Retroaortic Anomalous Coronary Artery Visualization on Transthoracic Echocardiogram.

Incidental findings are not uncommon in echocardiography. A transthoracic echocardiogram (TTE) of an adult woman with arterial hypertension showed a tubular structure with hyperechoic walls in the atrial side of the atrioventricular groove in apical views. Coronary computed tomography angiography correlated this finding with a retroaortic course of the anomalous circumflex artery (retroaortic anomalous coronary artery [RAC], benign coronary artery variant). Recently described as the RAC sign on TTE, practitioners should be aware of this finding to avoid mistaken it as artifacts, catheters/leads, or calcified mitral annulus. Copyright:

INTRODUCTION

Incidental findings are not uncommon in echocardiography. While there is a wide range of well-known abnormalities with variable significance, some may be unfamiliar to the practicing physician and therefore should not be neglected or mistaken as other diagnoses.

CASE REPORT

A 62-year-old woman with a history of long-lasting arterial hypertension was evaluated in the cardiac ambulatory clinic. The patient was in good general condition and did not manifest dyspnea or chest pain; she did not receive medications as well. Blood pressure in both arms was 150/90 mmHg, while the remaining of the vital signs were entirely normal. Physical examination was unremarkable, while the 12-lead electrocardiogram showed signs of left ventricular hypertrophy.

Transthoracic echocardiogram (TTE) showed mild left ventricular hypertrophy. In apical views, a tubular structure with hyperechoic walls was observed along the atrial side of the atrioventricular groove [Figure 1a and b and Videos 1 and 2]. For defining the origin of this finding, a coronary computed tomography (CT) angiogram was performed demonstrating the absence of the left main coronary artery, the left anterior descending artery originating directly from the left sinus of Valsalva, and the circumflex artery originating from the right sinus of Valsalva, independently of the right coronary artery origin [Figure 1c and d]. The circumflex artery encircled the noncoronary sinus of Valsalva and then directed posterior to the aorta, ran within the left atrioventricular groove, and finally, ended at the lateral wall of the left ventricle [Figure 1c and d]. No stenosis was found in the coronary arteries, and the coronary calcium score was 0.

Figure 1

Upper panel. Retroaor tic anomalous coronary ar tery visualization (“Retroaortic anomalous coronary artery sign”, arrows) on transthoracic echocardiogram. (a) Apical 5-chamber view; (b) Apical 3-chamber view. Lower panel (c and d). Coronary computed tomography angiogram showed the circumflex artery (CX) originating from the right sinus of Valsalva independently of the right coronary artery (RCA); it partially encircled the aortic valve along the noncoronary cusp and then traveled retroaortic

The patient started on antihypertensive drugs with an optimal control of arterial hypertension on follow-up visits.

DISCUSSION

Coronary anomalies occur in 1.3% of population.[1] Retroaortic anomalous coronary artery (RAC) is a variant involving the circumflex artery that originates from either the right coronary artery or the right coronary cusp. It is considered a benign anomaly given that is no related to myocardial ischemia or sudden cardiac death.[2] Nevertheless, given that the involved vessel partially encircles the aortic valve, concerns exist about its potential injury during the surgery of the valve.[2] Regarding the diagnosis, this anomaly may be suspected when the RAC sign is observed on TTE; however, this is an incidental finding that is often neglected by operators. The RAC sign was recently described in the literature, with a reported sensitivity of 63.3% and specificity of 93.4% and it should be distinguished from catheters/leads, artifacts, or calcified mitral annulus.[3] Coronary CT angiography in the first place or eventually magnetic resonance imaging aids in confirming the diagnosis;[2] however, given the benign nature of the RAC, studying all the patients is not mandatory when the RAC sign is observed in isolation on TTE, and therefore, it may be considered when there is suspicion of coronary stenosis, when planning aortic valve surgery, or eventually for estimating the patient's cardiovascular risk.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.