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13 replies

  1. If the waveform does not flow in reverse (below the baseline), how can it be biphasic? A triphasic waveform is forward, reverse, forward. A monophasic waveform is in a continual forward direction. If anything, this waveform represents a monophasic flow pattern with a post systolic half beat ejection. Very odd waveform.

  2. I agree with Delphia that this could be normal or abnormal depending on anatomically where, and the circumstances of the examination. Given the site and circumstances now known, I will stick with calling it normal, rather than a “phasic” descriptor.

  3. Looking at it at without any other info, monophasic. All flow is above the baseline, however it has been stated this is post exercise. The vessel would be dilated from increased demand reducing resistance keeping flow above the baseline. Just one possibility.

  4. Just FYI. Glossary of terms SVU:
    “Triphasic: having three phases or variations; commonly referred to as a normal arterial waveform, forward flow in systole, brief reverse flow, and a third forward component (multiphasic)”

    “Monophasic: a monophasic pattern as a readily distinguishable systolic pulse but lack of oscillatory activity during diastole. Such patterns demonstrate diminished arterial compliance. They may indicate stenosis proximal to the examination site and low resistance in distal vessels”.

    Of course there is no definition of Biphasic. Not sure if these definitions help our debate or not.

  5. This appears to be triphasic post exercise. The whole waveform is elevated above the baseline do to the hyperemic state.

  6. The very fact that there are diverse opinions on how to classify this waveform is why the SVU has started a task force to find a standardized nomenclature for peripheral Doppler waveform morphology. The term phasicity means different things to different people depending on how they were trained. And, as already pointed out in previous posts, without knowing the typical flow pattern of the tissue being supplied by the artery examined one cannot say if the waveform suggests hyperemia or not.
    Age has a very big effect on the viscoelastic properties of arteries. We refer to the typical multidirectional waveform of a 30 year old as normal but what is normal about a 30 year old being in a vascular lab? Our patients are typically in their 6th or 7th decade of life. 70 year old arteries are stiffer than 30 year old arteries. A tree is stiffer than a sapling. Which has the abnormal behavior in the wind? I think we need to focus not on what is “normal” but what is pathognomonic.

  7. Without knowing the context of the waveform one can not accurately analyze and interpret it. (should have been a choice)

  8. Given the waveform was gathered post exercise I think it is essentially normal and does not give a strong suggestion of significant arterial disease in that limb.
    The normal response to exercise, even in healthy individuals, is for blood flow to the muscles to increase by reducing the resistance that is controlled at the arteriolar level. That will increase diastolic flow. This will subside after 2 or three minutes. Many diagnosticians don’t appreciate this and are quick to condemn a transient drop in pressure or short lived elevation of diastolic flow. The most common mistake is to use a drop in ABI rather than a drop in absolute pressure. ABI is only a ratio. Muscles don’t care about ratios, they only care how much blood is being delivered – which we estimate with pressure. If pressures are unreliable (as in the case of increased arterial stiffness) we have to depend on the Doppler waveform and perhaps a PVR.

  9. Doppler waveforms can be described relative to their site. In a CCA or ICA this would be normal due to the properties of the low vascular resistance brain. In a Femoral artery this would be Monophasic, as the three phases in Triphasis feature an early diastolic reversal due to the elasticity of the distal vessels.

  10. Tony this waveform was of a common femoral artery immediately post exercise.


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