To explore the clinical characteristics, echocardiographic findings, and diagnostic challenges of low-flow/low-gradient aortic stenosis (LF/LGAS).

A retrospective analysis was conducted on the clinical data and imaging examinations of a LF/LGAS patient presenting with severe mitral regurgitation (MR) admitted to the Department of Cardiology of Northern Jiangsu People′s Hospital on February 26, 2024. Combined with literature review, the causes of misdiagnosis at the initial diagnosis were explored and relevant experiences were summarized.

The patient was a 78-year-old female who was admitted to the hospital due to chest tightness and shortness of breath for 2 years, which worsened with coughing and expectoration for more than 2 months. Transthoracic echocardiography upon admission showed a left ventricular ejection fraction (LVEF) of 33.0%, accompanied by severe functional MR. The EuroSCORE Ⅱ score was 11.2%, indicating a high-risk surgical condition. The mitral valve leaflet was > 10 mm and had good mobility. The initial plan was to perform transcatheter mitral valve edge-to-edge repair. Intraoperative transesophageal echocardiography (TEE) and low-dose dobutamine stress echocardiography (LDDSE) indicated that the aortic valve orifice area was 0.9 cm². Eventually, the main cause was determined as LF/LGAS, and transcatheter aortic valve replacement was performed instead. The valve was in good position after the operation, and no obvious perivalvular leakage or regurgitation was observed. One year later, a re-examination by echocardiography showed mild to moderate MR and the LVEF was 45.0%.

The possibility of LF/LGAS should be considered for patients with aortic stenosis whose clinical manifestations are inconsistent with conventional echocardiographic parameters. Intraoperative TEE combined with LDDSE facilitates definitive diagnosis, guides targeted interventional therapy, and improves patient prognosis.