Table 2. Quantitative ECG measurements in T.cruzi seropositive and seronegative subjects.

ECG variable	Seropositive	Seronegative	p- value*
	N = 499	N = 488
Heart Rate (bpm)	62 (57–69)	64 (58–72)	0.003
PR duration (ms)	160 (144–178)	156 (142–168)	0.007
QRS duration (ms)	90 (84–104)	88 (82–95,75)	<0.001
QT duration (ms)	420 (402–439)	412 (392–432)	<0.001
QTc duration (ms)	429 (412–447)	427 (411–442)	0.061
HRV sdnn (ms) **	16 (10–25)	22 (14–35)	<0.001
HRV rmssd (ms) **	18 (11–29)	24 (15–39)	<0.001

Data is presented as median (interquartile range).

^*Reported if <0.05.

^**HRV data available in 467 seropositive and 458 seronegative subjects. QTc: corrected QT interval by Bazett's formula; HRV: heart rate variability; rmssd: root mean square of successive differences in normal RR intervals; sdnn: standard deviation of all normal RR intervals.