Mechanisms of Myocardial Ischemia Inducing Sudden Cardiac Death in Athletes with Anomalous Coronary Origin from the Opposite Sinus: Insights from a computational fluid dynamic study.

AIMS: The left coronary anomalous origin from the opposite sinus (L- ACAOS) constitutes the most clinically relevant arterial abnormality among the wide spectrum of coronary artery anomalies. We investigated the physiology of L-ACAOS with and without intramural course (IM) in athletes, using the computational fluid dynamic (CFD) analysis. METHODS AND RESULTS: The coronary artery circulation with L-ACAOS with and without IM has been segmented and then reconstructed, after reviewing both the angiographic and computed tomography findings of 13 consecutive athletes (10 males, mean age 45.1 ±â€¯8.2 years) with L-ACAOS collected in our institution between 1st January 2003 and 1st January 2018. Vorticity magnitude, static pressure and wall shear stress (WSS) have been analysed in a model of L-ACAOS with no IM course and in L-ACAOS-IM at rest and during exercise. The mean vorticity magnitude and WSS significantly increased from rest to exercise in both models, in right coronary artery, left anterior descending and left circumflex coronary arteries. The mean static pressure significantly increased with exercise in IM (1.118e + 004 vs 1.164e + 004 Pa, p < 0.001) as well as the mean vorticity magnitude and the mean WSS (7012.78 1/s vs 9019.56 1/s, p < 0.001, Δ = 2006.78 1/s and 3.02 Pa vs 2.11 Pa, p < 0.001, Δ = 0.91 Pa). This net increment was transmitted to the entire left coronary system in L-ACAOS-IM but not in L-ACAOS with no IM. CONCLUSIONS: In L-ACAOS, different hemodynamic parameters observed in the intramural segment seem to confirm that IM is compressed during exercise. These rheological properties might propagated along the left coronary system, potentially predisposing, if confirmed in vivo, distal coronary segments to a higher risk of spasm and thrombosis in athletes.