Real-time aortic pulse wave velocity measurement during exercise stress testing

Area of Science:

• Cardiovascular imaging and physiology
• Biomedical engineering
• Vascular diagnostics

Background:

• Pulse wave velocity (PWV) is a key indicator of arterial stiffness and cardiovascular risk.
• Non-invasive measurement of PWV using cardiovascular magnetic resonance (CMR) is established.
• Existing CMR methods are not suitable for dynamic exercise stress testing.

Purpose of the Study:

• To adapt and validate a novel CMR technique for measuring PWV during exercise.
• To assess the feasibility of using this method in healthy volunteers under moderate workload.

Main Methods:

• A velocity-sensitive real-time acquisition and evaluation (RACE) pulse sequence was modified for interleaved aortic PWV measurements.
• Automated calculation of foot-to-foot transit time was employed.
• Validation was performed in phantoms and the method was applied to 50 healthy volunteers using a MR-compatible ergometer.

Main Results:

• The RACE method showed good agreement with a standard method in phantom studies.
• In healthy volunteers, PWV increased significantly with age at rest and during exercise.
• A significant increase in PWV was observed during exercise compared to rest (p=0.04).

Conclusions:

• This study validates the use of CMR for evaluating exercise-induced PWV changes in healthy subjects.
• The developed method is feasible and shows potential for assessing patients with systemic aortic diseases.