<unk> us origin of a<unk>  artery from the opposite sinus are relevant on a clinical level due to a significant association with sudden cardiac death, if they are accompanied by intramural course. Indeed, the main feature responsible for adverse outcomes is the “intramural” course (sometimes improperly referred to as inter-arterial) characterized by an acute ostial angulation (tangential course), “slit-like” ostium (compressed inside the aortic wall), and a proximal or initial section penetrating into the aortic tunica media<unk>  arteries normally take off at a 90 degree angle) with subsequent course reaching the “correct” side of the heart. As a consequence, lateral compression of the<unk>  artery leads to<unk>  luminal (inside opening) narrowing, with reduced supply of blood and oxygen to the depending myocardial tissue, that is phasic (worse in systole, the phase of cardiac contraction, and tachycardia). Furthermore, the intramural segment of the ectopic artery, located inside the aorta, is typically but variably “hypoplastic”, smaller in circumference than the distal, extramural segments (it is unable to grow properly either before or after birth). Autonomic and/or endothelial dysfunction may occur and induce spasm and/or thrombosis at<unk> us sites (and critical ischemia), although intracoronary clotting has been rarely observed. Therefore, stenosis of an intramural proximal segment, lateral compression and spastic hyperreactivity are the mechanisms that have been linked to clinical manifestation.<unk>  narrowing is most likely the main process implied in ACAOS, and it may result in symptoms such as chest pain (“angina pectoris”), dyspnea (shortness of breath), palpitations, cardiac arrhythmias (heart rhythm disorders), syncope (fainting). In most cases, however,<unk> es are silent for many years and the first clinical manifestation of these pathological entities is sudden cardiac death (e.g. due to malignant arrhythmias such as ventricular fibrillation) typically after strenuous physical exertion (when arterial compression is more severe, and cardiac work is maximal) such as in young athletes or military recruits. Of note, 19-33% (in different studies) of sudden deaths in young athletes are due to<unk> es. Clinical manifestations can be found in non-athletic, older individuals and are commonly associated with hypertension and aortic dilatation with worsening degree of compression. L-ACAOS-IM (intramural) is seen in 0.1% of young children and, among<unk> <unk> es, it has the highest probability of clinical repercussions, being consistently associated with sudden cardiac death following physical exercise. Several more varieties of L-ACAOS are described: - prepulmonic (L-ACAOS-PP): origin of the LCA (or only the LAD) from the right sinus of Valsalva (RSV) with an epicardial course (on the surface of the heart) anterior to the pulmonary outflow tract - this does not usually cause stenosis nor requires intervention (benign<unk> , unless spasm occurs); - subpulmonary, infundibular or intraseptal (L-ACAOS-SP): the LCA (or only the LAD) originates from the RSV, initially runs inter-arterially (outside the aortic wall) then intramyocardially inside in the ventricular septum and finally epicardially in the anterior interventricular groove - this<unk>  is considered benign since it is not associated with significant fixed degree of stenosis (but it could cause spasm); - retroaortic (L-ACAOS-RA): origin of the LCA or the only LCx from the RSV or from the RCA, running behind the aortic root and at the central fibrous mitro-aortic septum – this is considered as a benign<unk>  (but it could cause spasm); - retrocardiac (L-ACAOS-RC) – LCA originates from the RCA at the atrioventricular groove - or wrap-around the apex (L-ACAOS-WA) – generally benign, unless spasm occurs. General scheme to identify possible courses of normal and ectopic<unk>  origin. AL = antero-left; AR = antero-right; Cx = circumfles artery; IM = intramural; IS = intraseptal; LAD = left anterior descending artery; M = mitral valve; P = posterior; PP = prepulmonic; RA = retroaortic; RC = retrocardiac; RCA = right<unk>  artery; T = tricuspid valve. R-ACAOS-IM is observed in a higher percentage of cases (0.35% of adolescents) than L-ACAOS-IM but is less likely to be associated with sudden cardiac death in athletes. Varieties of R-ACAOS such as prepulmonic, retroaortic and intraseptal can occur and are considered generally benign. The most frequent symptomatic<unk><unk>  in infants and young children is<unk> us origin of the left<unk>  artery from the pulmonary artery, which may cause acute myocardial infarction at neonatal age and requires emergent surgery at the time of diagnosis.<unk> es at the mid segments include myocardial bridges, affecting >1% of the clinical population, and characterized by an intramyocardial course of<unk>  arteries within the muscle fibers. This may lead to systolic compression which is usually mild<unk>  blood flow is mostly diastolic). Significant ischemia is rare in isolated myocardial bridges, and if present this is generally due to localized endothelial dysfunction with a tendency to spasm. Most myocardial bridges are benign and do not require any intervention.<unk>  artery aneurysms are defined as a > 50% increase of the vessel diameter. Some cases are congenital/idiopathic, but most are secondary to atherosclerosis or Kawasaki disease (an immuno-inflammatory disease especially targeting<unk>  vessels wall). Potential complications include localized thrombosis, distal embolization, rupture, or late lipid deposits.<unk>  arteriovenous fistulas are<unk> es at the termination consisting of an<unk> us connection of<unk>  arteries to<unk>  veins, veins of the pulmonary or systemic circulations, or to any cardiac cavity. Smaller fistulas are usually benign, and only severe cases can be complicated by aneurysmatic dilatation with potential thrombosis and distal embolization, volume overload or “blood steal” from arterial circulation and subsequent ischemia. Treatment is generally not required.
Coronary artery anomaly
Congenital heart defect
Congenital heart block
Coronary artery ectasia
Ventricular aneurysm
Heart valve dysplasia
Valvular heart disease
Coronary artery aneurysm