Hyperventilation-induced ST segment elevation mimicking acute myocardial infarction in a comatose patient with tracheostomy.

Controlled hyperventilation leading to respiratory alkalosis may induce coronary artery spasm. This manoeuvre is currently used in the diagnosis of Prinzmetal's angina. We describe the case of a comatose patient with tracheostomy in whom hyperventilation, caused by excessive bronchial secretion resulting in partial obstruction of the tracheal cannula, was followed by ST segment elevation mimicking acute myocardial infarction.