Characterization of the coronary sinus ostium by cardiac magnetic resonance imaging.

The diameter and the angle of the coronary sinus (CS) ostium was analyzed in 101 patients who underwent cardiac magnetic resonance imaging and had left ventricular ejection fractions < or =0.35 (n = 40) or > or =0.65 (n = 61). The angle of the CS ostium in patients with LVEFs < or =0.35 was less acute than in patients with LVEFs > or =0.65 (73 degrees +/- 12 degrees vs 65 degrees +/- 10 degrees, p <0.01). There was no statistically significant difference in the diameter of the CS ostium in patients with LVEFs < or =0.35 compared with those with LVEFs > or =0.65 (8 +/- 3 vs 8 +/- 2 mm, p = 0.5). The diameter and the angle of the CS ostium were not different when analyzed on the basis of the duration of the QRS complex, left atrial dimension, or left ventricular end-diastolic dimension. In conclusion, on the basis of cardiac magnetic resonance imaging data, the angle of the CS is less acute in patients with LVEFs < or =0.35 than in those with LVEFs > or =0.65.