Assessment of arterial stiffness from pedal artery Korotkoff sound recordings: feasibility and potential utility

- We measured arterial pulse transit times from Korotkoff sounds (KSs) recorded with an electronic stethoscope.
- The optimal pressure for recording pedal artery KS is 20 mm Hg above diastolic pressure.
- The QKD interval is the time from the R wave peak to the KS peak.
- Pedal artery QKD values were correlated with age and with pulse wave velocity.
- This technique holds promise as an effective method to assess arterial stiffness.

Brachial artery (BA) Korotkoff sound (KS) timing reflects arterial stiffness. We recorded pedal artery (PA) KS in 68 healthy subjects using an electronic stethoscope and electrocardiography. Intervals between QRS complex of the electrocardiogram and KS waveform peaks (termed the QKD interval) were measured for 60 seconds, averaged, and QKD velocity (v) calculated. Carotid-BA and carotid-PA pulse wave velocities (PWVs) were measured by applanation tonometry. Analyzable KS recordings were obtained from BA and PA in 100% and 92% subjects. PA QKDv decreased less than BA QKDv with progressive cuff inflation. At diastolic blood pressure + 20 mm Hg (maximal yield), BA QKDv was independently associated with weight and pulse pressure, whereas PA QKDv was related to weight and age. PA QKDv correlated with its corresponding PWV stronger than BA QKDv. In conclusion, PA KS is optimally recorded at diastolic blood pressure + 20 mm Hg; PA QKDv is correlated with age and better correlates with PWV than does BA QKDv. This technique may provide a simple arterial stiffness measure.