User Manual Part 1

3-38
TACHYARRHYTHMIA DETECTION
VENTRICULAR DETECTION
If V Rate > A Rate is programmed to On and is True, it will take precedence
over all inhibitor enhancements.
Combinations of Onset and Stability
When Stability is pro gra mm e d to inhibit, it may be combined with Onset to
provide even greater specificity in classifying arrhythm ias.
This combination of detection enhancements is available only when the
Onset/S ta bility detec tion enhancement suite is enabled and is available only for
Initial Detection. The enhancements can be programmed to initiate ventricular
therapy if the following options are selected (Table 3-14 on page 3-38):
• Both Onset And S ta bility indicate to treat
• Either Onset Or S tability indicates to treat
Based on these programming decisions, ventricular therapy is inhibited when
any of the following criteria is met:
• If the combination prog r ammed is Onset And Stability, ventricular therapy
is inhibited if either parameter indicates that therapy should be withheld;
that is, the rhythm is gradual O r unstable (the And condition to treat is
not satisfi ed).
• If the co mbination p rogrammed is Onset Or Stab ility, ventricular therapy is
inhibited immediately at the end of Duration only if both parameters indicate
that therapy should be withheld; that is, the rhythm is gradual and unstable
(the Or co n dition to treat is not satisfied).
In either case, ventricular therapy will be initiated only if the And/Or conditions
to treat are satisfied. When these two combinations (And/Or) are used in
conjunction with SRD, and the And/Or conditions are not satisfied, ventricular
therapy will be inhibited until V Rate > A Rate is True or SRD times out
(Table 3-14 on page 3-38).
Table 3-14. Co mbinations of Onset A nd Stability and resulting therapy
Detection
Rhythm
Onset An d Stability C om bination
ab
Onset Or Stability Combination
c
Gradual, unstab le
Inhibit Inhibit
Gradual, stable
Inhibit Treat
- DRAFT -