Paradoxical coronary embolism, a rare cause of acute myocardial infarction on positive pressure ventilation.

A 65-year-old man developed respiratory failure and was admitted to the Intensive Care Unit for positive pressure ventilation and antibiotic and antifungal therapy.There was a sudden deterioration with chest pain, worsening hypoxia and hypotension. Serial electrocardiograms showed new onset right bundle-branch block with developing anterior ST-segment elevation. An urgent coronary angiogram revealed acute occlusion of the left anterior descending artery with a single large distinct thrombus, which was successfully removed with an aspiration catheter. A presumptive diagnosis of paradoxical coronary embolus was made. A short review is provided of this relatively rare clinical entity which has the potential to present in intensive care patients who have an underlying intra-cardiac defect and require positive pressure ventilation. This case emphasises the importance of being aware of less common causes of acute clinical deterioration and electrocardiographic changes in the ventilated patient.