Left ventricular diastolic function in the elderly

Quantification of Mitral Valve Regurgitation in Cavalier King Charles Spaniels and Chihuahuas Using Radius of Proximal Isovelocity Surface Area

Mitral regurgitation (MR) resulting from myxomatous mitral valve disease (MMVD) is a prevalent condition in dogs, particularly smaller breeds like Cavalier King Charles Spaniels (CKCSs) and Chihuahuas (CHHs). An accurate assessment of MR severity is essential for effective treatment and disease monitoring, yet a standardized method has yet to be established. In this retrospective study, we evaluated 124 client-owned dogs diagnosed with MMVD, including 64 CKCSs and 60 CHHs. Dogs were categorized into three stages: asymptomatic (B1), remodeled (B2), and congestive heart failure (CHF, C). The MR severity was quantified using the proximal isovelocity surface area (PISA) method, specifically focusing on the PISA radius (PISA-r). The PISA-r measurements exhibited significant increases across disease stages and demonstrated strong correlations with echocardiographic parameters (ranging from 0.83 to 0.94), including the left atrial size and left ventricular internal diameter. The receiver operating characteristic (ROC) curve analysis revealed the high sensitivity and specificity of PISA-r in classifying disease stages, establishing optimal cut-off values. The method displayed excellent repeatability (interobserver variability: 0.95) and reproducibility (intraobserver variability: 0.97). In conclusion, the PISA method, specifically PISA-r, was reliable for assessing MR severity in dogs with MMVD. By simplifying the diagnosis and management of MR, this research can potentially improve the life and management of MMVD-affected dogs.

A review of the impact, pathophysiology, and management of atrial fibrillation in patients with heart failure with preserved ejection fraction

Patients with heart failure with preserved ejection fraction (HFpEF) and atrial fibrillation (AF) have increased mortality and increased risk of stroke. Due to the heterogeneous nature of both disease processes, it is difficult to ascertain whether the diagnosis and progression of AF is the cause of deterioration or if it is a symptom of worsening heart failure. This presents physicians with a clinical conundrum of whether optimizing their heart failure will decrease the overall AF burden or if restoration of sinus rhythm is necessary to optimize patients with HFpEF. In this paper, we will review the impact of AF in patients with HFpEF, the pathophysiology and heterogeneity of HFpEF and AF, and the management of these patients. As HFpEF and AF become more prevalent, managing these disease processes needs standardization to improve outcomes. Further research is needed to understand the complex interplay between AF and HFpEF to help determine the best management strategy.

Accelerated ageing and coronary microvascular dysfunction in chronic heart failure in Tgαq*44 mice

Age represents a major risk factor in heart failure (HF). However, the mechanisms linking ageing and HF are not clear. We aimed to identify the functional, morphological and transcriptomic changes that could be attributed to cardiac ageing in a model of slowly progressing HF in Tgαq*44 mice in reference to the cardiac ageing process in FVB mice. In FVB mice, ageing resulted in the impairment of diastolic cardiac function and in basal coronary flow (CF), perivascular and interstitial fibrosis without changes in the cardiac activity of angiotensin-converting enzyme (ACE) or aldosterone plasma concentration. In Tgαq*44 mice, HF progression was featured by the impairment of systolic and diastolic cardiac function and in basal CF that was associated with a distinct rearrangement of the capillary architecture, pronounced perivascular and interstitial fibrosis, progressive activation of cardiac ACE and systemic angiotensin-aldosterone-dependent pathways. Interestingly, cardiac ageing genes and processes were represented in Tgαq*44 mice not only in late but also in early phases of HF, as evidenced by cardiac transcriptome analysis. Thirty-four genes and 8 biological processes, identified as being ageing related, occurred early and persisted along HF progression in Tgαq*44 mice and were mostly associated with extracellular matrix remodelling and fibrosis compatible with perivascular fibrosis resulting in coronary microvascular dysfunction (CMD) in Tgαq*44 mice. In conclusion, accelerated and persistent cardiac ageing contributes to the pathophysiology of chronic HF in Tgαq*44 mice. In particular, prominent perivascular fibrosis of microcirculation resulting in CMD represents an accelerated cardiac ageing phenotype that requires targeted treatment in chronic HF.

Anthropometric parameters of obesity can be alternative biomarkers for the potential cardiac dysfunction in obese children

Childhood obesity, as one of the potential risk factors of cardiovascular diseases, is closely associated with the incidence of cardiovascular disease at a younger age and has become a public health concern worldwide. However, its potential effects on the cardiovascular system have still remained elusive. In this study, we systematically evaluated the cardiovascular characteristics of 79 obese children and 161 normal weight children in Guangzhou (China) using the potential biomarkers for cardiovascular disease. Compared with normal weight children, obese children not only exhibited significantly higher levels of creatine kinase (CK), lactate dehydrogenase (LHD), soluble fms-like tyrosine kinase-1 (s-Flt-1), high-sensitivity C-reactive protein (hs-CRP), and uric acid (UA) (p = 0.0062, 0.0012, 0.0013, 0.0225, and <0.0001, respectively) but also significantly higher diastolic blood pressure (p = 0.0074) and the heart rate (p = 0.0049) were found in obese children. Of 79 obese children, cardiac functions of 40 cases were further assessed by color Doppler echocardiography. The results showed that there were significant differences between the obesity group and the healthy weight group in terms of interventricular septal wall thickness at end-diastolic (IVSd), the left ventricular posterior wall thickness at end-diastolic (LVPWD), and aortic annulus (AO) (p < 0.0001, 0.0003, and p < 0.0001, respectively). Besides, the left and/or right ventricular functions were declined in 52.4% of obese children. Correlation analysis revealed that the anthropometric parameters of obesity were not only significantly correlated with a blood lipid profile but also exhibited a more significant correlation with most of the parameters of cardiac dysfunction than a blood lipid profile. Therefore, our study indicated that obese children in Guangzhou suffered from functional damages related to cardiovascular events, which were characterized by cardiac dysfunction, and the anthropometric parameters of obesity could be economically alternative biomarkers for monitoring of cardiac dysfunction in obese children.

Multi-parametric analyses to investigate dependencies of normal left atrial strain by cardiovascular magnetic resonance feature tracking

Left-atrial (LA) strain is the result of complex hemodynamics, which may be better characterized using a multiparametric approach. Cardiovascular magnetic resonance (CMR) feature tracking was used to perform a comprehensive LA strain assessment of 183 enrolled healthy volunteers (11–70 years, 97 females, median 32.9 ± 28.3 years). Novel strain dependencies were assessed using multi-parametric regression (MPR) analyses. LA volumetric data, left ventricular strain, transmitral and pulmonary venous blood flow parameters were utilized to create clusters for MPR of all subjects and a heart rate controlled subgroup (pulse: 60–75/min, N = 106). The LA reservoir(r) and conduit(c) strains of the total cohort were significantly elevated (p ≤ 0.001) in women (r: 49.7 ± 12.9%, c: 32.0 ± 11.0%) compared to men (r: 42.9 ± 11.4%, c: 26.1 IQ 10.5%). In contrast, there were no gender-specific differences (p > 0.05) for subgroup LA reservoir, conduit and booster(b) strains (all, r: 47.3 ± 12.7%; c: 29.0 IQ 15.5%; b: 17.6 ± 5.4%) and strain rates (all, 2.1 IQ 1.0 s⁻¹; − 2.9 IQ 1.5 s⁻¹; − 2.3 IQ 1.0 s⁻¹). MPR found large effect sizes (|R²|≥ 0.26) for correlations between strain and various cardiac functional parameters. Largest effect size was found for the association between LA conduit strain and LA indexed booster volume, LA total ejection fraction, left ventricular global radial strain and E-wave (|R²|= 0.437). In addition to providing normal values for sex-dependent LA strain and strain rate, no gender differences were found with modified heart rate. MPR analyses of LA strain/strain rate and various cardiac functional parameters revealed that heart rate control improved goodness-of-fit for the overall model.

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.

Usefulness of left atrial strain for predicting incident atrial fibrillation and ischaemic stroke in the general population

AIMS

Left atrial enlargement predicts incident atrial fibrillation (AF). However, the prognostic value of peak atrial longitudinal strain (PALS) for predicting incident AF in participants from the general population is currently unknown. Our aim was to investigate if PALS can be used to predict AF and ischaemic stroke in the general population.

METHODS AND RESULTS

A total of 400 participants from the general population underwent a health examination, including two-dimensional speckle tracking echocardiography of the left atrium. The primary endpoint was incident AF at follow-up. All participants with known AF and prior stroke at baseline were excluded (n = 54). The secondary endpoint consisted of the composite of AF and ischaemic stroke. During a median follow-up of 16 years, 36 participants (9%) were diagnosed with incident AF and 30 (7%) experienced an ischaemic stroke, resulting in 66 (16%) experiencing the composite outcome. PALS was a univariable predictor of AF [per 5% decrease: hazard ratio (HR) 1.42; 95% confidence interval (CI) (1.19-1.69), P < 0.001]. However, the prognostic value of PALS was modified by age (P = 0.002 for interaction). After multivariable adjustment PALS predicted AF in participants aged <65 years [per 5% decrease: HR 1.46; 95% CI (1.06-2.02), P = 0.021]. In contrast, PALS did not predict AF in participants aged ≥65 years after multivariable adjustment [per 5% decrease: HR 1.05; 95% CI (0.81-1.35), P = 0.72]. PALS also predicted the secondary endpoint in participants aged <65 years and the association remained significant after multivariable adjustment.

CONCLUSION

In a low-risk general population, PALS provides novel prognostic information on the long-term risk of AF and ischaemic stroke in participants aged <65 years.

Aging and the relationships between long-axis systolic and early diastolic excursion, isovolumic relaxation time and left ventricular length-Implications for the interpretation of aging effects on e`

BACKGROUND

Both the left ventricular (LV) long-axis peak early diastolic lengthening velocity (e`) and long-axis early diastolic excursion (EDExc) decrease with age, but the mechanisms underlying these decreases are not fully understood. The aim of this study was to investigate the relative contributions to aging-related decreases in e`and EDExc from LV long-axis systolic excursion (SExc), isovolumic relaxation time (IVRT, as a measure of the speed of relaxation) and LV end-diastolic length (LVEDL).

METHODS

The study group was 50 healthy adult subjects of ages 17-75 years with a normal LV ejection fraction. SExc, EDExc, e`and IVRT were measured from pulsed wave tissue Doppler signals acquired from the septal and lateral walls. Multivariate modelling was performed to identify independent predictors of EDExc and e`which were consistent for the septal and lateral walls.

RESULTS

EDExc decreased with age and the major determinant of EDExc was SExc, which also decreased with age. There was also a decrease of e`with age, and the major determinant of e`was EDExc. IVRT decreased with age and on univariate analysis was not only inversely correlated with EDExc and e`, but also with SExc. IVRT was only a minor contributor to models of EDExc which included SExc, and was an inconsistent contributor to models of e`which included EDExc. LVEDL decreased with age independent of sex and body size, and was positively correlated with SExc, EDExc and e`.

CONCLUSION

Major mechanisms underlying the decrease in e`seen during aging are the concomitant decreases in long-axis contraction and early diastolic excursion, which are in turn related in part to long-axis remodelling of the left ventricle. After adjusting for the extent of systolic and early diastolic excursion, slowing of relaxation, as reflected in prolongation of the IVRT, makes no more than a minor contribution to aging-related decreases in EDExc and e`.

Comparison of the Effects of Nitroglycerin and Nitroprusside on Transmitral Doppler Flow Parameters in Patients with Hypertensive Urgency

BACKGROUND:

Sodium nitroprusside (NIP) and nitroglycerin (NIT) are frequently selected agents for acutely reducing blood pressure. However, it is not clear which agent is more efficacious in improving left ventricular filling pressure in hypertensive crises.

OBJECTIVE:

To compare the acute effects of nitroglycerin (NIT) and nitroprusside (NIP) on transmitral Doppler filling parameters in patients with hypertensive urgency.

METHODS:

We identified 37 patients from our emergency department with hypertensive urgency and left ventricular filling abnormalities. Hypertensive urgency was defined as a severe blood pressure elevation without evidence of progressive end-organ injury. Patients were randomized to receive an infusion of NIT or NIP. NIT was infused at a starting dose of 10 μg/min; NIP was infused at a starting dose of 0.25 μg/kg/min. The infusion rates were adjusted to decrease mean arterial pressure by 25%, and this reduction was obtained within 2 hours in all patients. Diastolic filling parameters were measured by using echocardiography before and after treatment. Pulsed-wave Doppler transmitral flow velocities were used. Early diastolic flow, atrial contraction signal, early diastolic flow/atrial contraction signal, deceleration time, and isovolumetric relaxation time (IVRT) were measured.

RESULTS:

There were no differences between groups in baseline demographic and echocardiographic parameters. Blood pressure decreased significantly in both treatment groups. In posttreatment echocardiographic examinations, atrial contraction signal, deceleration time, and IVRT were significantly decreased in both treatment groups. Early diastolic flow was significantly decreased in the NIT group. There were no significant differences between the groups in terms of posttreatment early diastolic flow, atrial contraction signal, deceleration time, and IVRT values.

CONCLUSIONS:

In hypertensive urgency with left ventricular filling abnormalities, reduction of blood pressure associated with NIT or NIP treatment may improve transmitral Doppler filling parameters. There were no differences demonstrated between the 2 agents.

Limits of ventricular function: from athlete's heart to a failing heart

The interest in the study of ventricular function has grown considerably in the last decades. In this review, we analyse the extreme values of ventricular function as obtained with Doppler echocardiography. We mainly focus on the parameters that have been used throughout the history of Doppler echocardiography to assess left ventricular (LV) systolic and diastolic function. The 'athlete's heart' would be the highest expression of ventricular function whereas its lowest expression is represented by the failing heart, independently from the original aetiology leading to this condition. There are, however, morphological similarities (dilation and hypertrophy) between the athlete's and the failing heart, which emerge as physiological and pathophysiological adaptations, respectively. The introduction of new assessment techniques, specifically speckle tracking, may provide new insight into the properties that determine ventricular filling, specifically left ventricular twisting. The concept of ventricular function must be always considered, although it may not be always possible to distinguish the normal heart of sedentary individuals from that of highly trained hearts based solely on echocardiographic or basic studies.

Changes in left ventricular filling parameters following catheter ablation of atrial fibrillation

BACKGROUND

Atrial fibrillation (AF) is common in the setting of abnormal ventricular relaxation. We evaluated the association between ventricular relaxation grade and atrial fibrosis and examined the change in left ventricular filling parameters following catheter ablation.

METHODS AND RESULTS

AF patients undergoing catheter ablation who had cardiac late gadolinium enhancement MRI (LGE-MRI) and echocardiographic examinations were included in the study. Left atrial (LA) tissue fibrosis and volume were quantified using LGE-MRI. Echocardiograms were performed at baseline and 3 months following catheter ablation to assess left ventricular (LV) filling. Two hundred and ninety three patients (60.8 % male) met the inclusion criteria. In patients in sinus rhythm at baseline (n = 115), ventricular relaxation pattern was identified as normal in 54 patients (47.0 %), impaired in 35 (30.4 %), pseudo-normal in 18 (15.7 %), and restrictive in 8 (7.0 %). Restrictive LV filling was associated with higher LA volume index (61.2 ± 30.5 vs 46.0 ± 18.5 ml/m²; p < 0.01) and LA fibrosis (21.8 ± 10.9 % vs 15.5 ± 9.4 %; p = 0.036) compared to non-restrictive filling. In patients in sinus rhythm on both pre- and post-ablation echocardiograms (n = 104), A waves decreased from 0.70 ± 0.23 at baseline to 0.60 ± 0.20 (p < 0.01) and E/E' decreased from 9.6 ± 4.0 at baseline to 8.6 ± 3.5 (p = 0.03). Thirty-two patients (27.2 %) had an improvement, and 24 patients (23.1 %) had a worsening in diastolic grade. Clinical heart failure and diabetes were associated with worse diastolic grade post-ablation.

CONCLUSIONS

Restrictive LV filling is associated with higher LA fibrosis. A change in echocardiographic LV filling pattern was noted in over 50 % of patients post-ablation.

Selection for atrial fibrillation ablation: Importance of diastolic function grading

BACKGROUND

Pulmonary vein isolation (PVI) has become an accepted therapy for patients with atrial fibrillation (AF) and the indications have widened to include non-paroxysmal AF-patients. Maintenance of sinus rhythm after PVI can be adversely affected by clinical or echocardiographic parameters, which should be clearly identified.

METHODS AND RESULTS

After baseline clinical and echocardiographic evaluations, PVI was performed in patients with paroxysmal or non-paroxysmal AF. The follow-up strategy after PVI included: (1) clinical follow up, 12-lead electrocardiography (ECG) and 24-h ECG every 3 months, (2) trans-telephonic ECGs twice daily and when symptomatic (over 4 weeks) every 3 months, or (3) continuous monitoring via implanted devices. A recurrence was an atrial arrhythmia lasting >30s. All 340 PVI procedures of 229 patients were analyzed. On average, 1.5 PVI procedures per patient (range, 1-6 PVI) were performed. The mean age was 58±11 years (73% male) with 109 paroxysmal and 120 non-paroxysmal AF cases. Clinical follow-up with 12-lead ECGs, 24-h ECGs, trans-telephonic ECGs, and implanted devices was complete in 100%, 63%, 51%, and 16% of cases, respectively. The overall one-year recurrence rate of 59% (range, 24-82%) was dependent on grades of diastolic function (normal - dysfunction grade III) in a multivariable analysis model. Patients with normal diastolic function had the lowest recurrence rates of 24% and 49% after 1 and 3 years of follow-up, respectively (p<0.0001).

CONCLUSION

Diastolic function could serve as a simple summary predictor for AF recurrence, and would facilitate clinical decision-making in AF treatment.

The Estimated Risk of Atrial Fibrillation Related to Alcohol Consumption

The risk of acute heavy alcohol intake on the development of atrial fibrillation (AF), aka ?holiday heart syndrome?, has been well-described. However, whether chronic alcohol intake is also associated with increased risk of AF, or might even be protective as has been observed with other cardiac conditions, is more uncertain. A number of studies, from basic science to large cohort studies have been performed to analyze the association between alcohol and AF. Basic-level studies have found that alcohol causes changes in tissue electrophysiology, ion channels, and circulating hormones, which might promote development and maintenance of AF. Clinical studies have generally shown groups with the highest regular intake of alcohol to be at increased risk, with no association with more moderate use. However, these studies have not always accounted for other AF risk factors, been inconsistent in the assessment and validation of the quantity of alcohol consumed across populations, and been unable to completely separate drinking patterns from overall health of participants. As a result, solid conclusions about a threshold level for ?safe? chronic alcohol intake cannot be made with regard to AF risk, but it appears to be safe within currently recommended limits of 1 drink daily for women and 2 for men. In this review, we discuss these findings, limitations, and conclusions.

Atrial dilation and altered function are mediated by age and diastolic function but not before the eighth decade

OBJECTIVES

This study investigated changes in left atrial (LA) volumes and phasic atrial function, by deciles, with normal aging.

BACKGROUND

LA volume increase is a sensitive independent marker for cardiovascular disease and adverse outcomes. To use this variable more effectively as a marker of pathology and a gauge of outcome, physiological changes due to aging alone need to be quantitated.

METHODS

A detailed transthoracic echocardiogram was performed in 220 normal subjects; 89 (41%) were male and their age ranged from 20 to 80 years (mean 45 ± 17 years). Maximum (end-ventricular systole), minimum (end-ventricular diastole), and pre-a-wave volumes were measured using the biplane method of disks. LA filling, passive emptying, conduit and active emptying volumes, and fractions were calculated. Transmitral inflow, pulmonary vein flow, and pulsed-wave Doppler tissue imaging parameters were measured as expressions of left ventricular diastolic function. For purposes of analysis, subjects were divided by age deciles.

RESULTS

LA indexed maximum (0.05 ml/m(2) per year) and minimum (0.06 ml/m(2) per year) volume increased with age but only became significant in the eighth decade (26.0 ± 6.3 ml/m(2), p = 0.02, and 13.5 ± 3.9 ml/m(2), respectively; p < 0.001). Impaired left ventricular diastolic relaxation was apparent in decade 6 and was associated with a shift in phasic LA volumes so that LA expansion index and passive emptying decreased with increasing age, whereas active emptying volume increased.

CONCLUSIONS

In normal healthy subjects, LA indexed volumes remain nearly stable until the eighth decade when they increase significantly. Therefore, an increase in LA size that occurs before the eighth decade is likely to represent a pathological change. Changes in phasic atrial volumes develop earlier consequent to age-related alteration in LV diastolic relaxation.

Left ventricular torsion, energetics, and diastolic function in normal human aging

This study determined, for the first time, whether the effects of normal aging on systolic and diastolic left ventricular function in subjects without cardiovascular disease are related to underlying energetic defects. Cardiac magnetic resonance imaging with tissue tagging and (31)P spectroscopy was used to determine global structure, function, myocardial strains, and the phosphocreatine-to-ATP ratio (PCr/ATP) in 49 healthy subjects aged 20-69 yr. The three major abnormalities that developed with increasing age were the early filling percentage (EFP, the left ventricular volume increase from end systole to mid-diastole divided by stroke volume × 100), which decreased with age, indicating impaired early diastolic filling (r = -0.72, P < 0.0001), the torsion-to-shortening ratio (TSR, measure of subepicardial torsion exerting mechanical advantage over subendocardial shortening), which increased with age indicating relative subendocardial dysfunction (r = 0.44, P < 0.02), and the PCr/ATP (decreased with increasing age, r = -0.52, P < 0.003). EFP and TSR were strongly correlated (r = -0.63, P < 0.0001), although they were not related to PCr/ATP [EFP vs. PCr/ATP: r = 0.34, not significant (NS) and TSR vs. PCr/ATP: r = -0.3, P = NS]. In normal aging, changes in EFP and TSR likely share the same pathophysiology, although it is unlikely that energetics have a major role in the functional effects of aging.

Echocardiographic diastolic parameters and risk of atrial fibrillation: the Cardiovascular Health Study

AIMS

Atrial fibrillation (AF) is the most common sustained arrhythmia in the elderly, and shares several risk factors with diastolic dysfunction, including hypertension and advanced age. The purpose of this study is to examine diastolic dysfunction as a risk for incident AF.

METHODS AND RESULTS

We examined the association of echocardiographic parameters of diastolic function with the incidence of AF in 4480 participants enrolled in the Cardiovascular Health Study, an ongoing cohort of community-dwelling older adults from four US communities. Participants underwent baseline echocardiography in 1989-1990 and were followed for incident AF on routine follow-up and hospitalizations. After 50 941 person-years of follow-up (median follow-up time 12.1 years), 1219 participants developed AF. In multivariable-adjusted age-stratified Cox models, diastolic echocardiographic parameters were significantly associated with the risk of incident AF. The most significant parameters were the Doppler peak E-wave velocity and left atrial diameter, which demonstrated a positive nonlinear association [HR 1.5 (CI 1.3-1.9) and HR 1.7 (CI 1.4-2.1) for highest vs. lowest quintile, respectively], and Doppler A-wave velocity time integral, which displayed a U-shaped relationship with the risk of AF [HR 0.7 (CI 0.6-0.9) for middle vs. lowest quintile]. Each diastolic parameter displayed a significant association with adjusted NT-proBNP levels, although the nature of the association did not entirely parallel the risk of AF. Further cluster analysis revealed unique patterns of diastolic function that may identify patients at risk for AF.

CONCLUSION

In a community-based population of older adults, echocardiographic measures of diastolic function are significantly associated with an increased risk of AF.

Exercise training and β-blocker treatment ameliorate age-dependent impairment of β-adrenergic receptor signaling and enhance cardiac responsiveness to adrenergic stimulation

Cardiac β-adrenergic receptor (β-AR) signaling and left ventricular (LV) responses to β-AR stimulation are impaired with aging. It is shown that exercise and β-AR blockade have a favorable effect on cardiac and vascular β-AR signaling in several cardiovascular diseases. In the present study, we examined the effects of these two different strategies on β-AR dysregulation and LV inotropic reserve in the aging heart. Forty male Wistar-Kyoto aged rats were randomized to sedentary, exercise (12 wk treadmill training), metoprolol (250 mg·kg−1·day−1 for 4 wk), and exercise plus metoprolol treatment protocols. Ten male Wistar-Kyoto sedentary young rats were also used as a control group. Old trained, old metoprolol-treated, and old trained plus metoprolol-treated rats showed significantly improved LV maximal and minimal first derivative of the pressure rise responses to β-AR stimulation (isoproterenol) compared with old untrained animals. We found a significant reduction in cardiac sarcolemmal membrane β-AR density and adenylyl cyclase activity in old untrained animals compared with young controls. Exercise training and metoprolol, alone or combined, restored cardiac β-AR density and G-protein-dependent adenylyl cyclase activation in old rats. Although cardiac membrane G-protein-receptor kinase 2 levels were not upregulated in untrained old compared with young control rats, both exercise and metoprolol treatment resulted in a dramatic reduction of G-protein-receptor kinase 2 protein levels, which is a further indication of β-AR signaling amelioration in the aged heart induced by these treatment modalities. In conclusion, we demonstrate for the first time that exercise and β-AR blockade can similarly ameliorate β-AR signaling in the aged heart, leading to improved β-AR responsiveness and corresponding LV inotropic reserve.

Tortuosity of coronary arteries: an indicator for impaired left ventricular relaxation?

OBJECTIVE

To investigate the relationship between coronary tortuosity and impaired left ventricular relaxation.

METHODS

One hundred and four subjects who underwent coronary angiography were included in the study. Left anterior descending, left circumflex, and right coronary arteries were traced. Tortuosity was identified by the finding of >/=3 bends (defined as >/=45 degrees change in vessel direction) along main trunk of at least one artery. Study population were divided into tortuosity (n = 54) and no tortuosity (n = 50) groups. Subjects were all submitted to pulsed-wave Doppler and two-dimensional echocardiographic examination to assess left ventricular functions.

RESULTS

For subjects with tortuosity, early transmitral inflow (E) velocity was lower, late transmitral inflow (A) velocity was higher, E/A ratio was smaller compared with subjects without tortuosity (P < 0.001). Subjects with tortuosity had longer deceleration time of E velocity (DT) and isovolumic relaxation time (IVRT) than did subjects without tortuosity (P < 0.001). End-diastolic interventricular septal and left ventricular posterior wall thicknesses were greater in subjects with tortuosity than those without tortuosity (P = 0.01 and P = 0.005). There was an inverse correlation between total number of arteries with tortuosity and E/A ratio (r = -0.750, P < 0.001). Total number of arteries with tortuosity displayed correlations with DT (r = 0.723, P < 0.001) and IVRT (r = 0.703, P < 0.001).

CONCLUSIONS

This study depicts that coronary tortuosity is associated with impaired left ventricular relaxation.Thus, coronary tortuosity might be an indicator of impaired left ventricular relaxation.

Utility of N terminal pro brain natriuretic peptide in elderly patients

OBJECTIVE

To evaluate the utility of N terminal pro brain natriuretic peptide (NT-proBNP) as a diagnostic marker for diastolic dysfunction or failure, systolic dysfunction, and significant valve disorders in patients over 75 years.

DESIGN

Cohort study.

SETTING

Outpatient echocardiography service in a district general hospital.

PARTICIPANTS

100 consecutive patients.

MAIN OUTCOME MEASURES

Sensitivity, specificity, positive predictive values, negative predictive values, and area under receiver operating characteristic curve for NT-proBNP assay in the diagnosis of left ventricular diastolic dysfunction or failure, systolic dysfunction, and significant valve disorders.

RESULTS

For diagnosis of systolic dysfunction NT-proBNP level of 424 pg/ml had a sensitivity of 96%, specificity of 45%, positive predictive value of 36%, and negative predictive value of 96%. The area under the curve was 0.71 (95% confidence intervals: 0.69 to 0.89). In valve heart disease, level of 227 pg/ml had sensitivity of 91%, specificity of 43%, positive predictive value of 40%, and negative predictive value of 92%. Patients with diastolic dysfunction/failure had lower plasma concentrations.

CONCLUSIONS

This study showed that NT-proBNP had excellent negative predictive value for systolic dysfunction and significant valve disorders in very elderly patients. It increased significantly in systolic dysfunction, valve heart disease, and atrial fibrillation. NT-proBNP is not useful in the diagnosis of diastolic dysfunction or diastolic heart failure using standard echocardiography criteria.

European reference values for Doppler indices of left ventricular diastolic filling

The European Study Group on diastolic heart failure requires objective evidence of abnormal left ventricular diastolic function to establish the diagnosis of diastolic heart failure, which is common in older people. Reference values for Doppler indices of transmitral flow, used to assess left ventricular diastolic function, have not been reported for people 70 years and over in Europe. The aim of this study was to establish reference values for these Doppler indices of transmitral flow in older people. A random sample of 355 subjects aged 70 and over, living in the community underwent clinical assessment and echocardiography. Asymptomatic subjects with no cardiovascular disease and cardiovascular risk factors were identified. Measurements of five commonly used Doppler indices of transmitral flow from these subjects were obtained and reference range expressed as mean+/-2 standard deviations and as percentiles. We have therefore generated reference Doppler values of transmitral flow for people aged over 70 in a British population.

Diastolic dysfunction in the elderly--the interstitial issue

Diastolic dysfunction is increasingly recognized as a cause of congestive heart failure. Meta-analyses of earlier studies of this disorder suggest that 40%-50% of patients with the congestive heart failure syndrome have preserved left ventricular systolic function, with current estimates ranging up to 74%. Among patients >or=65 years of age with congestive heart failure, 55% of all subjects and 67% of women had normal systolic function. Histopathologic evaluation reveals a maladaptive remodeling of the interstitium associated with aging, resulting in an increase in interstitial collagen content. The interstitium normally plays a critical role in the generation of early diastolic suction. When there is a significant enough increase in myocardial collagen volume fraction, with its increased viscoelastic burden, this normal early diastolic suction is compromised and diastolic pressures increase. Left ventricular diastolic dysfunction ensues. Neurohumoral abnormalities associated with diastolic dysfunction include activation of the renin-angiotensin-aldosterone system, including increased elaboration of myocardial aldosterone. This excess of aldosterone appears to play a major role in the development of myocardial fibrosis. Recent observations in animal models and humans have demonstrated regression of interstitial collagen volume fraction in response to inhibition of the renin-angiotensin-aldosterone system by angiotensin-converting enzyme inhibitors and aldosterone inhibition, with improvement in diastolic function. Therapeutic implications of these observations suggest targeting the maladaptive remodeling of the interstitium via inhibition of the renin-angiotensin-aldosterone system.

MRI and echocardiographic assessment of the diastolic dysfunction of normal aging: altered LV pressure decline or load?

Changes in diastolic indexes during normal aging, including reduced early filling velocity ( E), lengthened E deceleration time (DT), augmented late filling ( A), and prolonged isovolumic relaxation time (IVRT), have been attributed to slower left ventricular (LV) pressure (LVP) decay. Indeed, this constellation of findings is often referred to as the “abnormal relaxation” pattern. However, LV filling is determined by the atrioventricular pressure gradient, which depends on both LVP decline and left atrial (LA) pressure (LAP). To assess the relative influence of LVP decline and LAP, we studied 122 normal subjects aged 21–92 yr by Doppler echocardiography and MRI. LVP decline was assessed by color M-mode ( Vp) and the LV untwisting rate. Early diastolic LAP was evaluated using pulmonary vein flow systolic fraction, pulmonary vein flow diastolic DT, color M-mode ( E/ Vp), and tissue Doppler ( E/ Em). Linear regression showed the expected reduction of E, increase in A, and prolongation of IVRT and DT with advancing age. There was no relation of age to parameters reflecting the rate of LVP decline. However, older age was associated with reduced E/ Vp ( P = 0.008) and increased pulmonary vein systolic fraction ( P < 0.001), pulmonary vein DT ( P = 0.0026), and E/ Em ( P < 0.0001), all suggesting reduced early LAP. Therefore, reduced early filling in older adults may be more closely related to a reduced early diastolic LAP than to slower LVP decline. This effect also explains the prolonged IVRT. We postulate that changes in LA active or passive properties may contribute to development of the abnormal relaxation pattern during the aging process.

Long-term left ventricular echocardiographic follow-up of SHR and WKY rats: effects of hypertension and age

Long-term follow-up of left ventricular (LV) function using echocardiography has not been reported and, in this study, was carried out in normotensive (WKY) rats and spontaneously hypertensive rats (SHR). In 10 WKY rats and SHR, LV diastolic and systolic diameter (LVEDD and LVSD), shortening fraction (SF), and weight (LVW) were determined at 8, 15, 20, 35, and 80 wk of age. The ratio of early to late mitral flow and mitral annulus velocity (VE/VA and Em/Am), isovolumic relaxation time (IVRT), deceleration time of the E wave (DTE), Tei index, and mitral flow propagation velocity (Vp) were measured. No difference in LVEDD was found between SHR and WKY rats; however, LVEDD was increased at 80 wk in both strains. SF decreased slightly in old WKY rats. LVW progressively increased from 20 to 80 wk in both strains and was greater in SHR. VE/VA and Em/Am decreased at 80 wk in WKY rats. LV relaxation (IVRT, Tei index, and Vp) was progressively impaired in SHR compared with WKY rats. LV compliance (DTE) was altered in old SHR. Echocardiography permitted a long follow-up of LV function in SHR and WKY rats. Ventricular relaxation was impaired early in the life of SHR and progressed with aging. Furthermore, LV compliance was altered, but systolic function remained unchanged, in old SHR. In contrast, relaxation and SF were only slightly altered in old WKY rats, suggesting that pressure-related changes in LV function were the dominant features in the SHR.

Model of functional cardiac aging: young adult mice with mild overexpression of serum response factor

Serum response factor (SRF) is an important transcription factor that may have a role in the maintenance of cardiac structure and function. The level of SRF mRNA expression increases approximately 16% in the hearts of mice during adult aging. To model the effect of mild SRF elevation in the aging heart, transgenic mice with low levels of SRF overexpression were generated. By 6 mo of age, the transgenic mice had a 19% increase of heart-to-body weight ratio compared with nontransgenic mice. In addition, they had a 12% increase in myocyte size, a 6.7% increase in collagen deposition, and altered gene expression of a number of muscle-specific and cardiac genes. Doppler echocardiography revealed that these transgenic mice had increased left ventricular wall thickness and decreased left ventricular (LV) volumes, increased LV stiffness with 20% reduction in early diastolic LV filling (peak E), and 35% decline in peak E-to-peak A (late diastolic filling) ratio. The observed changes, especially those in the E/A ratio, are similar to those seen clinically in late life as a part of human adult myocardial aging.

Aging alters patterns of regional nonuniformity in LV strain relaxation: a 3-D MR tissue tagging study

Although age-related impairment of diastolic function is well documented, patterns of regional tissue relaxation impairment with age have not been characterized. MRI tissue tagging with a regional three-dimensional (3-D) analysis was performed in 15 younger (age 19-26 yr) and 16 older (age 60-74 yr) normal, healthy volunteers. The peak rate of relaxation of circumferential strain (RC) was decreased in the older group (on average, 105 +/- 28 vs. 163 +/- 18 %/s for older vs. younger, mean +/- SD, P < 0.001) to a greater extent in the lateral wall than in the septum (P = 0.016) and to a greater extent in the apex than in the base (P < 0.001). Peak rate of relaxation of longitudinal strain (RL) was also reduced with age (94 +/- 27 vs. 155 +/- 18 %/s, P < 0.001) to a greater extent in the apex than in the base (P < 0.001). Both RC and RL were greater in the apex than in the base only in the younger subjects (P < 0.001 for each). Peak rate of torsion reversal (RT) was reduced with age (74 +/- 16 vs. 91 +/- 15 degrees/s, P = 0.006) to a greater extent in the base than in the apex (P = 0.035). An increase in regional asynchrony in time to RC and time to RL (P < 0.001 for each), but not time to RT, occurred with age. Thus patterns of regional nonuniformity of myocardial relaxation are altered in a consistent fashion with aging.

Hormone replacement therapy and the risk of incident congestive heart failure: the Cardiovascular Health Study

BACKGROUND

The development of congestive heart failure (CHF) in older persons is related to a variety of mechanisms. Hormone replacement therapy (HRT) affects several of the pathways that may be important in the development of CHF. We hypothesized that HRT would be associated with a decreased risk of incident CHF.

METHODS

Using Cox proportional-hazards regression, we assessed the risk of incident CHF (n = 304) associated with time-dependent past and current use of HRT compared to never use. The Cardiovascular Health Study is a prospective cohort study of community-dwelling adults aged 65 years and older. This analysis included female participants without a history of CHF at baseline (n = 3223).

RESULTS

At baseline, 62% were never users, 26% were past users, and 12% were current users of HRT. Compared with never users, the multivariable relative risk (RR) of CHF was 1.01 (95% confidence interval [95% CI] 0.76,1.34) for past users and 1.34 (0.93,1.94) for current users. Results were similar among most treatment and clinical subgroups, except that the association of current HRT with CHF appeared to depend on body mass index (BMI) or osteoporosis status. The RR was 0.82 (0.43,1.60) for normal weight women, 1.65 (0.95,2.88) for overweight women, and 2.22 (1.06,4.67) for obese women (p = 0.01 for interaction). Similarly, the RR was 0.15 (0.04,0.65) for women with osteoporosis and 1.82 (1.25,2.65) for women without osteoporosis (p = 0.001 for interaction).

CONCLUSIONS

Overall, HRT was not associated with the risk of incident CHF, although BMI and osteoporosis appeared to modify the association of HRT with CHF. The risk of CHF was lower in patients with lower BMI or osteoporosis.

Patent foramen ovale: anatomy versus pathophysiology--which determines stroke risk?

This study investigated anatomic and pathophysiologic variables that may determine which patent foramen ovale (PFO) are associated with cerebrovascular accidents (CVAs). Anatomic features of a PFO have been identified as risk factors that predispose certain people to cryptogenic strokes (strokes of unknown cause). However, potential pathophysiologic variables that can determine the pressure gradient between left and right atria, which could influence the right-to-left shunt through a PFO, have not been examined. A retrospective study included 78 consecutive patients in whom PFOs were detected during routine transesophageal echocardiography examination. Group I included 36 patients with CVAs of unknown cause (cryptogenic stroke). Group II included 42 patients without CVAs whose PFOs were incidental findings. Anatomic features measured included separation and overlap between septum primum and septum secundum, interatrial septal motion, and the relative size of the right-to-left shunt with peripheral saline solution contrast injections. Pathophysiologic variables considered were those that could cause elevated left atrial pressure, thereby minimizing the right-to-left shunt.Patients with a clinical neurologic event (group I) had a larger right-to-left shunt volume of contrast bubbles than did patients with asymptomatic PFO (group II; P =.004). The size of the overlap between septum primum and septum secundum was less in patients from group I as compared with patients from group II (7.5 +/- 3.4 mm versus 9.9 +/- 6.0 mm; P =.026). However, other anatomic features of PFO that are determinants of the "opening" were not significantly different between the 2 groups. No statistically significant difference was found in the distance of the separation between septum primum and septum secundum (2.5 +/- 2.0 mm versus 1.9 +/- 1.6 mm; P = not significant). The prevalence of interatrial septal aneurysm was also similar between the 2 groups (28% versus 21%; P = not significant). However, the prevalence of variables that could potentially raise left atrial pressure was greater in patients without CVA as compared with those with a CVA (48% versus 14%; P =.01). In our study, anatomic features alone did not determine interatrial shunt size and pathophysiologic variables that could raise left atrial pressures did differentiate between patients with a PFO with a CVA/transient ischemic attack and those without it. Thus, both anatomic and pathophysiologic mechanisms should be considered in determination of the potential clinical significance of a PFO.