Medtronic PROTECTA XT DR D314DRG, Clinician Manual

Page: 382 / 508

9.3.2.2 Selecting the high-voltage electrodes and current pathway
The Active Can/SVC Coil parameter and the Pathway parameter specify the electrodes and
direction of current flow for defibrillation and cardioversion pulses. The Active Can/SVC Coil
parameter has the following settings:
●
The Can+SVC On setting connects the Active Can (HVA) and the SVC Coil (HVX).
Current flows between these electrodes and the RV Coil (HVB).
●
The Can Off setting disables the Active Can feature. In this case, an SVC lead must be
implanted. Current flows between the SVC Coil (HVX) and the RV Coil (HVB).
●
The SVC Off setting ensures that the SVC lead, if implanted, is not used. Current flows
between the Active Can (HVA) and the RV Coil (HVB).
The settings for the Pathway parameter are AX>B and B>AX. AX refers to the HVA and
HVX electrodes, which may be used individually or in combination. B refers to the HVB
electrode. The Pathway setting defines direction of current flow during the initial segment
of the biphasic waveform. If the parameter is set to AX>B, current flows from the Active Can
and SVC Coil to the RV Coil. If the parameter is set to B>AX, this current flow is reversed.
9.3.2.3 Confirming VT or FVT after detection
When the device begins charging its capacitors for a cardioversion therapy, it monitors the
cardiac rhythm to ensure that the tachyarrhythmia remains present before delivering the
therapy.
The device confirms the continued presence of the tachyarrhythmia using one of the
following confirmation intervals:
●
the programmed VT in 60 ms. This is the default confirmation interval.
●
an interval calculated from the ventricular cycle 60 ms. This interval is provided
by the Confi option.
If Confi is on, the device uses the Confi interval if it is shorter than the
default confirmation interval.
The device classifies any ventricular event that occurs within either confirmation interval as
an “arrhythmic event” and any event that occurs outside the interval as a “normal event”.
On each ventricular event during charging, the device reviews the last 5 events since
charging started. If the last 5 ventricular events included 4 “normal events”, the device stops
charging and cancels the therapy.
Medtronic PROTECTA™ XT DR D314DRG
382 Clinician Manual