Figure 3
From: Ultrafine carbon particle mediated cardiovascular impairment of aged spontaneously hypertensive rats
Relative changes in time domain and frequency domain measurements of heart rate variability (HRV) in spontaneously hypertensive rats (SHRs) following ultrafine carbon particle (UfCP ) exposure compared to control. HRV paralleled changes in heart rate (HR). HRV was decreased by ~36% in UfCP exposed SHRs during the 1st and 2nd days of recovery period as indicated by altered SDNN. Dotted horizontal lines are used to highlight the relative changes. Each bar represents a combined mean value of: (12 5-minutes segments/12 h dark period/rat) ± 7 rats. (n = 7/experimental group; *indicates p < 0.05). 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).