A Case of Anomalous Origin of Circumflex Artery from Right Sinus of Valsalva Recognized by Three-dimensional Transesophageal Echocardiography and Coronary Computed Tomography Angiography.

Anomalous origin of the circumflex coronary artery from the right sinus of Valsalva is the most common coronary anomaly. It is thought to be of no clinical relevance unless cardiac surgery is performed. We report a 53-year-old patient with aberrant circumflex coronary artery origin from the right aortic sinus of Valsalva which was first suspected from transthoracic 2D and transesophageal 3D echocardiographic views and confirmed by coronary CT angiography. The patient did not receive further diagnostic or therapeutic options. Therefore, we recommended medical therapy with optimal treatment of his cardiovascular risk factors together with regular clinical follow up.

INTRODUCTION

Anomalous origin of the left circumflex (Cx) coronary artery from the right sinus of Valsalva is a well-known coronary anomaly which is thought to be of no clinical significance per se.

However, the recognition and adequate visualization of the anomaly is essential for proper patient management.

Definitive diagnosis of coronary anomalies is generally made by coronary angiography. Recently, these anomalies have been recognized using noninvasive or minimally invasive techniques like transthoracic and transesophageal echocardiography (TEE).[1]

We present here a case with this anomaly in whom the diagnosis was made by transesophageal three-dimensional (3D) echocardiography and coronary computed tomography angiography (CTA).

CASE REPORT

A 53-year-old man presented to our clinic with a three-week history of palpitation. Hypertension and other risk factors of coronary artery disease were not present. Physical examination revealed a heart rate 75 beats/min and a blood pressure of 116/70 mmHg. Heart sounds were normal and there was a 2/6 systolic ejection murmur at the apex. Laboratory results showed no abnormality. Electrocardiography showed normal sinus rhythm, and incomplete right bundle branch block with no ST-T changes.

An echocardiogram revealed normal chamber size and left ventricular wall motion with mild to moderate mitral insufficiency. A tunnel shaped structure extending beneath the anterior mitral leaflet in the atrioventricular groove was also noticed [Figure 1]. However, the origin and anatomical properties of this abnormal image could not be sufficiently clarified in two-dimensional (2D) transthoracic echocardiography. Therefore, TEE was performed. Midesophageal long-axis TEE images gave the appearance of a communication between the non-coronary sinus of Valsalva and the left atrium (LA) [Figure 2]. However, flow between the chambers could not be demonstrated with color Doppler. In order to demonstrate anatomical properties of this structure 3D TEE was performed. On 3D TEE examination, raised the suspicion of anomalous Cx artery. Although its origin could not be identified, its path could be followed through behind the aortic root to its usual location in the atrioventricular groove [Figure 3].

Figure 1

Transthoracic apical for 4 chamber view shows an unusual finding in mitral annular region (LA: Left atrium, LV: Left ventricle)

Figure 2

Two-dimensional transesophageal midesophageal long-axis view shows the anomalous circumflex (Cx) as is follows its retroaortic course. Anomalous Cx artery gives the appearance of an apparent communication between the noncoronary sinus of Valsalva and the LA (Ao: Aorta, LA: Left atrium)

Figure 3

Three-dimensional upper transesophageal short axis view showed the retroaortic course of aberrant circumflex origin from the right aortic sinus of Valsalva (Ao: Aorta)

CTA was subsequently performed which showed aberrant Cx origin from the right aortic sinus of Valsalva with a further retroaortic course of Cx within the atrioventricular groove [Figure 4]. The Cx was originating as a slit like ostia with acute angulation from the right sinus. Myocardial perfusion scintigraphy (MPS) revealed mild ischemia in the inferolateral wall.

Figure 4

Computed tomography angiography image of patient shows the Cx arise from the right sinus of Valsalva separately from the RCA and passed posteriorly to the aortic root (Cx: Circumflex, RCA: Right coronary artery)

Holter electrocardiogram showed no arrhythmias. Our patient did not receive further diagnostic or therapeutic options, so we recommended medical therapy with optimal treatment of his cardiovascular risk factors.

DISCUSSION

Ectopic origin of the Cx artery from the right sinus of Valsalva or the right coronary artery (RCA) was first described by Antopol and Kugel[2] in 1933 with prevalence of 0.4-0.8% in angiographic series. The anomalous artery may arise as a proximal branch of the RCA, with the RCA from a common ostium, or from a separate orifice. The Cx artery always follows a retroaortic course in arriving at usual position in the left atrioventricular sulcus.[3]

Although this anomaly is usually benign and asymptomatic, it was reported that, it may cause ischemia, sudden death, and myocardial infarction.[456] These manifestations may be the result from repeated compression of the anomalous artery by a dilated aortic root or to slit-like ostia or to unusual angling as a result of the retroaortic course of the Cx.[7] In our patient, Cx was originating as a slit-like ostia with acute angulation and myocardial perfusion scan (MPS) revealed mild ischemia in the inferolateral wall.

Failure to recognize the anomaly can be hazardous to patient management. In our case, the initial echocardiographic images gave the appearance of a sinus of Valsalva to LA fistula or a coronary artery fistula. This might be the result of the tangential course of the anomalous Cx as it passed posteriorly the aortic root. This finding was evaluated in detail with 3D TEE to avoid misinterpretation.

Intraoperative complications from this anomaly have been described. In patients with this anomaly, surgical access for bypass grafting to surgical proximal Cx may be difficult because of its retroaortic course. Valve surgery may be complicated by the presence of an anomalous Cx Replacement of both aortic and mitral valves fixation rings of the prostheses may compress the lumen of the Cx artery during cardiac surgery.[8] In aortic root procedures, the presence of an anomalous retroaortic Cx artery is important to identify as it may be at risk during dissection or root enlargement.[1]

The diagnosis of coronary artery anomalies is usually made by angiography. However, it is difficult to define the course of these vessels by this test.[9] TEE and CTA are good semi-invasive and noninvasive tests to evaluate for these anomalies. Recently 2D and 3D TEE has been shown to be of value in identifying the anomalous origin of the Cx from the right sinus of Valsalva.[110] In our case, we suspected a coronary anomaly from transesophageal echocardiographic views. In order to demonstrate anatomical properties, 3D TEE was performed. The anomalous Cx coronary artery was noticed by 3D imaging as a vessel running around the posterior aortic wall. Color Doppler flow confirmed the course of an anomalous Cx coronary artery. CTA was subsequently performed which showed aberrant Cx origin from the right aortic sinus of Valsalva with a further retroaortic course.

CONCLUSION

The present case is a rare one in which the anatomical relation between the anomalous coronary artery and aorta was detectable by transesophageal 3D echocardiography. Transesophageal 3D echocardiography and CTA are useful for the assessment of this type of coronary anomaly.