Fluke Biomedical MPS450 - Manual (Page 52)

MPS450
Operators Manual
2-20
Alternatively, in the Numeric-Control Mode, press the number keys for the desired
simulation according to Table 2-14, and select RUN.
Table 2-14. Numeric Codes for Ventricular-Fibrillation-Amplitude Settings
Ventricular-Fibrillation-Amplitude Setting Numeric Code
VENT FIB COARSE 031
VENT FIB FINE 032
Asystole (Cardiac Standstill)
No ECG activity whatsoever.
Ventricular asystole is a critical condition characterized by the absence of a heartbeat
either in the ventricles or in the entire heart. This condition, also referred to as cardiac
standstill, is usually accompanied by loss of consciousness, apnea, and—if not treated
immediately—death.
The MPS450 simulates a condition of asystole by sending to the ECG a flatline signal,
which is completely devoid of P waves, P-R or R-R intervals, and QRS complexes.
Action in the Menu-Control Mode
1. Press the top-menu key labeled ARRHY.
2. Select VENT.
3. Scroll to the LCD screen ASYSTOLE.
4. Select RUN. The asystole-condition waveform runs continuously (repeats) until
another arrhythmia selection is made.
Alternatively, in the Numeric-Control Mode, press the number keys 033, and select
RUN.
Heart Block: First, Second, and Third Degree
Three heart-block simulations, running as repeating sequences.
A heart block is a condition wherein the signal generated by the SA node is delayed or is
blocked (partially or completely) in its journey to the ventricles. Because this condition
typically occurs at the AV (atrioventicular) junction, a more precise term for heart block
is atrioventricular block. When the conduction time from the atria to the ventricles
becomes delayed (usually resulting in a P-R interval greater than 0.20 seconds), it is
referred to as a first-degree block. When impulses from the atria occasionally do not
reach the ventricles, the block is considered partial or incomplete and is referred to as a
second-degree block. Finally, when no impulses whatsoever are able to enter the
ventricles from the atria, the heart block is complete and is referred to as a third-degree
block. As a consequence of a third-degree block, the atria and the ventricles beat at their
own separate rates.
The MPS450 simulates waveforms for all three heart-block conditions:
• first-degree-block waveforms, with normal beats (80 BPM), but with a long P-R
interval of 250 ms;
• second-degree-block waveforms, with normal beats, but with a P-R interval that
increases every beat for four beats (from 160 to 220 to 400 to 470 ms), followed by a
P wave only with no QRS response (the Wenckebach phenomenon); or
• third-degree-block waveforms, with normal beats, but with a P-wave rate of 80 BPM
and a QRS rate of 30 BPM, running independently.