When comparing two waveforms, which statement is true?

When comparing two waveforms, which statement is true?

• A. Waveform A shows a delayed systolic upstroke
• B. Waveform A shows decreased spectral broadening
• C. Waveform A indicates proximal disease and waveform B normal
• D. Waveform A indicates a low-resistance state compared to waveform B

Answer: (D)

The main idea is how downstream resistance shapes the diastolic portion of an arterial waveform. A low-resistance bed maintains forward flow during diastole, resulting in a waveform with notable end-diastolic velocity, whereas a high-resistance bed shows diminished or even reversed diastolic flow and a more pulsed systolic peak. So, if waveform A has more diastolic forward flow than waveform B, A reflects a lower-resistance state relative to B. The other statements don’t fit because a delayed systolic upstroke suggests proximal disease (higher resistance), decreased spectral broadening isn’t a direct indicator of the resistance difference being asked about, and concluding proximal disease in A versus normal B isn’t supported by a simple comparison of diastolic flow.

The main idea is how downstream resistance shapes the diastolic portion of an arterial waveform. A low-resistance bed maintains forward flow during diastole, resulting in a waveform with notable end-diastolic velocity, whereas a high-resistance bed shows diminished or even reversed diastolic flow and a more pulsed systolic peak. So, if waveform A has more diastolic forward flow than waveform B, A reflects a lower-resistance state relative to B. The other statements don’t fit because a delayed systolic upstroke suggests proximal disease (higher resistance), decreased spectral broadening isn’t a direct indicator of the resistance difference being asked about, and concluding proximal disease in A versus normal B isn’t supported by a simple comparison of diastolic flow.