Heart rate variability measurement and clinical depression in acute coronary syndrome patients: Narrative review of recent literature

Aim:We aimed to explore links between heart rate variability (HRV) and clinical depression*in patients with acute coronary syndrome (ACS), through a review of recent clinical research*literature. Background:Patients with ACS are at risk for both cardiac autonomic dysfunction and clinical*depression. Both conditions can negatively impact the ability to recover from an acute physiological insult, such as unstableangina or myocardial infarction, increasing the risk for adverse*cardiovascular outcomes. HRV is recognized as a reflection of autonomic function. Methods:A narrative review was undertaken to evaluate state-of-the-art clinical research, using*the PubMed database, January 2013. The search terms "heart rate variability" and "depression"*were used in conjunction with "acute coronary syndrome", "unstableangina", or "myocardial*infarction" to find clinical studies published within the past 10 years related to HRV and*clinical*depression, in patients with an ACS episode. Studies were included if HRV measurement and*depression screening were undertaken during an ACS hospitalization or within 2 months of*hospital discharge. Results:Nine clinical studies met the inclusion criteria. The studies' results indicate that there*may be a relationship between abnormal HRV and clinical depression when assessed early*after an ACS event, offering the possibility that these risk factors play a modest role in patient*outcomes. Conclusion:While a definitive conclusion about the relevance of HRV and clinical depression*measurement in ACS patients would be premature, the literature suggests that these measures*may provide additional information in risk assessment. Potential avenues for further research*are proposed.