3 ms·

I knew about the continuous flow, but hadn't considered that you wouldn't hear your own pulse as a result. My father in law has an LVAD, which has given him bac

I knew about the continuous flow, but hadn't considered that you wouldn't hear your own pulse as a result. My father in law has an LVAD, which has given him back a lot of freedom following a severe heart infection early last year which damaged his natural heart badly. He's now on the transplant list, so I'll point it out to him as a "hey, this could be weird" thing. Do they mean that blood pressure is stable too, since you presumably wouldn't have a diastolic reading - no pressure reduction between beats, since there are no beats?

BjoernKW 10y ago
The diastolic reading isn't about pressure reduction in-between heartbeats but about the pressure created by the vascular walls. When you usually measure blood pressure you increase the pressure to a value that's likely above the systolic value of the patient (say 180). Then you gradually release pressure. Once you hear a heartbeat that's the systolic value. Once you stop hearing the heartbeat that's the diastolic value, which is the vascular walls resisting the heartbeat In this particular case instead of the usual heartbeat you'd likely hear something more like a constant flow but you'd still have systolic and diastolic values.
- B1FF_PSUVM 10y ago
  "Clearest explanation" award for that second paragraph. So that's how doctors do it with a manual pump and stethoscope. Never thought of asking one ...
- et2o 10y ago
  Just to expand: With a blood pressure cuff, what you are doing is collapsing the arterial wall with outside pressure. You increase the pressure above systolic blood pressure and then gradually reduce it until you hear a sound. This sound isn't the heartbeat, but is instead the result of turbulent flow in the blood vessel. While you are between systolic and diastolic pressure, only spurts of blood can flow through the vessel creating noise. Eventually, you reduce the pressure enough and blood even during diastole (which is lower pressure) can expand the walls of the artery against the blood pressure cuff. So, in both cases what you are hearing is due to blood pushing open the vascular walls.

BjoernKW 10y ago

The diastolic reading isn't about pressure reduction in-between heartbeats but about the pressure created by the vascular walls. When you usually measure blood pressure you increase the pressure to a value that's likely above the systolic value of the patient (say 180). Then you gradually release pressure. Once you hear a heartbeat that's the systolic value. Once you stop hearing the heartbeat that's the diastolic value, which is the vascular walls resisting the heartbeat In this particular case instead of the usual heartbeat you'd likely hear something more like a constant flow but you'd still have systolic and diastolic values.

B1FF_PSUVM 10y ago
"Clearest explanation" award for that second paragraph. So that's how doctors do it with a manual pump and stethoscope. Never thought of asking one ...
et2o 10y ago
Just to expand: With a blood pressure cuff, what you are doing is collapsing the arterial wall with outside pressure. You increase the pressure above systolic blood pressure and then gradually reduce it until you hear a sound. This sound isn't the heartbeat, but is instead the result of turbulent flow in the blood vessel. While you are between systolic and diastolic pressure, only spurts of blood can flow through the vessel creating noise. Eventually, you reduce the pressure enough and blood even during diastole (which is lower pressure) can expand the walls of the artery against the blood pressure cuff. So, in both cases what you are hearing is due to blood pushing open the vascular walls.