Overestimation of Aortic Stenosis in Thiamine Deficiency: Two Cases With Distinct Underlying Conditions.

The severity of aortic stenosis (AS) can be overestimated in high-flow states, and thiamine deficiency is an underrecognized cause of high-output circulatory states. We report two elderly females who developed thiamine deficiency-related high-output circulatory states, initially leading to an overestimation of AS severity. Case 1 was assessed as severe but was downgraded to moderate after thiamine replacement, and case 2 was initially assessed as moderate but was reclassified as mild after treatment. Case 1 had a history of gastrectomy, predisposing her to thiamine deficiency due to limited postoperative intake and a more alkaline gastric environment. Case 2 had liver cirrhosis and was on long-term spironolactone and loop diuretics, contributing to thiamine depletion via renal losses and impaired gastrointestinal utilization. Both patients exhibited refractory edema and hyperdynamic left ventricular wall motion. Thiamine deficiency impairs adenosine triphosphate production, reducing systemic vascular resistance and triggering compensatory high-output circulatory states. Prompt thiamine replacement improved symptoms and hemodynamic parameters. These cases highlight the importance of recognizing reversible high-flow states to avoid misinterpretation of AS severity and ensure accurate evaluation and management.