Impact of Coronary Tortuosity on Coronary Blood Supply: A Patient-Specific Study

Abstract

BackgroundTortuous coronary arteries are commonly observed in clinical screenings and it may cause a reduction of the coronary pressure. However, whether this reduction leads to significant decreasing in the coronary blood supply is still unknown. The purpose of this study was to investigate the effect of the coronary tortuosity (CT) on the coronary blood supply.MethodA computational fluid dynamics (CFD) study was conducted to evaluate the impact of tortuosity on the coronary blood supply. Two patient-specific left anterior descending coronary artery (LAD) models and the corresponding non-tortuous models were reconstructed to perform three-dimensional CFD analysis. The lumped parameter model was coupled to the outlet of the simulated branches to represent the absent downstream vasculatures. The rest and exercise conditions were modeled by specifying proper boundary conditions.ResultUnder resting condition, the mean flow rate could be maintained by decreasing less than 8% of the downstream vascular bed's resistance for tortuous models. While during exercise (maximal dilatation condition), the maximal coronary blood supply would reduce up to 14.9% due to tortuosity. Assuming that the flow rate can be maintained by the auto-regulation effect under the maximal dilatation condition, the distal resistances for CT models still have to reduce more than 23% to maintain blood perfusion.ConclusionsCoronary tortuosity has minor influence on coronary blood supply at rest; while during exercise, patients with CT may lack the ability to adjust distal resistance sufficiently to compensate for the extra resistances generated by tortuosity and this may further lead to an ineffective regulation of the blood supply.

Coronary tortuosity and its role in myocardial ischemia in patients with no coronary obstructions

“…Meticulous vessel preparation with pre-dilatation, use of short stents with thinner structures, guidewires with magnetic navigation systems, use of a second guidewire for material progression ("buddy wire technique and "crooked buddy technique"), and use of the "over the wire" [36][37][38][39][40][41] system are employed. Once the lesion is overpassed with the guidewire, it may be difficult to recognize the location to implant the stent due to the rectification of the tortuous segment and appearance of phantom lesions -Concertina effect.…”

“Lambda‐wave” ST‐elevation is associated with severe prognosis in stress (takotsubo) cardiomyopathy

“…Presumably, in the absence of any sign of vasospasm, tortuous coronary anatomy may be also partly responsible for distal ischemia in our patients, as a recent retrospective case–control study showed about relation between TTC and coronary abnormalities (Arcari et al., ). Catecholamine surge may precipitate ischemia by increasing myocardial metabolic demand, and may compromise the blood flow in tortuous vessels, as illustrated in computational, in vivo and in vitro models (Han, ; Xie, Wang, Zhu, Zhou, & Zhou, ). Local intermittent microvascular constriction, maybe induced by neuropeptide‐Y released from sympathetic fibers, may also not be excluded (Yalta, Sivri, & Yalta, ).…”

Shear-Induced Platelet Activation in Tortuous Coronary Artery: A Numerical Study

“…12 The axis of the CT model was projected onto a reference plane to generate the axis of the nCT model. By using this method, the tortuosity was removed from the CT model while the curvature of the CT model (the curvature of the heart) was retained.…”

“…By using this method, the tortuosity was removed from the CT model while the curvature of the CT model (the curvature of the heart) was retained. 12 Compared to nCT models, the tortuous coronary arteries have some bend sections and are longer than nCT models. Thus, the two important geometry changes (bend sections and lengthen effect) caused by tortuosity are both included and the constructed nCT models were physiological.…”

“…10,11 Severe CT would make the regulation of the blood flow ineffective during exercise. 12 When blood flowed through CT sections, the velocity profiles were strongly skewed and high FSSs regions were formed due to the centrifugal effect. 11 This phenomenon was more pronounced during the exercise condition.…”