A Very Rare Coronary Anomaly

Case

A 67-year-old male presented to the emergency department with chest discomfort after the Thanksgiving holiday. The patient stated that he did not attend a family dinner for Thanksgiving because he was “having a migraine headache”, and later he began to feel some chest discomfort associated with shortness of breath and mild diaphoresis. The patient demonstrated Levine’s sign in describing his onset of symptoms. He denied any nausea or vomiting. He stated he did have some palpitations. He had no syncope. He denied any recent febrile illness. He stated no melena, hematemesis or hematuria, or hematochezia. The patient indicated he never has had discomfort like this before. In the emergency department, he presented with a blood pressure of 175/86, pulse of 79, respirations at 18, and a temperature of 97.1 degrees Fahrenheit orally. He was saturating 99% on room air. An electrocardiogram obtained a sinus rhythm at 88 beats per minute with a right bundle-branch block and left anterior fascicular block. There were no acute ischemic changes (Figure 1).

History:

The patient had a past medical history for hypertension, seizure disorder, and posttraumatic stress disorder. He is a military veteran of the United States. He has had left shoulder surgery. The patient does not smoke. He occasionally drinks and denied illicit drug use. He indicated no family history of early coronary artery disease. He has no known drug or food allergies. His medication includes amlodipine 5 mg, aspirin 81 mg, atorvastatin 20 mg, folate, lansoprazole 30 mg, levetiracetam 500 mg and metoprolol 50 mg only once daily.

Labs:

No leukocytosis, hemoglobin 12.2 g/dL, platelets were normal. Coags were normal. SMA-7 was normal. Calcium, mag and phos were 8.2 mg/dL, 1.6 mg/dL, and 2.4 mg/dL, respectively.  Magnesium improved from 0.6 mg/dL on admission. LFTs were normal. Troponins obtained in three sets over a course of 7 hours trended from less than 0.01 to 0.13 ng/mL. Pro-BNP was only 319 pg/mL. HDL was 37 mg/dL, LDL 154 mg/dL, triglycerides 111 mg/dL, and he was given a total cholesterol of 213. TSH was 1.51 uIU/mL. Urine drug screen was positive only for opiates and oxycodone. 

Examination:

The patient was afebrile. Pulse was 82, respirations 18/min, blood pressure was uncontrolled at 150/90. He was on nasal cannula, having been documented saturating at 98%. He was resting in a supine position in no acute distress. He did state experiencing some chest discomfort at the time; however, it was nonradiating. He had no jugular venous distention, bruits or thyromegaly. Extraocular muscles were intact. Pupils were equal, round, and reacted to light. He was anicteric. Lungs were clear bilaterally. Tones were regular in rate with no S3, S4, murmurs, or rubs. PMI was nondisplaced. Abdomen was soft and nontender with good bowel tones. He had no hepatosplenomegaly. Extremities demonstrated no clubbing, cyanosis or edema. Skin was warm and dry with normal turgor with no petechiae, rashes, or ecchymoses. Nonfocal exam, awake, alert, and oriented to person/place/time and purpose.

A diagnosis of non-ST-elevation myocardial infarction (NSTEMI) was entertained and the patient was taken to the cardiac catheterization lab. His procedure was without immediate complications or complaints. Cardiac catheterization demonstrated a single origin coronary artery tree with a hypoplastic right coronary artery (Figures 2A-2D).

Discussion

Congenital coronary anomalies are found in 0.2-1.6% of the population undergoing diagnostic coronary angiography.¹ The circulatory supply of the myocardium by a coronary system arising from a single ostium is extremely rare.² Coronary anomalies may be associated with chest pain, sudden death, cardiomyopathy, syncope, dyspnea, ventricular fibrillation, and myocardial infarction.³ Though most coronary anomalies are harmless, according to the Sudden Death Committee of the American Heart Association, coronary anomalies cause 19% of deaths in athletes.⁴ As previously stated, most coronary anomalies are clinically silent and are recognized only at the time of autopsy. The incidence of incidental coronary anomalies at autopsy includes a single coronary artery in 0.024%-0.066%.⁵ After hypertrophic cardiomyopathy, coronary artery abnormalities are the second most common cause of sudden death in young athletes.⁶ No racial or sexual predisposition is known.

Coronary artery anomalies have been described as follows by Kim et al⁷:

• High takeoff: the origin of either the right coronary artery (RCA) or the left coronary artery (LCA) at a point above the junctional zone between its sinus and the tubular part of the ascending aorta.
• Multiple ostia: either the RCA and the conus branch arise separately, or the left anterior descending coronary artery (LAD) and left circumflex (LCx) arteries arise separately with no LCA.
• Single coronary artery: only one coronary artery arises with a single ostium from the aortic trunk.
• Anomalous origin of the coronary artery from the pulmonary artery: one of the most serious congenital coronary anomalies.
• Origin of the coronary artery or branch from the opposite or noncoronary sinus and an anomalous course: four variants have been described; (I) the RCA arising from the left coronary sinus, (II) the LCA arising from the right coronary sinus, (III) the LCx or LAD artery arising from the right coronary sinus, and (IV) the LCA or RCA (or a branch of either artery) arising from the noncoronary sinus.
• Myocardial bridging: segment of an epicardial coronary tunnels under a band of myocardial muscle.
• Duplication of arteries.
• Coronary artery fistula: communication exists between one or two coronary arteries and either a cardiac chamber, the coronary sinus, the superior vena cava, or the pulmonary artery, creating a shunt effect.
• Coronary arcade: a direct anastomosis between the RCA and the LCA in the absence of coronary stenosis. They are differentiated from collateralization in that they are prominent, straight connections between the two vessels.
• Extracardiac termination: connections that exist between coronary arteries and extracardiac vessels.

Guidelines related to preparticipation screening for cardiovascular abnormalities in competitive athletes have been established by the American Heart Association/American College of Cardiology.⁸

As to the prognostic significance of the finding in this case, there is no clear increased risk for sudden cardiac death. Hypoplasia of the left coronary or multiple coronaries has been suggested as the cause of sudden death in some pathologic studies and case reports.⁹ Surgical treatment of anomalous origin of the coronary arteries is suggested in those where the artery is coursing inter-arterially; that is, between the great arteries, and only if there is evidence of ischemia.¹⁰ 

A “strategy” for identifying these patients was suggested by Basso et al, utilizing multiple diagnostic modalities such as echocardiography to visualize the coronary origin in individuals, who are usually young, athletic, and with prior complaints of exertional syncope or angina. Also suggested is computed tomography imaging (CT) and/or magnetic resonance imaging, which have become the modalities of choice in diagnosing cases of anomalous coronary arteries.^10,11

This article was reprinted with permission from Cath Lab Digest 2017;25(6):34-35. 

References

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