Cardiac pacing in the long QT syndrome: review of available data and practical recommendations.

A review of published data on cardiac pacing in the long QT syndrome (LQTS) is presented, in the hope that optimization of patient selection and pacemaker programming will prevent arrhythmic death. LQT3 patients may derive particular benefit from pacing because the dispersion of repolarization worsens steeply during bradycardia in this genotype. However, concluding that other genotypes will not benefit from pacing is premature. Pacing may be especially beneficial for patients with "pause-dependent" arrhythmias. Programming should include a sufficiently fast lower rate limit. Features that allow heart rate slowing beyond the lower rate limit or that may trigger pauses must be programmed "off" because pauses are proarrhythmic in this population. Pause-prevention pacing algorithms may be beneficial.