Reconfirmation

Reconfirmation refers to confirming a VA is still occurring either during or after charging.

No shocks are committed in current devices.

During the charging period, the device still senses.

The last 6 beats are used to confirm the pt remains in a tachyarrhythmia, before delivering a shock.

Shock may be aborted during charge

When shock confirmation is programmed on (?nominal), during the charging period, the device still senses.

If 3/4 cycles during charging fall below detection rate, charging is aborted.

At the end of a charge, a shock is delivered 30ms after a short cycle

If 3 long cycles are detected at the end of full charge, charge is abandoned

After a shock has been delivered, the next shock is still uncommitted (reconfirmation occurs).

If a charge is interrupted or abandoned, the next shock is committed (no reconfirmation) incase of undersensing.

•An attempt is made to synch the shock, however, if a R wave is not detected after 2 seconds, the shock will be unsynchronised.

Committed shocks are programmable (nominally off)

Reconfirmation window is 5/10 intervals

Sensing continues during charging – charging can be aborted mid way through.

Shocks are not committed.

But when the charge starts, the charge cannot be interrupted.

The device looks at the last 3 intervals to confirm the tachycardia is still present.

Only the 1st shock is a non committed shock

After the 1st shock, the rhythm is confirmed to be VF before delivering shock.

Subsequent shocks do not reconfirm arrhythmia once charge is complete, even if patient has already terminated to sinus rhythm.

The confirmation interval depends if confirmation+ is on

•ON: VCL + 60ms or min VF detection interval

•OFF: programmed VT interval +60ms or programmed VF interval (when VT detection off)

Shocks are not committed

Shocks can be terminated mid charge if episode terminates prior to charge completion