Osborn wave in patients with ST-elevation myocardial infarction undergoing mild therapeutic hypothermia after cardiac arrest.

OBJECTIVE: Experimental and clinical studies have proven the neuroprotective effects of hypothermia in unconscious patients with spontaneous circulation after out-of-hospital cardiac arrest. Based on this evidence, recommendations have been made to incorporate mild therapeutic hypothermia into practice. ECG changes are well documented in people with incidental hypothermia but there are only few studies on ECG abnormalities in patients undergoing mild therapeutic hypothermia after cardiac arrest due to ST-elevation myocardial infarction.

METHODS: Ten patients with ST-elevation myocardial infarction (STEMI) complicated by cardiac arrest and receiving mild therapeutic hypothermia (MTH) after return of spontaneous circulation and ten comparable patients but not receiving mild therapeutic hypothermia as a control group were incorporated into our prospective study. We analysed electrocardiographic (ECG) changes during hypothermia and its influence on ECG evolution in patients after STEMI.

RESULTS: MTH was mainly associated with decrease of heart rate (P = 0.014) and QTc interval prolongation (P = 0.005). In 60% of patients the Osborn wave was registered. The presence of a new Q wave or new negative T wave in ECGs registered on the 3rd day of STEMI was comparable in the two groups.

CONCLUSIONS: Although hypothermia is associated with typical ECG findings like Osborn wave, the electrocardiographic evolution of STEMI in patients receiving MTH is comparable with that in patients without it.