Association of coronary sinus diameter with pulmonary hypertension

Impaired venous drainage secondary to increased right atrial pressure (RAP) may result in coronary sinus (CS) dilatation.

Two hundred fifteen patients referred for transthoracic echocardiography were included in the study. CS diameters were measured from apical four-chamber view with the transducer being slightly tilted posteriorly to the level of the dorsum of the heart. Pulmonary artery systolic pressure (PASP) is estimated by measurement of tricuspid regurgitation velocity (v) and estimate RAP based on size and collapsibility of inferior vena cava (VCI) with the formula PASP: 4v(2)+RAP. Patients with PASP >35 mmHg were considered to have pulmonary hypertension (PH).

CS diameter was measured in 80.3% of the patients with normal PASP (8.1 +/- 2.4 mm) and 93.1% of the patients having PH (12.3 +/- 2.5 mm). PASP was significantly correlated with CS diameter (r = 0.647, P < 0.001), RA volume index (r = 0.631, P < 0.001), RV volume index (r = 0.475, P < 0.001), VCI diameter (r = 0.365, P < 0.001), and left ventricular ejection fraction (LVEF) (r =-0.270, P < 0.001). CS diameter was also correlated significantly with estimated RAP (r = 0.557, P < 0.001), RA volume index (r = 0.520, P < 0.001), RV volume index (r = 0.386, P < 0.001), LVEF (r =-0.327, P < 0.001), and VCI diameter (r = 0.313, P < 0.001). Multivariate analyses, testing for independent predictive information of CS size, VCI diameter, RA and RV volume indexes, and estimated RAP for the presence of PH revealed that estimated RAP (beta = 0.465, P < 0.001) and CS size (beta = 0.402, P = 0.003) were the significant predictors.

Coronary sinus is dilated in patients with pulmonary hypertension. Coronary sinus diameter significantly correlates with PASP, RAP, right heart chamber volumes, LVEF, and VCI diameter.