Marc
Forum Replies Created
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I’m not sure why the anesthesia input was omitted from the professors menu list. I added that (and a few more!). Thanks for pointing that out!
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Glad you found the V pacing/AV dissociation. It’s a fun one as you can see cannon a-waves come and go, in addition to the SPV. I recently saw that during a difficult epicardial pacer placement in the OR to dx faulty sensing of the a-lead (despite the numbers on the interrogation suggesting it was working!–a great example of the importance of knowing how to interpret a cvp waveform!).
For the respiratory variation, you should be able to see mitral flow variability. Make sure you select mechanical ventilation. We haven’t modeled airflow dynamics, but you can change lung compliance to SEVERE (and increase TV to 1000) to maximize the intrathororacic pressure changes. Let me know if you have any trouble with that–should work.
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And, yes, you can add changes in intrathoracic pressure and see systolic pressure variation magnified by the presence of pericardial fluid! In the anesthesia input panel, you can toggle between spontaneous and mechanical ventilation. You can also select different degrees of lung stiffness (this will change the peak pressure for a set tidal volume with mechanical ventilation). If you view a monitor plot, you can see the pressure variation with the ventilatory cycle on the PA and ABP tracings. BTW, another fun example of systolic pressure variation can be seen if you turn on V-pacing at a slightly different rate than the atrial rate (set by HR)–atrial and ventricular contraction come in an out of phase, generating a-waves on the CVP tracing when the RA contracts against a closed tricuspid valve, and reducing LV filling during that phase. Endless fun with the simulator!
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Increases in systemic vascular resistance (SVR) would simulate peripheral vasoconstriction. SVR is listed in many of the input panels; in some, the total peripheral resistance (which constitutes SVR) is divided into two different resistances (small and large vessels) in which case the term Ra (sys) would be used to simulate vasoconstriction.