User Manual

Lumax Technical Manual 79
The Enhanced VF Sensitivity setting is specifically designed to
improve VF detection when the VF signal is very small. Two
adjustments are made to ASC with this setting:
 The T-wave discrimination period (hold of upper
threshold) is decreased to 100 ms [110 ms for Lumax
600/640 and 700/740 models], thus eliminating the Upper
Threshold.
 The decay rate of the Lower Threshold is increased to
0.125 mV every 250 ms. This is not applicable for the
Lumax 600/640 and 700/740 models.
These adjustments ensure that the threshold reaches the lower
values more quickly in order to assure that all VF signals are
sensed appropriately.
The Enhanced T-Wave Suppression setting is specifically
designed to avoid double counting of each QRS-T complexes
during normal sinus rhythms. With sensitivity programmed to
Enhanced T-Wave Suppression:
 High pass filtering is increased to reduce low frequency
signal components such as T-waves and respiratory
artifacts.
 The Upper Threshold is increased to 75% of the
measured R-wave.
 The Upper Threshold may not retrigger with each sensed
event, it is only triggered when the new sensed R-wave
crosses the 50% point of the previous measured R-wave.
2.3.2 Minimum Right Ventricular Threshold
This parameter limits the minimum sensitivity of the ICD/CRT-D to
a programmable value. Nominally, the minimum threshold is set
to 0.8 mV, but it can be adjusted from 0.5 to 2.5 mV.
2.3.3 Atrial Sensitivity Settings
DR and HF versions only
The primary option for setting the sensitivity of the atrial input
stage is “Standard”. When atrial sensing is active, the sensitivity
is set to “Standard” for most patients, which is designed to adapt
the parameters of the input stage to various signal conditions.
The available settings are described in Table 28
.