Objective:
Newborns of mothers positive for anti-ro/ssa autoantibodies may develop a series of electrocardiographic (ekg) disturbances. prolongation of the corrected qt (qtc) interval was recently reported in a significant proportion of children with maternally acquired anti-ro/ssa antibodies, with a concomitant disappearance of ekg abnormalities and acquired maternal autoantibodies during the first year, suggesting a direct, reversible electrophysiologic effect of anti-ro/ssa antibodies on the ventricular repolarization. on this basis, we investigated whether these antibodies may also affect cardiac repolarization in anti-ro/ssa-positive adult patients with connective tissue diseases.
Methods:
Fifty-seven patients with connective tissue diseases were selected: 31 had anti-ro/ssa antibodies and 26 did not (controls). in all subjects, we analyzed the qtc interval, heart rate variability, and signal-averaged high-resolution ekg recording.
Results:
Anti-ro/ssa-positive patients showed a significant prolongation of the mean qtc interval compared with the controls (mean +/- sd 445 +/- 21 versus 419 +/- 17 msec; p = 0.000005). eighteen of the 31 anti-ro/ssa-positive patients (58%) and none of the 26 anti-ro/ssa-negative patients had qtc values above the upper limit of normal (440 msec). both groups had a reduction in heart rate variability, with a prevalence for the sympathetic nervous system and a high incidence of ventricular late potentials; these values were not significantly different between the 2 groups.
Conclusion:
Adult patients with anti-ro/ssa-positive connective tissue diseases showed a high prevalence of qtc interval prolongation. this feature, with the concomitant abnormalities in the autonomic tone and ventricular late excitability observed in all patients studied, suggests that anti-ro/ssa-positive patients may have a particularly high risk of developing life-threatening arrhythmias.