Strain rate and the coronary blood flow in patients with high normal blood pressure

Abstract

Background. The population studies demonstrated the direct relationship between blood pressure (BP) level and risk of cardiovascular complications. The BP elevation (even within high normal values) in the young adults is associated with early involvement of target organs. Moreover, the initial myocardial structural and functional changes associated with BP increase are not studied completely. Modern ultrasound diagnostic opportunities (development of high frequency broadband transthoracic transducer, implementation of Tissue harmonic imaging and development of “speckle tracking” echocardiography method — STE) allow to assess the coronary blood flow status and to reveal the earliest signs of left ventricle (LV) myocardial dysfunction. The aim of our study is to assess the LV longitudinal deformation and coronary blood flow at the level of left anterior descending (LAD) artery and perforant arteries (PA) in young patients with high normal BP (HNBP). Design and methods . The study involved 43 men aged 18–27 years old, who were divided into 2 groups depending on office BP level. The first group consists of the subjects with HNBP, the second group included persons with optimal and normal BP values. The standard physical examination was performed in all patients. Heart condition was assessed by transthoracic EchoCG data. The registration of blood flow spectrum in LAD and in apical PAs was performed by impulse Doppler regimen. LV functional status was assessed by STE with global longitudinal strain analysis. Results. The traditional parameters of systolic and diastolic LV function were comparable in patients with HNBP and in healthy subjects. In patients with prehypertension a significant decrease of global strain rate was registered; they negatively correlate with systolic BP. In patients with HNBP the significant decrease of maximal diastolic blood flow rate in PA was registered. Conclusions. The earliest preclinical sign of myocardial contractile dysfunction in the subjects with HNBP is the decrease of global longitudinal strain. In patients with prehypertension the decrease of maximal diastolic blood flow rate in performant arteries is found.