Biomedical Engineering Reference
In-Depth Information
Fig. 8.11
Counters screen view [32] (© 2012 Boston Scientific Corporation or its affiliates. All rights reserved. Used with permission of Boston
Scienti fi c Corporation)
8.6.3
Histograms
data from a period of time even before the onset and after the
end of the episode in the memory. The stored data include an
episode number, atrial and ventricular action at the time of
magnet application, and the time and date of the magnet
application.
The histogram function allows atrial and ventricular paced
and sensed events to be recorded during a recording period,
which is similar to that of counters, and to be displayed
graphically (Fig.
8.12
). Histograms show the range of the
patient's heart rate and facilitate the evaluation of set adap-
tive pacing parameters in case of chronotropic incompetence.
In certain systems, data collecting may be set so that data
including or excluding the events sensed in what is referred
to as a refractory period (see Chap.
9
) are recorded.
Atrioventricular histograms show atrial sensed events fol-
lowed by ventricular sensed or paced events and atrial paced
events followed by ventricular sensed or paced events.
Hence, the condition of atrioventricular conduction is moni-
tored. These events are classified according to heart rate.
Histograms of pacing/sensing show atrial paced and sensed
events and ventricular paced and sensed events, also classified
according to the heart rate. Histograms are reset together
with the counters.
8.6.2
Counters
Event counters record the number of intrinsic and paced
events occurring during the recording in all heart chambers
with active leads (Fig.
8.11
). This period starts with resetting
the counters and ends when the data is retrieved from the
pacemaker via telemetry. Neither data retrieval nor changing
the programmed parameters or the pacing mode resets the
counters. The following events are mostly counted and
recorded if programmed in the permanent pacing mode:
Paced and sensed events
-
-
Atrial tachy response (ATR) mode switch data
-
Total ATR mode switches
-
Total ATR mode switch time
-
Maximum mode switch time
8.7
Electrophysiologic Testing Using
a Pacemaker
-
Average mode switch time
-
Atrial extrasystoles
-
Ventricular extrasystoles
-
Atrial tachycardia detection
Electrophysiologic (EP) testing available in certain pace-
makers allows for the measurement and evaluation of atrio-
ventricular conduction properties or noninvasive induction
or termination of tachycardia. Real-time recording of EGMs,
ECG curves, and event markers are enabled at the same time.
The EP test allows a series of timed pacing pulses or bursts
-
Ventricular tachycardia detection
-
Ventricular interval variation
-
Hysteresis
-
Atrioventricular conduction hysteresis
-
Sensor data
