The MitraClip is a percutaneously implanted device approved for the treatment of symptomatic organic mitral regurgitation in poor surgical candidates. Despite its proven efficacy and safety for mitral regurgitation treatment, the MitraClip may unmask the true afterload of the left ventricle by removing the low-pressure left atrial system and may cause acute left ventricular systolic failure (afterload mismatch). Rapid diagnosis and treatment of afterload mismatch is crucial to ensure optimal patient outcomes. The authors present a case of acute hemodynamic deterioration after MitraClip implantation in a patient with chronic severe left ventricular systolic dysfunction. Transesophageal echocardiography was pivotal for the rapid recognition of acute left ventricular failure and aided in the intraoperative decision-making process and therapy.