Chapter 6
Statistics
Evia HF / HF-T Technical Manual
PAGE 85
• Mean heart rate reports the average of the ventricular rate over a 24-hour period (based on Vs, Vp,
Vrs, and PVCs).
• The resting heart rate reports minimum ventricular heart rate during the programmed resting period
(default beginning at 2:00 AM with a 4-hour duration, programmable under the Diagnostics/HM
tab).
• The minimum ventricular heart rate is determined by taking 11-minute averages during the resting
period and reporting the lowest of those averages.
Variability is based on the P-P interval, and uses only intrinsic P-P intervals, not atrial paced events.
• Variability is calculated by taking the standard deviation of the 5-minute mean P-P intervals.
Patient activity is available in both rate adaptive and non-rate adaptive pacing modes.
• Data is displayed as the percent of the day (24 hour period) the patient is active.
• Patient activity is present when the device sees motion on the accelerometer.
• Activity is based on the currently programmed sensor threshold.
• If the mode is DDD, activity is measured using a mean sensor threshold.
• Not available in single-chamber devices.
Thoracic Impedance is measured from the distal tip to the pacemaker housing.
• 8 measurements per hour
• Measurements averaged to a single data point
• Thoracic impedance should NOT be used as a stand alone parameter to determine CHF
Variables such as COPD and hypovolemia may affect measurement values
NOTE:
Pocket and or lead revisions may affect the TI trend data. Therefore, the TI trend data should be
interpreted cautiously within 6-10 weeks of a revision.
6.8 IEGM Recordings
Evia HF / HF-T pulse generators can provide IEGM Snapshots, which are stored intracardiac events
based on programmable triggers for later display and review via the programmer screen. The
intracardiac events are represented on the programmer screen by event markers. Recordings may be
triggered by the following events:
• High atrial rates
• High ventricular rates
• Patient activation (by applying a magnet)
• Mode Switches
Evia HF-T generators can be programmed to store an IEGM on any or all of the events listed above.
However, the programmability of the High Atrial Rate and Mode Switch triggers are linked such that
only one trigger can be activated at a time.
By applying a magnet over the pulse generator for approximately 2 seconds, the current heart rhythm
will be instantly recorded. However, Evia HF-T commits the recording to memory only when the magnet
has been removed.
The following intracardiac events are stored with each IEGM:
• Type of IEGM snapshot
• Date and time of IEGM snapshot
• Duration of episode (for Mode Switch and High ventricular rates only)
Summary of Contents for Evia HF
Page 1: ...Cardiac Rhythm Management Heart Failure Therapy Evia HF HF T Evia HF HF T Technical Manual...
Page 8: ...Chapter Table of Contents Evia HF HF T Technical Manual PAGE vi...
Page 12: ...Chapter 2 Indications Evia HF HF T Technical Manual PAGE 4...
Page 14: ...Chapter 3 Contraindications Evia HF HF T Technical Manual PAGE 6...
Page 98: ...Chapter 7 Product Storage and Handling Evia HF HF T Technical Manual PAGE 90...
Page 104: ...Chapter 9 Lead Connection Evia HF HF T Technical Manual PAGE 96...
Page 118: ...Chapter 10 Elective Replacement Indication ERI Evia HF HF T Technical Manual PAGE 110...
Page 130: ...Chapter 13 Order Information Evia HF HF T Technical Manual PAGE 122...
Page 132: ...Chapter 14 Order Information Evia HF HF T Technical Manual PAGE 124...
Page 136: ...PAGE 128 Appendix A Evia HF HF T Technical Manual...
