Coronary Anomalies

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Define the most common and clinically significant coronary anomalies.
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Define common types of coronary fistulae.
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Define which coronary anomalies are low versus high risk.
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Outline the advantages of cardiovascular magnetic resonance (CMR) imaging over conventional X-ray angiography.
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Understand treatment options for common coronary anomalies.

KEY POINTS

Coronary anomalies are a rare group of congenital disorders with an incidence of approximately 0.6 percent of births. These can broadly be defined as anomalies of origin and course, termination, or intrinsic anatomy ( Table 24-1 ). Patients may be asymptomatic or present with angina, palpitations, or exertional syncope. Although most have a benign course, these conditions can cause sudden cardiac death and myocardial infarction—especially in young adults and athletes. Diagnosis is highly dependent on cardiac imaging. Traditionally, X-ray coronary angiography was used to make the diagnosis. Currently CMR has emerged as a noninvasive method for defining the origin of coronary arteries and their three-dimensional proximal course, without radiation exposure or contrast administration. This makes CMR an ideal choice for young adults with suspected coronary anomaly. Treatment highly depends on the type of anomaly. For those associated with an interarterial course and/or myocardial ischemia, surgical correction is warranted.

TABLE 24-1

Types of Coronary Anomalies

Anomalies of origin and course: high risk
- Anomalous location of coronary ostium outside the aortic root (e.g., pulmonary artery, aortic arch)
- Anomalous origin of the coronary ostium from the contralateral coronary sinus
  - Interarterial (Preaortic)
    - LCA arising from right sinus
    - RCA arising from left sinus

Anomalies of origin and course: low risk
- Separate origin of the LAD and LCx
- Anomalous location of the coronary ostium from the proper aortic sinus of Valsalva (e.g., high, low, commissural)
- Anomalous origin of the coronary ostium from the contralateral coronary sinus
  - Retro-aortic
    - LCA arising from right sinus
    - LCA arising from noncoronary sinus
    - LCx arising from right sinus
  - Prepulmonary
    - LCA arising from right sinus

Anomalies of termination
- Coronary fistulae from coronary arteries to:
  - Pulmonary Artery or Vein
  - Ventricles or Atria
  - SVC or Coronary Sinus

Anomalies of intrinsic anatomy
- - Coronary ectasia or hypoplasia
  - Coronary aneurysms
  - Subendocardial course (myocardial bridge)

Adapted from Angelini P: Coronary artery anomalies: An entity in search of an identity. Circulation 2007;115:1296-1305.

ANOMALIES OF ORIGIN AND COURSE: HIGH RISK

Case 1

A 13-year-old boy presented with exertional syncope. CMR was ordered to assess for coronary anomaly. Based on the high-risk anatomy, the patient underwent successful surgery with reimplantation of the LM to the correct sinus ( Figure 24-1 ).

Left Coronary Artery from the Right Coronary Sinus with an Interarterial Course

Case 2

An 18-year-old man presented initially with exertional chest tightness and fatigue while playing basketball. A chest X-ray showed cardiomegaly, and an ECG showed nonspecific ST-T wave abnormalities. A transthoracic echocardiogram revealed moderate LV enlargement, a left ventricle ejection fraction (LVEF) of 35% with global hypokinesis, moderate to severe MR, and severe pulmonary HTN estimated at 100 mm Hg. An exercise myocardial perfusion stress test showed an infarct with severe peri-infarct ischemia in the distal anterior and inferolateral walls at 15 METs of exercise. X-ray coronary angiography revealed an anomalous left coronary artery (LCA) originating from the pulmonary artery (PA) and a large right coronary artery (RCA) providing collaterals to the LCA. He was referred for CMR to better delineate the coronary anomaly and to assess myocardial scar ( Figure 24-2 ). Based on the findings on CMR, he was referred for cardiac surgery where a LIMA graft to the LAD was placed as well as an annuloplasty ring to the mitral valve. His symptoms improved after surgery.