Morphometric Characteristics of the Conal Coronary Artery

Abstract

The right conal (conus) artery either presents as the first ventricular branch of the right coronary artery (RCA) or arises directly from the aorta, in which case, it is considered the third coronary artery (TCA). Morphometric characterization of this artery is important for interpretation of coronarography, surgical revascularization of myocardium and embryological interpretations. Eight out of 23 hearts presented the TCA (34.8%). The difference in the frequency of the TCA between the sexes was statistically insignificant (p>0.05). In all the specimens, the ostium of the TCA was to the left of and superior to the ostium of the RCA. The supernumerary (third) coronary artery formed Vieussens' arterial ring in 50% of the cases with the TCA, while the conal branch of the RCA formed the anastomosis with the conal branch at a higher frequency (63% of the cases). The ratio of external diameters of the RCA and TCA was 2.84 ±0.78, while the ratio of external diameters of the RCA and its conal branch was 2.61±0.74. The difference in the ratios was statistically insignificant (p>0.05). There were no findings indicating that the presence of the TCA could be detrimental or advantageous when compared to the classical coronary scheme (right and left coronary arteries originating from the aortic sinuses). Based solely on the TCA's morphological features, there is insufficient evidence to suggest that the presence of the TCA per se, is associated with a known clinical or disease state.

Keywords

• supernumerary coronary artery
• conal artery
• third coronary artery