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

Table 2 Correlation analysis between time-domain heart rate variability indices (traditional and novel) and the severity of coronary atherosclerosis assessed by the Gensini score

HRV indices	Correlation analysis (n = 139)
	r	P value
SDNN	-0.046	NS
RMSSD	0.013	NS
de Hann STI	-0.227	< 0.05
de Hann LTI	-0.087	NS
Yeh DI	-0.131	NS
Yeh II	-0098	NS
Organ BAND	-0.087	NS
van Geijn ID	-0.232	< 0.05
Huey STV	-0.137	NS
Huey LTV	-0.167	< 0.05
Dalton MABB	-0.169	< 0.05
Dalton SD	-0.091	NS
Zugaib STV	-0.142	NS
Zugaib LTV	-0.124	NS

DI: Differential index; HRV: Heart rate variability; ID: Interval difference; II: Interval index; LTI: Long-term irregularity; LTV: Long-term variability; NS: Not significant; r: Spearman’s Rank correlation coefficient; RMSSD: Square root of the mean of the sum of the squares of differences between adjacent NN intervals; SD: Standard deviation; SDNN: Standard deviation of all NN intervals; STI: Short-term irregularity; STV: Short-term variability; Dalton MABB: Dalton mean absolute beat-to-beat.