Cardiac findings in children with high blood pressure

CARDIAC FINDINGS IN CHILDREN WITH HIGH BLOOD PRESSURE PURPOSE: The childhood obesity has largely increased because of the spreading of obesity in the last two decades. Measurement of the blood pressure, and particularly ambulatory blood pressure monitoring (ABPM) outside the clinic will be helpful for making the accurate diagnosis. The relationship between the ABPM and the subclinical target organ damages have been evaluated in children and adolescents in many studies. Among these target organ damages, the left ventricular hypertrophy is the index that has been studied most thanks to the wide area of use of the echocardiography. It is accepted that changes including the left ventricular hypertrophy, left atrial enlargement and subclinical deterioration of the diastolic functions of the left ventricle are the precursors of the cardiac dysfunction and cardiac insufficiency in advanced ages. In this study, the possible interaction of the ABPM values with the indicators of cardiovascular exposure was evaluated in cases with documented clinical high blood pressure elevation by comparison with the healthy control group. MATERIALS AND METHOD: Thirty-eight patients (21 boys and 17 girls) with the average age was 11.81±3.72 years, BMI mean was 22.4 (13.5-35) kg/m2 referred to Adnan Menderes University Medical School Pediatric Health and Diseases Outpatient Clinic with suspicious high blood pressures were included in this study together with 33 healthy children (15 boys and 18 girls) with average age 10.98±3.03 years and BMI 17.7 (13-33) kg/m2. The patient group and the control group were evaluated using the ambulatory blood pressure monitoring (ABPM) values. In addition, the cardiac sizes and functions in the patient and control groups were evaluated with color M-mode echocardiography (MME) and conventional pulse Doppler echocardiography (PDE), as well as with more contemporary methods like tissue Doppler echocardiography (TDE). FINDINGS: According to the results of ABPM, white coat hypertension (WCH) was found in 23 patients (60.5%), pre-hypertension (preHT) in 6 patients (15.8%), ambulatory hypertension in 4 patients (10.5%) and severe ambulatory hypertension was found in 5 patients (13.2%) in the patient group. In the evaluation performed with M-mode echocardiography (MME), no significant differences were found between the end-diastolic thickness of the left ventricle (LVPWd), end-diastolic thickness of the interventricular septum (IVSd), and the end-diastolic and end-systolic dimensions of the left ventricular cavity (LVEDD and LVESD) between the patient and control groups. The left atrium diameter (LA) was found to be significantly greater in the patient group with MME as compared to control group. Statistically significant positive correlation was found in the patient group between the left atrial diameter and the body weight, BMI, and VYA. No significant correlation was found between the left atrial dimension and the ambulatory blood pressure parameters and diastolic parameters. When the left atrial diameter is indexed to the BMI, no significant differences were found between the patient and control groups as regards the left atrial diameters. No significant difference was found between the patient and control groups as regards the LVM. No significant difference was found between the patient and control groups as regards the RWT. No significant difference was found between the WCH and normotensive groups as regards LFMI (p=0.101). No significant difference was found between the ambulatory HT group (the ambulatory HT and severe ambulatory HT groups) and the normotensive group as regards the LVMI. LVMI was found between 90th and 95th percentiles in 4 patients (10.5%) in the patient group and in 2 individuals (6.1%) in the control group. These cases were classified as the "increased LVMI". No cases were found in the patient and control groups with LVMI exceeding 95th percentile and left ventricular hypertrophy (LVH). When the cases with LVMI between 90th and 95th percentiles were compared with cases with LVMI <90th percentile, there were no differences as regards BMI, SDS, clinical systolic blood pressure index (SBPI) and diastolic blood pressure index (DBPI), whole day SBPI and DBPI, whole day pulse pressure, whole day hear rate, daytime SBPI and DBPI, nighttime SBPI and DBPI, and diastolic drop. It was found that the systolic drop in the group with increased LVMI was significantly lower as compared to the group with normal LVMI. When the relationship between the whole day, daytime and nighttime SBPe and DBPe and the LVMI was compared, LVMI was found significantly higher in cases with SBPe over 25% as compared to those with SBPe under 25%. Concentric remodeling was found 2 cases (5.3%) in the patient group, while normal geometry was found in 36 cases (94.7%). No concentric hypertrophy or eccentric hypertrophy was found in the patient group. The left ventricular geometry was evaluated as normal in the control group. There were no significant differences between the patient group and the control group as regards the Mitral E, Mitral A, mitral E/A rate, deceleration time (DT), and isovolumic relaxation time (IVRT), which were measured with the classical pulsed Doppler echocardiography. While the maximum flow rate in the descending aorta was 63.5 cm/sec (range: 33.2-124.6) in the patient group, the same was 113.3 (81.6-158.6) cm/sec in the patient group, and the flow rate was significantly lower in the patient group. There were no significant differences between the patient group and the control group as regards A' lateral and E'/A' lateral rate, E' septal, A' septal and E'/A' septal rate, E/E' lateral and E/E' septal rates. There were significant differences in our study group as regards the tissue Doppler septal IVRZ values. There were significant differences between the two groups as regards the left ventricular MPI measured with pulse Doppler. While the MPI (Tei index) calculated with tissue Doppler was 0.51 (0.25-0.95) in the patient group, the same was 0.45 (0.22-0.55) in the control group. This increase in the patient group in the left ventricular MPI with tissue Doppler was statistically significant. It was seen that there was significant positive correlation between the tissue Doppler MPI and ambulatory HT stage. The tissue Doppler MPI was found over 0.5, which is accepted as the upper limit for tissue Doppler MPI in 8 cases in the control group (24.2%), 11 cases (47.8%) in the WCH group, in 5 cases (83.3%) in the group with pre-HT, and 6 cases (66.7%) in the ambulatory HT group. While tissue Doppler MPI was found as significantly higher in the group with WCH as compared to the control group (p=0.033), no significant differences were found between the ambulatory HT group and the control group as regards tissue Doppler MPI (p=0.052). There were no significant changes between patient and control groups as regards the mean value of the aortic stiffness (Ep*). The Ep value in the patient group was found to be higher as compared to the control group. There were statistically significant changes between the two groups as regards the S value. There were significant changes between the two groups as regards the aortic stiffness index. The aortic distensibility was found to be significantly lower in the patient group as compared to the control group. No correlation was found between the aortic stiffness parameters and the BMI and LVMI. CONCLUSION: In this study, the significant positive correlation between the left ventricular mass index with the systolic blood pressure loads in hypertensive cases suggests that systolic blood pressure loads can be more important in the prognosis of these cases. It was seen that the tissue Doppler MPI was the most valuable method in the evaluation of the cardiac diastolic functions. In addition, it was seen that the lowness of the maximal flow rate in the descending aorta is good criterion to differentiate the normal cases from the hypertensive group. It is considered that further studies are required to investigate this criterion.