This case report describes a young female Caucasian patient with newly presenting severe mitral stenosis at the peak of the coronavirus pandemic in the Republic of Ireland. The initial presumptive diagnosis was of severe coronavirus illness. This case report highlights the importance of keeping an open mind to alternative diagnoses and examines some of the challenges in the diagnosis and management of a rare condition in the pandemic environment. This patient gained 10 kg of weight within 6 weeks of percutaneous balloon mitral valvuloplasty, highlighting the contribution of cardiac cachexia to her low body weight and demonstrating the exceptional benefit that this treatment can offer to patients.