Methods for assessing integral parameters of arterial stiffness: comparative analysis and new potential

Abstract

Aim. To develop a new method for calculating integral parameter of arterial stiffness — volume elastic modulus (Ev).Material and methods. A retrospective analysis of integral hemodynamic parameters of 1660 patients (women, 60%, 58,6±16 (M±σ) years of age; men, 40%; 53,5±17,7 (M±σ) years of age) was carried out. The first group consisted of 898 patients with normal blood pressure (BP) (<140/90 mm Hg). The second group included 762 patients with hypertension (HTN). We studied following parameters: systolic and diastolic BP, stroke volume (SV), heart rate (HR). Calculation of Ev, total peripheral resistance (TPR), mean arterial pressure (MAP), systemic arterial compliance (SAC) and total bulk modulus (Е∑) was carried out.Results. The analysis showed that BP, SV, TPR and all parameters of the integral stif-f ness (Ev, SAC, and E∑) were significantly higher in hypertensive patients. Ev had a strong positive correlation with SAC (r=0,996, p<0,0011 and E∑ (r=0,985, p<0,001). This made it possible to calculate the dependence of Ev on SAC and E∑ using regression analysis.Conclusion. Using linear regression, the formula for calculating the Ev using SAC was obtained, which has a high accuracy at a heart rate of 60 to 90 bpm (error, no more than ±5%). With tachycardia and bradycardia, the error exceeds ±5%. In these cases, it is necessary to calculate the Ev using the mathematical model of A. E. Teregulov.Calculation of Ev from Ez using the diastolic duration calculated by the Karpman formula does not give a sufficiently reliable result. Thus, a direct measurement of diastolic duration using echocardiography is required.

Keywords

• integral arterial stiffness
• systemic arterial compliance
• volume elastic modulus
• hypertension