 2011, Schmitt et al. 2005, Rodriguez-Granillo et al, 2009). In a series of 28 patients with known ANOCOR (4 LMCA, 15 CX coronary arteries and 9 RCA), the origin and ectopic course was correctly identified in all patients (Ropers et al., 2001). All patients had had previously an X-ray coronary arteriography. A correct analysis was achieved in only 3 patients (11%) with the latter. Nine-teen ANOCOR in 12 patients were correctly analysed with CT angiography in another small series (Datta et al., 2004). Twelve ANOCOR (1 LMCA, 1 LAD coronary artery, 4 CX coronary arteries, 5 RCA and 1 single artery) in adults patients (mean age 63 years) were analysed retrospectively with invasive (11 patients) and non-invasive tests (Leddet et al., 2008). All ANOCOR were well identified with CT angiography. However, the interpretation of one photo is ambiguous in the paper with a listed preinfundibular course instead of a retroinfundibular course. Selective coronary angiography identified accurately the origin and the ectopic course of ANOCOR in 8 of 10 cases (80%) and in 2 of 10 cases (20%), respectively. The position of CT angiography cannot be ignored either before or after invasive coronary angiography. The latter and the CT imaging are complementary in most cases of ANOCOR in adult patients (Kim et al., 2006). The main characteristics of invasive and non-invasive imaging techniques are summarized in the table 8.


Table 8. Comparison of imaging techniques in adult populations. 3-D: three-dimensional, CAD: coronary artery disease, CTA: computed tomography angiography, IVUS: intravascular ultrasonography, MRA: magnetic resonance angiography, SCA: selective coronary angiography.

Regarding to tomographic studies, the analysis of the literature shows non rare erroneous interpretations of ectopic courses of some ANOCOR, especially anomalous origins of LMCA or LAD coronary artery arising from the opposite sinus, with a misinterpretation between the preaortic course and retroinfundibular course.
