Atypical Presentation of Massive Pulmonary Embolism Leading to In-Hospital Cardiac Arrest and Successful Thrombolysis.

Pulmonary embolism (PE) is a potentially fatal condition with a broad spectrum of clinical presentations, many of which are non-specific and may delay diagnosis, particularly in patients without classical risk factors. Although dyspnea, chest pain, and tachycardia are considered typical features, atypical symptoms such as dizziness, palpitations, and syncope can obscure early recognition and contribute to adverse outcomes. We describe a woman in her early 40s with a background of anemia and colonic disease who presented with dizziness, palpitations, and lethargy. Initial assessment revealed persistent tachycardia, tachypnea, metabolic acidosis, and elevated troponin and D-dimer levels. Despite early fluid resuscitation, the patient deteriorated rapidly with hemodynamic instability. Computed tomography pulmonary angiography confirmed a massive PE. She subsequently suffered a cardiac arrest and achieved return of spontaneous circulation following systemic thrombolysis administered during cardiopulmonary resuscitation. Her clinical course was complicated by catastrophic intra-abdominal hemorrhage, likely secondary to thrombolytic therapy, necessitating emergency laparotomy and intensive care unit admission. Planned catheter-directed thrombectomy was abandoned because of active bleeding and hemodynamic instability. She developed multiorgan failure requiring vasopressor support and continuous renal replacement therapy. Further complications included radial artery thrombosis requiring surgical thrombectomy, recurrent pulmonary edema, and non-ST-segment elevation myocardial infarction. The occurrence of recurrent arterial and venous thrombotic events raised suspicion for antiphospholipid syndrome as an underlying prothrombotic condition. Following a prolonged and complex hospital course involving multiple intensive care unit readmissions and surgical interventions, the patient recovered and was discharged after 33 days on anticoagulation with planned multidisciplinary follow-up. This case highlights the importance of maintaining a high index of suspicion for PE in patients presenting with atypical symptoms and underscores the need to consider underlying thrombophilia in severe or recurrent thrombotic disease.