Mintek Pacemaker LV-T Manuale Utente

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84  Stratos LV/LV-T Technical Manual   
The Stratos CRT-Ps have a specially designed header that 
allows the CRT-Ps to simultaneously sense and pace in both the 
right and left ventricles.  Biventricular pacing therapy requires 
programming of a bipolar pacing configuration in the ventricle.  
Refer to Section 8.1 for a summary of the sensing and pacing 
configurations in the ventricle. 
If a bipolar lead is connected to the CRT-P, unipolar or bipolar 
configuration can be programmed for pacing and sensing.  As 
compared to bipolar pacing, the unipolar pacing pulse has the 
advantage of being clearly identifiable on the ECG.  Unipolar 
pacing occasionally results in muscle stimulation in the device 
pocket or diaphragm. 
2.5 
Automatic Lead Check 
When Lead Check is activated, the lead impedance is 
automatically measured with every pace.  If the impedance 
values are consecutively greater or less than the limits (<200 Ω 
and >3000 
Ω) for repeated measurements, the system 
automatically switches from bipolar to a unipolar lead 
configuration.  A bipolar lead failure is verified if the lead 
impedance measurement falls outside of the acceptable range 
for three consecutive readings.  When a lead failure has been 
detected, a message is displayed on the programmer screen at 
the next follow-up visit in order to notify the physician of the 
change. 
Lead Check also may be activated with unipolar leads.  The 
pass-fail criterion remains the same as with bipolar leads.  In the 
event that a lead failure occurs, the Lead Check feature is 
disabled and a message is displayed on the programmer screen 
at the next follow-up visit to notify the physician of the lead 
status.