A Novel Angiographic Finding Observed During Coronary Angiography in a Misdiagnosed Case of Pulmonary Embolism

Abstract

Background: Pulmonary embolism (PE) is a potentially fatal condition with varied and often nonspecific clinical presentations. Its symptom overlap with other acute conditions such as acute coronary syndrome (ACS) frequently leads to misdiagnosis and delayed treatment. Early recognition is crucial to improving outcomes, and any novel sign that aids diagnosis during routine investigations could be of significant clinical value. Case Presentation: We report the case of a 58-year-old male with a history of hypertension who presented with chest pain and dyspnea. He was initially diagnosed as having non-ST-elevation myocardial infarction (NSTEMI) based on symptoms, ECG changes, and raised cardiac enzymes. Coronary angiography revealed non-obstructive coronary arteries with a striking finding: sluggish flow, particularly in the right coronary artery (RCA), where contrast persisted long after injection ceased. The patient was discharged on dual antiplatelet therapy but returned the next day with worsening symptoms and oxygen desaturation. Results: Computed tomography pulmonary angiogram (CTPA) confirmed bilateral pulmonary emboli extending from the main pulmonary artery into both main branches and subsegmental arteries. Venous Doppler revealed bilateral supra-popliteal deep vein thrombosis. The patient responded well to anticoagulation, initially with enoxaparin and later with apixaban. He remained clinically stable on follow-up at 21 days, 3 months, 6 months, and 9 months. Conclusion: This case highlights a novel angiographic sign—extremely sluggish coronary flow in the absence of obstructive lesions—which may serve as an early diagnostic clue for PE in patients undergoing coronary angiography for suspected ACS. Prompt recognition of this sign could expedite appropriate investigations like CTPA and lead to life-saving interventions.