Left ventricular function, cardiac dysrhythmias, atrial activation, and volumes in nondipper hypertensive individuals with left ventricular hypertrophy

Nondipping Pattern and Cardiovascular and Renal Damage in a Population-Based Study (The STANISLAS Cohort Study)

OBJECTIVE

The attenuation of physiological nocturnal decline of blood pressure (BP)-called nondipper pattern-has previously been reported to be associated with target organ damage in hypertensive subjects. However, this association remains debated and poorly studied in normotensive patients. This study aimed to investigate the association between nondipper pattern and subclinical cardiovascular and renal damage in an initially healthy population-based cohort study.

METHODS

The STANISLAS Cohort is a single-center, familial longitudinal cohort composed of 1,006 families (4,295 subjects) recruited in 1993-1995 for a 5-year periodic health examination. A total of 1,334 subjects from the 4th visit (2011-2016) of the STANISLAS cohort were included. This 4th examination included estimated glomerular filtration rate, albumin/creatinine ratio, pulse wave velocity, central systolic BP, carotid intima-media thickness and distensibility, left ventricular mass index, left ventricular hypertrophy, diastolic dysfunction, and ambulatory blood pressure monitoring (ABPM). Nondipping status was defined as a mean reduction in systolic BP (SBP) or diastolic BP (DBP) lower than 10% during nighttime.

RESULTS

Data were obtained from 798 normotensive subjects (45 ± 14 years, 395 [49%] nondippers, SBP/DBP mmHg 24 hours: 116/71 ± 7/5) and 536 hypertensive patients (56 ± 11 years, 257 [48%] nondippers, SBP/DBP mmHg 24 hours: 127/78 ± 10/7). Mean 24-hour and daytime ABPM measurements were within the normal range, even in hypertensive participants (19% treated). The nondipping pattern was not associated with cardiovascular or renal alterations in this population.

CONCLUSION

In this middle-aged population with an overall 24-hour optimal BP control, the nondipper pattern was not associated with increased cardiovascular or renal damage.

Comparison of left atrial volume and function in non-dipper versus dipper hypertensives: A real-time three-dimensional echocardiography study

OBJECTIVE

Non-dipper hypertension is associated with an increased cardiovascular morbidity and mortality. Besides this, the left atrial (LA) size and functions are accepted to be prognostic factors in various cardiovascular diseases. In this study, we aimed to evaluate the effect of nondipper hypertension on LA volume and functions using real-time three-dimensional echocardiography (RT3-DE).

METHODS

Forty dipper and 52 non-dipper hypertensives enrolled in this prospective cross-sectional study. Patients with any comorbidities that have a potential for causing structural cardiac alterations were excluded. Two-dimensional echocardiography (2-DE) and RT3-DE were performed to assess LA volumes and functions. The statistical tests used in this study were Shapiro-Wilk's test, Student's t-test, Mann-Whitney U test, chi-square test, Spearman's test, and Pearson's correlation test.

RESULTS

LA minimal volume, LA volume before LA contraction, and LA total systolic volume were higher in non-dipper hypertensives than in dipper hypertensives (p<0.001, p=0.003, and p=0.03, respectively). Only, the 2-DE measurements of interventricular septal thickness and E/Em ratio were higher in non-dipper hypertensives (p=0.001 and p=0.03, respectively). There was a moderate correlation between LA minimal volume and LA volume before LA contraction with E/Em (r=0.31, p=0.007 and r=0.32, p=0.005, respectively).

CONCLUSION

Although LA volume and passive LA systolic functions measured by RT3-DE are significantly increased in non-dipper hypertensives, the alterations in active LA systolic functions are not prominent. RT-3DE may be used to define LA volume and function alterations in conditions that have capabilities of adverse cardiac remodeling such as systemic hypertension.

Non-Dipping Pattern and Subclinical Cardiac Damage in Untreated Hypertension: A Systematic Review and Meta-Analysis of Echocardiographic Studies

AIM

The association of non-dipping (ND) pattern with cardiac damage is debated. We performed a meta-analysis in order to provide comprehensive information on subclinical cardiac alterations in untreated ND hypertensives.

DESIGN

A computerized search was performed using PubMed, OVID, EMBASE, and Cochrane library databases from 1 January 1990 up to 31 October 2014. Full articles published in English language providing data on subclinical cardiac damage in ND as compared to dipper (D) hypertensives, as assessed by echocardiography, were considered.

RESULTS

A total of 3,591 untreated adult subjects (1,291 ND and 2,300 D hypertensives) included in 23 studies were considered. Left ventricular (LV) mass index (LVMI) was higher in ND than in D hypertensives (122±3.8 g/m2 vs. 111±3.3 g/m2, standardized mean difference, SMD: 0.40±0.07, confidence interval (CI): 0.26-0.53, P < 0.001); relative wall thickness (RWT) and left atrium (LA) diameter were greater (SMD: 0.14±0.005, CI: 0.05-0.23, P = 0.002; 0.36±0.10, CI: 0.16-0.56, P < 0.001, respectively), while mitral E/A ratio was lower in ND than in D counterparts (SMD: -0.23±0.08, CI: -0.39 to -0.08, P = 0.003). After assessing data for publication bias, the difference between groups was still significant, with the exception of E/A ratio.

CONCLUSIONS

Our meta-analysis supports an association between ND pattern and increased risk of LV structural alterations in untreated essential hypertensives. This observation supports the view that an effective BP control throughout the entire 24-hour cycle may have a key role in preventing or regressing subclinical cardiac damage associated to ND pattern.

Percutaneous ligation of the left atrial appendage results in atrial electrical substrate modification

Debulking of electrically active atrial tissue may reduce the mass of fibrillating tissue during atrial fibrillation, eliminate triggers, and promote maintenance of normal sinus rhythm (NSR). We investigated whether left atrial appendage (LAA) ligation results in modification of atrial electrical substrate. Healthy male mongrel dogs (N = 20) underwent percutaneous epicardial LAA ligation. The ligation system grabber recorded LAA local electrograms (EGM) continuously before, during, and after closure. Successful ligation with a preloaded looped suture was confirmed intraprocedurally by LAA Doppler flow cessation on transesophageal echocardiography (TEE) and loss of LAA electrical activity, and after procedure by direct necropsic visualization. P-wave duration on surface electrocardiograms was measured immediately before and after LAA closure. Percent P-wave duration reduction was correlated with preclosure LAA internal dimensions measured by TEE and external dimensions measured on necropsy specimens to investigate associations of LAA geometry with the extent of electrical substrate modification. LAA ligation was successful in all dogs and accompanied by loss of LAA EGM. P-wave duration reduced immediately on ligation (mean 75 ms preligation to 63 ms postligation; mean difference ± standard error, 12 ± 1 ms; P < 0.0001). Percent P-wave reduction was associated with larger LAA longitudinal cross-sectional area (R(2) = 0.263, P = 0.04) and smaller external circumference (R(2) = 0.687, P = 0.04). All dogs were in sinus rhythm. Percutaneous LAA ligation results in its acute electrical isolation and atrial electrical substrate modification, the degree of which is associated with LAA geometry. These electrical changes raise the possibility that LAA ligation may promote NSR by removing LAA substrate and triggers.

Sphingomyelin levels in nondipper and dipper hypertensive patients

A number of studies have focused on the association between sphingomyelin (SM) levels and atherosclerosis, however, there are few data concerning the correlation of SM with nondipper hypertension. The present study aimed to investigate the correlation between plasma SM levels and nondipper status in patients with hypertension. A total of 200 hypertensive patients were enrolled and divided into two groups according to their ambulatory blood pressure monitoring (AMBP) results: Dipper group (84 patients) and nondipper group (116 patients). All patients were subjected to transthoracic echocardiography examination and laboratory tests. No statistically significant difference was observed between the two groups in terms of basic clinical characteristics. However, the plasma SM levels in the dipper group were significantly lower than those of the nondipper group (41.9±17.5 vs. 96.4±14.3 mg/dl, P=0.003). The left ventricular mass index (LVMI) was higher in the nondipper patients than in the dipper patients and the diastolic function parameters in the nondipper patients were less favorable. Correlation analysis showed that the SM level was negatively correlated with the magnitude of systolic blood pressure (SBP) fall at night (r=−0.42, P<0.01) and diastolic blood pressure (DBP) fall at night (r=−0.31, P<0.01). The nondipper status had contributory effects on hypertensive concentric hypertrophy and diastolic function impairment. In addition, the plasma SM level was associated with a nondipper pattern of hypertension.

Serum urotensin II levels in patients with non-dipper hypertension

Hypertension terms "dipper" and "non-dipper" are propounded by the change that occurs during ambulatory blood pressure (BP) monitoring. The purpose of this study is to present whether the serum urotensin II levels are different in patients with dipper and non-dipper hypertension and to put forward the effects causing this difference, if there are any. Patients recently diagnosed with hypertension were included in the study. With ambulatory BP monitoring, 81 patients with high BP were divided into two groups, dipper (n = 40) and non-dipper (n = 41). Serum urotensin II levels were analyzed by ELISA method. Serum urotensin II levels were higher in patients with non-dipper hypertension than in patients with dipper hypertension (204 [106-533] vs. 140 [96-309], P = .004). There was a positive correlation between total systolic BP and serum urotensin II levels (r = 0.408 and P = .009), but the relation in the non-dipper hypertension group was not significant (r = 0.194 and P = .2). In conclusion, serum urotensin II levels were higher in non-dipper HT patients than dipper HT patients. This higher urotensin II level might be responsible for poor prognoses.

Cardiovascular-sleep interaction in drug-naïve patients with essential grade I hypertension

Lack of nighttime blood pressure (BP) reduction by 10-20% from the mean daytime values (dipping) has been described as a distinguishing feature of essential hypertension and associated, also in normotensive subjects, with increased cardiovascular (CV) risk. Mechanisms involved in the loss of the nocturnal dip are still unclear, but involvement of autonomic nervous system (ANS) activity probably plays a crucial role. Sleep is fundamental in modulating ANS activity to maintain the physiological BP circadian rhythm, and for this reason its integrity has been widely investigated in hypertension. We investigated, under controlled conditions, the autonomic control of the CV system through an autonomic reflex screen in the awake condition and by assessment of circadian rhythm-, day-night-, time-, and state-dependent changes of BP and heart rate (HR) and associated sleep parameters in patients with a recent (≤1 yr) diagnosis of essential grade I hypertension naïve of therapy. Fourteen hypertensive patients (6 males, age: 43 ± 11 yrs; body mass index [BMI]: 24 ± 3 kg/m(2)) were compared with 28 healthy controls matched for sex, age, BMI (2 controls/patient) for cardiovascular reflex and to 8 different subjects from previous controls (6 males), comparable for age and BMI, for the day-night and nighttime CV profiles during two consecutive nights. The cardiovascular reflex screen data showed increased sympathetic effect in hypertensive patients, represented by higher overshoot of BP after Valsalva maneuver. Nighttime sleep architecture during the dark period in terms of duration, representation of sleep stages, sleep fragmentation, and incidence of arousals-periodic limb movements in sleep (PLMS) and PLMS arousals-was similar in patients and controls. Hypertensive patients displayed higher 24-h BP and HR values, but their sleep-related BP decrease was significantly reduced compared with controls. The circadian rhythms of BP and HR were intact and similar in patients and controls, coupling with the expected physiological peak time. BP and HR showed normal state-dependent modulation in hypertensive patients that, however, was higher in all sleep stages compared with controls. The lowering of systolic blood pressure (SBP) during non-rapid eye movement (NREM) sleep stages 1 and 2 and REM sleep, relative to daytime wake values, was significantly attenuated in the hypertensive group, whereas it was comparable to controls during slow-wave sleep. In hypertensive patients, analysis of sleep and CV parameters in the 90 min following sleep onset and preceding morning awakening showed normal depressor effect during the first part of the night after sleep onset and significantly higher BP rise in the hours preceding morning awakening. These findings were associated with comparable sleep architecture, sleep fragmentation, incidence of arousals, and PLMS and PLMS arousals in patients and controls. Our data suggest that drug-naïve essential grade I hypertension is associated with signs of increased vascular sympathetic response to standardized stress of the Valsalva maneuver during the awake condition, and during sleep with a non-dipping BP profile plus higher BP surge preceding morning awakening, assessable only by around-the-clock ambulatory BP monitoring, both representing additional CV risk already in early-stage hypertension and, therefore, requiring proper selection of pharmacological treatment.

Changes in P-wave area and P-wave duration after circumferential pulmonary vein isolation

AIMS

The effect of circumferential pulmonary vein isolation (CPVI) on P-wave characteristics is not clear. We used the signal-averaged (SA) electrocardiogram (ECG) and the ECG derived vector cardiogram (dVCG) to study the influence of CPVI on P-wave duration (PWD) and P-wave area (PWA) and studied whether changes were associated with successful outcome after initial CPVI.

METHODS AND RESULTS

Thirty-nine patients (56 +/- 10 years, 72% males) underwent CPVI for paroxysmal or persistent atrial fibrillation (AF). For each patient, an ECG recording was taken at the start and end of the ablation procedure. dVCG was derived using the inverse Dower transform. PWD was defined by manual annotation of earliest onset and latest offset of the SA-P-wave. PWA was calculated as the area under the SA-ECG curve averaged for the 12 ECG leads (PWA-ECG) and SA-dVCG curve (PWA-dVCG). Successful outcome after CPVI was defined as freedom from symptomatic and asymptomatic AF at the end of follow-up (11 +/- 5 months). Average PWD decreased from 132 +/- 14 to 126 +/- 16 ms (P < 0.01). PWA-ECG and PWA-dVCG decreased markedly from 4.64 +/- 1.40 to 3.65 +/- 1.61 mVms (P < 0.001) and from 4.27 +/- 1.66 to 2.48 +/- 1.59 mVms (P < 0.001). Parameters of PWA were not different between successes (n = 31) and failures (n = 8). In contrast, PWD after ablation was significantly shorter in patients with successful outcome (123 +/- 16 vs. 135 +/- 11 ms, P < 0.05).

CONCLUSION

(i) CPVI results in a modest but significant shortening in PWD and a marked decrease in PWA. (ii) PWD was significantly shorter in cases of successful outcome after CPVI.

Vascular endothelial functions, carotid intima-media thickness, and soluble CD40 ligand levels in dipper and nondipper essential hypertensive patients

OBJECTIVE

The lack of nocturnal decline in blood pressure (BP) is associated with an increase in cardiovascular events. Soluble CD40 ligand (sCD40L) is involved in the pathogenesis of risk factor-related vascular damage. The purpose of this study was to examine the relationship between vascular endothelial functions, carotid intima-media thickness (cIMT), plasma sCD40L levels and circadian BP profile in patients with essential hypertension.

MATERIAL AND METHODS

The study population consisted of 81 essential hypertensive out-patients. BP dipping was defined as a night-to-day systolic and diastolic decrease >or=10%. Forty-seven dipper and 34 nondipper patients were compared. High sensitivity C-reactive protein (hs-CRP), sCD40L and urinary albumin were measured. Brachial artery flow-mediated dilatation (FMD) and cIMT was compared between the groups.

RESULTS

sCD40L level (3.28 +/- 2.08 and 2.30 +/- 1.99 ng/ml, respectively, P = 0.036) and urinary albumin concentration (36.7 +/- 20.1 and 23 +/- 29.7 mg/l, respectively, P < 0.0001) were higher in nondippers than in dippers. Serum hs-CRP levels were not significantly different. FMD was found higher in dippers than nondippers (11.8 +/- 3.9% and 6.6 +/- 2.2%, respectively, P < 0.0001). The average cIMT was significantly higher in nondippers than dippers (0.928 +/- 0.060 Vs. 0.734 +/- 0.134 mm; P < 0.0001).

CONCLUSIONS

Nondipper patern has an additional negative effect on endothelial functions in hypertensive patients. Nondippers have enhanced sCD40L levels, which may contribute to their increased susceptibility to develop vascular damage.

Night-time blood pressure patterns and target organ damage: a review

BACKGROUND

Individuals who do not have a 10% to 20% reduction in blood pressure (BP) during the night are known as 'nondippers'. The cause of this nondipping phenomenon is not fully understood; however, there is a growing body of evidence linking a nondipping BP pattern with target organ damage.

OBJECTIVE

To review the literature and present an overview of the target organ damage found to be associated with a nondipping BP pattern.

METHODS

PubMed, CINAHL and Medscape searches of all available English language articles from 1986 to 2005 were performed. Search terms included 'BP nondipping', 'BP dipping' and 'target organ damage'.

RESULTS

There is evidence to suggest that individuals with hypertension who exhibit a nondipping BP profile are at higher risk of cardiac and extracardiac morbidity and mortality. In particular, nondippers with essential hypertension have been found to have more advanced left ventricular hypertrophy, left ventricular mass and left ventricular mass index, carotid artery wall thickness, carotid artery atherosclerotic plaques, silent cerebral infarct, stroke, cognitive impairment and microalbuminuria.

CONCLUSION

A better understanding of the importance of the circadian variations of BP may help to identify those at higher risk of cardiovascular morbidity and mortality, as well as lay the foundation for interventions to prevent/treat alterations in night-time BP patterns.

Nondipping blood pressure patterns among individuals with essential hypertension: a review of the literature

BACKGROUND

Researchers have discovered that blood pressure (BP) varies in a diurnal manner throughout a 24-hour period, being higher during the day and lower at night. Most people have a dipping BP pattern characterized by a nighttime BP that is 10-20% lower than their daytime BP. Individuals who experience a less than 10% reduction in nighttime BP are described as having a nondipping BP pattern. Although controversial, there is a growing body of evidence suggesting that a nondipping BP pattern is associated with a greater risk of target organ damage among individuals with essential hypertension.

AIM

To review the literature on the most common factors associated with nondipping BP patterns among individuals with essential hypertension.

METHODS

CINAHL (1982-March 2006), PubMed (1950-March 2006) and Cochrane Library (1966-March 2006) databases were searched using the keywords: dipper, dipping, nondipper, nondipping, ambulatory blood pressure monitoring, ABPM, hypertension, essential hypertension, high blood pressure, blood pressure, nocturnal blood pressure, nighttime blood pressure, diurnal blood pressure, and blood pressure patterns. Published studies, abstracts, dissertations as well as the reference lists of retrieved articles were reviewed. Studies were included if they involved subjects with only treated or untreated essential hypertension or those with samples of both nomotensive and treated or untreated essential hypertensive individuals. Additionally, studies needed to evaluate 24-hour, daytime and nighttime BP patterns.

RESULTS

There is some evidence to suggest advanced age, African-American ethnicity, female sex, postmenopausal status, sodium sensitivity, sleep apnea, sleep quality, anger, hostility, depression, stress, social support, and socioeconomic status have an association with nondipping BP patterns.

CONCLUSION

Knowledge of the potential factors associated with an altered nighttime BP pattern is of importance because it can help identify persons at risk for nondipping BP patterns and potential target organ damage. Furthermore, knowledge of these factors associated with a nondipping BP profile will lay the foundation for interventions to prevent/treat alterations in nighttime BP patterns.

The influence of circadian blood pressure changes on aortic distensibility and left ventricular diastolic function in hypertensive individuals

BACKGROUND

Failure to decrease blood pressure (BP) normally during nighttime, which is called non-dipper, in hypertensive individuals is associated with higher cardiovascular morbidity and mortality. In addition, non-dipper BP leads to structural changes in the left ventricle; however, the influences of non-dipper BP on aortic elastic properties and left ventricular diastolic function have not been studied yet.

METHODS

In this study, we evaluated aortic elastic properties and left ventricular diastolic function of 22 subjects with non-dipper hypertension, and 15 subjects with dipper hypertension using transthoracic second harmonic standard and tissue Doppler echocardiography (Acuson Sequoia C256). None of the subjects had any systemic disease or coronary risk factor except hypertension.

RESULTS

Age, gender, body mass index, lipids, and standard echocardiographic findings including left ventricular mass index were similar between the groups. Office BP recordings were similar between non-dipper and dipper groups (147.9+/-6.1/93.9+/-4.3 vs. 144.0+/-8.0/93.0+/-3.7). Daytime and 24-h ambulatory BP measurements were similar within the groups, but nighttime BPs were significantly greater in non-dipper group than those were in dipper group. Left ventricular diastolic parameters obtained by both standard and tissue Doppler did not differ between the non-dipper and dipper groups. However, aortic distensibility was found to be slightly lower (4.1+/-2.4 vs. 4.9+/-1.9, p=0.08), and aortic stiffness index (6.3+/-0.5 vs. 6.1+/-0.4, p=0.08) and elastic modulus (6.2+/-2.5 vs. 4.8+/-2.3, p=0.08; groups non-dipper and dipper respectively) higher in non-dipper group than in dipper group. However, these differences were not statistically significant.

CONCLUSION

Left ventricular remodeling and diastolic function were similar in patients with non-dipper and dipper hypertension. However, aortic elastic properties were slightly impaired in non-dipper hypertensives than those were in dipper ones, but these differences did not reach statistically significance.

Effects of dipper and non-dipper status of essential hypertension on left atrial mechanical functions

AIM

This study was designed in order to investigate the effects of dipper and non-dipper status of hypertension on left atrial mechanical (reservoir, conduit and booster pump) functions with left atrial volume measurements by means of two-dimensional echocardiography in untreated systemic hypertensive patients.

METHOD

A total of 27 untreated dipper hypertensive patients, group I (15 female, 12 male, mean age 57+/-12 years); 23 untreated non-dipper hypertensive patients, group II (12 female, 11 male, mean age: 53+/-18 years); and 25 voluntary healthy individuals, group III (13 female, 12 male, mean age 53+/-10 years) were included into the study. Twenty-four hour blood pressure (BP) measurement was performed by the cuff-oscillometric method to evaluate the nocturnal decrease of BP. The patients whose night time mean blood pressure measurements were found 10% or more lower compared to mean day time measurements were classified as dipper hypertensive patients and the ones with a decrease of less than 10% were classified as non-dipper hypertensive patients. Left atrial (LA) volumes were measured echocardiographically according to biplane area-length method in apical four-chamber and two-chamber views. LA maximal volume (V(max)) was recorded at the onset of mitral opening, LA minimal volume (V(min)) was recorded at the onset of mitral closure and LA presystolic volume (V(p)) was recorded at the beginning of the atrial systole (p wave on ECG). All volume measurements were corrected to body surface area, and following LA emptying functions parameters were calculated: LA passive emptying volume (LAPEV)=V(max)-V(p), LA passive emptying fraction (LAPEF)=LAPEV/V(max), Conduit volume (CV)=left ventricular output volume-(V(max)-V(min)), LA active emptying volume (LAAEV)=V(p)-V(min), LA active emptying fraction (LAAEF)=LAAEV/V(p), LA total emptying volume (LATEV)=V(max)-V(min), LA total emptying fraction (LATEF)=LATEV/V(max).

RESULTS

LA volume indexes, V(max), V(min), and V(p), were significantly increased in the hypertensive subgroups (groups I and II) than in controls (p<0.001, p<0.001, p<0.001, respectively), but no significant difference was found in the V(p) values between group I and group II. V(max) and V(min) were larger in non-dipper hypertensive group than in dipper hypertensive group (p<0.05 and p<0.05, respectively). LAPEV and LAPEF were observed to be significantly reduced in both dipper and non-dipper hypertensives than in control (p<0.001 and p<0.05, respectively), and this difference was more obvious in non-dipper than dipper cases (p<0.001). Conduit volume was significantly lower in hypertensive groups than controls (p<0.05). LA active emptying volume (p<0.001) and LAA active emptying fraction (p<0.001) were significantly greater in hypertensive cases than in controls. Furthermore, LA active emptying volume in non-dipper hypertensive subjects was significantly greater than dipper hypertensive cases (p<0.05). Left atrial total emptying volume and left atrial total emptying fraction in both hypertensive groups were similar to control (p>0.05).

CONCLUSIONS

Atrial reservoir and booster pump functions increase in hypertensive patients, but this result is more prominent in non-dipper hypertensives than in dipper hypertensive patients.

Does impaired left ventricular relaxation affect P wave dispersion in patients with hypertension?

OBJECTIVE

P wave dispersion (PD) is considered to reflect the heterogeneous conduction in atria. We investigated whether there was a correlation between the left ventricular (LV) relaxation and PD.

METHOD AND RESULTS

Fifty-three hypertensive patients < or =60 years old were divided into two groups: Group A, 27 patients, aged 54+/-5 years with the impaired LV relaxation and Group B, 26 patients, aged 51+/-8 years with normal LV relaxation. The P wave durations were measured in all 12 leads of ECG and PD was defined as the difference between maximum and minimum P wave duration (Pmax-Pmin). Mitral inflow velocities (E and A), E deceleration time (DT), isovolumic relaxation time (IVRT), left atrial and ventricular diameters, and wall thickness of LV were obtained by echocardiography. Clinical characteristics of both groups were comparable. The wall thickness of LV, Pmax, and left atrial dimension were not different in both groups. A velocity was higher (P<0.001), but E velocity (P=0.03) and E/A ratio (P<0.001) were lower in group A than in group B. IVRT and DT were also significantly longer in group A. PD was significantly higher in group A compared to group B (51+/-9 vs 41+/-11 ms, P=0.01). This difference resulted from the Pmin (61+/-10 vs 67+/-9 ms, P=0.03, respectively). Multivariate analysis revealed a significant correlation between PD and A velocity (r=0.46, P=0.01), E/A ratio (r=-0.53, P=0.001), DT (r=0.65, P<0.001), and IVRT (r=0.73, P<0.001).

CONCLUSION

This study suggests that impaired LV relaxation contributes to the heterogeneous atrial conduction in hypertensive patients.

Ambulatory Pulse Pressure, Left Ventricular Hypertrophy and Function in Arterial Hypertension

BACKGROUND

A wide pulse pressure (PP) can provide important risk assessment information about myocardial infarction, carotid artery atherosclerosis, and global cardiovascular risk. Ambulatory pulse pressure (APP) does not have a well-known prognostic value in hypertensive patients.

METHODS

To evaluate the relationship among high APP, atrial volumes, and cardiac function, an observational study was performed on 108 untreated non-elderly hypertensive patients (mean age 54.23 +/- 7.12). Twenty-four-hour ambulatory blood pressure monitoring, Doppler and echocardiographic measurements of systolic, diastolic function, left and right atrial volumes, left ventricular mass index and dimensions, were performed in subjects with both clinic and APP > 60 mmHg (APP1 Group). A control group of hypertensive selected subjects with both clinic and APP < 60 mmHg was chosen (APP 2 Group).

RESULTS

The APP1 group showed left atrial volume enlargement, high left ventricular mass index, and impaired diastolic function. A positive correlation was found in the APP1 group results among left ventricular end diastolic diameter (r = 0.39, P < 0.01), left atrial volume (0.38, P < 0.05), and left ventricular mass index (r = 0.33, P < 0.05); clinic PP showed a statistically significant correlation with left atrial volume, left ventricular end diastolic diameter, and left ventricular mass index only in the APP1 group.

CONCLUSIONS

These results suggest that elevated APP can be considered an effective predictor of cardiovascular risk in hypertensive subjects. In these patients echocardiographic evaluation of left ventricular function and morphology can increase the prognostic value of PP.

Seasonal variation of fibrinogen in dipper and nondipper hypertensive patients

BACKGROUND

A seasonal variation with higher values in winter has been previously reported in plasma fibrinogen, a recognized marker of the potential risk of myocardial infarction and stroke. The lack of nocturnal decline in blood pressure has also been associated with an increase in cardiovascular events. Accordingly, we have compared the yearly variation of plasma fibrinogen in dipper and nondipper hypertensive patients.

METHODS AND RESULTS

We studied 1006 stage 1 to 2 hypertensive patients (482 men and 524 women, 53.0+/-13.4 years of age). Blood pressure was measured every 20 minutes during the day and every 30 minutes at night for 48 consecutive hours. Physical activity was simultaneously evaluated at 1-minute intervals with a wrist actigraph. A blood sample was collected on the same day before starting blood pressure monitoring. The circannual variation of fibrinogen was established for all patients as well as for subgroups of dippers and nondippers (n=513; nocturnal blood pressure decline <10%) by multiple-component analysis. For the whole group of patients, fibrinogen was characterized by a highly significant seasonal variation (P<0.001) with a mean value of 318 mg/dL, double circannual amplitude (extent of predictable change along the year) of 40 mg/dL, and time of peak value in February. Throughout the year, the nondippers showed higher plasma fibrinogen levels than did the dippers (P<0.001).

CONCLUSIONS

The elevated plasma fibrinogen levels in nondipper patients appear to be directly related to their increased risk in vascular events, which are more prominent during the late winter months.

[Seasonal variation in plasma fibrinogen in dipper and non-dipper patients with mild-moderate essential hypertension]

BACKGROUND AND OBJECTIVE

Increased plasma fibrinogen is recognized as a significant parameter for assessing the potential risk of myocardial infarction and stroke. A seasonal variation has been reported for plasma fibrinogen, with highest values occurring in the coldest months of the year. On the other hand, the lack of nocturnal decline in blood pressure has been associated with an increase in cardiovascular events. Accordingly, we have quantified the yearly variation in plasma fibrinogen in hypertensive patients classified according to their nocturnal decline in blood pressure.

PATIENTS AND METHOD

We studied 577 mild-to-moderate hypertensive patients (254 men), 53.8 13.8 years of age. Blood pressure was measured every 20 min during the day and every 30 min at night for 48 consecutive hours. Physical activity was simultaneously evaluated at 1-min intervals with a wrist actigraph. A complete blood test was performed on the same day before starting blood pressure monitoring. The circannual variation of plasma fibrinogen was established for all patients as well as for subgroups of dippers (n = 287) and non-dippers (n = 290; patients with a nocturnal blood pressure decline < 10% of the diurnal mean) by multiple-component analysis.

RESULTS

For the whole group of hypertensive patients, plasma fibrinogen was characterized by a highly significant seasonal variation (p < 0.001), with a mean value of 324 mg/dl, double circannual amplitude (i.e, extent of predictable change along the year) of 75 mg/dl, and time of peak value on the first week of March. This circannual variation can be best represented by a model that includes components with periods of 12 and 6 months. The same model also characterized dippers as well as non-dippers, analyzed separately. Non-dippers showed higher plasma fibrinogen throughout the whole year as compared to dippers (p = 0.002).

CONCLUSIONS

The elevation of plasma fibrinogen in non-dipper patients as compared to dippers could support the association between the lack of nocturnal decline in blood pressure with an increase in cardiovascular events, since the circannual variation in fibrinogen is timely correlated with the reported yearly variation in coronary events.

[Holter EKG for the hypertensive heart disease]

During chronic mechanical overload induced by hypertension, left ventricular hypertrophy predisposes to atrial and ventricular arrhythmias. Atrial arrhythmias, mainly atrial fibrillation, decrease cardiac output and increase the risk of embolism whereas ventricular arrhythmias remain the major cause of sudden death. In hypertensive patients, Holter EKG recordings frequently detect atrial or ventricular premature beats and more rarely atrial or ventricular tachycardia. In these patients, the presence of non-sustained ventricular tachycardia is considered as an independent predictor of mortality. Moreover, this non invasive method through the assessment of heart rate variability allows the study of the autonomic control of the heart, known to modulate occurrence of arrhythmias.

Relationship between physical activity and blood pressure in dipper and non-dipper hypertensive patients

BACKGROUND

The lack of nocturnal decline in blood pressure has been associated with an increase in end-organ damage and cardiovascular events, although results remain controversial, partly because of the inability to reproduce correctly, over time, the classification of patients into dippers and non-dippers. Moreover, the non-dipping status has been frequently related to an increase in nocturnal activity, differences in quality of sleep, or both.

OBJECTIVE

To assess the relationship between activity and blood pressure in patients with hypertension.

METHODS

We studied 306 mild-to-moderately hypertensive patients (130 men), 53.7 +/- 14.0 years of age (mean +/- SD). Blood pressure and heart rate were measured for 48 consecutive hours, at 20-min intervals during the day and at 30-min intervals at night, using an ambulatory device, and physical activity was simultaneously evaluated at 1-min intervals by wrist actigraphy. Circadian parameters of blood pressure, heart rate and activity established by population multiple-components analysis were compared between dippers and non-dippers, by non-parametric testing. Diurnal and nocturnal means of blood pressure and activity were computed for each patient according to individual resting hours determined by actigraphy, and compared among groups by analysis of variance.

RESULTS

Despite highly statistically significant differences between dippers and non-dippers with respect to nocturnal means and in each hourly nightly mean of blood pressure, there were no differences between them for the same parameters during activity, whether or not the patients were receiving medication at the time of monitoring. The average duration of sleep and the 24-h mean and standard deviation of activity were also similar between the groups.

CONCLUSIONS

The highly significantly different circadian variation in blood pressure between dippers and non-dippers with essential hypertension is not related to a significant increase in nocturnal physical activity. Differences in blood pressure could, however, be related to the absence of 24-h therapeutic coverage in most non-dipper patients receiving antihypertensive medication.

[Blood pressure differences between consecutive days of ambulatory monitoring in hypertensive patients: the ABPM effect]

BACKGROUND

Ambulatory blood pressure monitoring is a method of blood pressure assessment that compensates for some of the limitations of office values. While a white-coat pressor effect on conventional determination has been defined and frequently used for the improved evaluation of hypertensive patients, there is no evidence that the ambulatory technique could also influence blood pressure.

PATIENTS AND METHOD

Aimed at testing and quantifying the extent and duration over time of a possible pressor effect due to ambulatory monitoring, we studied 387 mild-to-moderate hypertensive patients (160 men), aged 54.2 (14.3) (mean [SD]). Blood pressure and heart rate were measured at 20-min intervals during the day and at 30-min intervals at night for 48 consecutive hours, and physical activity was simultaneously evaluated at 1-min intervals by means of a wrist actigraph. One third of patients were evaluated twice or more times.

RESULTS

In hypertensive patients who were evaluated for the first time, results indicate a highly significant (p < 0.001) reduction, in the second day of monitoring as compared to the first, in the diurnal mean of systolic and diastolic blood pressure, but not in heart rate or physical activity. This pressor effect remains significant for at least the first 5 hours of monitoring. The nocturnal mean of blood pressure was, however, similar in the two days of sampling. This ambulatory monitoring effect could not be observed when patients were evaluated following the same sampling scheme at the second or further times.

CONCLUSIONS

Ambulatory monitoring for 48 consecutive hours reveals a statistically significant pressor response that could reflect a novelty effect in the use of the monitoring device for the first time. This effect has notable implications in both research and clinical daily practice, both for proper diagnosis of hypertension and evaluation of treatment efficacy.

Rescue of contractile parameters and myocyte hypertrophy in calsequestrin overexpressing myocardium by phospholamban ablation

Cardiac-specific overexpression of murine cardiac calsequestrin results in depressed cardiac contractile parameters, low Ca(2+)-induced Ca(2+) release from sarcoplasmic reticulum (SR) and cardiac hypertrophy in transgenic mice. To test the hypothesis that inhibition of phospholamban activity may rescue some of these phenotypic alterations, the calsequestrin overexpressing mice were cross-bred with phospholamban-knockout mice. Phospholamban ablation in calsequestrin overexpressing mice led to reversal of the depressed cardiac contractile parameters in Langendorff-perfused hearts or in vivo. This was associated with increases of SR Ca(2+) storage, assessed by caffeine-induced Na(+)-Ca(2+) exchanger currents. The inactivation time of the L-type Ca(2+) current (I(Ca)), which has an inverse correlation with Ca(2+)-induced SR Ca(2+) release, and the relation between the peak current density and half-inactivation time were also normalized, indicating a restoration in the ability of I(Ca) to trigger SR Ca(2+) release. The prolonged action potentials in calsequestrin overexpressing cardiomyocytes also reversed to normal upon phospholamban ablation. Furthermore, ablation of phospholamban restored the expression levels of atrial natriuretic factor and alpha-skeletal actin mRNA as well as ventricular myocyte size. These results indicate that attenuation of phospholamban function may prevent or overcome functional and remodeling defects in hypertrophied hearts.