Anatomic spectrum of left coronary artery anomalies and associated mechanisms of coronary insufficiency

Abstract

This is a novel re-appraisal of an understudied and misunderstood group of important coronary anomalies. The general name of the group is "anomalous origin of the left coronary artery," but several additional details should be included in this group of anomalies and the explanation of their pathophysiology. The most lethal form in young athletes or military recruits features intramural aortic proximal course. This comprehensive review is based on a large experience at a dedicated center for coronary artery anomalies, using evolving knowledge (over 20 years) while employing prospective and disciplined programs of evaluation and treatment, according to the nature and severity of each anomaly. The most common pathogenic mechanism of coronary dysfunction relates to intramural coronary course, with or without ectopic origin, leading to variable lateral compression and stenosis inside the aortic tunica media; this compression is present at rest and worsens with exertion. We propose that such variable and dynamic stenoses can be best studied by examining their specific anatomy and clinical presentation, stress testing, and, most importantly, in vivo evaluation by intravascular ultrasonography. Such methods should be used to support individual risk evaluation and selection among treatment options.

Coronary Artery Anomaly in Takotsubo Cardiomyopathy: Cause or Innocent Bystander?

“…3 Intermittent vasospasm and endothelial dysfunction of coronary arteries can induce TC, so it can be hypothesized that our patient's left CAA with an intraseptal course affected her LV apical ballooning. 4 In cases of TC, vasospasm and endothelial dysfunction are best evaluated by means of an intracoronary acetylcholine challenge, 5 which our patient did not undergo. Regardless, the apical myocardial regions typically affected in TC do not correlate with a specific epicardial coronary vessel distribution territory; they are supplied by multiple left and right coronary vessels.…”

Symptomatic right coronary anomaly with dynamic systolic intramural obliteration and isolated right ventricular ischemia

“…Finally, in view of our case findings, the question can be discussed as to why a congenital lesion like R‐ACAOS‐IM (and also left ACAOS‐IM) typically manifests only in adult or even elderly patients (our patient had been quite physically active in his college years). ACAOS may also be found at autopsy in those with sudden cardiac death as the first clinical manifestation of disease . On the basis of our recent experience with IVUS, we believe that multiple mechanisms may contribute to the development of ischemic symptoms in ACAOS.…”

“…IVUS is critically useful in showing that ostial coronary atherosclerotic build‐up is not present in this type of congenital pathology, although it is frequently assumed (incorrectly) to be the causative mechanism of stenosis. The absence of ostial atherosclerosis is helpful in recognizing and explaining the unique biology of this anomaly: the intramural segment of such ectopic coronary arteries lay inside the aortic tunica media, where adventitial or fat tissue is not typically found . Lifelong protection from atherosclerosis is probably explained by this peculiar and unique feature.…”

High-Risk Cardiovascular Conditions in Sports-Related Sudden Death: Prevalence in 5,169 Schoolchildren Screened via Cardiac Magnetic Resonance

“…In ACAOS, 23,24 athletic exercise can affect intramural lateral compression of a coronary artery inside the aortic tunica media: acute and chronic exercise-related aortic root dilation and increased stroke volume 32,33 exacerbate narrowing of the coronary cross-sectional area during periods of increased demand. Long-term prognosis in ACAOS-IM might depend on the variable phenomenon of aortic root expansion that has been reported in athletes.…”

“…Long-term prognosis in ACAOS-IM might depend on the variable phenomenon of aortic root expansion that has been reported in athletes. 33…”