Post-anesthetic shivering (PAS) is common after general anesthesia and causes sympathetic excitement, followed by elevated blood pressure. Mitral valve transcatheter edge-to-edge repair (TEER) with MitraClip® (Abbott, Santa Clara, CA) increases left ventricular output resistance because of mitral valve narrowing. PAS after TEER synergistically raises cardiac load, surpassing the left ventricular working reserve and greatly increasing the risk of left ventricular failure in patients. A 64-year-old woman diagnosed with functional severe mitral regurgitation underwent implantation of MitraClip under general anesthesia and was subsequently transferred to the intensive care unit (ICU). Thirty minutes after admission to the ICU, the patient exhibited shivering, elevated blood pressure, and reduced oxygen saturation. There was no evidence of clip displacement, and the cause of this oxygenation impairment was considered to be hypertensive heart failure triggered by shivering. Noninvasive mechanical ventilation, antihypertensive medication, and body surface warming were initiated. The patient showed signs of recovery within two hours. Shivering can increase patient risk after TEER. Effective prevention of shivering is essential because TEER, along with shivering, can increase left ventricular ejection resistance, known as afterload mismatch.