Background. Left ventricular hypertrophy is an independent risk factor of cardiovascular morbidity and mortality in adults. The results of 24-hour ambulatory blood pressure monitoring (ABPM) correlate better with signs of organ damage than values of casual blood pressure. The objective of this study was to investigate the relationships between the results of 24-hour ABPM and left ventricular geometry in school-aged children and adolescents with elevated blood pressure. Methods and Results. 24-hour ABPM and echocardiographic assessment of left ventricle were performed in 108 children and adolescents age 8-20 years (77 boys and 31 girls) with repeatedly elevated casual blood pressure (BP) values. Patients with secondary cause of hypertension were not included in this study. Based on ABPM results 57 patients out of total 108 had hypertension, the rest of 51 subjects had their ambulatory BP values below 95. percentil and were labelled as white coat hypertensive (WCH). The left ventricular measurements in hypertensive subject were higher when compared with WCH (left ventricle posterior wall thickness 8.4±1.0 mm in hypertensive vs. 8.0±1.1 mm in WHC (p=0.047) and supurscript left ventricular mass index 81.8±13.8 g/m 2 vs 74.3±12 g/m 2 respectively; p=0,003). No differences were found in anthropometric data including body mass index in both groups. There was a significant correlation between ambulatory BP and both left ventricle posterior wall thickness and left ventricular mass index. The strongest correlation was found between diurnal systolic ambulatory BP and left ventricle posterior wall thickness (r=0.42; p<0.001) as well as between 24-hour and diurnal systolic ambulatory BP and left ventricular mass index (both r=0.47; p<0.001). Conclusions. Both left ventricle posterior wall thickness a left ventricle mass index are higher in patients with hypertension documented by ABPM compared with WCH subjects. The strongest correlation was found between diurnal systolic ambulatory BP and both left ventricle posterior wall thickness and left ventricular mass index.

        Key words: ambulatory blood pressure monitoring, hypertension, white coat hypertension, left ventricular