Correlation between heart rate variability and severity of coronary atherosclerosis: Looking for non-invasive indicators of the disease severity

Figure 1 Novel time-domain heart rate variability indices. Yeh DI: Yeh differential index; HR: Heart rate; HRV: Heart rate variability; II: Interval index; LTI: Long-term irregularity; LTV: Long-term variability; STV: Short-term variability; SD: Standard deviation; de Hann STI: De Hann sinus tachycardia index; van Geijn ID: Van Geijn interbeat interval difference; Huey STV: Huey short-term variability; Dalton MABB: Dalton mean absolute beat-to-beat; IQR: Interquartile range.

Figure 2 Joint time-frequency domain heart rate variability indices. HRV: Heart rate variability.

Figure 3 Scatter plot. A: Scatter plot showing the association between the severity of coronary atherosclerosis and selected heart rate variability (HRV) measure (de Hann sinus tachycardia index); B: Scatter plot showing the association between the severity of coronary atherosclerosis and selected HRV measure (van Geijn interbeat interval difference); C: Scatter plot showing the association between the severity of coronary atherosclerosis and selected HRV measure (Huey long-term variability); D: Scatter plot showing the association between the severity of coronary atherosclerosis and selected HRV measure (Dalton mean absolute beat-to-beat). De Hann STI: De Hann sinus tachycardia index; van Geijn ID: Van Geijn interbeat interval difference; Huey LTV: Huey long-term variability; Dalton MABB: Dalton mean absolute beat-to-beat.