User Manual Part 1

3-8

TACHYARRHYTHMIA DETECTION

VENTRICULAR DETECTION

NOTE: There is no clinical data to suggest that one detection enhancement

suite is superior to the other for any given patient indication. Therefore,

individual programming and evaluation of detection enhancement speciﬁcity

is recommended.

Rhythm ID

Rhythm ID uses Vector Timing and Correlation analysis in addition to atrial and

ventricular interval analysis to determine if a patient’s rhythm should be treated

(VT) or if therapy should be inhibited (SVT).

With Rhythm ID, the pulse generator performs a vector timing and correlation

analysis using the shock EGM and rate EGM. Based on this data, it saves a

reference template of the patient’s normal sinus rhythm.

During Rhythm ID analysis, the pulse generator ﬁrst determ ine s if the

ventricular rate is greater than th e atrial rate. If so, therapy will be initiated. If

the ventricular rate is not greater than the atrial rate, Rhythm ID evaluates the

following criteria to determine if therapy should be inhibited or initiated:

• Vector Timing and Correlation analysis during initial detection determines

if the rhythm is SVT by com p aring it to the previously stored reference

template. If the rhythm is declared SVT, therapy is inhibited.

• If Vector Timing and Correlation does not decla re the rhythm SVT, Stability

and AFib Rate Threshold determine if the ventricular rhythm is unstable

and th e atrial ra te is fast. If the ventricular rhythm is u nstable a nd the atrial

rate is fast, the rhythm is declared SVT and therapy is inhibited.

Rhythm ID does not consider atrial detection criteria (V Rate > A Rate or A

greater than AFib Rate Threshold) for the following conﬁgurations:

• Dual-chamber devices if Atrial Tachyarrhythmia Discrimination is

programmed to O ff

When conﬁgured this way, Stability is not evalu a ted for initial detection. This

may be u seful in instances whe re atrial lead problems ha ve occurred. For

these conﬁgura tions,therapy is inhibited at initial detection if the rhythm is

declared SVT (correlated based on Vector Timing and Correlation). Otherwise,

therapy is initiated.

Two methods are available for the device to aut omatically acquire a Rhythm

ID reference template: passive and active. The active method may be useful

for patients who are frequently ventricular paced.

- DRAFT -