Comparison of heart rate variability and stroke volume variability

Area of Science:

• Physiology
• Cardiovascular System Dynamics
• Autonomic Nervous System Research

Background:

• Heart rate variability (HRV) is a widely used non-invasive indicator of autonomic nervous system (ANS) activity.
• Stroke volume variability (SVV) is an emerging metric that may also reflect ANS function, but its relationship with HRV requires further investigation.
• Understanding the distinct contributions of HRV and SVV can enhance cardiovascular monitoring and assessment.

Purpose of the Study:

• To quantitatively compare the spectral characteristics and fractal dimensions of HRV and SVV in healthy adults.
• To determine if SVV provides similar or complementary information to HRV regarding ANS activity.
• To explore the relationship between HRV and SVV parameters.

Main Methods:

• Acquisition of supine electrocardiographic (ECG) and left ventricular (LV) volume time series data from 12 healthy adult males.
• Power spectral analysis to evaluate low frequency (LF) and high frequency (HF) peaks for both HRV and SVV.
• Box-counting method to analyze the fractal dimension (FD) of HRV and SVV time series data.

Main Results:

• Both HRV and SVV exhibited clear LF (around 0.1 Hz) and HF (around 0.3 Hz) peaks.
• The LF/HF ratio was significantly lower in SVV compared to HRV.
• The fractal dimension (FD) was significantly higher in SVV than in HRV, with no significant correlation observed between HRV and SVV parameters.

Conclusions:

• SVV analysis reveals distinct patterns compared to HRV, suggesting it reflects different aspects of autonomic nervous system regulation.
• The observed differences in LF/HF ratio and FD indicate that SVV may offer complementary information to HRV.
• Further research is warranted to fully elucidate the clinical implications of SVV in cardiovascular assessment.