Short-term effects of fine particulate matter and ozone on the cardiac conduction system in patients undergoing cardiac catheterization

Table 2 Descriptive statistics and Spearman correlation coefficients of ECG parameters (n=28578)

	Mean ± SD		Min	25%	Median	75%	Max	Correlation coefficients
	Geometric	Arithmetic	Min	25%	Median	75%	Max	PR	QRS	QTc
PR (ms)	170 ± 1	173 ± 31	100^a	152	168	188	400^a	--
QRS (ms)	91 ± 1	91 ± 12	53	83	90	99	120^a	0.18	--
QTc (ms)	434 ± 1	435 ± 33	350^a	412	433	456	587	-0.02	0.24	--
HR (bpm)	73 ± 1	74 ± 17	31	62	72	85	160	-0.28	-0.09	0.32

SD standard deviation, Min minimum, 25% the 25th percentile, 75% the 75th percentile, Max maximum, QTc heart rate-corrected QT interval, HR heart rate, bpm beats per minute
^aThe minimum and maximum values were set by the exclusion criteria

ISSN: 1743-8977