Altered Heart Rate Variability During Rest in Schizophrenia: A State Marker

Area of Science:

• Neuroscience
• Psychiatry
• Cardiology

Background:

• Autonomic nervous system (ANS) imbalance is linked to psychiatric disorders like schizophrenia.
• Autonomic dysfunction in schizophrenia correlates with psychosis symptoms.
• Heart rate variability (HRV) assesses ANS activity and sympathovagal balance.

Purpose of the Study:

• Investigate heart rate variability (HRV) frequency domain measures in schizophrenia patients and their first-degree relatives.
• Compare HRV parameters between patients, relatives, and healthy controls.
• Understand changes in sympathovagal balance in schizophrenia.

Main Methods:

• Included 25 schizophrenia patients, 24 first-degree relatives, and 24 healthy controls (ages 18-45).
• Measured HRV from ECG lead II after a 5-minute rest period.
• Analyzed frequency domain HRV parameters (LF, HF, total power, LF/HF ratio) and heart rate using general linear model multivariate analysis.

Main Results:

• Schizophrenia patients exhibited significantly higher minimum heart rate and lower high frequency (HF) power (normalized units) than first-degree relatives.
• A trend indicated lowest HF power in patients, followed by healthy controls and relatives.
• The LF/HF ratio was highest in patients, followed by controls and relatives, though not statistically significant.
• No significant differences were found between first-degree relatives and healthy controls.

Conclusions:

• Altered HRV in schizophrenia suggests reduced vagal tone and sympathetic dominance.
• These HRV changes may serve as state markers for schizophrenia.
• Further research can explore HRV as a diagnostic or prognostic tool.