Computed Tomography Angiography as a Method for Diagnosing Intracavitary Coronary Arteries

The intracavitary coronary arteries (ICCA) course is a rare phenomenon, where the segments of the coronary artery go through the atria or ventricles of the heart. In the past, these changes were incidentally detected during invasive diagnostic procedures for other reasons, as well as during postmortem examinations. As the use of multidetector computed tomography angiography (CTA) becomes more widespread, it has emerged that the incidence of ICCA has been underestimated. We present images from two coronary computed tomography angiography cases, which document the existence of ICCA in patients with non-specific chest pain. In the first case, in a 66-year-old woman, in addition to confirming coronary artery disease without significant stenosis (CAD-RADS 2-category 2 in the coronary-artery-disease-reporting and data system), the course of the middle section of the right coronary artery (RCA) in the lumen of the right atrium was demonstrated. In the second case, in a 47-year-old man in whom the presence of atherosclerotic lesions in the coronary arteries was excluded (CAD-RADS 0), the course of the distal segment of the left anterior descending (LAD) was found in the lumen of the apical layers of the right ventricle. To sum up, it should be stated that coronary CTA is a non-invasive diagnostic method that allows for visualization of the ICCA. In coronary CTA performed for indications consistent with the guidelines of scientific societies, attention should also be paid to the possible intracavitary course of the coronary arteries. The identification of such a course of the coronary arteries may be useful when preparing the patient for potential future invasive procedures involving the cardiac cavities.

The next panels on the right show axial images.White arrows indicate successive RCA segments in these panels.From the top, these will be the level above the intra-atrial RCA segment, the beginning of the intra-atrial RCA segment, the middle of the intra-atrial RCA segment, and the end of the intra-atrial RCA segment.(F) Left ventricular systolic function is preserved.The estimated left ventricular ejection fraction (LV EF) is 66%.The image shows long-axis, four-chamber images from different phases of the cardiac cycle.On the left panel, there is an end-diastolic image; on the right panel, there is an end-systolic image.The frequency of intracavitary coronary arteries (ICCA) course based on computed tomography scans was estimated in previous studies to range from 0.36% to 1.3% [2].In a cohort study, where the frequency of this anomaly was found to be 1.3%, the most common anomaly was associated with the left anterior descending artery (LAD) at 0.9%, followed by the right coronary artery (RCA) at 0.4%.Due to the increased number of implanted pacemakers and other invasive cardiac procedures performed, attention should be paid to the potential risk of coronary artery injury.Uncommon anomalies of the right coronary artery (RCA) are not frequent, and abnormal courses of the RCA are even rarer.There is only one paper in which a systematic review of case reports about the intra-atrial course of the RCA was performed.The authors noted that most cases with intra-atrial RCA course involved women, and patients were aged between 45 and 78 years [3][4][5].Regarding the frequency of intra-atrial course of specific coronary artery segments, the following observations were made: the mid-segment of the RCA was the most common segment to have an intra-atrial course, representing 76.2% of the studied group; the distal segment of the RCA accounted for 23.8% of these cases; none of these patients showed an intra-atrial course involving the proximal RCA segment; and there were no cases where the artery exhibited an intra-atrial course in two segments simultaneously [3].Regarding the lengths of the intra-atrial course of the coronary artery, data were collected on the lengths of the artery and the specific area of the RCA segment located intramuscularly.The distance of the mid-segment ranged from 13.2 mm to 55 mm.As for the extent of the distal segment, it ranged from 14 mm to 53 mm [5].Interestingly, in none of the cited cases were coronary artery stenoses detected, nor were signs of atherosclerosis found there.The authors explain this situation via the lack of mechanical stress on the segments of the arteries that course intramurally, rather than physiologically, in the epicardial fat tissue [6].
have an intra-atrial course, representing 76.2% of the studied group; the distal segment of the RCA accounted for 23.8% of these cases; none of these patients showed an intra-atrial course involving the proximal RCA segment; and there were no cases where the artery exhibited an intra-atrial course in two segments simultaneously [3].Regarding the lengths of the intra-atrial course of the coronary artery, data were collected on the lengths of the artery and the specific area of the RCA segment located intramuscularly.The distance of the mid-segment ranged from 13.2 mm to 55 mm.As for the extent of the distal segment, it ranged from 14 mm to 53 mm [5].Interestingly, in none of the cited cases were coronary artery stenoses detected, nor were signs of atherosclerosis found there.The authors explain this situation via the lack of mechanical stress on the segments of the arteries that course intramurally, rather than physiologically, in the epicardial fat tissue [6].
(A)  The segment running in the RV was located on the border between the free wall of the RV and the interventricular septum.It was shown that this course concerned the middle and distal segments of the LAD.It was also revealed that the average distance from the entry of the coronary artery to the RV in these subjects was 74.5 ± 17.1 mm.The average length of the intraventricular artery was 25.1 ± 14.0 mm [8].A study conducted by La Mura et al., which included patients who underwent the examination from 2021 to 2022, showed that 14 (1.73%) of the subjects had an intraventricular course of the coronary artery.In 11 of them, this course concerned LAD running in the RV [9].When describing the case by Hussein et al., they drew attention to possible underestimations of this phenomenon.This may result from the increasingly widespread use of coronary computed tomography angiography [10].
In research conducted by Buckley et al., 39 of patients with intraventricular LAD were identified, where the average length of the intraventricular course was 15.6 mm [1].
Typically, patients with intracavitary coronary arteries (ICCA) course did not present symptoms, and the detection of this type of anomaly occurred during coronary CTA conducted due to other symptoms such as palpitations, atrial fibrillation [11], atypical chest pain [12], chest tightness [13], dyspnea on exertion, chest pain, nausea, diaphoresis [14], hypertension, or previous acute coronary syndrome [1].It has also been observed that individuals with an intramural course of the right coronary artery (RCA) more commonly exhibit other anomalies related to coronary arteries.Additionally, some patients have described an intramuscular course of the left anterior descending artery (LAD) or nonphysiologic origins of the left circumflex artery [6].Diagnosed ICCA usually does not require any special therapeutic approach.However, traumatic injury to the coronary artery with an intracavitary course during other medical procedures usually requires cardiac surgery [15].
To sum up, it should be stated that CCTA is a non-invasive diagnostic method with high sensitivity and specificity in ICCA imaging.Therefore, in CCTA examinations performed for indications consistent with the guidelines of scientific societies, attention should also be paid to the possible intracavitary course of the coronary arteries.The identification of such a course of the coronary arteries may be useful when preparing the patient for potential future invasive procedures involving the heart chambers.