Stratos LV/LV-T Technical Manual 131

6.4Magnet Effect

Automatic Magnet Effect:

After magnet application the pulse generator paces at 90 ppm for 10 cycles asynchronously. Thereafter, the pulse generator paces synchronously at the programmed basic rate. During asynchronous pacing, the AV interval is reduced to 100 ms.

Asynchronous Magnet Effect:

When programmed to asynchronous operation, magnet application results in asynchronous pacing. Stratos CRT-Ps pace asynchronously at 90 ppm as long as the magnet is over the CRT-P. Upon magnet removal, the current basic interval is completed before the CRT-P reverts to its original operating mode.

If the magnet effect is set to asynchronous, the AV delay is reduced to 100 ms (or the programmed AV delay, whichever is shorter). Shortening of the AV delay to 100 ms during asynchronous AV sequential stimulation is provided to avoid ventricular fusion beats in the presence of intact AV conduction. This allows efficient diagnosis of ventricular capture or failure to capture.

Synchronous Magnet Effect:

If the magnet effect is programmed to synchronous operation, magnet application does not affect timing and sensing behavior of the CRT-P. Synchronous operation is of particular importance during follow-up, if sensing and inhibition functions are desired during magnet application.

Trend monitor and event counter operation is interrupted during magnet application with either ‘Asynchronous’ or ‘Synchronous’ magnet effect.

6.5Position Indicator

The position indicator facilitates positioning of the programmer head. The programmer optically and acoustically indicates whether the programmer head is in communication with the CRT-P.