Mimma Caserta

Hypertension and Cognitive Function

Arterial hypertension, cerebrovascular disease, and dementia are related pathologies. This paper has reviewed comparatively the incidence of arterial hypertension and adult-onset dementia disorders. Hypertension is associated with cerebrovascular disease, which is in turn associated with dementia. It is the most important modifiable risk factor for stroke, which is a recognized cause of vascular dementia. In terms of pathophysiology of hypertensive brain damage, several hypotheses were developed, such as that vascular alterations induced by hypertension can induce lacunar or cortical infarcts and leucoaraiosis, that hypertension is responsible for cerebrovascular disease and acts into the contest of a pre-existing subclinic Alzheimers disease (AD), that hypertension determines neurobiologic alterations (such as β-amyloid accumulation) resulting in neuropathologic damage, and that aging and cerebrovascular risk factors act together to cause cerebral capillary degeneration, mitochondrial disruption, reduced glucose oxidation, and reduced ATP synthesis. The consequence of these alterations are neuronal death and dementia. Macroscopic results of these mechanisms are the so-called white matter lesions (WML), the significance of which is analyzed. Increasing clinical evidence suggests a close relationship between the reduction of elevated blood pressure and countering of both vascular dementia and AD. Antihypertensive treatment probably influences cognitive performances and prevents cognitive function alterations and the development of dementia. It is therefore important to evaluate as soon as possible cognitive functions of hypertensive patients.

Baroreflex sensitivity correlates with left ventricular morphology and diastolic function in essential hypertension

Objectives Arterial hypertension is a common cause of cardiac organ damage, inducing morphological and functional modifications. Spontaneous baroreflex sensitivity (BRS) control of the heart rate is a key mechanism of blood pressure homeostasis, and is impaired in patients with hypertension. This study sought to assess the association between BRS and left ventricular morphology and function. Methods We studied 224 hypertensive patients (125 men; aged 47.8 ± 10.8 years, mean ± SD) compared with 51 normotensive control subjects (25 men, aged 45.7 ± 12.5 years). Left ventricular morphology, systolic and diastolic function were evaluated by echocardiography. Spontaneous BRS was measured using the sequence method. Results BRS was inversely associated with relative wall thickness (R2 = 0.17; P < 0.0001) and left ventricular mass index (R2 = 0.03; P = 0.01); in particular, BRS was significantly impaired in patients with concentric left ventricular remodelling (median [interquartile difference] 9.4 [4.1]) and hypertrophy (9.05 [3.9]) compared with the normal left ventricle (12.3 [5]; P < 0.001). BRS showed a significant association with systolic function evaluated by midwall fractional shortening (r = 0.28; P < 0.001), stroke volume (r = 0.27; P < 0.001), stroke work (r = 0.17; P < 0.05), and fractional shortening (r = 0.17; P < 0.05). BRS was significantly decreased in patients with diastolic dysfunction; it was lower in patients with diastolic dysfunction compared with both the control group and hypertensive patients with normal diastolic function. Conclusion BRS is associated with left ventricular morphology, systolic and diastolic function in hypertensive patients. In particular BRS is impaired in patients with diastolic dysfunction. These findings suggest a role for BRS as a target in arterial hypertension.

Blood pressure levels, left ventricular mass and function are correlated with left atrial volume in mild to moderate hypertensive patients

Arterial hypertension is associated with an increased risk of atrial fibrillation (AF), and leads to a pronounced increase in morbidity and mortality. Left atrial volume (LAV) is an important prognostic marker in the older populations. The aim of our study was to identify the clinical and echocardiographic determinants of LAV in middle-aged (<70 years old) essential hypertensive patients.We evaluated cardiac structure and function in 458 patients, 394 treated and untreated mild to moderate essential hypertensives patients (mean±s.d. age 48.4±11.1 years) with no associated clinical condition and 64 normotensive control participants (age 45.7±12.8 years; P=0.12). A multivariate analysis was performed to calculate the relative weight of each of the variables considered able to predict LAV. The LAV index (LAVi) was significantly increased in the essential hypertensive group vs the control group and was significantly dependent on blood pressure levels (SBP and DBP, P<0.05 for both) and body mass index (BMI) (P<0.0001). Considering the left ventricular (LV) variables, the LV mass index (LVMI) (R2=0.19, P<0.001) and LAV were increased in essential hypertensive patients with left ventricular hypertrophy (LVH), and patients with enlarged LAV showed lower systolic and diastolic function and an increased LVMI. The LAVi is dependent on blood pressure levels and anthropometric variables (age and BMI). Further structural (LVMI) and functional (systolic and diastolic) variables are related to the LAVi; LVMI is the most important variable associated with LAV in mild to moderate essential hypertensive adult patients. These findings highlight the importance of left atrium evaluation in adult, relatively young, essential hypertensive patients.

QT interval in patients with primary aldosteronism and low-renin essential hypertension.

Introduction QT interval prolongation increases the risk of sudden death in several medical conditions. Patients with primary aldosteronism and salt-sensitive hypertension experience more cardiovascular events than those with normal-renin essential hypertension. QT interval prolongation might represent one of the risk factors for cardiovascular events in these patients. The aim of the present study was to evaluate the QT interval in patients with primary aldosteronism and low-renin essential hypertension (LREH). Methods Twenty-seven patients with primary aldosteronism, 17 patients with LREH, 117 patients with essential hypertension and 25 healthy individuals were studied. Plasma aldosterone, plasma renin activity, and aldosterone to plasma renin activity ratio (ARR) were determined. Corrected QT intervals (QTcs) were measured from a 12-lead electrocardiogram. Results The QTc was longer in primary aldosteronism (434 ± 23 ms) and LREH (430 ± 18 ms) compared with essential hypertension (419 ± 22 ms) and healthy controls (412 ± 19 ms) (P = 0.0004). The prevalence of QTc longer than 440 ms was higher in primary aldosteronism (48%) and LREH (23%) compared with essential hypertension (11%) and healthy controls (4%) (P < 0.0001). QTc correlated with plasma aldosterone (P = 0.01), ARR (P = 0.02), and diastolic blood pressure (P = 0.01). ARR (P = 0.01) and systolic blood pressure (P = 0.01) were identified as independent predictors of QTc. Conclusions We postulate that the elevated aldosterone secretion contributes to the prolongation of the QT interval in patients with primary aldosteronism and LREH through both a depletion of intracellular potassium concentration and higher blood pressure values. QTc measurement might represent one simple, non-invasive and reproducible index to characterize the cardiovascular risk in patients with primary aldosteronism and LREH.

Cognitive Decline and Low Blood Pressure: The Other Side of the Coin

Low blood pressure has been found to be associated with cognitive decline and dementia in cross-sectional studies. Two mechanisms have been proposed to interpret this association: blood pressure levels decrease during the course of the dementia process, and low blood pressure induces or accelerates cognitive decline by lowering cerebral blood flow. Results of the prospective studies are contradictory. Low blood pressure and orthostatic hypotension have been found to predict cognitive impairment in the elderly population in some studies only. While hypotension may play a protective role in healthy elderly people, low blood pressure levels in frail elderly patients with associated diseases may cause cerebral hypoperfusion and accelerate cognitive decline.

Aortic size index enlargement is associated with central hemodynamics in essential hypertension.

The aim of this study was to evaluate the association between brachial and central blood pressure (bBP and cBP) levels and aortic root dilatation (ARD) in essential hypertensive patients. A total of 190 untreated and treated essential hypertensive patients (mean age, 55±11 years) were considered for this analysis. We measured pulsatile hemodynamics and the proximal aortic diameter directly using tonometry, ultrasound imaging (echocardiography) and Doppler. Ninety-one hypertensive patients had an ARD (defined as aortic size index (ASi)>2 cm/m2). Central hemodynamic variables were significantly associated with ASi. Patients with increased ASi were significantly older (60±10 vs. 50±11 years, P<0.0001) and had higher levels of the augmentation index (AIx; 28±10 vs. 21±10 P<0.0001), augmentation pressure (AP; 13±6 vs. 8±5 mm Hg, P<0.0001), and central pulse pressure (cPP; 44±10 vs. 39±8 mm Hg, P<0.0001) compared with patients with normal ASi. In a logistic regression analysis, the AIx was the only significant predictor of ASi. In hypertensive patients, the AIx and cBP were associated with ARD, whereas the bBP was not. Patients with an increased ASi may lose part of the elastic properties of the aorta, demonstrating a strict correlation between ASi and central hemodynamic indexes, in particular, the cPP and AIx.

Baroreflex sensitivity is impaired in essential hypertensives with central obesity.

Recently, much interest has focussed on the potential interaction between sympathetic nervous system and global cardiovascular risk. We investigated how baroreflex sensitivity (BRS), an index of autonomic function, interacts with central obesity (CO) in an essential hypertensive (EH) population. We selected 170 EHs and 43 normotensives (NT), (median age 47.3±11.3 and 49.1±13 years, respectively). Anthropometric parameters were measured for each and BRS was evaluated by a non-invasive method using Portapres TNO. The BRS evaluation was made using the sequences method. Systolic blood pressure (SBP) and heart rate were significantly higher in EH (P<0.001 and P=0.007, respectively). BRS was significantly greater in NT (P=0.02), and was associated inversely with waist circumference (WC) (P=0.005), but not with SBP or with other metabolic risk factors. Body mass index, total and high-density lipoprotein cholesterol, age and WC were not significantly different between the two groups. These results were confirmed by age pounded analysis. Finally, a separate analysis of the hypertensive group with CO (n=84) demonstrated a significantly lower BRS compared with the other hypertensive patients (n=86) (P<0.001). BRS is associated with WC but not with arterial pressure values and metabolic risk factors. Hypertensive subjects with CO show an impairment of BRS. Owing to its association with abdominal fat distribution and subsequently insulin resistance, BRS could represent a further and reliable index for evaluation of global cardiovascular risk in hypertensive patients.

Anti-hypertensive drugs and left ventricular hypertrophy: a clinical update.

Structural remodelling of the heart, known as left ventricular hypertrophy (LVH), is a consequence of systemic hypertension, and is associated with an increased risk of cardiovascular morbidity and mortality. Therefore, particular attention should be paid to the identification, prevention and treatment of this condition in hypertensive patients. LVH seems to benefit from all classes of anti-hypertensive drugs; however, antagonists of the renin–angiotensin–aldosterone system (RAAS) have demonstrated an additional benefit in the inhibition and reversal of myocardial interstitial fibrosis. Nevertheless, in evaluating the degree of arterial hypertension and organ damage, many neuro-hormonal systems are involved, primarily the sympathetic nervous system, thereby explaining the use of different classes of anti-hypertensive drugs to prevent or reduce LVH. The RAAS antagonists are actually the recommended anti-hypertensive agents to prevent organ damage in hypertensive subjects or in hypertensives with evidence of LVH to reduce cardiovascular mortality and morbidity.

Aldosterone as an Independent Factor in Cerebrovascular Damage

Aldosterone is produced not only in the adrenal gland but also in other tissues, including the brain, where it plays an important role in the control of blood pressure and water and electrolyte homeostasis. Aldosterone has also been demonstrated to be a major factor in target organ damage independent of its effects on blood pressure. Herein we review the pathophysiology of aldosterone action in the brain and the clinical and experimental studies on the detrimental effects of aldosterone in the brain.

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.