Introduction Papillary muscle rupture is a catastrophic complication of acute myocardial infarction (AMI). Delayed diagnosis and recognition often lead to refractory cardiogenic shock, which is difficult to manage. We present a case of papillary muscle rupture resulting in acute severe mitral regurgitation following AMI.

Case Presentation We report the case of a 71-year-old male who presented with acute chest pain and worsening breathlessness over one day. On admission, his blood pressure was 110/76 mmHg, and his pulse rate was 108 bpm. An electrocardiogram (ECG) revealed ST elevation in the inferior leads. The patient subsequently experienced cardiac arrest but was successfully resuscitated after one cycle of cardiopulmonary resuscitation (CPR), followed by mechanical ventilation. In the ward, the patient required four inotropic agents to maintain blood pressure, but his oxygenation remained poor, with a PaO2/FiO2 ratio of 100. A chest X-ray showed features of acute pulmonary oedema. Serial echocardiograms revealed a rupture of the posteromedial papillary muscle head, leading to acute severe mitral regurgitation. Despite adequate diuresis, the patient continued to suffer from persistent hypotension and ultimately succumbed to cardiogenic shock.

Discussion Acute severe mitral regurgitation is a fatal complication of papillary muscle rupture and requires prompt diagnosis and urgent surgical intervention. Acute mitral regurgitation leads to a sudden increase in left atrial pressure, causing acute pulmonary oedema, without allowing time for the atrium to adapt. This results in refractory cardiogenic shock unless immediate surgical repair is performed. In this case, the refractory cardiogenic shock prevented further resuscitation and intervention, leading to the patient’s inevitable death. Mechanical circulatory support as a bridge to valve intervention would have been crucial, but financial constraints made this option unavailable. Even in developed countries, the mortality rate for acute severe mitral regurgitation remains high. A high index of suspicion for acute mitral regurgitation is essential in cases of refractory cardiogenic shock.

Conclusion Papillary muscle rupture with acute mitral regurgitation represents a deadly mechanical complication of myocardial infarction. Early recognition, supported by appropriate clinical and echocardiographic findings, is critical to optimizing patient management.