Implantable rhythm devices in the management of vasovagal syncope.

The ECG registration during syncope allows physicians either to confirm or exclude an arrhythmia as the mechanism of syncope. Implantable loop recorders have an over-writeable memory buffer that continuously records and deletes the patient's ECG for up to three years. Many studies have analyzed the utility of implantable loop recorders in recurrent unexplained or high risk syncope. These studies suggest that early use of the ILR provides more and earlier diagnoses and could help in selecting patients with vasovagal syncope and prolonged asystolic pauses who might benefit from pacemaker therapy. However many questions remain, including its performance in the community by physicians with a range of experience in diagnosing syncope. Furthermore there is no evidence that the use of the ILR changes outcome. Numerous attempts have been made to determine whether patients with predominantly cardioinhibitory syncope benefit from permanent pacemakers, especially if symptoms are frequent and debilitating. While the first open label trials of pacemakers in the treatment of vasovagal syncope showed promising results, this effect has not been confirmed by blinded randomized clinical trials. More recent data seem to suggest that patients over 40years with severe asystolic vasovagal syncope might benefit from permanent pacemakers.