Racial differences in the association between heart rate variability and left ventricular mass

Area of Science:

• Cardiology
• Physiology
• Race and Health

Background:

• Decreased heart rate variability (HRV) is linked to increased cardiovascular disease (CVD) risk, including greater left ventricular mass (LVM).
• African Americans have an enhanced CVD risk profile but paradoxically higher HRV compared to Whites.
• The relationship between HRV and LVM in African Americans remains unclear.

Purpose of the Study:

• To investigate whether race influences the association between parasympathetic cardiac control and LVM.
• To determine if higher HRV predicts LVM differently across racial groups.

Main Methods:

• Echocardiography was used to assess LVM in 148 African American and White adults.
• High-frequency heart rate variability (HF-HRV) from ECG recordings measured parasympathetic cardiac control.
• Regression analysis examined the association between HF-HRV and LVM.

Main Results:

• Greater HF-HRV was significantly associated with greater LVM in African Americans (P=0.002).
• No significant association was found between HF-HRV and LVM in White participants (P=0.919).
• Race was identified as a moderator in the HRV-LVM relationship.

Conclusions:

• These findings demonstrate that race significantly moderates the relationship between HRV and LVM.
• Current interpretations of higher HRV as a universal marker for better cardiac health may not apply to African Americans.
• Race may be a crucial factor when assessing parasympathetic control and CVD risk.