Figure 3From: Exposure to ultrafine carbon particles at levels below detectable pulmonary inflammation affects cardiovascular performance in spontaneously hypertensive ratsRelative Changes in time domain and frequency domain measures of heart rate variability (HRV) of SHRs associated with filtered air (control)/ultrafine carbon particles (UfCPs; exposed) exposure. Bars represent arithmetic mean values ± SE of control (white bars; n = 7) and exposure groups (gray bars; n = 7): (12 5-minutes segments/12h dark period/rat) × 7 rats. Dotted horizontal lines are used to highlight the relative changes. HRV, paralleled changes in HR was decreased by about 30% in UfCPs exposed SHRs during the recovery periods (second and third day). *: indicates significant differences of HRV (p < 0.05) between exposed (gray) and control (white) SHRs. SDNN: standard deviation of normal to normal (NN) intervals. RMSSD: square root of the mean of squared differences between adjacent NN intervals. LF/HF: ratio of the absolute powers in the low-frequency (LF: 0.20 Hz to 0.75 Hz) and high-frequency bands HF: 0.75 Hz to 2.5 Hz).Back to article page