1 Arterial stiffness 2 INTIMA MEDIA ADVENTITIA MEDIA + ADVENTITA - responsible for arterial stiffness Stiffness is ability to resist distension when a force is applied to it. Compliance COMPLIANCE 3 COMPLIANCE Endothelial cells: •endothelial dysfunction •↑ permeability Intima: •↑ collagen •↓ elastin •↑ AGE`s, TGF-β, VSMC Media: •↑ collagen •↓ elastin •↑ AGE`s, MMP, VSMC Adventicia: •↑ collagen •fibroblasts Extrinsic influences 4 MEASUREMENT OF THE COMPLIANCE §Indirect ways § ØUltrasound ØSphygmography (PWV a PWA) ØCAVI measurement ØBioimpedance 5 ULTRASOUND MEASUREMENT 5 Intima Media Thickness (IMT) věk IMTR (mm) IMTL (mm) 6 ULTRASOUND MEASUREMENT 6 6 β – index measurement 7 CAVI MEASUREMENT 7 8 CAVI MEASUREMENT 9 PWV MEASUREMENT A highly compliant aorta has a relatively low PWV (< 6 m/s) PWV = distance (m) / transit time (s) transit time = t2 – t1 PULSE WAVE PULSE WAVE PULSE WAVE 13 P1 corresponds to the pressure at peak systolic flow and is usually identified by the first shoulder of the pressure wave. P2 corresponds to the peak of the reflected wave and is usually identified by the peak of the pressure wave after the first shoulder. PULSE WAVE ANALYSIS 14 PULSE WAVE ANALYSIS 14 Higher values of AP and AIx indicate increased wave reflection from the periphery and/or early return of the reflected wave as a result of increased pulse wave velocity (due to increased arterial stiffness) 15 Čas [s] Tlak [mmHg] SBP DBP TTI DTI PULSE WAVE ANALYSIS SEVR>140% PBP TTI - Tension Time Index (area under systolic part of the pulse curve) DTI - Diastolic Time Index (area under diastolic part of the pulse curve) SEVR - Buckberg Sub-Endocardial Viability Ratio – subendocardial blood supplying 16 PULSE WAVE ANALYSIS