Table.

Comparison of Device Parameters After MRI With Baseline Values Before MRI^*

	Difference Immediately After MRI	P	Difference at Follow-Up (Median 99 Days After MRI)	P
P-wave amplitude, mV	0.06±0.07	0.44	−0.14±0.27	0.61
R-wave amplitude, mV	−0.09±0.15	0.58	0.96±0.70	0.19
Atrial lead impedance, Ω	−2.68±5.01	0.60	−6.17±11.53	0.60
Ventricular lead impedance, Ω	−0.49±2.74	0.86	6.15±12.56	0.63
Atrial capture, V	0.02±0.02	0.28	−0.07±0.18	0.69
Ventricular capture, V	−0.001±0.013	0.93	−0.01±0.05	0.85
Battery voltage, V	−0.004±0.002	0.08	−0.05±0.02	0.06

^*Values are reported as mean difference between immediate or long-term and baseline parameter ±SEM. Student t test was not performed on left ventricular lead thresholds in cardiac resynchronization therapy systems because there were not enough data points for a meaningful comparison; there were no significant changes in individual left ventricular lead thresholds after testing, however.