Table 2. Baseline cardiac electrophysiological parameters in Pitx+/+ and Pitx2+/− mice.

ECG, electrocardiogram; RR, time interval between two consecutive R wave peaks; PR, interval from the onset of P wave to the start of QRS complex; QRS, time interval from start of Q wave to end of S wave; QT, interval from start of Q wave to end of T wave; AVERP, atrioventricular nodal effective refractory period; WCL, Wenckebach cycle length. All data displayed as mean ± SD and analyzed using unpaired t-test.

ECG intervals (ms)	Pitx2+/+ (n=14 mice)	Pitx2+/− (n=22 mice)	P values
Heart rate	564.2 ± 27.1	563.1 ± 33.4	0.914
RR	106.6 ± 5.3	106.9 ± 6.3	0.869
PR	35.6 ± 1.8	34.9 ± 2.1	0.293
QRS	10.4 ± 0.5	10.5 ± 0.8	0.755
QT	46.9 ± 1.9	47.8 ± 2.4	0.270
AVERP	44.6 ± 3.6	45.8 ± 3.7	0.324
WCL	71.7 ± 2.9	70.5 ± 3.3	0.290