HRV & Respiratory

Methods

Cross-sectional analysis in ARIC study, the largest HRV-lung function analysis conducted

Key Findings

• HRV associated with lung function measures
• Association with self-reported lung disease confirmed
• Directionality of association varied by HRV measurement type
• Important for studying obstructive airways and cardiovascular disease

Limitations

Cross-sectional design, association not causation

Methods

Comprehensive review of HRV in OSA, COPD, and overlap syndrome

Key Findings

• Overlap syndrome shows synergistic autonomic dysfunction
• 1.7x greater risk of acute exacerbations vs COPD alone
• Short-term HRV particularly sensitive to autonomic changes
• Wearables viable for screening in overlap syndrome
• CPAP therapy efficacy can be evaluated via HRV

Limitations

Review of existing literature

Methods

Systematic review and meta-analysis of HRV in COPD

Key Findings

• COPD patients show reduced overall HRV (SDNN, RMSSD)
• Both sympathetic and parasympathetic modulation decreased
• Relative sympathetic predominance persists
• Hypoxemia and hypercapnia contribute to autonomic dysfunction
• Beta-agonist medications may also affect HRV

Limitations

High variability in HRV measurement methodology across studies

Methods

Prospective observational study with continuous nighttime monitoring

Key Findings

• 7-night average HF power cutoff of 1316 nU for COPD detection
• Sensitivity 83.6%, specificity 81.0%
• Nighttime monitoring avoids daytime motion artifacts
• Respiratory rate combined with HRV improves accuracy
• Wearable-derived metrics show clinical utility

Limitations

Requires multiple nights of data, not diagnostic alone

Methods

Cross-sectional HRV comparison in controlled vs uncontrolled asthma

Key Findings

• Uncontrolled asthma associated with lower overall HRV
• Enhanced parasympathetic modulation in controlled asthma
• Longer asthma duration = greater autonomic changes
• Beta-agonist use affects HRV measurements
• Well-controlled asthmatics similar to healthy controls

Limitations

Medication effects complicate interpretation

Methods

Stress challenge with HRV biofeedback intervention in asthmatics

Key Findings

• HRV biofeedback prevented stress-induced airway constriction
• FEV1% and FVC% improved compared to baseline
• Single short session showed protective effects
• Psychological stress can trigger bronchoconstriction
• Autonomic regulation impacts airway function

Limitations

Single session study, long-term effects need study