Cardiac arrhythmias and left ventricular hypertrophy in dipper and nondipper patients with essential hypertension

Certain beta blockers (e.g., bisoprolol) may be reevaluated in hypertension guidelines for patients with left ventricular hypertrophy to diminish the ventricular arrhythmic risk

Hypertensive left ventricular hypertrophy (HTN LVH) is associated with almost threefold increased risk of ventricular tachycardia (VT)/ventricular fibrillation (VF). Furthermore, HTN LVH increases the risk of sudden cardiac death (SCD). The reverse LV remodeling due to efficient antihypertensive therapy lowers the incidence rates of cardiovascular events and SCD and the vast majority of available arterial hypertension (HTN) guidelines recommend renin angiotensin system (RAS) blockers and calcium channel blockers (CCBs) for HTN LVH aiming for LVH regression. On the other hand, beta blockers (BBs) as a class are not recommended in HTN LVH due to their insufficient capacity to reverse LVH remodeling even though they are recommended as the first-line drugs for prevention/treatment of VT/VF (in general, unrelated to HTN LVH). Moreover, BBs are the best antiarrhythmic (against VT/VF) among antihypertensive drugs. Despite that, BBs are currently not recommended for LVH treatment in HTN Guidelines. It is important to prevent VT/VF in patients at high risk, such as those with HTN LVH. Therefore, certain BBs (such as Bisoprolol) may be reevaluated in guidelines for HTN (in the section of HTN LVH).

Relationship between nocturnal blood pressure patterns and end organ damage and diastolic dysfunction in heart transplant recipients

BACKGROUND

We assessed the relationship between circadian blood pressure (BP) patterns and clinical outcomes in a contemporary cohort of adult heart transplant recipients.

METHODS

This retrospective, cross-sectional study included adult heart transplant recipients at least 6 months post-transplant. Ambulatory BP measurements were recorded over 24 hours. Nondippers were defined as a decline in average nighttime BP ≤ 10% compared with daytime. Primary outcomes were the presence of end organ damage, that is, microalbuminuria, chronic kidney disease, and/or left ventricular hypertrophy. Secondary outcomes were measures of diastolic dysfunction (ie, mitral valve deceleration time, e/e', E/A, and isovolumetric relaxation time), microalbumin/creatinine ratio, eGFR, interventricular septal thickness, and left ventricular posterior wall thickness.

RESULTS

Of 30 patients, 53.3% (n = 16) were systolic nondippers and 40% (n = 12) were diastolic nondippers. Diastolic nondippers had three times higher urine microalbumin/creatinine ratios than diastolic dippers (P = .03). Systolic nondippers had 16.3% lower mitral valve deceleration time (P = .05) than systolic dippers, while diastolic nondippers had 20.4% higher e/e' (P = .05) than diastolic dippers. There were no significant relationships between BP dipping status and any of the primary outcomes.

CONCLUSIONS

These data suggest that systolic and diastolic nondipping BP patterns are associated with subclinical kidney damage and diastolic dysfunction in heart transplant recipients.

Hypertension and Arrhythmias

Hypertension is the most common cardiovascular risk factor and underlies heart failure, coronary artery disease, stroke, and chronic kidney disease. Hypertensive heart disease can manifest as cardiac arrhythmias. Supraventricular and ventricular arrhythmias may occur in the hypertensive patients. Atrial fibrillation and hypertension contribute to an increased risk of stroke. Some antihypertensive drugs predispose to electrolyte abnormalities, which may result in atrial and ventricular arrhythmias. A multipronged strategy involving appropriate screening, aggressive lifestyle modifications, and optimal pharmacotherapy can result in improved blood pressure control and prevent the onset or delay progression of heart failure, coronary artery disease, and cardiac arrhythmias.

Hypertension and Atrial Fibrillation: Doubts and Certainties From Basic and Clinical Studies

Hypertension and atrial fibrillation (AF) are 2 important public health priorities. Their prevalence is increasing worldwide, and the 2 conditions often coexist in the same patient. Hypertension and AF are strikingly related to an excess risk of cardiovascular disease and death. Hypertension ultimately increases the risk of AF, and because of its high prevalence in the population, it accounts for more cases of AF than other risk factors. Among patients with established AF, hypertension is present in about 60% to 80% of individuals. Despite the well-known association between hypertension and AF, several pathogenetic mechanisms underlying the higher risk of AF in hypertensive patients are still incompletely known. From an epidemiological standpoint, it is unclear whether the increasing risk of AF with blood pressure (BP) is linear or threshold. It is uncertain whether an intensive control of BP or the use of specific antihypertensive drugs, such as those inhibiting the renin-angiotensin-aldosterone system, reduces the risk of subsequent AF in hypertensive patients in sinus rhythm. Finally, in spite of the observational evidence suggesting a progressive relation between BP levels and the risk of thromboembolism and bleeding in patients with hypertension and AF, the extent to which BP should be lowered in these patients, including those who undergo catheter ablation, remains uncertain. This article summarizes the main basic mechanisms through which hypertension is believed to promote AF. It also explores epidemiological data supporting an evolutionary pathway from hypertension to AF, including the emerging evidence favoring an intensive BP control or the use of drugs, which inhibit the renin-angiotensin-aldosterone system to reduce the risk of AF. Finally, it examines the impact of non-vitamin K antagonist oral anticoagulants compared with warfarin in relation to hypertension.

Hypertension and cardiac arrhythmias: a consensus document from the European Heart Rhythm Association (EHRA) and ESC Council on Hypertension, endorsed by the Heart Rhythm Society (HRS), Asia-Pacific Heart Rhythm Society (APHRS) and Sociedad Latinoamericana de Estimulación Cardíaca y Electrofisiología (SOLEACE)

Hypertension is a common cardiovascular risk factor leading to heart failure (HF), coronary artery disease, stroke, peripheral artery disease and chronic renal insufficiency. Hypertensive heart disease can manifest as many cardiac arrhythmias, most commonly being atrial fibrillation (AF). Both supraventricular and ventricular arrhythmias may occur in hypertensive patients, especially in those with left ventricular hypertrophy (LVH) or HF. Also, some of the antihypertensive drugs commonly used to reduce blood pressure, such as thiazide diuretics, may result in electrolyte abnormalities (e.g. hypokalaemia, hypomagnesemia), further contributing to arrhythmias, whereas effective control of blood pressure may prevent the development of the arrhythmias such as AF. In recognizing this close relationship between hypertension and arrhythmias, the European Heart Rhythm Association (EHRA) and the European Society of Cardiology (ESC) Council on Hypertension convened a Task Force, with representation from the Heart Rhythm Society (HRS), Asia-Pacific Heart Rhythm Society (APHRS), and Sociedad Latinoamericana de Estimulación Cardíaca y Electrofisiología (SOLEACE), with the remit to comprehensively review the available evidence to publish a joint consensus document on hypertension and cardiac arrhythmias, and to provide up-to-date consensus recommendations for use in clinical practice. The ultimate judgment regarding care of a particular patient must be made by the healthcare provider and the patient in light of all of the circumstances presented by that patient.

Ambulatory blood pressure results and heart rate variability in patients with premature ventricular contractions

BACKGROUND

The presence of premature ventricular contractions (PVCs) is a sign of arrhythmia and typically trigerred by over stimulation of the sympathetic nervous system. This study examined the relationships among PVCs, heart rate variability (HRV), and 24-hour ambulatory blood pressure (ABP) results.

METHODS

This observational clinical study evaluated a cohort of 100 consecutive patients (58 women and 42 men) with PVCs. The individuals were split into occasional (n = 50) and frequent (n = 50) PVCs groups. All Holter recordings were performed during a working day.

RESULTS

Daytime low-frequency power (LFP), daytime low frequency/high frequency (LF/HF), nighttime LFP, and nighttime LF/HF and 24-hour systolic blood pressure (SBP) were slightly higher in the frequent PVCs group (p = 0.046, p = 0.027, p = 0.038, p = 0.032, and p < 0.001, respectively). Hypertension, LF, LF/HF, 24-hour SBP were positively correlated with PVCs (r = 0.305, p = 0.002; r = 0.269, p = 0.007; r = 0.403, p < 0.001, respectively).

CONCLUSION

Frequent PVCs reflect dominance of the sympathetic system according to the results of Holter recordings. This study showed that PVC had a significant association with high blood pressure values. Assessment of ABP and HRV in patients with PVCs is part of a comprehensive approach to the assessment of cardiovascular regulation.

Low frequency of cardniac arrhythmias and lack of structural heart disease in medically-naïve acromegaly patients: a prospective study at baseline and after 1 year of somatostatin analogs treatment

BACKGROUND

The incidence of arrhythmias may be increased in acromegaly, but the pathophysiologic mechanisms involved are still unclear, and it has never been correlated with structural heart changes analyzed by the gold-standard method cardiac magnetic resonance (CMR).

AIM

Evaluate the frequency of arrhythmias in drug-naïve acromegaly patients at baseline and after 1 year of somatostatin analogs (SA) treatment and to correlate the occurrence of arrhythmias with the presence of structural heart changes.

PATIENTS AND METHODS

Consecutive drug-naïve acromegaly patients were recruited. The occurrence of arrhythmias and structural heart changes were studied through 24-h Holter and CMR, respectively, at baseline and after 1-year SA treatment.

RESULTS

Thirty-six patients were studied at baseline and 28 were re-evaluated after 1 year of SA treatment. There were 13 females and median age was 48 years (20-73 years). Nine patients (32 %) were controlled after treatment. No sustained arrhythmias were reported in the 24-h Holter. No arrhythmia-related symptoms were observed. Only two patients presented left ventricular hypertrophy and three patients presented fibrosis at baseline. There was no correlation of the left ventricular mass with the number of episodes of arrhythmias and they were not more prevalent in the patients presenting cardiac fibrosis.

CONCLUSION

We found no sustained arrhythmias and a lack of arrhythmia-related symptoms at baseline and after 1 year of SA treatment in a contemporary cohort of acromegaly patients that also present a low frequency of structural heart changes, indicating that these patients may have a lower frequency of heart disease than previously reported.

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.

Prognostic Significance of Neuroadrenergic Dysfunction for Cardiovascular Events in Patients With Acute Myocardial Infarction

BACKGROUND

The dysregulation of systemic blood pressure (BP) variation or cardiac neuroadrenergic dysfunction is associated with adverse cardiovascular events. We aimed to clarify the prognostic significance of neuroadrenergic dysfunction for cardiovascular events in patients with acute myocardial infarction (AMI).

METHODS AND RESULTS

We enrolled 63 AMI patients (mean age, 67±12 years) underwent ambulatory BP monitoring (ABPM) and cardiac iodine-(123)metaiodobenzylguanidine (MIBG) imaging within 4 weeks after AMI onset. We analyzed the circadian BP pattern and heart-to-mediastinum (H/M) MIBG uptake ratio. All the patients were followed for 2 years. The study endpoint was a composite of major adverse cardiovascular events, including all-cause death, MI, coronary revascularization except for the MI culprit lesion, and stroke. Patients with a non-dipper pattern (n=29) or an H/M ratio <1.96 (n=28) had a worse prognosis than those with either a dipper pattern (n=34) or an H/M ratio ≥1.96 (n=35; log-rank, P=0.013 and 0.010, respectively). Patients with both a non-dipper pattern and an H/M ratio <1.96 (n=12) had a significantly worse prognosis than did the other patients (P=0.0020).

CONCLUSIONS

Dysregulation of BP variation and cardiac MIBG uptake were associated with cardiovascular events following AMI. Examining ABPM with MIBG imaging may potentially improve risk stratification in these patients.

Circadian blood pressure pattern in sarcoidosis patients

OBJECTIVES

Autonomic dysfunction (AD) is frequent in sarcoidosis and considered a result of small fiber neuropathy. A non-dipper blood pressure (BP) pattern, which is also linked to AD, is associated with increased risk of cardiovascular and renal diseases. The aim of the present study was to evaluate the non-dipping BP pattern in normotensive patients with pulmonary sarcoidosis (PS).

METHODS

Sixty-three normotensive patients with PS (group 1) and 49 healthy subjects (group 2) were prospectively enrolled. Ambulatory BP monitoring was performed in all participants over a 24-h period.

RESULTS

The non-dipping BP pattern was significantly more frequent in patients with PS compared with the control group (80% vs 53%, respectively, p = 0.002). More advanced PS (grade 2) was an independent predictor of non-dipper BP pattern (odds ratio = 10.4, 95% confidence interval 1.1-95.4, p = 0.03). Masked hypertension and body mass index were also found to be other predictors of non-dipping BP pattern.

CONCLUSIONS

The present study showed that non-dipping BP pattern is frequently observed in normotensive patients with PS. The probable mechanism underlying the non-dipping BP in PS is autonomic nervous system dysfunction. PS represents an independent risk factor for non-dipping BP and these patients have increased cardiovascular risk.

Red blood cell distribution width in 'non-dippers' versus 'dippers'

OBJECTIVES

Because both high red cell distribution width (RDW) and non-dipping hypertension are closely related to adverse cardiovascular outcomes and higher inflammatory status, we aimed to investigate whether there is any relationship between RDW and dipping/non-dipping hypertension status.

METHODS

The present study involved 123 hypertensive patients and 65 age- and gender-matched healthy, normotensive subjects. Hypertensive patients were divided into two groups: 56 dipper patients (20 males, mean age 51.9 ± 15.3 years) and 67 non-dipper patients (27 males, mean age 55.6 ± 15.0 years). If the systolic daytime blood pressure (BP) of the patients decreased by at least 10% during the nighttime, these subjects were 'dippers', and all other subjects were 'non-dippers'.

RESULTS

Both dipper patients and non-dipper patients had higher levels of RDW compared to normotensives (13.5 ± 0.89 and 14.1 ± 1.33 vs. 13.0 ± 1.42%, p = 0.027 and p < 0.001, respectively). Also RDW values in non-dippers were statistically higher compared to those in dippers (p = 0.008). Although there were negative correlations between RDW values and nocturnal systolic BP fall (p = 0.027, r = -0.199) and diastolic BP fall (p = 0.383, r = -0.079) in all hypertensive patients, these correlations did not reach a statistically significant level.

CONCLUSION

Our study demonstrates that non-dippers have high RDW levels compared to both dippers and controls.

Determinants of inappropriate circadian blood pressure variability in children with essential hypertension

BACKGROUND

Inappropriate daily profile of blood pressure deteriorates the clinical outcome of hypertension and increases distant cardiovascular risk. The problem is important, especially in children and adolescents in whom early intervention helps to prevent complications of hypertension such as left ventricular hypertrophy and hypertensive retinopathy.

OBJECTIVES

To assess circadian blood pressure profile and basic determinants of inappropriate daily blood pressure variability in hypertensive children.

METHODS

The project was conducted retrospectively in 106 children six to 18 years of age (mean [+/- SD] 14.9+/-2.5 years) with essential hypertension and no use of antihypertensive drugs. The study group included 43 children with inappropriate daily blood pressure variability ('nondippers') and 63 controls with appropriate daily blood pressure variability ('dippers').

RESULTS

Nondippers, compared with dippers, had higher systolic and diastolic blood pressure at night (systolic, 123.9+/-10.3 mmHg versus 113.9+/-8.2 mmHg; diastolic, 65.1+/-7.6 mmHg versus 59.5+/-6.5 mmHg; P<0.0001), and higher blood pressure load at night (systolic, 61.9% versus 27.6%; diastolic, 20.0% versus 9.6%; P<0.0001). Male sex increased the risk for nondipping by 2.5 times (logistic OR=2.45; 95% CI 0.87 to 6.87). However, the increase was statistically nonsignificant (P=0.08). No differences were observed between dippers and nondippers in terms of anthropometric profile, family history of hypertension, morphological and biochemical blood parameters, and birth weight.

CONCLUSIONS

Among hypertensive children, nondippers have a more severe degree of hypertension. Male sex increases the risk of nondipping. To assess determinants of nondipping more precisely, further clinical investigations are needed.

Association of premature ventricular complexes with central aortic pressure indices and pulse wave velocity

BACKGROUND

Although premature ventricular complex (PVC) occurs frequently, its predisposing factors have rarely been studied. We examined the connection between PVC and aortic stiffness.

METHODS

We recruited 200 consecutive patients (< 50 years, 95 men, mean age 36 +/- 10 years) who received a 24-hour ambulatory electrocardiography examination for palpitation and PVC loads. Muscular artery pulse wave velocity (PWVm) and 4 main aortic pressure indices-augmented pressure, augmentation index (AI(x)), AI(x) corrected for a steady heart rate of 75 beat/min, and the extra workload-were measured, and atherosclerosis risk was evaluated.

RESULTS

Eighty-three (42%) patients had no PVC loads; 58 (29%) patients had low loads (< 24 beat/d), and 59 (29%) had high loads (> or = 24 beat/d). Only age and hyperlipidemia were significantly associated with PVC loads. Using a multivariate logistic regression model adjusted for potential confounders, we found that AI(x) (odds ratio [OR] 1.88, 95% CI 1.20-2.91, P = .005); augmented pressure (OR 1.57, 95% CI 1.02-2.43, P = .042); AI(x) corrected for a steady heart rate of 75 beat/min (OR 1.82, 95% CI 1.18-2.82, P = .007); and PWVm (OR 1.53, 95% CI 1.07-2.19, P = .021) were independent factors for PVC loads.

CONCLUSION

Increased central aortic pressure indices as well as PWVm were associated with increased PVC loads in young patients undergoing 24-hour ambulatory electrocardiography. Central aortic properties probably contributed to the occurrence of PVC.

Correlation between 24-hour profile of blood pressure and ventricular arrhythmias and their prognostic significance in patients with arterial hypertension

Background/Aim. Left ventricular hypertrophy (LVH), apart from arterial hypertension, is a risk factor for electrophysiologic heart condition disorder and sudden cardiac death. The aim of this study was to examine a relationship between complex ventricular arrhythmias and parameters of 24-hour ambulatory blood pressure monitoring in the patients with arterial hypertension and left ventricular hypertrophy (LVH), as well as their prognostic significance during a five-year follow-up. Methods. Ninety patients with arterial hypertension and LVH were included in this study (mean age 55.2?8.3 years). There were 35 healthy people in the control group (mean age 54.5?7.1 years). Left ventricular mass index was 171.9?32.4 g/m2 in the LVH group and 102.4?13.3 g/m2 in the control group. Clinical examination, echocardiogram, 24-hour ambulatory blood pressure monitoring and 24-hour holter monitoring were done in all of the examined persons. Ventricular arrhythmias were classified by the Lown classification. Results. In the LVH group there were 54 (60.0%) of the patients with ? III Lown class. The best predictor of a Lown class were left ventricular mass index by using multivariate stepwise regression analyses (? = 0.212; p < 0.05) and small decrease of diastolic blood pressure during the night (? = -0.293; p < 0.01). The main predictor of bad prognosis was left ventricular mass index during a five year follow-up (? = 0.302; p < 0.01, for stepwise regression model: F = 8.828; p < 0.01, adjusted R2 = 0.091). Conclusion. Left ventricular arrhythmias are frequent in patients with lower decrease of blood pressure during the night. There was no correlation between the degree of ventricular arrhythmias and parameters from 24-hour blood pressure monitoring and a five-year prognosis in the patients with arterial hypertension and LVH. A bad five-year follow-up outcome of hypertensive disease depends on left ventricular mass index.

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.

Abnormal blood pressure circadian rhythm: a target organ damage?

Blood pressure (BP) varies according to cycles characterized by a reduction during sleep and an increase on awakening. The nighttime decrease is absent or blunted in some patients (termed "non-dippers"). Cross-sectional and prospective data have shown that non-dippers have more target organ damage than have dippers in normotensive and hypertensive subjects. We reviewed the English language literature regarding this association. A non-fortuitous association seems to exist between non-dipper status and cardiovascular risk such as stroke and cardiac events. Among diabetic patients, this phenomenon has been described to occur more often in individuals with autonomic neuropathy and with different degrees of diabetic nephropathy. In normoalbuminuric normotensive type I diabetic patients without any degree of autonomic dysfunction, according to traditional cardiovascular tests, diastolic BP (dBP) night/day ratio is associated with an increased glomerular filtration rate and an increased extracellular volume. The disruption of the circadian rhythm of sympathovagal activity in non-dipper patients was associated with higher levels in systolic BP (sBP) and dBP and with a reduced decline in sBP and dBP levels during the night. Therefore, the prognostic implications of the non-dipper status may be important since the overall 24-h blood pressure load is elevated in these individuals. These data suggest that patients in whom blood pressure decreases during the night incur less damage to their brain, kidneys, heart, and blood vessels than people with elevated nocturnal BP.

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.

Increased Ambulatory Pulse Pressure Is a Strong Risk Factor for Coronary Endothelial Vasomotor Dysfunction

OBJECTIVES

This study was aimed to determine the relationship between pulse pressure (PP) and coronary vasomotor dysfunction, a predictor of coronary events.

BACKGROUND

Pulse pressure is a strong risk factor for coronary artery disease (CAD). However, the mechanisms by which an increase in PP affects the pathogenesis of CAD are unclear.

METHODS

Ambulatory blood pressure (BP) monitoring for 24 h was performed in 103 consecutive patients with normal coronary angiograms (51 hypertensive and 52 normotensive; age 42 to 70 years). The relationship between changes in coronary arterial diameter and blood flow during an intracoronary infusion of acetylcholine (ACh) (5, 10, 50 microg/min), and BP parameters, and other traditional risk factors was evaluated using univariate and multivariate linear regression analyses.

RESULTS

With multivariate analyses, the 24-h PP showed an inverse correlation with the epicardial coronary dilator response to ACh independently of other covariates including age, smoking, and 24-h systolic BP in normotensive as well as hypertensive patients. Furthermore, multivariate analysis showed that the 24-h PP was inversely and independently correlated with the increase in coronary blood flow in response to ACh. The dilator response of epicardial coronary arteries to nitrate was not significantly correlated with 24-h PP.

CONCLUSIONS

Increased 24-h PP is independently associated with endothelial vasomotor dysfunction in conduit and resistance coronary arteries irrespective of the presence of hypertension. Increased ambulatory PP may have an intimate relation to coronary endothelial vasomotor dysfunction.

Blunted Reduction of Pulse Pressure during Nighttime Is Associated with Left Ventricular Hypertrophy in Elderly Hypertensive Patients

Increased pulse pressure (PP) is recognized as a risk factor for cardiovascular disease, especially in elderly patients. However, blood pressure (BP) is known to have a circadian variation. Therefore, this study asked whether or not PP has a circadian variation and, if so, whether a circadian variation of PP has clinical importance. Ambulatory BP monitoring (every 30 min for 48 h) was performed in 255 patients with untreated essential hypertension (24 to 82 years old; mean: 52+/-12 years). Left ventricular mass index (LVMI) was estimated from M-mode echocardiography. PP was decreased during nighttime (10+/-11% reduction from daytime PP). Multivariate linear regression analysis showed that, among four variables-the degree of nighttime PP reduction, daytime PP, 48-h systolic BP, and nondipper hypertension-the degree of nighttime PP reduction had the strongest (inverse) correlation with LVMI in a subgroup of elderly patients (> or =60 years old, n =67) (standardized regression coefficient=-0.32, p =0.02), whereas this association was not significant in the whole patient population unclassified by age. Furthermore, a blunted reduction of nighttime PP in combination with nondipper hypertension was an incremental risk for increase in LVMI in the elderly patients. In conclusion, PP is reduced during nighttime, but the degree of reduction varies among patients. The blunted reduction of nighttime PP is a risk for left ventricular hypertrophy, an established predictor of hypertension-induced cardiovascular events, and it may thus play a role in cardiovascular complications, especially in elderly patients with nondipper hypertension.

Association between Altered Circadian Blood Pressure Profile and Cardiac End-Organ Damage in Patients with Renovascular Hypertension

BACKGROUND

Patients with renovascular hypertension (RVH) have a higher degree of cardiovascular end-organ damage compared to patients with essential hypertension (EH). The precise mechanisms underlying this phenomenon, however, have not been fully elucidated. This study investigated the relationship between circadian blood pressure (BP) profile and cardiac involvement in patients with RVH and EH.

METHODS

Twenty patients with RVH and 20 with EH, matched for demographic characteristics, underwent simultaneous 24-hour ambulatory BP recording and Holter ECG monitoring. Also, each participant underwent echocardiographic assessment of left ventricular mass. Cardiac damage was defined as the presence of left ventricular hypertrophy, myocardial ischemia or arrhythmias.

RESULTS

Casual BP was similar in both groups, whereas 24-hour ambulatory BP values were higher in RVH than in EH patients; moreover, RVH patients had higher blood pressure variability and blunted nocturnal BP fall compared to those with EH. Left ventricular mass, as well as the prevalence of myocardial ischemia and the presence and severity of cardiac arrhythmias, were higher in RVH than in EH patients.

CONCLUSIONS

Patients with RVH have altered circadian BP profile compared to those with EH. This abnormality might contribute to their increased prevalence of cardiac damage and might adversely affect the prognosis of these patients.

Twenty-four-hour ambulatory blood pressure monitoring in atrial fibrillation

BACKGROUND

Due to large beat-to-beat blood pressure variation the use of 24-h ambulatory blood pressure monitoring in patients with atrial fibrillation has been questioned.

METHODS

Repeatability and variability of 24-h ambulatory blood pressure (Accutraccer II or Diasys Integra), and daily blood pressure variation was examined in 42 patients aged 51-81 (median 73.5) years admitted for elective electrocardioversion of atrial fibrillation.

RESULTS

Before cardioversion 24-h ambulatory systolic blood pressure was slightly lower and nocturnal blood pressure reduction was larger in the group of patients who achieved sinus rhythm than in the group who maintained atrial fibrillation (11.5/10.5 versus 4.1/4.7 mmHg; P < 0.05). No statistically significant change was observed in ambulatory blood pressure after cardioversion in any of the two groups. Blood pressure variability (SD/mean) was 10-14% both in patients with and without conversion to sinus rhythm. Coefficient of repeatability (2 SD of difference) was 13.6 mmHg (16.6%) for diastolic blood pressure and 30.2 mmHg (24.7%) for systolic blood pressure in patients with normalized heart rhythm and 17.0 and 29.0 mmHg (21.5 and 22.4%) in patients with maintained atrial fibrillation, respectively.

CONCLUSION

Ambulatory blood pressure monitoring provides data with similar variability and repeatability in patients with atrial fibrillation as in subjects with normal cardiac rhythm. Twenty-four-hour ambulatory blood pressure measurement is applicable in atrial fibrillation in the same way as during sinus rhythm.