Coronary sinus diameter to inferior vena cava diameter ratio in the diagnosis of cardiac tamponade: a novel approach
Abstract Background and aim Coronary sinus (CS) as an intrapericardial, low-pressure, thin-walled structure can be easily compressed in cardiac tamponade. Whereas, inferior vena cava (IVC) is an extrapericardial structure which dilates in tamponade as opposed to the response of CS. The inverse relationship between these two venous structures may augment their role in the evaluation of tamponade imaging. Therefore, we assessed the usefullness of computerized tomographic measures of CS diameter, and also CS to IVC ratio (CS/IVC) to predict tamponade in clinically stable patients with large pericardial effusion. Materials and methods 66 clinically stable patients who had large pericardial effusions, were included to the study. CS diameter was measured from the point at 1 cm proximal to the CS ostium11. IVC diameter was measured from the segment between its right atrial orifice and hepatic vein. Results Patients with tamponade had 40% smaller CS diameter (5.3±1.8 vs 8.8±2.6 mm p<0.001) and 35% lower CS/IVC ratio (20.7±5.5 vs 34.7±10.5% p<0.001).After adjusting with other parameters, only either CS diameter or CS/IVC ratio predicted tamponade respectively. (Nagelkerke r square value for CS diameter was 53.7% and 72.1% for CS/IVC ratio). 1 mm increase in CS diameter and 1% increase in CS/IVC ratio were associated with an increased odds ratio of 59% and 39% in predicting tamponade, respectively (p value <0.001).In ROC analysis, a cut of value of 6.85 mm for CS diameter, had 82.6% sensitivity and 83.7% specificity for predicting cardiac tamponade (Area under the curve 0.879, p<0.001). Additionally, a cut of value of 27% for CS / IVC ratio had 87.0% sensitivity and 86.0% specificity for predicting cardiac tamponade (Area under the curve 0.945, p<0.001). Conclusion The tomographic measures of both the CS diameter and the CS/IVC ratio predicted tamponade in clinically stable patients with large pericardial effusion. Compared with CS diameter, CS/IVC ratio seemed to be a more powerful predictor of tamponade Figure 1 Funding Acknowledgement Type of funding source: None