Anomalous origin of circumflex arteries evaluated with MDCT

Abstract

To date, coronary angiography (CA) is the gold standard technique for the evaluation of coronary vessels (CVs). However, CA provides only a two-dimensional view of the CVs and sometimes fails to clearly visualise the relationship between CVs and surrounding structures. This issue becomes critical when anomalous CVs must be visualised. Moreover, it is not always easy to selectively engage the anomalous CV which may lead to the erroneous assumption that the CV is occluded. Congenital coronary artery anomalies are rare and occur in 0.17% of the autopsy cases. The incidence of anomalous origin of the CVs is higher in the population of patients referred for CA (0.6–1.3%) [1]. Although anomalous CVs lack clinical significance, in the majority of the patients, there are some ‘‘malignant’’ anomalies that may cause non-fatal or fatal acute myocardial infarction or sudden death especially in young athletes without atherosclerotic coronary artery disease (CAD). In older patients, both CAD and CV anomalies may be present and in these cases it is difficult to clarify the exact mechanism of myocardial ischaemia. In the last few years, several studies showed the usefulness of non-invasive modalities for the detection of CV anomalies such as magnetic resonance imaging, electron beam computed tomography (EBCT) and especially multidetector computed tomography (MDCT). Although the clinical role of MDCT is under discussion, several studies have been published where MDCT with retrospective ECG-gating was used as a non-invasive tool to visualise coronary anatomy. In clinical practice, MDCT is being used for the detection of CV lesions in symptomatic patients with low–intermediate pre-test probability to have CAD, to follow-up CAD patients treated with bypass surgery or percutaneous angioplasty [2]. This is possible because MDCT has an excellent spatial resolution which allows a good assessment of the atherosclerotic plaque. In the recent scientific statement of the American Heart Association, MDCT was pointed as a class IIa technique (level of evidence C) for the visualisation of CV anomalies [3]. In the literature, there are several interesting papers where MDCT was successfully used to visualise anomalous CVs [4, 5]. In this paper, we describe the anomalous origin and course of two circumflex arteries.