Tiziana Grosso

Assessing resting heart rate in adolescents: determinants and correlates.

The aim of this study was to evaluate the distribution of resting heart rate and its biological and environmental determinants in adolescents. The study was cross- sectional and the population consisted of 2230 children and adolescents, age range 12–18 years, enrolled randomly from state schools in Turin, Italy. In all participants the following parameters were evaluated: heart rate, blood pressure (BP), weight, height, degree of sexual development, physical activity, parental socio-cultural level. Heart rate and BP were measured after 5, 10 and 15 min in a sitting position. Furthermore, to obtain regression equations to define heart rate as a function of the other variables available, a multiple regression analysis was performed. In both sexes BP, but not heart rate, declined significantly from the first to the last determination. Heart rate was positively and significantly correlated to BP level in both sexes; heart rate was higher in girls (3 bpm) and followed a progressive decreasing trend with age in both sexes, that was opposite to BP values. Age, sexual maturation, height, physical activity and parental socio-cultural level were independent determinants of resting heart rate. In conclusion, resting heart rate in adolescents is related to several methodological, constitutional and environmental factors that have to be taken into account when assessing heart rate values and constructing tables of normal values.

Comparison between generalized retinal arteriolar narrowing and left ventricular mass in young untreated hypertensive patients.

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.

Assessment of Heart Rate Variability after Calcium Antagonist and β-Blocker Therapy in Patients with Essential Hypertension

AbstractObjective: 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.

Pulse rate in childhood: reference limits

BACKGROUND AND AIM Systematic quantitative resting pulse rate measurements may represent an additional parameter for the study of cardiovascular risk factors in youth as well as in adulthood. The aim of this study was to evaluate resting pulse rate and its distribution curve in order to define reference limits in a sample of adolescents from Turin, Italy. METHODS AND RESULTS The study population consisted of 2230 children aged 12-18 years, who were randomly enrolled from Turin Junior High Schools. All of the participants underwent pulse rate, blood pressure and height measurements. The 5th and 95th percentiles of the pulse rate in boys and girls are reported by age and height. The pulse rate was higher in the girls, but progressively decreased with age and somatic growth in both genders. CONCLUSIONS The present study provides reference blood pressure values by age, gender and height in a sample of male and female adolescents.