Diastolic dysfunction in hypertension

Sex-specific differences and predictors of echocardiographic measures of diastolic dysfunction in rhesus macaques (Macaca mulatta)

BACKGROUND

Diastolic dysfunction in humans is an age-related process with an overrepresentation in women. In rhesus macaques (Macaca mulatta), the incidence and predictors of diastolic dysfunction have yet to be reported.

METHODS

Data from routine echocardiographic evaluations on clinically healthy rhesus macaques was obtained and used for univariate, bivariate, hypothesis testing, and linear regression statistical analyses interrogating differences and predictors of diastolic function.

RESULTS

Rhesus macaques fully recapitulate previously reported human hemodynamic studies. Female monkeys display impaired diastology and are at an increased risk for developing diastolic dysfunction. Age, sex, and proxies of exercise activity are confirmed predictors for measures of diastolic dysfunction, regardless of specific pathogen-free status.

CONCLUSIONS

Rhesus macaques share common sex- and age-related echocardiographic findings as humans, therefore, serve as a valuable translational nonhuman primate model for future studies of diastolic dysfunction. These findings confirm the importance of sex- and age-matching within future rhesus macaque cardiovascular research.

Management of hypertension in heart failure with preserved ejection fraction: is there a blood pressure goal?

PURPOSE OF REVIEW

Hypertension remains a leading risk factor for heart failure with preserved ejection fraction (HFpEF), and elevated blood pressure (BP) portends an adverse prognosis in patients with established HFpEF. We summarize current evidence for mechanisms linking hypertension to HFpEF and management of hypertension in HFpEF.

RECENT FINDINGS

Data suggest a complex, multifactorial pathophysiology driving the association between hypertension and HFpEF, including left ventricular hypertrophy, diastolic dysfunction, atrial dysfunction, coronary microvascular disease, endothelial dysfunction, myocardial injury and fibrosis. Although intensive BP control may attenuate these processes, this hypothesis has not been tested on clinical outcomes in a dedicated randomized controlled trial (RCT) in HFpEF. Antihypertensive therapies variably improve key surrogate markers in HFpEF, though BP reduction generally does not account for these benefits. Accordingly, BP targets are extrapolated from observational studies and RCTs testing heart failure therapies that affect BP in addition to dedicated RCT data in patients at elevated risk (without heart failure).

SUMMARY

Clinicians should recognize the risk of disease progression and poor outcomes associated with uncontrolled hypertension in HFpEF. Intensive BP control, preferably by therapies known to improve outcomes in heart failure, may slow key pathways in disease progression. Future RCTs testing intensified BP control strategies in HFpEF are warranted.

Signs of diastolic dysfunction are graded by serum testosterone levels in aging C57BL/6 male mice

We investigated whether maladaptive, age-associated changes in heart structure and function were linked to circulating testosterone levels. Male C57BL/6 mice had a gonadectomy (GDX) or sham surgery at 4 weeks and effects of GDX on the heart were examined with echocardiography. Serum testosterone was measured with ELISA. Left ventricular (LV) mass increased with age but was smaller in GDX mice than sham at 18 months (144.0 ± 8.7 vs 118.2 ± 11.9 mg; p = 0.009). The isovolumic relaxation time (IVRT) declined with age but was prolonged in GDX mice at 18 months (10.5 ± 0.8 vs 12.5 ± 0.5 msec, p = 0.008). Ejection fraction did not change with age or GDX, but E/A ratios were lower in GDX mice than controls at 18 months (1.6 ± 0.2 vs 1.3 ± 0.1, p = 0.021). When links between serum testosterone and cardiac parameters were examined longitudinally in 18-24-month-old mice, LV mass declined with decreasing testosterone (β = 37.70, p = 0.016), however IVRT increased as testosterone decreased (β=-2.69, p = 0.036). Since longer IVRT and lower E/A ratios are signs of diastolic dysfunction, low circulating testosterone may promote or exacerbate diastolic dysfunction in older males. These findings suggest that lower testosterone directly modifies heart structure and function to promote maladaptive remodeling and diastolic dysfunction in the aging heart.

Coronary tortuosity relation with carotid intima-media thickness, coronary artery disease risk factors, and diastolic dysfunction: is it a marker of early atherosclerosis?

Background

Coronary tortuosity (C-Tor) is a common finding in coronary angiography (CAG). There are conflicting data about its link to atherosclerosis: one study found a negative relationship with coronary artery disease (CAD), although it had been linked to age and hypertension (HTN), which are CAD risk factors. Carotid intima-media thickness (C-IMT) is a measure of early atherosclerosis and a surrogate for CAD, diastolic dysfunction is also associated with CAD risk factors. In this retrospective case-control study, we investigated the relationship between C-Tor, C-IMT, diastolic dysfunction, and the other risk factors in patients undergoing CAG in a tertiary hospital between July 2017 and June 2018, after excluding patients with significant CAD. C-Tor was defined as the presence of ≥ 3 bends (≥ 45°) along the trunk of at least one main coronary artery in CAG.

Results

After excluding 663 patients due to exclusion criteria, 30 patients with C-Tor were compared with age and gender-matched controls. HTN was significantly more common in the C-Tor group (86.7% vs. 30%, p < 0.002); other clinical characteristics were similar. The C-IMT was abnormal in the C-Tor group only (p: 0.007). The diastolic dysfunction parameters differed between the two groups: the E/A ratio was < 1 in the C-Tor group and > 1 in the normal group (p: < 0.001); the E velocity and deceleration time were significantly lower in the C-Tor group (p: 0.001 and < 0.001 respectively); the E/E′ ratio, A, and A′ velocities were significantly higher (p: 0.005, < 0.001, < 0.001 respectively); while the S′ velocity was similar in the 2 groups (p: 0.078). The C-Tor group had higher total cholesterol and LDL (p: 0.003 and 0.006 respectively). All C-Tor patients undergoing stress tests had positive results. The only independent C-Tor predictors in a regression analysis were HTN, total cholesterol, A-wave velocity, and deceleration time (DT) (odds ratio: 14.7, 1.03, 1.15, and 0.95, all p: < 0.05). A-wave velocity had the best area under the curve, sensitivity, and specificity for C-Tor prediction (0.88, 73.3%, and 96.7% respectively) followed by DT (0.86, 66.67%, and 96.6% respectively).

Conclusion

C-Tor is associated with increased C-IMT, HTN, hyperlipidemia, and left ventricular diastolic dysfunction; all contributing to an ongoing atherosclerotic process. A-wave velocity and DT were independent predictors of C-Tor. C-Tor may cause microvascular ischemia that merits further investigation.

Mechanisms of Left Atrial Enlargement in Obesity

Left atrial (LA) enlargement is common in obesity. We sought to determine the influence of ventricular (LV) remodeling on LA size in obesity. We studied 50 otherwise healthy obese subjects (body mass index 37.2 ± 4.6 kg/m², 50 ± 6 years) and 58 age and gender-matched nonobese controls (body mass index 26.2 ± 2.9 kg/m², 52 ± 5 years). Diastolic function, relative wall thickness (RWT), and LV mass were assessed using echocardiography. LA and LV volume was measured by 3D-echocardiography. Primary outcome was the ratio of LA volume indexed to LV volume in obese and control subjects. Obese subjects had substantially larger LA volumes compared with control subjects (61.0 ± 16.9 vs 38.9 ± 9.2 ml, p < 0.0001). When scaled to body size or lean mass, differences in LA size persisted. However, when indexed to LV end-diastolic volume, LA volumes between control and obese subjects were comparable (obese vs controls: 0.44 ± 0.15 vs 0.42 ± 0.10, p = 0.46). A small subset of obese subjects (26%) had LA volume markedly out of proportion to LV volume (LA/LV volume ratio ≥0.5) and displayed concentric LV remodeling with larger RWT and LV mass compared with obese subjects with LA/LV <0.5 (RWT: 0.46 ± 0.09 vs 0.36 ± 0.06, p < 0.0001; LV mass: 79 ± 18 vs 62 ± 13 g/m² p < 0.01). In conclusion, LA enlargement in patients with obesity generally occurs commensurate with LV enlargement and parallels eccentric LV remodeling. LA enlargement out of proportion to LV size is associated with increased RWT and mass. This unique signature may identify obese subjects with pathologic LA remodeling.

Right ventricle may be involved in regional diastolic dysfunction earliest in primary hypertension patients

BACKGROUND

Impaired ventricular diastolic function is common in hypertensive patients and is one of the major causes of heart failure. Both left and right ventricle diastolic dysfunction have been reported, but the order of involvement is not clear.

METHOD

A total of 161 primary hypertensive patients and 40 healthy volunteers were enrolled. Pulsed wave tissue Doppler was used to measure regional diastolic dysfunction (defined as early peak diastolic [Em] and late diastolic [Am] velocity ratios (Em/Am) < 1) at right ventricular tricuspid valve annulus lateral side (RAVP1), right ventricular tricuspid valve annulus septum side (RAVP2), left ventricular mitral valve annulus septum side (LAVP1) and left ventricular mitral annulus lateral side (LAVP2).

RESULTS

The prevalence of regional diastolic dysfunction at RAVP1, RAVP2, LAVP1, and LAVP2 was all higher in the hypertensive group (P < .001 for all). In both the hypertensive group and the control group, more cases were presented with RAVP1 diastolic dysfunction, while the least number of cases had LAVP2 diastolic dysfunction. In patients with stage 1 hypertension, most cases had RAVP1, or RAVP1 and RAVP2/LAVP1 diastolic dysfunction, while in patients with more advanced hypertension stages, significantly more cases had both RAVP1 and LAVP2, or all four locations diastolic dysfunction (P < .001). A similar trend was observed in patients with longer hypertension duration (duration of 6-9.9 years and 10-18 years compared with 2-5.9 years of duration, P < .001).

CONCLUSIONS

With a more advanced stage and longer duration of hypertension, the range of regional diastolic dysfunction increased, showing a trend from the right ventricular wall, to the septum and left the ventricular wall. In primary hypertension, regional diastolic dysfunction in the right ventricle might happen earlier than that in the septum and the left ventricle.

Impacts of Predischarge Diastolic Functional Recovery on Clinical Outcomes in Patients With Hypertensive Heart Failure

BACKGROUND

Diastolic function is an independent predictor of death in heart failure (HF), but the effect of a change in diastolic function during hospitalization on clinical outcomes in patients with hypertensive HF (HHF) has been poorly studied. Therefore, the aim of this study was to investigate the effect of predischarge diastolic functional recovery (DFR) on future clinical outcomes in hospitalized patients with a first diagnosis of HHF.Methods and Results:A total of 175 hospitalized patients with HHF were divided into 2 groups according to the change in diastolic function on predischarge echocardiography in comparison with baseline echocardiography: DFR group (n=74, 54.2±17.1 years, 55 males) vs. no DFR group (n=101, 59.1±16.8 years, 72 males). During 66.5±37 months of clinical follow-up, major adverse cardiac events (MACE) occurred in 89 patients: 85 HF rehospitalizations, 4 deaths, no MI. The number of MACE were significantly higher in the no DFR group than in the DFR group (61.6% vs. 32.4%, P<0.001). Predischarge systolic functional recovery was not a predictor of MACE, but impaired DFR was an independent predictor of MACE (RR=2.952, P=0.010, confidence interval, 1.878-6.955).

CONCLUSIONS

Impaired predischarge DFR, regardless of the type of HF or predischarge systolic functional recovery, is an independent predictor of future MACE in HHF. Changes in diastolic function should be carefully monitored and would be useful in risk stratification of HHF.

Decreased left atrial myocardial strain in patients with suboptimal blood pressure control

BACKGROUND

Suboptimal blood pressure (BP) control is commonly observed in patients receiving antihypertensive agents, but the relationship between uncontrolled BP and left atrial (LA) impairment remains unknown.

METHODS

This study enrolled 279 hypertensive patients who had been medicated, as well as 85 matched normal controls. The BP of systolic <140 mmHg and diastolic<90 mmHg was defined as optimal (HT1 group, n=146), otherwise as suboptimal BP control (HT2 group, n = 133). LA myocardial function was assessed by the systolic (S_Sa), early diastolic (S_Ea), and late diastolic (S_Aa) LA strains.

RESULTS

Both the HT1 group and HT2 group had higher BP reading, thicker interventricular septum, larger LA volume index, and enhanced active atrial emptying fraction than the control group (all <0.05). When compared with normal subjects, hypertensive patients displayed obvious reduction in the S_Sa (50.0 ± 10.9 vs. 35.9 ± 8.0%), S_Ea (30.1 ± 7.7 vs. 18.5 ± 7.1%) and S_Aa (19.9 ± 6.4 vs. 17.8 ± 4.2%) (all p < 0.001). In addition to a further impaired S_Ea found in the HT2 group than in the HT1 group (17.2 ± 5.3 vs. 19.8 ± 8.3%, p = 0.002), the treated BP of >140/90 mmHg appeared an independent risk factor associated with the abnormal S_Ea (odds ratio, 2.957; interval of confidence, 1.614-5.415; p = 0.001).

CONCLUSIONS

Suboptimal BP control status in hypertensive patients is related to a further reduction of LA myocardial function assessed by the novel 2DSTI free strain, and suboptimal BP might be regarded as a composite risk factor and therefore a simplified treatment target. However, the prognostic value of LA free strain in patients with inability to achieve the BP target needs to be evaluated in future prospective studies.

Prevalence and correlates of left ventricular diastolic dysfunction and heart failure with preserved ejection fraction in elderly community residents

BACKGROUND

Left ventricular diastolic dysfunction (LVDD) is closely related to heart failure with preserved ejection fraction (HFpEF), while the prevalence and correlates of either LVDD or HFpEF in elderly population remain largely unknown.

METHODS

The study was performed in 1274 community residents (769 women, aged ≥65years) who participated in the Shanghai Heart Health Study. Demographic, laboratory and echocardiographic data were obtained to analyze correlates of LVDD and HFpEF using univariate and multivariate Logistic analysis.

RESULTS

LVDD was detected in 31.9% (406/1274) residents and it was significantly higher in women than in men (34.2% vs. 28.3%, P=0.027). HFpEF prevalence was 2.8% (35/1274), and increased with aging in the whole cohort. For residents with left ventricular ejection fraction ≥50% and normal-sized ventricular cavity, female sex (odds ratio [OR] 1.69, 95% confidence interval [CI] 1.24-2.29), heart rate (OR 0.76, 95% CI 0.68-0.86), atrial fibrillation (OR 7.37, 95% CI 3.13-17.36), hypertension (OR 1.32, 95% CI 1.00-1.75), N-terminal pro-B type natriuretic peptide (OR 2.33, 95% CI 1.50-3.61) and high-sensitivity troponin T (hs-TnT) (OR 1.90, 95% CI 1.12-3.23) were independent correlates of asymptomatic LVDD. While age (OR 1.44, 95% CI 1.01-2.06), heart rate (OR 0.66, 95% CI 0.47-0.93) and hs-TnT (OR 4.37, 95% CI 1.46-13.12) were independently related to HFpEF.

CONCLUSIONS

LVDD is common in this community elderly population, and HFpEF is also not rare. Different factors played roles in different stages of HFpEF. Future studies are warranted to explore the predictors of LVDD and HFpEF in the community elderly.

Uncontrolled blood pressure as an independent risk factor of early impaired left ventricular systolic function in treated hypertension

BACKGROUND

Uncontrolled blood pressure (BP) is commonly observed in patients receiving antihypertensive agents. However, its relationship with early left ventricular (LV) dysfunction has not been elucidated.

METHODS

This study enrolled 276 patients with treated hypertension and 85 healthy controls. The 140/90 mm Hg was used to define controlled (HT1 group, n=145) or uncontrolled BP (HT2 group, n=131) according to the concurrent guidelines. LV myocardial function was assessed by two-dimensional speckle tracking imaging, and the circumferential end-systolic wall stress (cESS)-corrected mid-wall fraction shortening (MWFS), systolic longitudinal (εLs-18), circumferential (εCs-18), and radial (εRs-18) strain were measured.

RESULTS

Despite similar ejection fraction, the HT1 and HT2 groups displayed an overall reduction in the cESS-corrected MWFS (13.4±2.7 vs 11.7±1.7 vs 15.5±1.2), εLs-18 (15.6±2.8 vs 13.0±2.2 vs 17.4±2.8), εCs-18 (17.3±3.4 vs 14.1±2.7 vs 18.9±3.3), and εRs-18 (18.4±4.0 vs 14.8±3.1 vs 20.5±4.5) %·cm² /kdyne·10^-2 when compared with the control group (all P<.001). The changes were more obvious in the HT2 group, regardless of LV hypertrophy. Reductions in the cESS-corrected MWFS and εLs-18 were seen in 68 (25%) and 52 (19%) patients, respectively. Uncontrolled BP were 4.365 times (95% CI 2.203-8.648, P<.001) and 3.928 times (1.851-8.337, P<.001) more likely to be associated with the changes.

CONCLUSIONS

Uncontrolled BP in hypertensive patients is associated with further reduction in LV myocardial function detected by advanced echocardiographic techniques, which cannot be explained by the increase in afterload. It might be regarded as a composite risk factor for earlier and faster development of clinical heart failure, therefore, a simplified treatment target.

Impaired longitudinal deformation measured by speckle-tracking echocardiography in children with end-stage renal disease

BACKGROUND

Left ventricular dysfunction is an important co-morbidity of end-stage renal disease (ESRD) and is associated with a poor prognosis in the adult population. In pediatric ESRD, left ventricular function is generally well preserved, but limited information is available on early changes in myocardial function. The aim of this study was to investigate myocardial mechanics in pediatric patients with ESRD using speckle-tracking echocardiography (STE).

METHODS

Echocardiographic studies, including M-mode, tissue Doppler imaging (TDI) and STE, were performed in 19 children on dialysis, 17 transplant patients and 33 age-matched controls. Strain measurements were performed from the apical four-chamber and the short axis view, respectively.

RESULTS

The interventricular and left ventricular posterior wall thickness was significantly increased in dialysis and transplant patients compared to healthy controls. No significant differences were found in shortening fraction, ejection fraction and systolic tissue Doppler velocities. Dialysis and transplant patients had a decreased mean longitudinal strain compared to healthy controls, with a mean difference of 3.1 [95 % confidence interval (CI) 2.0-4.4] and 2.7 (95 % CI 1.2-4.2), respectively. No differences were found for radial and circumferential strain.

CONCLUSIONS

Speckle-tracking echocardiography may reveal early myocardial dysfunction in the absence of systolic dysfunction measured by conventional ultrasound or TDI in children with ESRD.

Plzf as a candidate gene predisposing the spontaneously hypertensive rat to hypertension, left ventricular hypertrophy, and interstitial fibrosis

BACKGROUND

The spontaneously hypertensive rat (SHR) is the most widely used model of essential hypertension and is susceptible to left ventricular hypertrophy (LVH) and myocardial fibrosis. Recently, a quantitative trait locus (QTL) that influences heart interstitial fibrosis was mapped to chromosome 8. Our aim was to dissect the genetic basis of this QTL(s) predisposing SHR to hypertension, LVH, and interstitial fibrosis.

METHODS

Hemodynamic and histomorphometric analyses were performed in genetically defined SHR.PD-chr.8 minimal congenic strain (PD5 subline) rats.

RESULTS

The differential segment, genetically isolated within the PD5 subline, spans 788kb and contains 7 genes, including the promyelocytic leukemia zinc finger (Plzf) gene that has been implicated in hypertrophy and cardiac fibrosis. Mutant Plzf allele contains a 2,964-bp deletion in intron 2. The PD5 congenic strain, when compared with the SHR, showed significantly reduced systolic blood pressure by approximately 15mm Hg (P = 0.002), amelioration of LVH (0.23±0.02 vs. 0.39±0.02g/100g body weight; P < 0.00001), and reduced interstitial fibrosis (17,478±1,035 vs. 41,530±3,499 μm(2); P < 0.0001). The extent of amelioration of LVH and interstitial fibrosis was disproportionate to blood pressure decrease in congenic rats, suggesting an important role for genetic factors. Cardiac expression of Plzf was significantly reduced in prehypertensive (8 and 21 days) congenic animals compared with controls.

CONCLUSIONS

These results provide compelling evidence of a significant role for genetic factors in regulating blood pressure, LVH, and cardiac fibrosis and identify mutant Plzf as a prominent candidate gene.

The role of the emergency department in the patient with acute heart failure

The diagnosis and management of the patient with acute decompensated heart failure (ADHF) presents a unique challenge to the emergency medicine (EM) physician. ADHF is one of the most common cardiac emergencies managed in the emergency department (ED). ED presentations for ADHF will grow as survival rates after myocardial infarction continue to increase and thus, the incidence and prevalence of heart failure (HF) increases. There are very little data to aid EM physicians when trying to identify low-risk patients who are safe for ED discharge and observation units are not yet universally utilized. This results in 80% of patients with ADHF getting admitted to the hospital. The aim of this review is to evaluate current strategies for diagnosis, treatment, and disposition of the ADHF patient in the ED while highlighting new approaches for treatment and disposition, and areas in need of additional research.

Initial management of patients with acute heart failure

Pressure exists to manage patients with acute decompensated heart failure (ADHF) efficiently in the acute-care environment. Although most patients present with worsening of chronic heart failure, some may present with undifferentiated dyspnea and new-onset heart failure. Others have significant comorbidities that complicate both the diagnosis and treatment. The treatment of patients with ADHF is prioritized based on vital signs and presenting phenotype. The risk stratification of patients is the subject of ongoing evaluation. The disposition of patients to areas other than a monitored inpatient bed, such as an emergency department-based observation unit, may prove effective.

Alterations in diastolic function in masked hypertension: findings from the masked hypertension study

BACKGROUND

In a prior study of patients with diabetes, diastolic function was similarly impaired in masked hypertension (MHT) and sustained hypertension (SHT). We evaluated whether MHT is associated with impaired diastolic function compared with SHT and sustained normotension (NT) in the general population.

METHODS

From February 2005 to December 2010, 798 participants without a history of cardiovascular disease or treated hypertension, were enrolled in the Masked Hypertension Study. Participants underwent clinic blood pressure (CBP) and 24-hour ambulatory blood pressure (ABP) measurements. A 2-dimensional Doppler echocardiogram was performed to evaluate diastolic function,s cardiac structure, volume, and systolic function. The 9 CBPs obtained across 3 clinic visits and awake ABP measurements were averaged. Clinic hypertension was defined as systolic/diastolic blood pressure (SBP/DBP) ≥ 140/90 mmHg. Ambulatory hypertension was defined as awake SBP/DBP ≥ 135/85mm Hg. MHT was defined as having ambulatory but not clinic hypertension. White-coat hypertensives (n = 8) were excluded from the analysis.

RESULTS

Of the 790 participants, 116 (14.7%) participants had MHT, 37 (4.7%) participants had SHT, and 637 (80.6%) participants had NT. After age, sex, race/ethnicity, and body mass index adjustment, compared with NT, E'-velocities were significantly lower in MHT (P < 0.01) and SHT (P < 0.05), and E/E' ratios were significantly higher MHT (P < 0.05) and SHT (P < 0.05). These associations were independent of left ventricular mass. Diastolic function parameters did not significantly differ between MHT and SHT.

CONCLUSIONS

Diastolic function was impaired in MHT compared with NT independent of changes in left ventricular mass.

Association of E/E' and NT-proBNP with renal function in patients with essential hypertension

Objectives

To evaluate the association of left ventricular (LV) diastolic function and N-terminal pro-brain natriuretic peptide (NT-proBNP) with renal function in essential hypertension.

Methods

LV diastolic function was estimated by the ratio of early diastolic velocities (E) from transmitral inflow to early diastolic velocities (E′) of tissue Doppler at mitral annulus (septal corner); NT-proBNP was measured in 207 hypertensive patients (mean age 56±14 years). The subjects were classified into 3 groups: E/E′≤10 group (n = 48), 10<E/E′≤15 group (n = 109) and E/E′>15 group (n = 50). The renal function was estimated by glomerular filtration rate (GFR) with ^99mTc-DTPA. GFR from 30 to 59 ml/min/1.73 m² was defined as Stage 3 chronic kidney disease (CKD). GFR was also estimated using the modified MDRD equation. Albuminuria was defined by urinary albumin/creatinine ratio (UACR).

Results

GFR was lower and UACR was higher in E/E′ >15 group than in 10< E/E′ ≤15 group or E/E′ ≤10 group (p<0.0001), GFR was significantly negative and UACR was positive correlated with E/E′ and NT-proBNP (p<0.0001). In multivariate stepwise linear analysis, GFR had significant correlation with age (p = 0.001), gender (p = 0.003), E/E′ (p = 0.03), lgNT-proBNP (p = 0.001) and lgUACR (p = 0.01), while eGFR had no significant correlation with E/E′ or lgNT-proBNP. Multivariate logistic regression analysis, adjusted for potential confounding factors, showed that participants in E/E′>15 group were more likely to have Stage 3 CKD compared with those in E/E′≤10 group with an adjusted odds ratio of 8.31 (p = 0.0036).

Conclusions

LV diastolic function, assessed with E/E′ and NT-proBNP is associated with renal function in essential hypertension.

Echocardiographic predictors of progression from prehypertension to hypertension

BACKGROUND

Prehypertension (PHT) was recently introduced by replacing former categories of high-normal and above-optimal blood pressure (BP). The rationale for redefining this new category was to emphasize the excess cardiovascular risk associated with BP in this range and to focus high risk for developing hypertension (HT). However, no clear definite markers to identify prehypertensive patients at high risk of progressing to HT have been established yet. Accordingly, we aimed to establish echocardiographic predictors of progression from PHT to HT.

METHODS AND RESULTS

The study population consisted of 98 eligible prehypertensive patients. All patients underwent echocardiographic examination including coronary flow reserve (CFR) at baseline. Twenty-nine (30%) patients developed HT during the 3-year follow-up period. Creatinine level, left ventricular mass index (LVMI), mitral Em and Em/Am had a trend towards a significant crude odds ratio (OR) for the development of HT; however, only baseline SBP [OR = 1.18, 95% confidence interval (CI) = 1.06-1.31; P = 0.002), having metabolic syndrome (OR = 3.75, 95% CI = 1.43-9.78; P = 0.007), high-density lipoprotein (HDL) cholesterol (OR = 0.92, 95% CI = 0.86-0.98; P = 0.01), presence of microalbuminuria (OR = 3.53, 95% CI = 1.11-11.2; P = 0.03) and CFR (OR = 0.65, 95% CI = 0.53-0.77; P = 0.02) were significant independent predictors of progression of PHT into HT. The best cutoff value of CFR to predict incident HT was 1.98 with 94% sensitivity and 79% specificity.

CONCLUSION

This prospective study suggested that baseline SBP, having metabolic syndrome, HDL cholesterol level, presence of microalbuminuria and CFR reflecting coronary microvascular function, but not left ventricular diastolic function parameters, were significant independent markers to identify participants with PHT at high risk for incident HT.

Exaggerated exercise blood pressure response is related to tissue Doppler imaging estimated diastolic dysfunction in the early stages of hypertension

We investigated the plausible interrelationship of exaggerated blood pressure response (EBPR) during exercise with left ventricular (LV) diastolic dysfunction, both associated with adverse cardiovascular outcomes, in the early stages of essential hypertension (EH). Sixty-five consecutive patients (aged 54 years, 56 males) with stage I to II EH underwent 24-hour ambulatory blood pressure (BP) recording and treadmill exercise testing and were classified as subjects with (n = 21) and without EBPR (n = 44) based on the systolic BP elevation at peak exercise (>/=210 mm Hg for men and >/=190 mm Hg for women). LV diastolic function was estimated by pulsed tissue Doppler imaging (TDI), averaging diastolic mitral annular velocities (Em, Am) from four separate sites (LV lateral, septal, anterior, and inferior wall). Hypertensives with EBPR, compared with those without EBPR, exhibited increased 24-hour pulse pressure by 4.8 mm Hg (P < .05) and significantly lower values of Em/Am ratio by 0.07 (P < .05). Univariate logistic regression analysis revealed that only 24-hour pulse pressure (odds ratio [OR] = 1.069; P = .043) and Em/Am (OR = 0.041; P = .049) were independent predictors of EBPR. Hypertensives with EBPR compared to their counterparts without EBPR are characterized by more pronounced LV diastolic dysfunction - assessed by TDI. Moreover, the increased pulsatile load seems to be a common denominator of these hypertension-linked states.

[The various forms of left ventricular hypertrophy: diagnostic value of echocardiography]

Left ventricular hypertrophy is a non-specific physiological or maladaptive cardiac response to a large array of stimuli mediated by exercise and numerous cardiac and systemic diseases. The precise characterization and quantification of left ventricular hypertrophy may allow a more timely diagnosis of the underlying condition. The clinical reference standard to assess left ventricular hypertrophy is echocardiography, but a comprehensive description of how to approach this frequent finding in clinical practice is lacking. The current review systematically describes the typical echocardiographic patterns of important types of cardiac hypertrophy using both established and advanced imaging modalities. In hypertrophic obstructive cardiomyopathy a markedly reduced regional systolic function is found in the prominent thickened septum, whereas in essential arterial hypertension a typical concentric left ventricular hypertrophy with a less prominent basal septal bulge is present. The echocardiographic characteristics of cardiac amyloidosis are ventricular hypertrophy with sparkling granular myocardial texture and a small epicardial effusion. In addition, the strain rate curve for longitudinal function shows a typically reduced function which reaches maximum already in early systole. The typical feature of Friedreich cardiomyopathy is concentric left ventricular hypertrophy and sparkling granular texture with preserved regional systolic function. In Fabry cardiomyopathy a prominent papillary muscle is presented and a typical strain rate curve can be extracted from the basal lateral wall, indicating replacement fibrosis. Prominent hypertrabecularisation (ratio of non-compacted to compacted myocardium >2) in the apical and mid left ventricular segments is typical for non-compaction cardiomyopathy. Knowledge of these typical echocardiographic features enables the cardiologist to distinguish between the different hypertrophic entities, thus paving the way to early diagnosis.

The onset of left ventricular diastolic dysfunction in SHR rats is not related to hypertrophy or hypertension

Left ventricular (LV) diastolic dysfunction, particularly relaxation abnormalities, are known to be associated with the development of LV hypertrophy (LVH). Preliminary human and animal studies suggested that early LV diastolic dysfunction may be revealed independently of LVH. However, whether LV diastolic dysfunction is compromised before the onset of hypertension and LVH remains unknown. We therefore evaluated LV diastolic function in spontaneously hypertensive rats (SHR) at different ages and tested whether LV diastolic dysfunction is associated with abnormal intracellular calcium homeostasis. LV systolic and diastolic functions were evaluated by invasive and echocardiographic methods in 3-week-old (without hypertension) and 5-week-old (with hypertension) SHR and Wistar-Kyoto control rats. Basal intracytoplasmic calcium and sarcoplasmic reticulum (SR) Ca2+ contents were measured in cardiomyocytes using fura-2 AM. Sarco(endo)plasmic Ca2+-ATPase isoform 2a (SERCA 2a) and phospholamban (PLB) expressions were quantified by Western blot and quantitative RT-PCR techniques. LV relaxation dysfunction was observed in 3-week-old SHR rats before onset of hypertension and LVH. An increase in basal intracytoplasmic Ca2+ and a decrease in SR Ca2+ release were demonstrated in SHR. Decreased expression of SERCA 2a and Ser16 PLB (p16-PLB) protein levels was also observed in SHR rats, whereas mRNA expression was not decreased. For the first time, we have shown that LV myocardial dysfunction precedes hypertension in 3-week-old SHR rats. This LV myocardial dysfunction was associated with high diastolic [Ca2+]i possibly due to decreased SERCA 2a and p16-PLB protein levels. Diastolic dysfunction may be a potential predictive marker of arterial hypertension in genetic hypertension syndromes.

Activation of GPR30 attenuates diastolic dysfunction and left ventricle remodelling in oophorectomized mRen2.Lewis rats

AIMS

GPR30 is a novel oestrogen receptor expressed in various tissues, including the heart. We determined the role of GPR30 in the maintenance of left ventricular (LV) structure and diastolic function after the surgical loss of ovarian hormones in the female mRen2.Lewis rat, a model emulating the cardiac phenotype of the post-menopausal woman.

METHODS AND RESULTS

Bilateral oophorectomy (OVX) or sham surgery was performed in study rats; the selective GPR30 agonist, G-1 (50 µg/kg/day), or vehicle was given subcutaneously to OVX rats from 13-15 weeks of age. Similar to the cardiac phenotype of sham rats, G-1 preserved diastolic function and structure relative to vehicle-treated OVX littermates independent of changes in blood pressure. G-1 limited the OVX-induced increase in LV filling pressure, LV mass, wall thickness, interstitial collagen deposition, atrial natriuretic factor and brain natriuretic peptide mRNA levels, and cardiac NAD(P)H oxidase 4 (NOX4) expression. In vitro studies showed that G-1 inhibited angiotensin II-induced hypertrophy in H9c2 cardiomyocytes, evidenced by reductions in cell size, protein content per cell, and atrial natriuretic factor mRNA levels. The GPR30 antagonist, G15, inhibited the protective effects of both oestradiol and G-1 on this hypertrophy.

CONCLUSION

These data show that the GPR30 agonist G-1 mitigates the adverse effects of oestrogen loss on LV remodelling and the development of diastolic dysfunction in the study rats. This expands our knowledge of the sex-specific mechanisms underlying diastolic dysfunction and provides a potential therapeutic target for reducing the progression of this cardiovascular disease process in post-menopausal women.

Relation of anemia to echocardiographically estimated left ventricular filling pressure in hypertensive patients over 50 year-old

BACKGROUND

Anemia is associated with worse long term outcomes in heart failure. However, there is little evidence on the effect of low hemoglobin level to the left ventricular (LV) structure and diastolic function in hypertensive patients. This study assessed the relationship of hemoglobin level to LV filling pressure in elderly hypertensive patients.

METHODS

From January 2005 to January 2009, 200 newly diagnosed hypertensive patients over 50 years old (mean age 60 ± 6 years, 116 women) were analyzed. The clinical parameters and comprehensive echocardiographic data were obtained. The patients with and without anemia were compared.

RESULTS

There were significant differences between the anemic and non-anemic groups in the LV mass index (115.27 ± 34.95 vs. 103.75 ± 28.21 g/m(2)), left atrial (LA) volume index (29.31 ± 10.74 vs. 24.99 ± 7.43 mL/m(2)), and E/E' (11.92 ± 4.34 vs. 9.37 ± 2.51). Chronic renal failure was more prevalent in anemic group. On multivariate logistic analysis, anemia was significantly correlated with high LV filling pressure, reflected by E/E', even after controlling for LV mass index and LA volume index. Furthermore, E/E' was significantly correlated with the hemoglobin level (R(2) = 0.093, p < 0.001).

CONCLUSION

In newly-diagnosed hypertensive patients over 50 years old, the presence of anemia was significantly associated with elevated LV filling pressure and LV structural changes. And the hemoglobin level was negatively correlated with noninvasively estimated LV filling pressure.

Ventricular activation time as a marker for diastolic dysfunction in early hypertension

BACKGROUND

A standard 12-lead electrocardiogram (ECG) is performed in all hypertensive patients, primarily to detect left ventricular hypertrophy. Echocardiographic assessment of hypertensive subjects reveals that abnormalities in diastolic function occur more commonly and earlier than increased left ventricular mass. However, ECG changes associated with diastolic dysfunction (DD) remain poorly defined; we assessed the ventricular activation time (VAT) (i.e., the time for the ventricle to depolarize) as a potential marker for DD in early hypertension.

METHODS

Ninety subjects (aged 46 +/- 1.3 years; 43 men) with newly diagnosed, untreated hypertension underwent ECG and comprehensive two-dimensional echocardiography. Left ventricular DD was echocardiographically assessed using Canadian Consensus Guidelines. We compared VAT, which corresponds to the QR interval in the 12-lead ECG, with echocardiographic parameters of DD.

RESULTS

VAT was prolonged in subjects with DD (46.3 +/- 0.4 vs. 39.6 +/- 0.3 ms, P < 0.01). There was a significant correlation between VAT and tissue Doppler imaging (TDI) (early diastolic velocity) e' (r = -0.53, P < 0.0001), (ratio of early and late diastolic velocities) e'/a' (r = -0.53, P < 0.0001), transmitral Doppler (TMD) (early peak filling rate, and early deceleration peak) E/A (r = -0.32, P = 0.001), and (ratio of early diastolic mitral inflow and early diastolic velocities) E/e' (r = 0.44, P < 0.0001).

CONCLUSION

Prolongation of the VAT is associated with DD in patients with newly diagnosed untreated hypertension.

Advances in diastolic heart failure

More than 50% of people living with congestive heart failure have diastolic heart failure (DHF). Most of them are older than 70 years, and female. The prevalence of DHF has increased with time. DHF is caused by left ventricular (LV) diastolic dysfunction (DD) which is induced by diastolic dyssynchrony. Cardiac and extracardiac factors play important roles in the development of heart failure (HF) symptoms. The diagnosis of DHF is generally based on typical symptoms and signs of HF, preserved or normal LV ejection fraction, DD and no valvular abnormalities on examination, using noninvasive and invasive methodologies. The outcomes with pharmacological therapy in patients with DHF are frequently neutral in clinical trials, and prognosis still remains poor with a 5-year mortality of 42.3% after hospitalization for HF. Further trials are necessary.

Incremental value of subclinical left ventricular systolic dysfunction for the identification of patients with obstructive coronary artery disease

BACKGROUND

Left ventricular (LV) diastolic dysfunction and subclinical systolic dysfunction may be markers of coronary artery disease (CAD). However, whether these markers are useful for prediction of obstructive CAD is unknown.

METHODS

A total of 182 consecutive outpatients (54 +/- 10 years, 59% males) without known CAD and overt LV systolic dysfunction underwent 64-slice multislice computed tomography (MSCT) coronary angiography and echocardiography. The MSCT angiograms showing atherosclerosis were classified as showing obstructive (> or =50% luminal narrowing) CAD or not. Conventional echocardiographic parameters of LV systolic and diastolic function were obtained; in addition, (1) global longitudinal strain (GLS) and strain rate (indices of systolic function) and (2) global strain rate during the isovolumic relaxation period and during early diastolic filling (indices of diastolic function) were assessed using speckle-tracking echocardiography. In addition, the pretest likelihood of obstructive CAD was assessed using the Duke Clinical Score.

RESULTS

Based on MSCT, 32% of patients were classified as having no CAD, whereas 33% showed nonobstructive CAD and the remaining 35% had obstructive CAD. Multivariate analysis of clinical and echocardiographic characteristics showed that only high pretest likelihood of CAD (odds ratio [OR] 3.21, 95% 1.02-10.09, P = .046), diastolic dysfunction (OR 3.72, 95% CI 1.44-9.57, P = .006), and GLS (OR 1.97, 95% CI 1.43-2.71, P < .001) were associated with obstructive CAD. A value of GLS > or =-17.4 yielded high sensitivity and specificity in identifying patients with obstructive CAD (83% and 77%, respectively), providing a significant incremental value over pretest likelihood of CAD and diastolic dysfunction.

CONCLUSIONS

The GLS impairment aids detection of patients without overt LV systolic dysfunction having obstructive CAD.

Distribution and determinants of Doppler-derived diastolic flow indices in African Americans: the Jackson Heart Study (JHS)

OBJECTIVES

The objective of this study is to investigate the distribution and determinants of diastolic function in a middle-aged cohort of African Americans (AA).

BACKGROUND

The distribution and determinants of left ventricular (LV) diastolic function in AA are not well-described despite high rates of AA with diastolic heart failure and a five-fold higher risk of death in those with diastolic dysfunction (DD) compared to normal diastolic function.

METHODS

Four categories of diastolic function were defined in JHS participants undergoing echocardiograms at the first examination (2001-2004) using mitral and pulmonary vein velocities. Investigators used logistic regression to assess the independent relation of DD to traditional risk factors and LV systolic dysfunction.

RESULTS

Of the 3,571 study participants (mean age, 56 +/- 12 years; 63.9% female), 70.4% had normal diastolic function, and 18.0%, 10.6%, and 0.9% had mild, moderate, and severe DD, respectively. In the multivariable analysis, DD was significantly related to age (OR 1.2, 95% CI 1.1-1.4), male sex (OR 1.3 CI 1.0-1.5), LV systolic dysfunction (OR 1.5, CI 1.2-2.0), body mass index (OR 0.8, CI 0.8-0.9), and heart rate (OR 1.2; CI 1.1-1.2). The severity of DD was significantly related with age (OR 0.3; CI 0.3, 0.4), male sex (OR 1.6; CI 1.2-2.2), hypertension (OR 0.6, CI 0.4-0.8), and heart rate (OR 0.7; CI 0.6-0.8).

CONCLUSION

This is the largest community-based analysis of LV diastolic function in middle-aged AA. DD was present in 29.5% and independently related to several traditional risk factors and LV systolic dysfunction.

EXCEED: Exforge®-intensive control of hypertension to evaluate efficacy in diastolic dysfunction: study rationale, design, and participant characteristics

Background: Both diastolic dysfunction and increased vascular stiffness represent important measures of target-organ damage in hypertension. Whether intensive blood pressure (BP) control can further improve these measures remains unknown.

Methods: EXCEED is a prospective, randomized open-label blinded endpoint trial (PROBE) design, aiming to test the hypothesis that more aggressive BP lowering would result in greater improvement in diastolic function among patients with stage II hypertension, evidence of diastolic dysfunction and preserved systolic function (EF ≥ 50%). Patients were randomized to one of two treatment strategies, targeting systolic blood pressure (SBP) <140 mmHg or <130 mmHg using a combination of amlodipine/valsartan with additional antihypertensive medications as needed to achieve the prescribed targets. Diastolic function was assessed using Doppler tissue imaging of early diastolic velocity of lateral mitral annulus (E'), while vascular stiffness was assessed using radial augmentation index (RAI) derived from radial artery tonometry. The study primary endpoint will be the change in lateral E' velocity between baseline and 24 weeks.

Results: Two hundred and twenty eight patients (50% female) with mean age of (59.6±9.7) years and mean BP of (162±14/92±13 mmHg) were randomized equally to either treatment strategies. Left ventricular hypertrophy was present among <4% of the enrolled patients. Inspite diastolic function was impaired, baseline lateral E' velocity (7.6±1.2 cm/s) was not related to baseline SBP while baseline RAI was weakly related ( r = 0.2, p <0.01) to SBP even after adjustment to age, gender and heart rate.

Conclusion: EXCEED will determine whether intensive BP lowering will further improve diastolic dysfunction and vascular stiffness among patients with uncontrolled hypertension.

Diastolic dysfunction as a link between hypertension and heart failure

LVDD as an early measure of myocardial end-organ damage is commonly associated with hypertension and may well precede development of LVH in hypertension. About half of the patients presenting with heart failure have a normal ejection fraction, a clinical syndrome that is commonly referred to as HFPEF or diastolic heart failure and is commonly associated with impaired LV relaxation and increased diastolic stiffness. DD and HFPEF are commonly associated with advancing age and hypertension and increase in prevalence in association with these conditions, but there is a paucity of data on any specific therapeutic regimen. Hypertension control appears to be the most effective strategy in improving diastolic function and possibly for reducing the morbidity and mortality associated with HFPEF.

Myocardial and aortic stiffening in the early course of primary aldosteronism

BACKGROUND

Primary aldosteronism (PA) has been experimentally and clinically linked to myocardial and vascular fibrosis, and it has been further associated with left ventricular (LV) structural adaptations.

HYPOTHESIS

Functional cardiovascular adaptations in hypertensive patients with PA precede structural alterations in the early stages of the disease.

METHODS

We studied 17 hypertensive subjects with a recent diagnosis of PA (10 male patients, aged approximately 55 y, with office blood pressure [BP] of 137/88 mm Hg), and 30 essential hypertensives matched for age, sex, office BP levels, treatment status, and LV mass index (LVMI). Apart from standard 2-Dimensional (2-D) and conventional Doppler parameters, tissue Doppler imaging (TDI) methodology was used to assess LV diastolic function; averaging early and late diastolic mitral annular peak velocities (Emav/, Amav, Emav/Amav ratio) from 4 separate sites of measurement (septal, lateral, anterior, and inferior walls). Aortic stiffness was evaluated by means of carotid-femoral pulse wave velocity (cf-PWV) measurements.

RESULTS

Although transmitral E/A ratio was similar in both groups (0.95+/-0.26 versus 0.98+/-0.24, p=0.66), hypertensive subjects with PA compared with essential hypertensives are characterized by significantly higher relative wall thickness (0.50+/-0.07 versus 0.41+/-0.06, p<or=0.001), decreased values of Emav (7+/-1.7 versus 8.1+/-1.8 cm/s, p=0.048), and Emav/Amav ratio (0.63+/-0.16 versus 0.77+/-0.17, p=0.015). The higher PWV in the PA population failed to reach statistical significance (8.5+/-1.6 versus 7.9+/-0.9 msec, p=0.19).

CONCLUSION

Our study demonstrates altered LV geometry and TDI-revealed diastolic dysfunction in hypertensives with PA compared with demographically- and LVMI-matched essential hypertensives. Furthermore, the increased aortic stiffening in PA patients failed to reach statistical significance.

The assessment of diastolic function in patients with rheumatoid arthritis

Introduction. Rheumatoid arthritis (RA) is a systemic inflammatory autoimmune chronic disease. In comparison with the overall population, mortality and morbidity of RA patients are increased due to cardiovascular diseases. There is increasing evidence that autoimmunity mechanisms are included in pathogenesis of cardiovascular diseases. Isolated disorder of diastolic function can, even with normal heart contractility, lead to heart failure. The aim of this study was to assess diastolic function in RA patients and determine factors causing diastolic dysfunction. Material and methods. The study included 88 patients with RA treated at Rheumatology Department, Clinical Hospital Centre, Zemun. All the patients were thoroughly examined (clinical findings, laboratory and echocardiographic examination). All parameters of diastolic function (mitral and pulmonary flow) were measured. Results. In RA patients 98,9% had diastolic function disorder. This parameter had been changed prior to clinical signs of heart failure and decrease of ejection fraction. Indicators of diastolic function, velocities E, A and their ratio VE/VA, as well as velocities S, D and their ratio VS/VD were lower in patients with positive rheumatoid factor. The patients' age (p<0.01), duration of the disease (p<0.05), high level of cholesterol (p<0.05), triglycerides (p<0.05) and arterial hypertension (p<0.05) were significant factors considerably affecting diastolic function. Conclusion. These findings suggest subclinical myocardial disorder in a great number of RA patients. Apart from early and aggressive treatment of the chronic inflammatory process, it is also necessary to prevent further heart complications by timely recognition and treatment of 'standard' risk factors for cardiovascular diseases.

Noninvasive techniques to assess myocardial ischemia in hypertensive patients

Hypertensive patients are more affected by coronary artery disease (CAD) than normotensive patients. Currently, established techniques are able to diagnose myocardial ischemia/CAD in hypertensive patients with suspected CAD. An irrevocable role remains for exercise electrocardiogram (ECG) owing to the many parameters evaluated under physiologic conditions. However, the suboptimal specificity of a positive exercise ECG demands further examination of hypertensive patients with either myocardial single-photon emission computed tomography (SPECT) or stress echocardiography, both more specific than exercise ECG in diagnosing CAD. The high specificity of imaging techniques also makes them highly predictive of cardiac events. Additional techniques to help diagnose CAD are available. Tissue Doppler imaging, strain and other echo-derived techniques may add quantitative elements to recognize CAD in hypertensive hearts. The accuracy of MRI is improving to study myocardial function and perfusion. Positron emission tomography and multislice computed tomography, also in-built with fusion scanners, are playing roles in combining coronary angiography and myocardial function/ischemia assessment. However, no significant application of these additional techniques is available for hypertensive patients. Epicardial CAD assessed by coronary angiography remains the gold standard to decide for revascularization procedures. The presence of microcirculatory dysfunction, a symptom typical of hypertensive hearts, is opening up new areas of noninvasive diagnostic techniques for the detection of coronary flow reserve (CFR) and related myocardial ischemia. The quantification of CFR may render this parameter pivotal to deciding the need for revascularization procedures of intermediate coronary stenosis and it may become an additional gold standard in evaluating coronary vessels. Moreover, even with normal epicardial coronary arteries, microcirculation dysfunction bears prognostic stratification capabilities for hypertensive patients and it may become a promising therapeutic target in the near future.

Treatment of hypertension in heart failure with preserved ejection fraction: role of the kidney

Heart failure can present clinically as primarily diastolic or systolic dysfunction or both. There is an increasing awareness that heart failure can occur in the presence of a normal left ventricular ejection fraction. Heart failure with normal left ventricular ejection fraction is frequently referred to as diastolic heart failure because of the presence of diastolic left ventricular dysfunction evident from impaired left ventricular relaxation. This article focuses on the treatment of hypertension and the role the kidney plays in selecting appropriate agents.

Improvement of cardiac diastolic function by long-term centrally mediated sympathetic inhibition in one-kidney, one-clip hypertensive rabbits

BACKGROUND

Hypertension is associated with left ventricular hypertrophy (LVH) and diastolic dysfunction. The sympathetic nervous system (SNS) is strongly implicated in these alterations. The possible beneficial effect of a centrally mediated sympathetic inhibition on the diastolic function in severe hypertension has never been studied. We have evaluated the cardiac effects (remodeling, diastolic and systolic functions) of a long-term treatment with a centrally acting drug, rilmenidine, in a model of severe renovascular hypertension.

METHODS

One-kidney, one-clip (1K,1C) Goldblatt hypertensive rabbits were randomized in two groups, one receiving rilmenidine (5 mg/kg/day) for 6 weeks and the other treated with vehicle only. Hemodynamic effects and left ventricular (LV) remodeling were evaluated by serial tail cuff pressure measurements, and echocardiography every 15 days. These measurements were followed up with invasive hemodynamic measurements and histological analysis.

RESULTS

Rilmenidine induced a decrease of 8% in blood pressure, a significant bradycardia (19% at 6 weeks after treatment) and an 18% reduction in LV mass, without reduction of ejection fraction (EF). These effects were accompanied by an improvement of the diastolic function, as shown by isovolumic relaxation time and decrease in Tau index, an E/A ratio reversion, and an Ea velocity increase. Moreover, reduction in the atrial (A) and atrial reverse (Ar) velocities, without any effect on LV filling pressures, was observed.

CONCLUSIONS

In 1K,1C Goldblatt rabbits, which mimic most of the characteristics of human hypertensive cardiopathy, we have shown, for the first time, that a central inhibition of the SNS rapidly reverses cardiac hypertrophy and problems associated with primary LV relaxation, without negative inotropic action.

Echocardiography in conscious 1K,1C Goldblatt rabbits reveals typical features of human hypertensive ventricular diastolic dysfunction

Diastolic dysfunction is a major component of hypertensive cardiomyopathy contributing to a progressive evolution towards overt heart failure. To establish an experimental model that could mimic the human clinical pattern, we standardized the surgery in one-kidney, one-clip Goldblatt (1K,1C) rabbits and characterized their hypertensive cardiopathy by echocardiography. Five weeks after placement of a stenotic string around the left renal artery and removal of the right kidney, arterial pressure was measured and an echocardiography performed in conscious animals. An hypertrophic cardiopathy associated with hypertension and a primary trouble of the LV relaxation was observed. This trouble was characterized by a reversion of E/A and Ea/Aa ratios and an increase of the isovolumic relaxation time and Tau index, without augmentation of left ventricular filling pressures. We show for the first time, in this experimental model, a diastolic dysfunction pattern close to the human one. Moreover, echocardiography in a conscious state gives the opportunity to use this model for future chronic pharmacological studies.

Adenylyl cyclase activity and function are decreased in rat cardiac fibroblasts after myocardial infarction

Myocardial infarction (MI) results in left ventricular remodeling (e.g., ventricular hypertrophy, dilatation, and fibrosis). Fibrosis contributes to increased myocardial stiffening, impaired ventricular filling and function, and reduced cardiac output. Adenylyl cyclase (AC) expression and activity are reduced in animal models of heart failure. Stimulation of AC can inhibit extracellular matrix production in isolated cardiac fibroblasts; however, a role for reduced AC expression and activity in fibrosis associated with cardiac remodeling after chronic MI has never been determined. We tested the hypothesis that AC expression and activity are reduced in cardiac fibroblasts after chronic (18 wk) MI. Rats underwent coronary artery ligation or sham surgery (control), and echocardiography was used to assess left ventricular remodeling 1, 3, 5, 7, 10, 12, and 18 wk after surgery. Cardiac fibroblasts were isolated from the noninfarcted myocardium and compared for differences in AC activity and collagen synthesis. End-diastolic dimension was increased [control: 0.76 +/- 0.02 cm and MI: 1.0 +/- 0.02 cm (means +/- SE), P < 0.001] and fractional shortening was decreased (control: 44 +/- 2% and MI: 17 +/- 2%, P < 0.001) in MI compared with control rats. Basal and forskolin-stimulated cAMP production were decreased by 90% and 93%, respectively, and AC5/6 expression was decreased 39% in fibroblasts isolated from MI rats compared with sham controls. Serum-stimulated collagen production was increased twofold and forskolin-mediated inhibition of collagen synthesis was reduced in fibroblasts from MI rats compared with controls. Our data demonstrate that AC expression and activity are reduced and collagen production is increased in cardiac fibroblasts of rats after MI.

Effects of normal blood pressure, prehypertension and hypertension on left ventricular diastolic function and aortic elastic properties

BACKGROUND

The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (BP) provides guideline for the new category of BP levels as normal, prehypertension (PHT), and hypertension. Although PHT is associated with a markedly increased risk of developing hypertension within 4 years, its prognostic significance and predisposition to target-organ damage is unknown. Accordingly, we evaluated the effects of normal BP, PHT and hypertension on left ventricular (LV) diastolic function and aortic elasticity, which are sensitive indicators of target-organ damage.

METHODS

We evaluated LV diastolic function and aortic elastic properties of 60 subjects with PHT, 70 patients with hypertension and 50 normotensive healthy volunteers using transthoracic echocardiography. None of the subjects had any systemic disease.

RESULTS

LV diastolic function was more significantly impaired in the hypertension group than in the PHT group compared with controls, but it was not strongly different between the PHT and control group. Aortic distensibility was significantly lower, and aortic stiffness index was significantly higher in both the hypertension and the PHT group than those in the control group. However, aortic elastic properties did not significantly differ between the PHT and hypertension groups. Furthermore, we found that the presence of the PHT was significant predictor of impaired aortic elasticity in a multivariable model that adjusted for other variables.

CONCLUSIONS

Aortic elastic properties are significantly and LV diastolic function is slightly impaired in subjects with PHT, and impairment of aortic elasticity is as severe as that in hypertension.

Cardiac tissue Doppler imaging in sports medicine

The differentiation of training-induced cardiac adaptations from pathological conditions is a key issue in sports cardiology. As morphological features do not allow for a clear delineation of early stages of relevant pathologies, the echocardiographic evaluation of left ventricular function is the technique of first choice in this regard. Tissue Doppler imaging (TDI) is a relatively recent method for the assessment of cardiac function that provides direct, local measurements of myocardial velocities throughout the cardiac cycle. Although it has shown a superior sensitivity in the detection of ventricular dysfunction in clinical and experimental studies, its application in sports medicine is still rare. Besides technical factors, this may be due to a lack in consensus on the characteristics of ventricular function in relevant conditions. For more than two decades there has been an ongoing debate on the existence of a supernormal left ventricular function in athlete's heart. While results from traditional echocardiography are conflicting, TDI studies established an improved diastolic function in endurance-trained athletes with athlete's heart compared with controls.The influence of anabolic steroids on cardiac function also has been investigated by standard echocardiographic techniques with inconsistent results. The only TDI study dealing with this topic demonstrated a significantly impaired diastolic function in bodybuilders with long-term abuse of anabolic steroids compared with strength-trained athletes without abuse of anabolic steroids and controls, respectively.Hypertrophic cardiomyopathy is the most frequent cause of sudden death in young athletes. However, in its early stages, it is difficult to distinguish from athlete's heart. By means of TDI, ventricular dysfunction in hypertrophic cardiomyopathy can be disclosed even before the development of left ventricular hypertrophy. Also, a differentiation of left ventricular hypertrophy due to hypertrophic cardiomyopathy or systemic hypertension is possible by TDI. Besides the evaluation of different forms of left ventricular hypertrophy, the diagnosis of myocarditis is also of particular importance in athletes. Today, it still requires myocardial biopsy. The analysis of focal disturbances in myocardial velocities might be a promising non-invasive method; however, systematic validation studies are lacking. An important future issue for the implementation of TDI into routine examination will be the standardisation of procedures and the establishment of significant reference values for the above-mentioned conditions. Innovative TDI parameters also merit further investigation.

Low serum bilirubin concentrations are associated with impaired aortic elastic properties, but not impaired left ventricular diastolic function

Elevated serum bilirubin concentrations protect from atherosclerotic diseases; however,it is not clear whether higher serum bilirubin concentrations in physiological ranges do the same. To investigate the association of high and low serum bilirubin concentrations with left ventricular diastolic function and aortic elastic properties.We evaluated left ventricular diastolic function and aortic elastic properties of 42 healthy subjects with hypobilirubinemia (total bilirubin 0.40 ± 0.08 mg ⁄ dl; mean age 37.0 ± 3.9) and 40 healthy subjects with hyperbilirubinemia (total bilirubin 1.56 ± 0.49 mg ⁄ dl; mean age 36.2 ± 6.0) using transthoracic second harmonic Doppler echocardiography. Age, gender, body mass index and coronary risk factors were similar between the groups, except high-sensitivity C-reactive protein (hsCRP).Left ventricular diastolic parameters were similar between the two groups. Aortic distensibility (AoD) was found to be significantly lower (11.1 ± 3.9 vs. 13.2 ± 4.9,p = 0.03) and aortic stiffness index (AoSI) (1.99 ± 0.30 vs. 1.85 ± 0.26,p = 0.02) and elastic modulus (AoEM) (2.06 ± 0.83 vs. 1.73 ± 0.68, p = 0.03;the low and high bilirubin groups, respectively) higher in the low bilirubin group.Serum total bilirubin concentration correlated with hsCRP levels, AoD, AoSI and AoEM. In conclusion, left ventricular systolic and diastolic functions were similar between hypo- and hyperbilirubinemic subjects, but aortic elastic properties were impaired in subjects with lower serum bilirubin concentrations.

Curriculum in cardiology: integrated diagnosis and management of diastolic heart failure

Among the general heart failure (HF) population, over half have diastolic HF (DHF). The proportion of DHF increases with age, from 46% in patients younger than 45 years to 59% in patients older than 85 years. The diagnosis of DHF is made by the combination of signs and symptoms of HF with preserved systolic function (left ventricular ejection fraction >50%), and evidence of diastolic dysfunction obtained by echocardiographic Doppler examination, invasive hemodynamic evaluation, or an elevation of serum B-type natriuretic peptide. The most common risk factors for the development of diastolic dysfunction and DHF include long-standing hypertension, older age, female sex, obesity, diabetes, chronic kidney disease, and coronary artery disease. Acute decompensation occurs in the setting of pressure overload, volume overload, or superimposed cardiac ischemia. The cornerstones of in-hospital management include blood pressure and volume control, heart rate control, and correction of precipitating factors. Priorities in the outpatient clinic include optimal blood pressure control, maintenance of euvolemia with minimal or no diuretics, and, potentially, use of disease-modifying drugs including angiotensin-converting enzyme inhibitors, angiotensin II receptor blockers, aldosterone receptor blockers, beta-blockers, and digoxin. Long-term regression of left ventricular hypertrophy, improvement in diastolic filling parameters, and sustained reductions in B-type natriuretic peptide may be future treatment targets for this condition.

Echocardiographic measurement of ventricular function

PURPOSE OF REVIEW

We review new findings concerning ventricular function in patients in intensive care units with shock or unexplained respiratory distress syndrome analyzed using echocardiography.

RECENT FINDINGS

Bedside echocardiography is not only an imaging technique but should be considered as a hemodynamic method. Left-ventricular systolic function can be assessed in daily clinical practice by measuring shortening fraction, fraction area change and ejection fraction. But these indices are dependent on load conditions. Index of myocardial performance can be also used. Rate of left-ventricular pressure increase may be measured from mitral regurgitation. Other indices such a maximal elastance and preload-adjusted maximal power were developed to evaluate myocardial systolic function but are not still used in clinical practice in patients in intensive care. Cardiac output measurement can be calculated easily from aortic annulus diameter and the velocity time integral of aortic blood flow. To complete the assessment of ventricular function, left-ventricular diastolic function and pressure as well as right ventricular size, septal movement and right pressures should be analyzed.

SUMMARY

Using echocardiography the intensivist can examine both the mechanism and the cause of shock or pulmonary edema. It is time to increase the use of this technique in intensive care units.