Table 3.

Effect of EPA/DHA treatment on ECG measures.

Normal distribution	Placebo	EPA/DHA		P-value
	Mean ± SD	Mean ± SD	Net change % (95% CI)
PR interval, ms			2.68 (0.82, 4.54)	0.005
Baseline	171 ± 25	173 ± 28
2-year	173 ± 27	177 ± 29
P wave duration, ms			2.07 (0.20, 3.93)	0.03
Baseline	114 ± 12	114 ± 13
2-year	108 ± 14	110 ± 15
P wave amplitude, mV			0.004 (0.000, 0.007)	0.037
Baseline	0.125 ± 0.037	0.121 ± 0.036
2-year	0.121 ± 0.036	0.121 ± 0.036
P terminal force, mVms			64.0 (− 222, 350)	0.66
Baseline	2372 ± 1960	2382 ± 2104
2-year	3088 ± 2209	3174 ± 2330
QRS duration, ms			0.21 (− 0.72, 1.14)	0.66
Baseline	93 ± 13	94 ± 14
2-year	94 ± 13	95 ± 15
Cornell, mV			− 0.17 (− 0.60, 0.26)	0.44
Baseline	1.12 ± 0.52	1.19 ± 0.56
2-year	1.25 ± 0.54	1.29 ± 0.55
Heart rate, bpm			− 0.08 (− 1.02, 0.86)	0.87
Baseline	66 ± 10	64 ± 10
2-year	64 ± 10	63 ± 10

Non-normal distribution	Placebo	EPA/DHA		P-value
	Median (25–75 percentile)	Median (25–75 percentile)	Net change % (95% CI)
QTc interval 1, ms			− 0.10 (− 0.73, 0.53)	0.74
Baseline	414 (411–417)	418 (415–420)
2-year	418 (415–420)	421 (418–424)
QTc interval 2, ms			− 0.09 (− 0.54, 0.36)	0.68
Baseline	426 (424–427)	426 (424–428)
2-year	426 (424–428)	426 (424–428)
SDNN, ms			5.66 (− 2.57, 14.58)	0.18
Baseline	18.7 (17.8–19.7)	18.1 (17.2–19.1)
2-year	17.6 (16.6–18.6)	17.8 (16.9–18.8)
RMSSD, ms			8.84 (0.41, 17.97)	0.040
Baseline	18.9 (17.8–20.0)	18.2 (17.2–19.3)
2-year	18.3 (17.3–19.4)	19.2 (18.1–20.3)

Treatment effect model adjusted for age, gender, race, BMI, mean blood pressure, and active treatment.

QTc interval 1 represents QTc calculated with the Framingham formula, QTc interval 2 with the Fredericia formula.