Time to onset of anxiety- and depression-like behaviors in rats after myocardial infarction and association with autonomic control of heart

Although emotional factors increase the risk of cardiac deaths in patients with coronary artery disease, exact mechanisms underlying the increased risk has not been identified. The aim of the study was to investigate the anxiety-like and depression-like behaviors in rats after myocardial infarction and the association with the autonomic control of heart rate. Anxiety-like and depression-like behaviors were assessed during 28-day post myocardial infarction period. Myocardial infarction was induced surgically by the ligation of left anterior descending artery. Elevated plus-maze and forced swimming tests were chosen for assessment of anxiety and depression, respectively. Autonomic control of heart rate was evaluated by power spectral analysis of heart rate variability. Our findings showed that both anxiety-like and depressive-like behaviors were seen after myocardial infarction. However anxiety-like behaviors were seen in the acute period of myocardial infarction, depression-like behaviors were significant in the late period. Anxiety but not depression was associated with reduced autonomic control of heart rate after myocardial infarction. These data lead to the conclusion that emotional factors seem to be involved in the prognostic factors in coronary artery disease. Adding of antidepressant/anxiolytic therapy to the reperfusion strategies in patients after myocardial infarction is very important.