Differential response to isometric handgrip depending on the heart failure condition in patients with functional mitral regurgitation: a case report.

Background: Functional mitral regurgitation (MR) changes dynamically depending on the loading conditions and can cause acute heart failure (HF). Isometric handgrip is a simple stress test and can be performed during early phase of acute HF for the evaluation of MR. Case summary: A 70-year-old woman with a prior myocardial infarction four months before, and with history of recurrent HF admission with functional MR, who received optimal HF medications, was hospitalized for acute HF. On the following day of the admission, isometric handgrip stress echocardiography was performed to evaluate functional MR. During the handgrip, MR deteriorated from moderate to severe and the tricuspid regurgitation pressure gradient increased from 45 to 60 mmHg. After HF stabilization 2 weeks after admission, repeat handgrip stress echocardiography showed that the degree of MR did not significantly change being moderate and the tricuspid regurgitation pressure gradient was only mildly elevated from 25 to 30 mmHg. She underwent transcatheter edge-to-edge mitral repair, and thereafter she has not experienced the rehospitalization for acute HF. Discussion: Exercise stress test is recommended for the evaluation of functional MR in HF patients; however, exercise tests are difficult to perform during the early phase of acute HF. In this regard, handgrip test is an option to investigate the exacerbating impact of functional MR during early-phase acute HF. This case indicated that response to isometric handgrip can vary depending on HF condition, highlighting the importance of taking into account the timing of the handgrip procedure in patients with functional MR and HF.