A Case of Malignant Course of Right Coronary Artery: Frequent Angina in Young Person

Congenital anomalous coronary artery is a rare condition, but it might be the biggest pitfall for cardiologist. We present a case of young adult with activity-triggered atypical chest pain and diagnose with anomalous origin of right coronary artery (RCA) from the left coronary sinus with inter-arterial course between the aorta and the main pulmonary artery that was detected by CT coronary angiography. This anomaly has been called malignant course RCA. Coronary artery anomaly is a congenital condition. Most of the cases are remain asymptomatic. This condition also one of the most cause for sudden cardiac death because the coronary artery examination is not regularly done. Nevertheless, during high intense activity, it will be symptomatic and might be lethal. Diagnose coronary artery anomalies might be tricky and cardiologist must be aware with this. More devastating, no firm guideline in treatment of right anomalous coronary artery from opposite sinus. Original Research A Case of Malignant Course of Right Coronary Artery: Frequent Angina in Young Person Sidhi Laksono Purwowiyoto1,2, Steven Philip Surya3 Head of Cardiac Catherization Laboratory, Department of Cardiology and Vascular Medicine, RSUD Pasar Rebo, East Jakarta. Faculty of Medicine, Universitas Muhammadiyah Prof. DR. Hamka, Tangerang. Primaya Hospital, Tangerang.


Introduction
Coronary artery anomalies (CAAs) are still becoming a noteworthy matter to discuss in basic and clinical practice. There is extensively discussed in the literature regarding definition of CAAs, especially in how it can be different with normal variant of the coronary artery. However, the "normal" terminology in CAA means commonly observed and more frequent variant (normal variant) and the "abnormal" terminology comes from less than 1% of the general human coronary course [1] . Normal course of CAA related to Valsalva sinuses in one point and dependent area of myocardium in the other point. Nevertheless, Angelini [2] had proposed assessable of the definition of the normal variant shown in the table 1.
Historically, coronary artery was studied by gross anatomic inspection during autopsy examination. It was provided adequate examination especially in locating ostia with respect to aortic root references structure, evaluating artery's course, distal distribution, termination and also intrinsic anatomy features. Nowadays we has modern medical technology like catherization laboratory for diagnostic and treatment, however coronary angiography is not appropriate as a primary screening test for ruling out coronary anomalies.
Otherwise, non-invasive clinical imagine techniques (like CT angiography) consider more safer, convenient for the patient, and suitable cost [3] . CT-angiography could be better in diagnosing CAA than intraluminal coronary angiography [6] .

ARTICLE INFO
Specifically, the incident of the malignant course of the CAAs from the right coronary artery origins is pretty rare, around 0.03-0.17% [7] . The clinical spectrum of CAAs is enormously extensive, from asymptomatic to resting ischemia. The awareness of atypical coronary anatomy could aid the cardiologist to give precise diagnosis and treatment, including catherization laboratory and surgical procedure [2] . Here we are presenting right malignant course of CAAs with symptomatic atypical chest pain in the young adult.

Case Presentation
A 34 years old man complained of having vague chest pain since more than six months ago. There ml of non-ionic iodinated contrast was administered at the rate of 5 ml/sec, followed by 20 ml of saline.
The total scan time was 8.6 seconds.
Reconstruction was done with 0.6 mm slice thickness at 0.5 mm increment.
CT coronary angiography showed at the right coronary artery originated from the left coronary sinus, coursing between the aortic root and pulmonary artery (Figure 1, a). The rest of the coronary arteries, left coronary artery and its branches, have normal course (Figure 1, b and c). September 2021 | Vol 2 | Article 6 The calibre of RCA was small with no sign of stenosis in the RCA. The RCA routes through right atrioventricular sulcus and vascularized the right part of the heart. The proximal one distributed through ascending aorta and pulmonary artery.
According to the normal course of the rest coronary artery's courses and no stenosis was found, we conclude CAA was the most possible aetiology from the ischemic sign and symptoms. However, we not yet decide the treatment for this patient and still need follow up for reassurance.

Discussion
The CAAs are frequently found as cause of the sudden death (SD) case in the young. Even though it is congenital condition, many subject survive asymptomatic until young adult. Previous coronary angiography study found that 0,95% people with range 26-68 years old had CAA and RCA was the commonest anomalous vessel (48.74%) [8] .
However, anomalous coronary artery (CA) origin, either left main artery from right sinus or vice versa, has been found 0.17% during autopsy [7] . Specific incidence of RCA originate from left sinus is 0.019-0.49% [9]. Even-though most CAA case is benign, but it could potentially become catastrophic [3,9] .
Concerning clinical manifestation about RCA that originate from contralateral sinus are sudden death (SD), myocardial ischemia, arrhythmia, and syncope [10] . Multi-detector CT (MDCT) is preferred method in diagnose anomalous RCA from the left coronary sinus with inter-arterial course.
There are two common types of clinical picture from anomalous origin of RCA from left sinus, first one is sudden death in the young after persistent physical activity and the other is atypical clinical picture of chest pain [10,11] . In some occasion, the only clues for anomalous coronary artery from the opposite sinus (ACAOS) either positive sign of ischemic due stress test or resting electrocardiogram (ECG) [10] .
The clinical picture could be as accumulation of several patho-mechanical condition such as acute take-off angle, slit-like orifice, and compression of the intramural segment by the aortic valve commissure thought to narrow the orifice [9] . The anomalous origin of RCA from opposite Valsalva September 2021 | Vol 2 | Article 6 doesn't change its function and nomenclature of the coronary artery [3] . However inter-arterial course, coronary artery course runs between aorta and pulmonary artery, might associated with ischemic episodes. During high intensity activity, especially in young people or athletes who has capability aorta's dilatation, the aorta and pulmonary could compress the coronary artery [12] . Meanwhile, RCA has responsibility to nutritive free wall of right ventricle.
One clinical study of 42 consecutives right ACAOS study shows that 69% are male with 57% has nonexertional chest pain symptoms [13] . Histologic examination proposes that chronic ischemia as the one principal mechanism of myocardial fibrosis in CAA [14] . Other mechanisms that might be involved such as; artery intussusception, coronary hypoplasia and lateral compression of the coronary wall by the aorta [15] .
Unfortunately, management of right ACAOS is still become debatable issue [17] .

Conclusion
In conclusion, the CAAs condition are a rare situation, especially right ACAOS. However, cardiologist need to be aware with congenital anomalies because it might help in clinical practice.
There are some imaging modalities in diagnosis CAA, however CT angiography might be preferred.
Even though right ACAOS might concealed for long