Pattern analysis of temporal changes in the carotid artery diameter under normal and pathological conditions

Area of Science:

• Vascular Ultrasound
• Cardiovascular Physiology
• Biomedical Engineering

Background:

• Age-related and cyclic changes in common carotid artery (CCA) diameters are crucial indicators of vascular health.
• Understanding these dynamic changes in both normotensive and hypertensive individuals is essential for early disease detection.

Purpose of the Study:

• To investigate age-related and temporal cyclic diameter variations in the left and right CCA in healthy and hypertensive subjects.
• To identify characteristic patterns of CCA diameter changes that may indicate pathological conditions, particularly in hypertensive individuals with internal carotid artery (ICA) stenosis.

Main Methods:

• Ultrasound imaging was used to acquire cross-sectional images of the left and right CCA.
• Arterial wall contours were manually traced from digitized images to calculate diameters, assuming circular geometry.
• Temporal diameter changes were analyzed by averaging consecutive heartbeats, and patterns like left vs. right peak diameter delay (LRPDD) and diameter-diameter loops (DDloops) were computed.

Main Results:

• Healthy subjects exhibited a consistent LRPDD (right CCA preceding left) and counter-clockwise DDloops.
• Hypertensive subjects with >50% ICA stenosis showed reduced or negative LRPDD (left CCA preceding right) and clockwise DDloops.
• CCA elastic index was significantly higher in hypertensive subjects, and the relative systolic diameter change was smaller compared to normotensive subjects.

Conclusions:

• Temporal diameter change patterns in the CCA can serve as indicators of underlying pathological vascular states.
• Significant alterations in CCA diameter dynamics and increased arterial stiffness are associated with hypertension and ICA stenosis.