Evolution of Left Atrial Systolic and Diastolic Functions in Different Stages of Hypertension: Distinct Effects of Blood Pressure Control

Ultrasonography to detect cardiovascular damage in children with essential hypertension

Background

Essential hypertension in adults may begin in childhood. The damages to the heart and blood vessels in children with essential hypertension are hidden and difficult to detect. We noninvasively examined changes in cardiovascular structure and function in children with hypertension at early stage using ultrasonography.

Methods

All patients with essential hypertension admitted from March 2020 to May 2021 were classified into simple hypertension (group 1, n = 34) and hypertension co-existing with obesity (group 2, n = 11) isolation. Meanwhile 32 healthy children were detected as control heathly group (group 3). We used pulse-wave Doppler to measure carotid–femoral pulse wave velocity (cfPWV), intimal–medial thickness (cIMT) and distensibility of carotid artery (CD). Cardiac structure and function (left atrial diameter [LAD], left ventricular mass [LVM], LVM index [LVMI], relative wall thicknes [RWT], end-diastolic left ventricular internal diameter [LVIDd], diastolic interventricular septum thickness [IVSd], diastolic left ventricular posterior wall thickness [LVPWd], root diameter of aorta [AO], E peak, A peak, E' peak, A' peak, E/E' ratio, and E/A ratio) were measured by echocardiography.

Results

The cfPWV of children in group 1 and group 2 were significantly higher than healthy children in group 3. Significant differences were observed in LVM, LVMI, RWT, LVIDd, IVSd, LVPWd, LAD, A peak, E' peak, A' peak, and E/E’ among three groups.

Conclusion

Children and adolescents with essential hypertension demonstrate target organ damages in the heart and blood vessels.

Asymmetrical left atrial remodelling in atrial fibrillation: relation with diastolic dysfunction and long-term ablation outcomes

Aims

The association between anatomical left atrial (LA) remodelling and ventricular diastolic dysfunction (DD) in atrial fibrillation (AF) patients is not well studied. We aimed to examine the effect of DD on anatomic LA remodelling and their relation with ablation outcomes.

Methods and results

In 104 patients (58 ± 10 years, 69% male) referred for AF ablation, LA volume (LAV) was determined by computed tomography. A cutting plane, between the pulmonary vein (PV) ostia and the appendage and parallel to the posterior wall, divided LAV into anterior- (LA-A) and posterior-LA parts. The ratio of LA-A and LAV was defined as the LA asymmetry index (ASI). According to the current guidelines, the presence of DD was evaluated by echocardiography. Regression analysis was used to identify predictors of asymmetry changes and long-term success. Univariate linear regression revealed that ASI is associated with LAV, the presence of DD, and mitral regurgitation. Asymmetry index was higher in patients with DD (n = 35, 62 ± 5 vs. 59 ± 6%, P = 0.013) or mitral regurgitation (n = 67, 61 ± 6 vs. 58 ± 5%, P = 0.025). Multiple linear regression analysis showed that DD (B = 2.6, β = 0.207, 95% confidence interval, CI: 0.167-5.011, P = 0.036) and LAV (B = 0.037, β = 0.211, 95% CI: 0.003-0.071, P = 0.033) were the only factors independently associated with ASI (adjusted r2 = 0.92, F = 6.2, P = 0.003). Regression analysis showed that AF recurrence (33% after 24 months) is associated with asymmetric LA changes, while DD is not.

Conclusions

Left atrial symmetry changes are associated with DD and dilatation. Since DD could cause LA remodelling, appropriate early treatment should be considered for AF patients with DD, before geometrical changes occur.

Renin-angiotensin system inhibitors prevent the recurrence of atrial fibrillation: a meta-analysis of randomized controlled trials

OBJECTIVE

This study was designed to assess whether angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) could prevent the recurrence of atrial fibrillation (AF).

METHODS

A systemic literature search of PubMed, EMBASE, and Cochrane Controlled Trials Register till 2012 was performed to identify randomized controlled trials involving the prevention of recurrence of AF with renin-angiotensin system blockade therapy. Subgroup analysis and meta-regression were performed. Publication bias was checked through funnel plot and Egger's test.

RESULTS

Twenty-one randomized controlled trials including 13,184 patients with AF were identified. Overall, the recurrence of AF was significantly reduced in patients using ACEI/ARBs [odds ratio (OR), 0.43; 95% confidence interval (CI), 0.32-0.56; P < 0.00001], especially both in irbesartan subgroup (OR, 0.38; 95% CI, 0.21-0.68; P = 0.001) and in patients receiving antiarrhythmic drug (AAD) (OR, 0.37; 95% CI, 0.29-0.48; P < 0.00001), and there was no significant difference between ACEIs and ARBs (ACEIs: OR, 0.42; 95% CI, 0.31-0.57 and ARBs: OR, 0.42; 95% CI, 0.31-0.57). Moreover, it was found that the benefits of ACEI/ARBs revealed positive correlation to systolic blood pressure (regression coefficient: -0.0700257, P = 0.000) in no-AAD users.

CONCLUSIONS

ACEI/ARBs are effective on the secondary prevention of AF, especially in patients receiving AAD and suffering from hypertension.

Evolving strategies for the use of spironolactone in cardiovascular disease

The evolution of strategies for the use of spironolactone and its analogue, eplerenone, has, over the years, encompassed favourable modification of the natural history of symptomatic heart failure in subjects with subnormal left ventricular ejection fraction (LVEF), and mitigation of the risk of new-onset atrial fibrillation in mildly symptomatic systolic heart failure. Given the fact that these benefits might be attributable, at least in part, to mitigation of severity of diastolic dysfunction when the latter co-exists with subnormal LVEF, what needs to be explored is the possibility of similar benefits from the use of these agents in patients such as those with hypertension, and aortic valve stenosis, in whom left ventricular dysfunction is of the predominantly diastolic subtype.

A functional variant in the promoter region regulates the C-reactive protein gene and is a potential candidate for increased risk of atrial fibrillation

OBJECTIVES

In a large population-based cohort, the level of C-reactive protein (CRP) in patients at baseline predicts an increased risk of future development of atrial fibrillation (AF). The mechanism of this increased risk is unknown. Furthermore, both the molecular effects of CRP on atrial myocytes and fibroblasts and whether genetic variants in the CRP gene predispose to AF are also unknown.

METHODS

A genetic association study between CRP gene polymorphisms and AF was performed in two independent populations (I: 100 AF patients and 101 controls; II: 348 AF patients and 356 controls), with functional studies to elucidate the mechanism of association.

RESULTS

Three polymorphisms (T-861C, A-821G and C-390A/C-390T) were found in the 1-kb promoter of CRP. A triallelic polymorphism (C-390A/C-390T) captured all haplotype information and determined the CRP gene promoter activity and the plasma CRP level, and was in nearly complete linkage disequilibrium with G1059C polymorphism in exon 2. The -390A variant was associated with a higher CRP gene promoter activity, a higher plasma CRP level and a higher risk of AF. Patients with AF also had a higher plasma CRP level than controls. CRP significantly increased the inward L-type calcium current in atrial myocytes with no changes in other ionic currents. CRP did not affect the expressions of type I alpha 1 (COL1A1), type III alpha 1 (COL3A1) and type 1 alpha 2 (COL1A2) procollagens in atrial fibroblasts.

CONCLUSION

A CRP gene promoter triallelic polymorphism was associated with CRP gene promoter activity, determined the plasma level of CRP, and predicted the risk of AF. The mechanism of this may be via augmention of calcium influx by CRP in atrial myocytes, but not because of atrial fibrosis.

Effects of renin-angiotensin system inhibition on left atrial function of hypertensive patients: an echocardiographic tissue deformation imaging study

BACKGROUND

Although renin-angiotensin system (RAS) inhibitors have beneficial effects on left ventricular myocardium, their effect on left atrial (LA) function remains unknown. The aim of this study was to evaluate the effect of treatment with RAS inhibitors on LA function of patients with essential hypertension.

METHODS

Forty hypertensive patients (17 males, mean age 47.1 +/- 1.5, mean blood pressure 158.3 +/- 1.8/97.1 +/- 0.7 mm Hg) were studied using LA strain and strain rate (SR) imaging before and after 9 months of treatment with angiotensin-converting enzyme (ACE) inhibitors or angiotensin II receptor blockers (ARBs).

RESULTS

Standard echocardiographic parameters of LA function (LA volumes, ejection fraction, active and passive emptying fraction, and ejection force), as well as left ventricular diastolic indexes did not change with RAS-blocking treatment. However, peak systolic LA strain and SR were significantly higher at study end compared to baseline (77.8 +/- 5.2% vs. 63.3 +/- 4.1%, P < 0.001 and 3.9 +/- 0.2 s(-1) vs. 3.1 +/- 0.2 s(-1), P < 0.0001, respectively). No correlation was found between changes in systolic or diastolic blood pressure, and changes in strain or SR change during treatment.

CONCLUSIONS

LA strain and SR imaging improved after reduction of blood pressure with RAS inhibitors in hypertensive patients, whereas standard LA echocardiographic parameters remained unchanged. LA strain/SR values may have a role in detecting subclinical myocardial involvement in essential hypertension at an early stage; the association between change in these indexes after antihypertensive treatment and clinical outcome merits further evaluation.

Hypertension and atrial fibrillation

Atrial fibrillation (AF) is an emerging public health problem. The most important risk factor for developing chronic AF is uncontrolled hypertension. Uncontrolled hypertension promotes the initiation and perpetuation of AF through atrial remodeling. Experimental evidence has demonstrated the important role of the renin-angiotensin system in atrial remodeling. Retrospective analysis of several large clinical trials and small prospective trials suggests the beneficial role of angiotensin-converting enzyme inhibitors and angiotensin receptor blockers in preventing the onset and recurrence of AF in different populations. Several large prospective trials with longer follow-up periods are in progress. These trials may provide definitive evidence for the use of these agents in the prevention of AF.