What distinguishing feature separates low resistant waveforms from high resistant waveforms?

Low resistant waveforms are characterized by a prolonged and more continuous blood flow, which typically corresponds to vascular beds that have a high demand for blood supply, such as those associated with organs that actively engage in metabolic activities. A distinguishing feature of low resistant flow is the presence of reversed flow during the diastolic phase of the cardiac cycle, indicating that there is a large volume of blood being supplied to these areas, even when the heart is not actively pumping.

In contrast, high resistant waveforms are characteristic of vascular beds with lower blood demands, such as those serving muscles at rest. These waveforms demonstrate more pulsatile flow with little to no diastolic flow and typically do not exhibit reversal of flow during diastole.

The choice regarding higher peak flow rate can be misleading, as both types of waveforms can exhibit varying peak flow rates depending on the overall hemodynamics of the system and the specific vascular territory being examined. Increased flow duration relates to the visibility of flow throughout the cycle, which is more a measure of how well the blood is flowing consistently rather than indicating the resistance type. Variation in blood viscosity does not distinctly separate low resistant waveforms from high resistant ones since it's a property that affects all types of blood flow but does not serve