HRV & Health

Methods

Review of long-term studies on HRV and health outcomes

Key Findings

• 24-hour SDNN < 50ms associated with higher mortality
• Low HRV predicts cardiovascular events independently of other risk factors
• Association holds across age groups
• Short-term RMSSD also predictive but less studied for mortality

Limitations

Most studies in populations with existing heart disease

Methods

Umbrella review summarizing meta-analyses on HRV and mental disorders

Key Findings

• HRV consistently lower in depression, anxiety, and PTSD
• Effect sizes moderate to large across conditions
• HRV improves with successful treatment
• May serve as biomarker for autonomic dysregulation in mental illness

Limitations

Heterogeneous measurement methods across studies

Methods

Meta-analysis of cohort studies on HRV and mortality in CVD patients

Key Findings

• Low HRV associated with 2.27x higher all-cause mortality risk
• Cardiovascular event risk increased 1.41x
• Association independent of other risk factors
• Both time and frequency domain measures predictive

Limitations

Primarily studied in patients with existing heart disease

Methods

Prospective study of 501 twins with 24-hour Holter ECG monitoring

Key Findings

• HRV predicted mortality independent of genetic factors
• Deceleration capacity showed strongest mortality association
• Effect persisted after controlling for traditional CVD risk factors
• Suggests HRV reflects brain-heart-autonomic network health

Limitations

All-male veteran population

Methods

Review of HRV in anxiety disorder diagnosis and treatment monitoring

Key Findings

• Lower HRV associated with anxiety disorders vs healthy controls
• HRV improves after successful CBT in panic disorder
• May predict treatment response
• Potential for personalized treatment selection

Limitations

Not yet validated as clinical diagnostic tool