The magnet usage with implantable cardioverter-defibrillators (ICD) excludes detection and therapy of ventricular arrhythmias (anti-tachycardia pacing
and shocks), whereas the use of magnet does not affect anti-bradycardia pacing.
Various mechanisms could explain the tachycardia; to us a plausible one is an ectopic automatic focus in the left side of the ventricular septum with the anti-tachycardia pacing
changing the depolarization pathway of the ventricular tachycardia by concealed conduction into the pathway(s).
Additionally, the advanced sensing technology designed to avoid sensing unwanted signals (T-waves) and offer more anti-tachycardia pacing
options, which can convert many fast ventricular arrhythmias painlessly and avoid the need for high voltage shocks.
Potentially life-threatening ventricular tachyarrhythmias were appropriately aborted, either by anti-tachycardia pacing
or ICD shock, after a median follow-up of 36 months in patients with implanted devices for secondary prevention (10, 11).
reported that the all-cause mortality of patients in the MADIT II trial who received appropriate and inappropriate shocks (but not anti-tachycardia pacing
[ATP]) was 4 times higher than for those without shock therapy.
The device is fully programmable for treating ventricular tachyarrhythmias with shock therapy, but does not provide anti-tachycardia pacing
With a view to interrupting the arrhythmia, the ICD can fire a burst of pulses at a frequency that is faster than the spontaneous heart rate, in order to "capture" the tachycardia and stop it (the "anti-tachycardia pacing