Left atrial size in 164 hypertensive patients: an echocardiographic and ambulatory blood pressure study

Blood Pressure Trajectories for 16 Years and the Development of Left Ventricular Hypertrophy and Increased Left Atrial Size: The Korean Genome and Epidemiology Study

Background

Elevated single blood pressure (BP) measurement can be associated with the development of hypertension-mediated target organ damage including left ventricular hypertrophy (LVH) and left atrial (LA) enlargement (LAE). However, long-term patterns of BP and their effects on LVH and LAE are poorly understood. We evaluated the association between the BP trajectories and the presence of LVH and LAE.

Methods

We analyzed a total of 2,565 participants (1,267 males, 47.8 ± 6.7 years old) from the first biennial examination (2001-2002) of the Korean Genome and Epidemiology Study. The presence of LVH and LAE was identified by echocardiography performed at the 8^th biennial examination (2015-2016). Latent mixture modeling was used to identify trajectories in mid-BP ((systolic BP + diastolic BP)/2) over time. Linear logistic regression was used for assessing BP trajectories with the outcomes.

Results

We identified 4 distinct mid-BP trajectories: group 1 (lowest, 20.9%, n = 536), group 2 (36.2%, n = 928), group 3 (32.3%, n = 828), and group 4 (highest, 10.6%, n = 273). Compared with the lowest group, trajectories with elevated mid-BP had greater odds ratios having LVH and LAE by multivariable-adjusted regression models. Adjusted odd ratios for LVH were 2.033 (95% CI = 1.462–2.827, P < 0.001) for group 2, 3.446 (95% CI = 2.475–4.797, P < 0.001) for group 3, and 4.940 (95% CI = 3.318–7.356, P < 0.001) for group 4. Adjusted odd ratios for LAE were 1.200 (95% CI = 0.814–1.769, P = 0.358) for group 2, 1.599 (95% CI = 1.084–2.360, P = 0.018) for group 3, and 1.944 (95% CI = 1.212–3.118, P = 0.006) for group 4.

Conclusions

Higher long-term mid-BP was an independent risk factor of cardiac structural changes such as LVH and LAE among middle-aged population.

Prevalence of echocardiographic left atrial enlargement among hypertensive Nigerian subjects

BACKGROUND

Left atrial enlargement (LAE) predispose to arrhythmias, atrial thrombogenesis and cardioembolic stroke. Whether LAE constitute a major risk among African hypertensive subjects is not well described. This study was aimed to describe the epidemiologic pattern of LAE among hypertensive subjects and determine their correlates.

METHODS

Clinical and demographic details of 414 hypertensive subjects used were taken. Echocardiography was done. LAE was defined as Left atrial dimension (LAD)>3.7 cm. Statistical analysis was done using SPSS 17.0.

RESULT

414 subjects including 258 (62.3%) males were recruited. The mean age was 56.8±16.8 years. LAE was present in 57.73% of hypertensive subjects. Those with LAE were likely to be older (58.23±14.5 vs. 54.8 ±19.7 years, p<0.05), had a higher waist circumference (88.1 ±26.8 ±75.8 ±28.4 cm, p<0.05), left ventricular mass index (79.2 ± 12.4 vs. 48.7 ±15.5g/m2.7, p<0.05) and a higher frequency of left ventricular hypertrophy (LVH) (65.3% vs. 40.0 %, p<0.05) respectively than those without LAE. LAD was significantly higher among those with LVH than those without LVH (41.4 ±8.4 vs. 35.6 ±5.9 mm respectively, p<0.05).

CONCLUSION

LAE is common among Nigerian hypertensive subjects. Age, waist circumference, left ventricular wall dimension and mass index are the important correlates of LAE in hypertensive Nigerians.

Effects of body mass index and gender on left atrial size in Chinese hypertensive patients

BACKGROUND

Left atrial enlargement (LAE) is a common cardiac structural change in patients with hypertension, and obesity could further promote LAE. However, little is known about the effect of overweight on left atrial size, and if there is a gender difference of the effect. The aim of this study was to analyze the effects of different body mass index (BMI) grades (normal weight, overweight, and obesity) on left atrial size in both male and female patients with hypertension.

METHODS

A total of 710 patients with hypertension were divided into 3 study groups: normal weight group (BMI < 24 g/m², n = 302), overweight group (24 kg/m² ≤ BMI < 28 kg², n = 318), and obesity group (BMI ≥28 kg/m², n = 90). The clinical data, echocardiographic indexes and left atrial size were obtained from all the subjects. Pearson correlation analysis was used to analyze the correlation between clinical variables and left atrial diameter (LAD)/left atrial diameter index (LADI), and stepwise regression evaluation was used to study the relevant factors affecting LAD/LADI among all patients, male and female patients for possible gender difference.

RESULTS

The significant difference in LADI was noted in the three study groups with obesity group of 23.96 ± 2.90 mm/m, overweight group of 22.50 ± 3.02 mm/m and normal weight group of 21.08 ± 2.80 mm/m, respectively (P < . 05). After adjusting for age and gender, there was still significant difference in LADI among the three groups (P < . 05). The correlation between BMI and LADI was higher than that between systolic blood pressure (SBP) and diastolic blood pressure (DBP) (r = 0.348 vs 0.092 and -0.068, respectively, P < .05). After adjusting for other influencing factors, there was still a significant correlation between BMI and LADI (β = 0.326, P < .001), but no correlation was found between SBP and DBP (P > .05). For each additional unit of BMI, LAD increased by 0.034 mm and LADI increased by 0.305 mm/m. Multiple linear regression analysis showed that BMI, left ventricular mass index (LVMI), age and female gender were independently correlated with LADI (P < .05). And BMI was the most significant influencing factor of LADI in male patients (β = 0.350, P < .001), followed by LVMI (β = 0.343, P < .001). While in female patients, LVMI was the most significant (β = 0.353, P < .001), followed by BMI (β = 0.302, P < .001).

CONCLUSION

Overweight and obesity were significantly associated with LAE in hypertensive patients, with obesity more significant than overweight. While BMI had the greatest correlation with LAE in male, LVMI was the most important determinant of LAE in female. Therefore, in addition to weight loss, more attention should be paid to early inhibition of left ventricular remodeling in female with hypertension.

Platelets Promote Ang II (Angiotensin II)-Induced Atrial Fibrillation by Releasing TGF-β1 (Transforming Growth Factor-β1) and Interacting With Fibroblasts

Hypertension is a risk factor of atrial fibrillation (AF), and a certain number of patients with hypertension were found with an enlarged left atrium. Platelet activation is found in patients with hypertension or pressure overload/Ang II (angiotensin II)-induced hypertensive animal models and contribute to ventricular fibrosis. Whether hypertension-induced atrial fibrosis is mediated by platelets remains unknown. Our previous experimental data showed that platelet-derived TGF-β1 (transforming growth factor-β1) was reduced in patients with hypertensive AF. The present study is to investigate whether platelet-derived TGF-β1 promotes Ang II-induced atrial fibrosis and AF. Platelet activation and atrial platelet accumulation were measured in sinus rhythm controls, normotensive AF, and patients with hypertensive AF. Ang II (1500 ng/kg per minute, 3 weeks) infused mice with pharmacological (clopidogrel) and genetic platelet inhibition (TGF-β1 deletion in platelets) were used. Platelet activation, atrial structural remodeling, atrial electrical transmission, AF inducibility, inflammation, and fibrosis were measured in mice. We found that circulating platelets were activated in patients with hypertensive AF. A large amount of platelet was accumulated in the atriums of patients with hypertensive AF. Both clopidogrel treatment and platelet-specific deletion of TGF-β1 attenuated Ang II-induced structural remodeling, atrial electrical transmission, AF inducibility, as well as atrial inflammation and fibrosis than mice without interventions. Furthermore, clopidogrel blocked atrial platelet accumulation and platelet-fibroblast conjugation. Platelets promoted atrial fibroblast differentiation in cell culture. Profibrotic actions of platelets are largely via activation of atrial fibroblasts by releasing TGF-β1 and inducing platelet-fibroblast conjugation, and platelet inhibition is sufficient to inhibit atrial fibrosis and AF inducibility.

Strain Echocardiography and Myocardial Mechanics: From Basics to Clinical Applications

The aim of this review is to summarize the recent developments in strain imaging, an evolving technique – from tissue Doppler to 3D echocardiography – for resolving the complex left ventricular mechanics. Following a brief overview of the different used technique to extract myocardial deformation data, the authors summarize the role of the technique in the assessment of cardiac mechanics and its role in the clinical arena.

Atrial fibrillation in essential hypertension: an issue of concern

Many clinical studies indicate that atrial fibrillation is closely related to hypertension. Atrial fibrillation is not only associated with the level of blood pressure (BP) but also with the circadian rhythms of BP. However, the underlying mechanisms of atrial fibrillation in essential hypertension patients remain largely unknown. Hypertension may facilitate the onset and persistence of atrial fibrillation by stretch-induced changes in the repolarization of atrial myocytes (triggers of atrial fibrillation) and atrial remodeling (structural and electrical remodeling). Importantly, the effects of hypertension on atrial fibrillation are progressive. These progressive anatomic, functional, electrophysiological and structural changes occur at different times. This characterization of the time course of atrial changes presents an intervention window before remodeling progresses to changes that are difficult to reverse. Given that the medium to long-term efficacy of antiarrhythmic drugs has proved poor, it is essential to seek new therapies to prevent the onset of atrial fibrillation and to effectively control recurrences of atrial fibrillation. The study of nonantiarrhythmic drugs that act on the atrial remodeling that constitutes the substrate of the arrhythmia is a new and very interesting field of research. Treatment with angiotensin-converting enzyme inhibitors angiotension-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) seems more promising. However, from recent trials, only hypertension with structural heart disease, left ventricular dysfunction and left ventricular hypertrophy benefit from ACEIs and ARBs. This article reviews many aspects of atrial fibrillatio in essential hypertension patients to provide the foundation of atrial fibrillatio treatment.

The early stage of the atrial electroanatomic remodeling as substrates for atrial fibrillation in hypertensive patients

BACKGROUND

Hypertension is one of the most important risk factors for atrial fibrillation (AF). Recent studies suggest right atrial remodeling in hypertensive patients may be associated with increased inducibility of AF. This study sought to characterize the electroanatomic features of left and right atria and pulmonary veins (PVs) in hypertensive patients.

METHODS AND RESULTS

A prospective observational study was conducted on patients who underwent ablation for paroxysmal supraventricular tachycardia or paroxysmal AF. Electrophysiological features of the PVs and atria, including event-related potentials, conduction time, and inducibility and vulnerability of AF, were characterized during cardiac catheterization. Anatomic and hemodynamic features were assessed by using echocardiographic and computer tomography imaging. When 15 hypertensive patients with paroxysmal supraventricular tachycardia were compared with 17 normotensive patients with paroxysmal supraventricular tachycardia, the hypertensive patients had significantly shortened PV event-related potentials with increased dispersions (P<0.001) but slightly prolonged atrial event-related potentials (P=NS) and had prolonged interatrial and intra-atrial conduction times (P<0.001). Additionally, the hypertensive patients had increased vulnerability and inducibility of AF and prolonged duration of induced AF (P<0.01). All of these changes were more pronounced in hypertensive patients with paroxysmal AF. Anatomically, compared with the normotensive patients, the diameters of 4 PVs in the hypertensive patients with paroxysmal supraventricular tachycardia were significantly enlarged (P<0.01) and became more remarkable in hypertensive patients with paroxysmal AF (P<0.0001), although the diameter and volume index of the left atrium among 3 groups were similar.

CONCLUSIONS

The hypertensive patients showed electroanatomic changes associated with increased vulnerability to AF, including shortened event-related potentials with increased dispersion, prolonged conduction time, and increased PV diameter, but these changes were not appreciated in the atria. Additionally, these changes became more dramatic in hypertensive patients with paroxysmal AF.

Increased pulse pressure is associated with left atrial enlargement in resistant hypertensive patients

Resistant hypertension (RH) is frequently associated with a high prevalence of target organ damage, which impairs the prognosis of these patients. Considering cardiac alterations in RH, most attention has been devoted to left ventricular hypertrophy (LVH), but data concerning left atrial enlargement (LAE) is less known. This cross-sectional study assessed the factors associated with LAE, with special focus on blood pressure (BP) estimates obtained by ambulatory blood pressure monitoring (ABPM), in 250 patients with RH, aged 64 ± 11 years. LAE and LVH were observed in 10.0% (95% CI 6.3-13.7) and 57.1% (95% CI 50.8-63.5) of patients, respectively. Compared with patients with normal atrium size, those exhibiting LAE were older, more frequently women, had elevated pulse pressure (PP) measured both at the office and by ABPM, and showed higher prevalence of LVH (83% vs 54%; p = 0.016). In a logistic regression analysis, adjusting for age, gender, body mass index, left ventricular mass index and BP pressure estimates, night-time PP was independently associated with LAE (OR for 5 mmHg = 1.28, 95% CI 1.24-1.32; p = 0.001). In conclusion, besides classical determinants of LAE, such as age and LVH, an elevated night-time PP was independently associated with LAE in patients with RH.

Echocardiographic indices of left ventricular hypertrophy and diastolic function in hypertensive patients with preserved LVEF classified as dippers and non-dippers

INTRODUCTION

Long-lasting arterial hypertension causes left ventricular hypertrophy (LVH) and impairs left ventricular diastolic function. Our aim was to compare echocardiographic parameters between hypertensive patients defined as dippers and non-dippers during ambulatory blood pressure (BP) monitoring.

MATERIAL AND METHODS

We analysed 61 consecutive subjects with treated hypertension undergoing 24-h BP monitoring and transthoracic echocardiographic examination and included in the study patients with preserved left ventricular ejection fraction (EF ≥ 50%). Echocardiographic and arterial pressure parameters were compared between the group classified as dippers (n = 26, 57 ±13 years, 16 males) and non-dippers (n = 35, 60 ±12 years, 24 males) according to present or absent decrease of BP during the night > 10%. Echocardiographic data were compared between both groups and control subjects without hypertension.

RESULTS

Dippers had lower average systolic, diastolic and mean arterial pressure during the night hours but did not differ according to the mean pressure calculated from a 24-hour period. All echocardiographic parameters were similar in dippers and non-dippers. All patients with arterial hypertension presented with larger dimension of both ventricles and left atrium, thicker left ventricular walls, higher LV mass and mass index and preserved EF and E/A ratio as compared with normotensive controls. Normal geometry, concentric remodelling and eccentric hypertrophy were similarly distributed in both groups. Concentric hypertrophy was more prevalent in non-dippers as compared to the dippers (71.4% vs. 38.5%, p < 0.043).

CONCLUSIONS

The concentric type of LVH is the prevalent pattern in non-dippers. Non-dipping blood pressure pattern may be responsible for the development of left ventricular concentric hypertrophy secondary to hypertension.

Prevalence of echocardiographic left-atrial enlargement in hypertension: a systematic review of recent clinical studies

BACKGROUND

Left atrial enlargement (LAE) is a marker of hypertensive heart disease associated with increased cardiovascular risk. We reviewed recent literature about the prevalence of LAE, as assessed by echocardiography, to update our information about the clinical relevance of this cardiac phenotype in human hypertension.

METHODS

We performed a search of MEDLINE using the key words "left atrial enlargement," "left atrial dilatation," "left atrial size," "hypertension," "echocardiography," and "atrial fibrillation" to identify relevant papers. We considered full articles published in English from January 1, 2000 to July 1, 2012 reporting studies involving adult individuals.

RESULTS

We analyzed a total of 15 studies, including 10,141 untreated and treated subjects. LAE was defined according to 11 different criteria (4 studies applied two or three criteria), and its prevalence consistently varied among studies, from 16.0-83.0%, with a prevalence in the pooled population of 32%. A gender-based analysis of 9 studies (8,588 patients) showed the prevalence of LAE as being similar in women and men (OR, 1.23; 95% CI, 0.83-1.83; P = 0.30). Data provided by 10 studies (n = 9,354 patients) showed the prevalence of left-ventricular hypertrophy as being significantly higher in patients with LAE (68.2%) than in their counterparts without LAE (41.8%) (OR, 2.97; 95% CI, 2.68-3.29; P < 0.01).

CONCLUSIONS

Our analysis shows that LAE is present in a relevant fraction of the hypertensive population. Because LAE is an independent predictor of cardiovascular events, the accurate detection of this phenotype may improve the evaluation of risk in hypertensive patients.

WITHDRAWN: Left atrial function and arterial hypertension

Left atrial enlargement is frequently observed in many cardiac diseases. One of the main determinants of left atrial size is ventricular diastolic function. It has recently been suggested that left atrial volume might be the morphophysiologic expression of long-term modifications induced by diastolic function. Furthermore, left ventricular remodelling, such as it happens in hypertensive patients, is another important determinant of atrial volume. All the volumetric modifications of the left atrium, during cardiac cycle, are involved in hypertensive damage. Therefore, left atrial function impairment represents the result of morphological and haemodynamic alterations observed in hypertension. Actually, many techniques, invasive and non-invasive, are available with the purpose to investigate the real atrial dimensions and provide a suitable assessment of atrial function. Recently, it has been demonstrated that the degree of left atrial enlargement is associated with adverse prognosis in different clinical setting. The predictive value of left atrial volume seems to be independent of left ventricular systolic and diastolic function, but the use of left atrial volume for risk stratification is yet an evolving science: more data are required with respect to the natural history of left atrial remodelling in disease, the degree of left atrial modifiability with therapy and whether regression of left atrial size translates into improved cardiovascular outcome.Journal of Human Hypertension advance online publication, 14 August 2008; doi:10.1038/jhh.2008.96.

Noninvasive assessment of left atrial function by strain rate imaging in patients with hypertension: a possible beneficial effect of renin-angiotensin system inhibition on left atrial function

Renin-angiotensin system (RAS) inhibitors are likely to reduce the development of atrial fibrillation by preventing atrial fibrosis. Strain rate (SR) imaging is a novel echocardiographic technique to quantify left atrial (LA) function. However, it has not been determined whether SR imaging is applicable for detection of LA dysfunction in hypertensive (HT) patients. We used SR imaging to assess alteration in LA function in HT patients and its modification by RAS inhibitors. SR imaging was performed in 80 HT patients and 50 age-matched normotensive (NT) subjects. HT patients were divided into two groups according to left ventricular hypertrophy (LVH) and LA dilatation. Peak SR was measured at each LA segment (septal, lateral, posterior, anterior, and inferior) and mean peak systolic SR (SR-LAs) was calculated by averaging data in each segment. Mean SR-LAs levels in the dilated LA group (1.97+/-0.45 s(-1), n=25) and non-dilated LA group (2.15+/-0.57 s(-1), n=55) were significantly (p<0.05) lower than that in NT subjects (2.53+/-0.71 s(-1)). Irrespective of the presence or absence of LVH, mean SR-LAs in HT patients was lower than that in NT subjects. When RAS inhibitors were used, the mean SR-LAs level in the non-dilated LA group was equivalent to that in NT subjects. In HT patients, mean SR-LAs, an index of LA reservoir function, decreases before development of LA enlargement and LVH. Treatment with RAS inhibitors appears to preserve LA reservoir function in HT patients without dilated LA. SR imaging can detect LA dysfunction in HT patients and is useful for evaluation of the therapeutic benefit on LA reservoir function.

Ambulatory blood pressure, target organ damage and left atrial size in never-treated essential hypertensive individuals

OBJECTIVE

To investigate the relationship between ambulatory blood pressure and different markers of target organ damage with left atrial size in never-treated essential hypertensive individuals.

METHODS

A total of 519 grade 1 and 2 hypertensive patients (mean age 46 +/- 12 years), referred for the first time to our outpatient clinic, underwent routine examinations: 24-h urine collection for microalbuminuria, ambulatory blood pressure monitoring over two 24-h periods in 4 weeks, echocardiography and carotid ultrasonography.

RESULTS

Left atrial diameter was increased in 17.3% of patients. No significant differences were found between subjects with and without increased left atrial size with regard to sex, duration of hypertension, clinic and mean 48-h ambulatory blood pressure, and daytime and night-time values. Compared with 429 patients with normal left atrial size, the 90 patients with enlarged left atria were older, had higher body mass index, were more frequently smokers, and included more individuals with the metabolic syndrome. The prevalence of left ventricular hypertrophy, of intima-media thickening, but not of microalbuminuria was significantly higher in subjects with increased left atrial size.

CONCLUSION

Left atrial enlargement is not an early echocardiographic finding in relatively young never-treated hypertensive individuals, as its prevalence is lower than that of well-validated markers of target organ damage, and it is unrelated to ambulatory blood pressure. Overweight, left ventricular hypertrophy, carotid intima-media thickening and metabolic syndrome are independent predictors of left atrial dimension, suggesting that changes in left atrial size represent an adaptive response when high blood pressure is associated with other cardiovascular or metabolic abnormalities.

Early cardiac morphologic and functional changes in neurofibromatosis type 1 hypertensives: an echocardiographic and tissue Doppler study

BACKGROUND

Hypertension is frequently associated with neurofibromatosis type 1 (NF1), a common inherited disease that limits life expectancy. No data are available on cardiac damage in NF1 patients with hypertension. We evaluated cardiac function in NF1 patients with hypertension diagnosed by 24-h ambulatory blood pressure monitoring (ABPM), compared with normal children.

METHODS

We studied 73 NF1 patients (41 boys; mean age 12 years) and 30 normal children comparable for age and sex, using standard 2D echocardiography, standard Doppler and Doppler tissue imaging (DTI). Twelve patients (16%) showed 24-h systolic blood pressure (SBP) or 24-h diastolic blood pressure (DBP) >95th percentile for age and sex. We divided the NF1 group into two subgroups: group A, patients with 24-h SBP and DBP </=95th percentile for age and sex, and group B, patients with 24-h SBP or DBP >95th percentile for age and sex.

RESULTS

Group B presented a thicker end-diastolic interventricular septum (p<0.0001), posterior wall (p=0.02), LVMI (p<0.001) and relative wall thickness (p<0.03) than group A and controls. Left atrial dimension in group B was also significantly larger. Examination by standard Doppler showed a deceleration and isovolumic relaxation time significantly prolonged in group B. DTI parameters were significantly higher in NF1 patients than controls. In group B, myocardial early diastolic (E(m)) and systolic (S(m)) velocities were significantly lower than group A. Myocardial early/late diastolic ratio (E(m)/A(m)) in NF1 patients was lower than controls and 19% of group A and 20% of group B showed an E(m)/A(m) ratio <1. No healthy subjects presented an E(m)/A(m) ratio <1.

CONCLUSIONS

We demonstrated early cardiac morphologic and functional changes in young NF1 patients with hypertension. Because DTI directly studies cardiac muscle, it can detect changes induced by hypertension as well as those independent of blood pressure.

Relationship between left ventricular geometry and left atrial size and function in patients with systemic hypertension

BACKGROUND

Arterial hypertension determines distinct adaptive left ventricular geometric responses, which may differently affect left ventricular function and left atrial performance.

OBJECTIVES

In this study, the effect of left ventricular geometry on left atrial size and function, and the relationship between left atrial size and left ventricular mass were assessed in 336 patients with systemic arterial hypertension who had undergone Doppler echocardiography.

METHODS AND RESULTS

Patients were classified into concentric (110 patients with concentric left ventricular geometry defined as relative wall thickness > or = 0.44) and eccentric groups (226 patients with relative wall thickness < 0.44). Comparison to the latter, the former had greater left atrial size, left atrial ejection force, left ventricular mass and lower left ventricular midwall fractional shortening. Left ventricular concentric, rather than eccentric, geometry emerged by multivariate analysis as a factor independently associated with the highest degree of left atrial ejection force. Left atrial size was positively related to left ventricular mass in the whole population (r = 0.65, SEE = 6 ml, P < 0.00001). This relationship was maintained in the subgroups with concentric (r = 0.65, SEE = 6 ml, P < 0.00001) or eccentric geometry (r = 0.59, SEE = 6 ml, P < 0.00001).

CONCLUSIONS

Our results indicate that the relationship of left ventricular geometry to both left atrial size and ejection force in hypertensive patients is relevant. Concentric left ventricular geometry is associated with greater left atrial size and ejection force than eccentric geometry, suggesting that increased left ventricular stiffness has a greater effect in stimulating left atrial performance than left ventricular end-systolic stress. The degree of left atrial enlargement similarly depends on left ventricular mass in patients with concentric and eccentric geometry.

Cardiac remodeling in systemic hypertension

Experimental and clinical studies provide evidence that hypertension is causally related to adverse cardiac structural changes, such as LA enlargement, LV hypertrophy and myocardial fibrosis, and functional changes inclusive of LV systolic and diastolic dysfunction. These changes are induced by both hemodynamic and nonhemodynamic factors. There is accumulating evidence from several small and large clinical trials that various classes of antihypertensive therapy prevent and regress LVH and myocardial fibrosis. Prevention and reversal of LVH are associated with an improvement in cardiac function and with a decline in risk of adverse cardiovascular outcomes. Prevention of LVH should be a priority in subjects with hypertension. In patients with hypertensive heart disease, the components of therapy must comprise optimization of BP and regression of LVH. Future targets of therapy in hypertensive heart disease may include regression of myocardial fibrosis, normalization of LA size, and improvement in LV diastolic function.

Atrial fibrillation: hypertension as a causative agent, risk factor for complications, and potential therapeutic target

Atrial fibrillation and hypertension are 2 prevalent, and often coexistent, conditions in the North American population. Their incidence increases with advancing age, and they are responsible for considerable morbidity and mortality. Although the relation between the 2 conditions has long been known, the treatment of hypertension is not currently a focus in the clinical management of atrial fibrillation. Hypertension is associated with left ventricular hypertrophy, impaired ventricular filling, left atrial enlargement, and slowing of atrial conduction velocity. These changes in cardiac structure and physiology favor the development of atrial fibrillation, and they increase the risk of thromboembolic complications. Conventional therapy of atrial fibrillation has focused on interventions to control heart rate and rhythm and the prevention of stroke through the use of anticoagulant medications. In patients with atrial fibrillation, aggressive treatment of hypertension may reverse the structural changes in the heart, reduce thromboembolic complications, and retard or prevent the occurrence of atrial fibrillation. Specific pharmacotherapy could potentially play a major role in the primary and secondary prevention of atrial fibrillation and its complications.

Determinants of left atrial size in patients with newly diagnosed untreated hypertension

The present study determined the relationships between ambulatory blood pressure, left ventricular mass, body mass index, and other clinical and demographic variables to left atrial size in previously untreated hypertensive and normotensive subjects. Left atrial size was measured uni-dimensionally using M-mode echocardiography in 58 newly diagnosed never-treated hypertensive patients (office blood pressure 149/96 +/- 15/7 mmHg) and 28 normotensive control subjects (office blood pressure, 122/78 +/- 8/8 mmHg). Left ventricular mass, septal and posterior wall thickness were significantly increased in hypertensive compared to normotensive subjects (230 +/- 63 g versus 181 +/- 45 g, 1.1 +/- 0.2 cm versus 0.94 +/- 0.2 cm, and 1.04 +/- 0.2 cm versus 0.92 +/- 0.2 cm respectively; all p < 0.001). Left ventricular internal diameter (4.9 +/- 0.6 versus 4.8 +/- 0.4 cm, = 0.54) and left atrial size (3.74 +/- 0.48 versus 3.70 +/- 0.34 cm, p = 0.86) were not different between the two groups respectively. Body mass index, weight, left ventricular mass, wall thickness, and 24-h pulse pressure were significant correlates of left atrial size in the entire group and in the hypertensive subgroup. In the normotensive subgroup, body weight, body mass index, 24-h systolic and pulse pressure, and left ventricular mass were significant correlates. Multiple regression analyses in the entire group and the hypertensive subgroup alone showed that body mass index and left ventricular mass were the two best predictors of left atrial dimension. These data demonstrate that body mass index and left ventricular mass were the main correlates of left atrial size in patients with previously untreated stage I-II hypertension.