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Objective: Antihypertensive agents of different classes may have profound effects on heart rate variability (HRV). HRV changes in patients with essential hypertension were evaluated after pharmacological treatment by time domain (TD) analysis on 24-hour electrocardiographic (ECG) recordings. Design and Patients: In this randomised block single-blind trial, 45 patients with essential hypertension were randomly assigned to either atenolol, a cardioselective β-blocker, carvedilol, a β-blocker with vasodilator properties, or lacidipine, a long-acting dihydropyridine calcium antagonist, and underwent simultaneous 24-hour ECG and ambulatory blood pressure monitoring before and after 8 weeks' treatment. TD measures were calculated. Results: During treatment with atenolol and carvedilol, the 24-hour average normal RR [mean normal to normal intervals (NN)] was significantly increased (p < 0.0001 and p < 0.0002, respectively). Measures of tonic vagal activity were increased significantly only with atenolol: increase of 64.3% for the percentage of differences >50msec between adjacent NN intervals and increase of 45.2% for root mean square successive differences. By contrast, standard deviations (SD) of all NN over a 24-hour period and SD of means of 5-minute blocks of NN related to total and diurnal HRV were significantly increased by lacidipine (13.4 and 18.9%, respectively) and decreased by carvedilol (-12.0% and -22.0%, respectively) but not significantly modified by atenolol. Modifications in TD parameters were unrelated to the degree of 24-hour blood pressure reduction. Conclusions: HRV, assessed by TD, is modified differently according to the specific type of antihypertensive monotherapy used. These modifications could have prognostic importance. TD measures of HRV may be a practical and powerful instrument for the evaluation of the effect of antihypertensive drugs. [ABSTRACT FROM AUTHOR]

Purpose: This study aims to examine the relationship between retinal arteriolar narrowing and left ventricular hypertrophy in hypertensive patients., Methods: A total of 30 patients with a recent history of hypertension (22 M, 8 F; 33 +/- 8; BMI 24,96 +/- 2.8;), consecutively referred to the Hypertension Unit by their family doctors, were studied. Generalized retinal arteriolar narrowing was measured by two ophthalmologists from computer-scanned images on retinal photographs, and summarized as arteriole-to-venule ratio (AVR). Left ventricular hypertrophy was evaluated by quantitative M-mode echocardiography., Results: All patients were stratified according to the 2003 European Society of Hypertension (ESH) guidelines: 20 subjects (66.7%) were affected by hypertension grade 1, and 10 (33.3%) were affected by hypertension grade 2. Retinal vessel diameters did not differ significantly by grade 1 vs grade 2 hypertension. Echocardiographic left ventricular hypertrophy was present in 10 (33%) patients. No significant correlation was shown between arteriole-to-venule ratio (AVR) and left ventricular mass. [Spearman r = 0.22; p = 0.23]., Conclusions: We suggest some explanations for the fact that we did not find any correlation between AVR and left ventricular mass. Further clinical studies are required for a greater understanding as to whether early microvascular changes relate with other clinical indicators of hypertensive organ damage.

Objective: To investigate the cardiovascular autonomic function in pediatric obesity of different duration by using standard time domain, spectral heart rate variability (HRV), and nonlinear methods., Research Methods and Procedures: Fifty obese children (13.9 +/- 1.7 years) were compared with 12 lean subjects (12.9 +/- 1.6 years). Obese children were classified as recent obese (ROB) (<4 years), intermediate obese (IOB) (4 to 7 years), and long-term obese (OB) (>7 years). In all participants, we performed blood pressure (BP) measurements, laboratory tests, and 24-hour electrocardiogram/ambulatory BP monitoring. The spectral power was quantified in total power, very low-frequency (LF) power, high-frequency (HF) power, and LF to HF ratio. Total, long-term, and short-term time domain HRV were calculated. Poincaré plot and quadrant methods were used as nonlinear techniques., Results: All obese groups had higher casual and ambulatory BP and higher glucose, homeostasis model assessment, and triglyceride levels. All parameters reflecting parasympathetic tone (HF band, root mean square successive difference, proportion of successive normal-to-normal intervals, and scatterplot width) were significantly and persistently reduced in all obese groups in comparison with lean controls. LF normalized units, LF/HF, and cardiac acceleration (reflecting sympathetic activation) were significantly increased in the ROB group. In IOB and OB groups, LF, but not nonlinear, measures were similar to lean controls, suggesting biphasic behavior of sympathetic tone, whereas nonlinear analysis showed a decreasing trend with the duration of obesity. Long-term HRV measures were significantly reduced in ROB and IOB., Discussion: Autonomic nervous system changes in adolescent obesity seem to be related to its duration. Nonlinear methods of scatterplot and quadrant analysis permit assessment of autonomic balance, despite measuring different aspects of HRV.

Background: Several studies have found a relation ship between small size at birth and high blood pressure (HBP). However, this association has not been fully evaluated in adolescence. The aim of the present study was to evaluate the relation of birth weight (BW) to BP in adolescence, controlling for factors related to BP, to extrauterine environment, and to maternal risk of fetal distress., Methods: In 1310 adolescents (ages 12-14 years), randomly selected from Turin school children, we evaluated BP, heart rate (HR), weight, height, familial risk of hypertension, parental cultural level, BW, and maternal history of diseases during pregnancy. The BW-BP association was tested by using multiple regression analysis and adjusting for the other variables mentioned above. The same analysis was done for the subgroup at high risk of fetal distress., Results: The association between BW and BP was negative but weak when we adjusted for all confounders (= -0.07 in males; = -0.27 in females). The association was negative and became stronger after the inclusion of all confounders, particularly HR (= -3.92), in the group of children at high risk of fetal distress., Conclusions: Intrauterine environment, as reflected by BW, has little effect on BP in early adolescence without concomitant maternal diseases or environmental conditions leading to severe placental hypoperfusion., (Copyright 1999 American Health Foundation and Academic Press.)