Visualization of anomalous origin and course of coronary arteries in 748 consecutive symptomatic patients by 64-slice computed tomography angiography

Abstract

Background: Coronary artery anomalies (CAAs) are currently undergoing profound changes in understanding potentially pathophysiological mechanisms of disease. Aim of this study was to investigate the prevalence of anomalous origin and course of coronary arteries in consecutive symptomatic patients, who underwent cardiac 64-slice multidetector-row computed tomography angiography (MDCTA).

Methods: Imaging datasets of 748 consecutive symptomatic patients referred for cardiac MDCTA were analyzed and CAAs of origin and further vessel course were grouped according to a recently suggested classification scheme by Angelini et al.

Results: An overall of 17/748 patients (2.3%) showed CAA of origin and further vessel course. According to aforementioned classification scheme no Subgroup 1- (absent left main trunk) and Subgroup 2- (anomalous location of coronary ostium within aortic root or near proper aortic sinus of Valsalva) CAA were found. Subgroup 3 (anomalous location of coronary ostium outside normal "coronary" aortic sinuses) consisted of one patient with high anterior origin of both coronary arteries. The remaining 16 patients showed a coronary ostium at improper sinus (Subgroup 4). Latter group was subdivided into a right coronary artery arising from left anterior sinus with separate ostium (subgroup 4a; n = 7) and common ostium with left main coronary artery (subgroup 4b; n = 1). Subgroup 4c consisted of one patient with a single coronary artery arising from the right anterior sinus (RAS) without left circumflex coronary artery (LCX). In subgroup 4d, LCX arose from RAS (n = 7).

Conclusions: Prevalence of CAA of origin and further vessel course in a symptomatic consecutive patient population was similar to large angiographic series, although these patients do not reflect general population. However, our study supports the use of 64-slice MDCTA for the identification and definition of CAA.

Figure 1

High origin of the left and anterior origin of the right coronary artery (Subgroup 3). In this complex case a high origin of LM above the commissure between right and left coronary sinuses within the aortic root was reported. Furthermore RCA originates in a somewhat anterior position. Image A (Volume Rendering Technique) depicts the acute angle of LM (white arrow) above the aortic cusp (grey arrow), which is suspected as a possible mechanism of ischemia. In image B the close proximity of both coronary ostia in ICA is shown. Curved Multiplan Reformatting (Image C) displays further proximal course of LM and RCA between aorta and pulmonary artery. Note the ovoid cross sections of both intramural courses (cross-sectional images of RCA and LM), which is suspicious of lateral compression that may result in further compression during each systole especially under exercise conditions. DB: diagonal branch; LCX: left circumflex ramus; LA: left atrium; LAD: left anterior descending coronary artery; LM: left main coronary artery; PA: pulmonary artery; RCA: right coronary artery.

Figure 2

RCA arising from left sinus of Valsalva with a separate ostium (Subgroup 4a). Image A (Volume Rendering Technique) depicts the whole coronary artery tree. RCA and LM are originating from the left sinus of Valsalva (LSV) with separate ostia (as shown in Image B, curved Multiplane Reformatting). Again note the ovoid cross-sectional image of the proximal intramural RCA course (left cross-sectional picture of Image A). Additionally, this patient obviously underwent stent implantation procedure (stent in mid LAD with good contrast enhancement within the stent lumen) due to CHD. Furthermore note the bright calcified plaque proximal to the previously implanted stent. This severe calcification causes so-called "blurring" impairing the luminal view. A high grade stenosis therefore cannot be ruled out. Interestingly, proximal LAD and RCA do not show any additional atherosclerotic plaque formation as depicted in the remaining cross-sectional images. Furthermore small calcified deposits (spotty calcification) are found at the aortic valve leaflets. LCX: left circumflex ramus; DB: diagonal branch; LAD: left anterior descending coronary artery; LM: left main coronary artery; LSV: left sinus of Valsalva; PA: pulmonary artery; RCA: right coronary artery.

Figure 3

Single coronary artery originating from left sinus of Valsalva (Subgroup 4b). This example illustrates a single coronary artery arising from the left coronary sinus of Valsalva with further intramural proximal course RCA (Image A; Volume Rendering Technique). The axial slice nicely depicts the close proximity of RCA and pulmonary artery (Image B). Again proximal RCA appears elliptical suspicious of lateral compression (Image C1, cross-sectional image) widening up after its intramural course (Image C2, cross-sectional image). Curved Multiplan Reformat shows the common ostium of left main coronary artery and RCA (Image D). DB: diagonal branch, LCX: left circumflex coronary artery, LM: left main coronary artery; LSV: left sinus of Valsalva; PA: pulmonary artery; RCA: right coronary artery.

Figure 4

Single coronary artery originating from right sinus of Valsalva (Subgroup 4c). This case shows a single coronary artery arising from right sinus of Valsalva (common ostium of RCA and LAD without circumflex ramus) in a Maximum Intensity Projection (Image A). Myocardial territory usually supplied by LCX is fed by RCA (right dominant type) and LAD is noted to run intra-myocardial within the left ventricular septum (Image B; Curved Multiplane Reformatting). Note the surrounding muscular tissue (also depicted in the cross-sectional image of LAD) marked with black arrows which appears lighter grey compared to epicardial adipose tissue (white arrow). LAD: left anterior descending coronary artery; LV: left ventricle; RA: right atrium; RCA: right coronary artery; RSV: right sinus of Valsalva; RV: right ventricle.

Figure 5

Circumflex ramus originating from right sinus of Valsalva with further posterior vessel course (Subgroup 4d). This case shows an abnormal origin of LCX from the right sinus of Valsalva with a further posterior (retroaortic) course of LCX within the atrioventricular groove (Image A, Volume Rendering Technique, posterior view). Cross-sectional curved Multiplane Reformats nicely depict the anatomic relationships of the vessel, left atrium and Aorta (Images B). In Image B2 the retroaortic course within the atrioventricular groove of LCX is marked with a black arrow. LCX: left circumflex ramus; LA: left atrium; LAD: left anterior descending coronary artery; LVOT: left ventricular outflow tract; RCA: right coronary artery; RSV: right sinus of Valsalva.