Osborn waves associated with ventricular fibrillation in a patient with vasospastic angina

A 52-year-old man with a history of vasospastic angina experienced a severe ischemic episode accompanied by a non-Q wave myocardial infarction. Two episodes of ventricular fibrillation (VF) occurred during the acute phase of the event. Osborn waves were observed on the ECG preceding each episode of VF. In the second episode, the gradual development of Osborn waves until VF occurred was confirmed on ECG. The Osborn waves appeared to be related to the occurrence of VF. This case may provide clinical evidence that a prominent I(to) participates in the development of VF during myocardial ischemia.