Fig. 2From: Commissural Malalignment as a predictor of coronary artery abnormalities in patients with transposition of great arteries Measuring the C-Ratio. The Distance from the anterior commissure to the right sided commissure of the pulmonary valve is labelled ad D1, while the distance from the anterior commissure to the left sided commissure of the pulmonary valve is labelled as D2. C-Ratio = D1 or D2 whichever is shorter divided by D1 + D2Back to article page