Comparison of flow-independent parameters for grading severity of aortic stenosis using intraoperative transesophageal echocardiography – A prospective observational study

Abstract

Introduction: Discrepancies have been reported in grading of severity of aortic stenosis. We propose to compare Aortic valve area by continuity equation, Dimensionless Index and Acceleration time/Ejection time in patients with documented severe aortic stenosis with normal left ventricular function by TEE after induction of anesthesia. This might give use insight about the best parameter we can rely on intra-operatively for decision making. Methodology: 60 patients with severe AS undergoing elective cardiac surgery were enrolled in our study. Post intubation trans-thoracic echocardiography (TEE) was performed and above mentioned parameters was noted. Results: 96.7 % of patients continued in severe AS category when AS was measured using AVA as echo parameter. So there is 3.3 % disparity. There was disparity in 13.3% of cases when DI was considered. And there was 43.3% disparity when AT/ET was considered. Conclusion: Perioperative grading of aortic stenosis continues to be a challenge for cardiac anesthesiologists. Multiple echocardiographic parameters have to be considered. We have found AVA and DI to have less disparity compared to AT/ET.

Keywords

• acceleration time/ejection time
• aortic stenosis
• dimensionless index