Background-Left ventricular compliance appears to decrease with aging, which may contribute to the high incidence of heart failure in the elderly. However, whether this change is an inevitable consequence of senescence or rather secondary to reduced physical activity is unknown. Methods and Results-Twelve healthy sedentary seniors (69.8Ϯ3 years old; 6 women, 6 men) and 12 Masters athletes (67.8Ϯ3 years old; 6 women, 6 men) underwent pulmonary artery catheterization to define Starling and left ventricular pressure-volume curves. Data were compared with those obtained in 14 young but sedentary control subjects (28.9Ϯ5 years old; 7 women, 7 men). Pulmonary capillary wedge pressures and left ventricular end-diastolic volumes by use of echocardiography were measured at baseline, during decreased cardiac filling by use of lower-body negative pressure (Ϫ15 and Ϫ30 mm Hg), and after saline infusion (15 and 30 mL/kg). Stroke volume for any given filling pressure was greater in Masters athletes compared with the age-matched sedentary subjects, whereas contractility, as assessed by preload recruitable stroke work, was similar. There was substantially decreased left ventricular compliance in healthy but sedentary seniors compared with the young control subjects, which resulted in higher cardiac pressures for a given filling volume and higher myocardial wall stress for a given strain. The pressure-volume curve for the Masters athletes was indistinguishable from that of the young, sedentary control subjects. Conclusions-A sedentary lifestyle during healthy aging is associated with decreased left ventricular compliance, leading to diminished diastolic performance. Prolonged, sustained endurance training preserves ventricular compliance with aging and may help to prevent heart failure in the elderly.
AimsPeak oxygen uptake (VO 2 ) is diminished in patients with heart failure with preserved ejection fraction (HFpEF) suggesting impaired cardiac reserve. To test this hypothesis, we assessed the haemodynamic response to exercise in HFpEF patients. Methods and resultsEleven HFpEF patients (73 + 7 years, 7 females/4 males) and 13 healthy controls (70 + 4 years, 6 females/7 males) were studied during submaximal and maximal exercise. The cardiac output (Q c , acetylene rebreathing) response to exercise was determined from linear regression of Q c and VO 2 (Douglas bags) at rest, 30% and 60% of peak VO 2 , and maximal exercise. Peak VO 2 was lower in HFpEF patients than in controls (13.7 + 3.4 vs. 21.6 + 3.6 mL/kg/min; P , 0.001), while indices of cardiac reserve were not statistically different: peak cardiac power output ConclusionContrary to our hypothesis, cardiac reserve is not significantly impaired in well-compensated outpatients with HFpEF. The abnormal haemodynamic response to exercise (decreased peak VO 2 , increased DQ c /DVO 2 slope) is similar to that observed in patients with mitochondrial myopathies, suggesting an element of impaired skeletal muscle oxidative metabolism. This impairment may limit functional capacity by two mechanisms: (i) premature skeletal muscle fatigue and (ii) metabolic signals to increase the cardiac output response to exercise which may be poorly tolerated by a left ventricle with impaired diastolic function.--
Background Healthy but sedentary aging leads to cardiovascular stiffening, whereas life-long endurance training preserves left ventricular (LV) compliance. However, it is unknown whether exercise training started later in life can reverse the effects of sedentary behavior on the heart. Methods and Results Twelve sedentary seniors and 12 Masters athletes were thoroughly screened for comorbidities. Subjects underwent invasive hemodynamic measurements with pulmonary artery catheterization to define Starling and LV pressure-volume curves; secondary functional outcomes included Doppler echocardiography, magnetic resonance imaging assessment of cardiac morphology, arterial stiffness (total aortic compliance and arterial elastance), and maximal exercise testing. Nine of 12 sedentary seniors (70.6±3 years; 6 male, 3 female) completed 1 year of endurance training followed by repeat measurements. Pulmonary capillary wedge pressures and LV end-diastolic volumes were measured at baseline, during decreased cardiac filling with lower-body negative pressure, and increased filling with saline infusion. LV compliance was assessed by the slope of the pressure-volume curve. Before training, V̇O2max, LV mass, LV end-diastolic volume, and stroke volume were significantly smaller and the LV was less compliant in sedentary seniors than Masters athletes. One year of exercise training had little effect on cardiac compliance. However, it reduced arterial elastance and improved V̇O2 max by 19% (22.8±3.4 versus 27.2± 4.3 mL/kg/mL; P<0.001). LV mass increased (10%, 64.5±7.9 versus 71.2±12.3 g/m2; P=0.037) with no change in the mass-volume ratio. Conclusions Although 1 year of vigorous exercise training did not appear to favorably reverse cardiac stiffening in sedentary seniors, it nonetheless induced physiological LV remodeling and imparted favorable effects on arterial function and aerobic exercise capacity.
Healthy aging results in changes in Doppler measures of diastolic function. It is unclear whether these alterations are a specific manifestation of the aging process or reflect a cardiac adaptation to a more sedentary lifestyle. It was hypothesized that healthy, but sedentary, aging would result in slowing of diastolic filling and myocardial relaxation, whereas lifelong endurance training would prevent such changes. Doppler data were measured in young subjects and sedentary and fit seniors across a broad range of loading conditions. Thirteen sedentary healthy (70 ± 4 years) and 12 fit Masters athlete (68 ± 3 years) seniors were recruited. Twelve young healthy (32 ± 9 years) subjects were used for comparison. Pulmonary capillary wedge pressure and Doppler variables were measured at the 6 loading conditions of baseline (twice), -15 and -30 mm Hg lower body negative pressure, and 2 levels of saline solution infusion. Doppler variables consisted of early and late mitral inflow velocity (E/A) ratio, isovolumetric relaxation time (IVRT), tissue Doppler velocities (TDI E mean ), and propagation velocity of mitral inflow. Aging resulted in a decrease in E/A ratio (p <0.001), TDI E mean (p <0.001), and propagation velocity of mitral inflow (p <0.001) and an increase in IVRT (p = 0.001). Lifelong endurance training did not completely prevent the changes in E/A ratio (p = 0.212), IVRT (p = 0.546), or propagation velocity of mitral inflow (p = 1.00). Fit seniors were able to achieve E/A ratios of 1.0 during baseline and saline solution infusion. TDI E mean was higher in fit versus sedentary seniors at baseline (p = 0.012) and during maximal lower body negative pressure (p = 0.036), but not during saline solution infusion (p = 0.493). In conclusion, age-associated abnormalities in Doppler measures of myocardial filling and relaxation are only partially minimized by lifelong endurance training and therefore may be more specific to the aging process than secondary to years of deconditioning.Normal aging, even in the absence of co-morbidities, results in marked changes in Doppler measures of ventricular filling and relaxation, including reversal of the early and late mitral inflow velocities (decreased E/A ratio) and prolongation of isovolumetric relaxation time (IVRT). 1 These variables, although reproducible, have several limitations in their ability to accurately reflect diastolic function, including significant preload dependence and lack of specificity for dynamic relaxation processes. 2 In addition, it is unclear whether alterations in these Doppler variables with senescence are a specific manifestation of the aging process or reflect a secondary cardiac adaptation to a more sedentary lifestyle. Recently, our laboratory showed that static left ventricular stiffness markedly increased during healthy sedentary aging, whereas lifelong endurance training preserved static left ventricular compliance. 4 These data showed that ≥1 component of diastole, namely static chamber compliance, was significantly influenced by fit...
Aging results in marked abnormalities of cardiovascular regulation. Regular exercise can improve many of these age-related abnormalities. However, it remains unclear how much exercise is optimal to achieve this improvement or whether the elderly can ever improve autonomic control by exercise training to a degree similar to that observed in healthy young individuals. Ten healthy sedentary seniors [71 +/- 3 (SD) yr] trained for 12 mo; training involved progressive increases in volume and intensity. Static hemodynamics were measured, and R-wave-R-wave interval (RRI), beat-to-beat blood pressure (BP) variability, and transfer function gain between systolic BP and RRI were calculated at baseline and every 3 mo during training. Data were compared with those obtained in 12 Masters athletes (68 +/- 3 yr) and 11 healthy sedentary young individuals (29 +/- 6 yr) at baseline. Additionally, the adaptation of these variables after completion of identical training loads was compared between the seniors and the young. Indexes of RRI variability and baroreflex gain were decreased in the sedentary seniors but preserved in the Masters athletes compared with the young at baseline. With training in the seniors, baroreflex gain and resting BP showed a peak adaptation after moderate doses of training following 3-6 mo. Indexes of RRI variability continued to improve with increasing doses of training and increased to the same magnitude as the young at baseline after heavy doses of training for 12 mo; however, baroreflex gain never achieved values equivalent to the young at baseline, even after a year of training. The magnitude of the adaptation of these variables to identical training loads was similar (no interaction effects of age x training) between the seniors and the young. Thus RRI variability in seniors improves with increasing "dose" of exercise over 1 yr of training. In contrast, more moderate doses of training for 3-6 mo may optimally improve baroreflex sensitivity, associated with a modest hypotensive effect; however, higher doses of training do not lead to greater enhancement of these changes. Seniors retain a similar degree of "trainability" as young subjects for cardiac autonomic function to dynamic exercise.
Background Congestive heart failure in the setting of a preserved left ventricular (LV) ejection fraction is increasing in prevalence among the senior population. The underlying pathophysiologic abnormalities in ventricular function and structure remain unclear for this disorder. We hypothesized that patients with heart failure with preserved ejection fraction (HFPEF) would have marked abnormalities in LV diastolic function with increased static diastolic stiffness and slowed myocardial relaxation compared with age-matched healthy controls. Methods and Results Eleven highly screened patients (4 men, 7 women) aged 73±7 years with HFPEF were recruited to participate in this study. Thirteen sedentary healthy controls (7 men, 6 women) aged 70±4 years also were recruited. All subjects underwent pulmonary artery catheterization with measurement of cardiac output, end-diastolic volumes, and pulmonary capillary wedge pressures at baseline; cardiac unloading (lower-body negative pressure or upright tilt); and cardiac loading (rapid saline infusion). The data were used to define the Frank-Starling and LV end-diastolic pressure-volume relationships. Doppler echocardiographic data (tissue Doppler velocities, isovolumic relaxation time, propagation velocity of early mitral inflow , E/A-wave ratio) were obtained at each level of cardiac preload. Compared with healthy controls, patients with HFPEF had similar LV contractile function and static LV compliance but reduced LV chamber distensibility with elevated filling pressures and slower myocardial relaxation as assessed by tissue Doppler imaging. Conclusions In this small, highly screened patient population with hemodynamically confirmed HFPEF, increased end-diastolic static ventricular stiffness relative to age-matched controls was not a universal finding. Nevertheless, patients with HFPEF, even when well compensated, had elevated filling pressures, reduced distensibility, and increased diastolic wall stress compared with controls. In contrast, LV relaxation as assessed by tissue Doppler variables appeared consistently impaired in patients with HFPEF.
Background In select patient populations, Doppler echocardiographic indices may be used to estimate left sided filling pressures. It is not known, however, whether changes in these indices track changes in left-sided filling pressures within individual healthy subjects or patients with heart failure with preserved ejection fraction (HFpEF). This knowledge is important as it would support, or refute, the serial use of these indices to estimate changes in filling pressures associated with the titration of medical therapy in patients with heart failure. Methods and Results Forty seven volunteers were enrolled: 11 highly screened elderly outpatients with a clear diagnosis of HFpEF, 24 healthy elderly subjects and 12 healthy young subjects. Each patient underwent right heart catheterization with simultaneous transthoracic echo. Pulmonary capillary wedge pressure (PCWP) and key echo indices (E/e’ & E/Vp) were measured at two baselines and during four preload altering maneuvers: lower body negative pressure (LBNP) -15 mmHg; LBNP -30 mmHg; rapid saline infusion of 10-15 ml/kg; and rapid saline infusion of 20-30 ml/kg. A random coefficient mixed model regression of PCWP vs. E/e’ and PCWP vs. E/Vp was performed for: 1) a composite of all data points; 2) a composite of all data points within each of the three groups. Linear regression analysis was performed for individual subjects. With this protocol, PCWP was manipulated from 0.8 to 28.8 mmHg. For E/e’, the composite random effects mixed model regression was PCWP = 0.58×E/e’+7.02 (p<0.001) confirming the weak but significant relationship between these two variables. Individual subject linear regression slopes (range: -6.76 to 11.03) and r2 (0.00 to 0.94) were highly variable and often very different than those derived for the composite and group regressions. For E/Vp, the composite random coefficient mixed model regression was PCWP = 1.95×E/Vp +7.48 (p=0.005); once again, individual subject linear regression slopes (range: -16.42 to 25.39) and r2 (range: 0.02 to 0.94) were highly variable and often very different than those derived for the composite and group regressions. Conclusions Within individual subjects the non-invasive indices E/e’ and E/Vp do not reliably track changes in left-sided filling pressures as these pressures vary, precluding the use of these techniques in research studies with healthy volunteers or the titration of medical therapy in patients with HFpEF.
Oxidative pathways in the subendothelial space activate pro-infl ammatory, immunogenic, and atherogenic processes, resulting in endothelial dysfunction, plaque growth and destabilization, platelet activation, and thrombosis, ultimately leading to clinical events ( 1 ). A variety of oxidation-specifi c epitopes (OSE) are generated during oxidative modifi cation of plaque components. These epitopes are not only expressed on modifi ed lipoproteins but also on apoptotic cells and proteins in the extracellular matrix of atherosclerotic vessels ( 2 ).Extensive experimental data exists defi ning the role of oxidation in both progression and regression of atherosclerosis. Atherosclerotic lesions of hypercholesterolemic animal models, which represent primarily early and intermediate stage atherosclerosis, contain signifi cant amounts of OSE, often in proportion to plaque burden. OSE in the vessel wall of atherosclerotic animals can also be imaged with nuclear and magnetic resonance techniques using murine and human oxidation-specifi c antibodies, such as MDA2, E06, and IK17 ( 3-5 ). Dietary interventions in hypercholesterolemic animals that promote regression result in more rapid removal of OSE than apoB, which occurs prior to plaques diminishing signifi cantly in size, and is associated with markers of plaque stabilization, such Abstract The relationships between oxidation-specifi c epitopes (OSE) and lipoprotein (a) [Lp(a)] and progressive atherosclerosis and plaque rupture have not been determined. Coronary artery sections from sudden death victims and carotid endarterectomy specimens were immunostained for apoB-100, oxidized phospholipids (OxPL), apo(a), malondialdehyde-lysine (MDA), and MDA-related epitopes detected by antibody IK17 and macrophage markers. The presence of OxPL captured in carotid and saphenous vein graft distal protection devices was determined with LC-MS/MS. In coronary arteries, OSE and apo(a) were absent in normal coronary arteries and minimally present in early lesions. As lesions progressed, apoB and MDA epitopes did not increase, whereas macrophage, apo(a), OxPL, and IK17 epitopes increased proportionally, but they differed according to plaque type and plaque components. Apo(a) epitopes were present throughout early and late lesions, especially in macrophages and the necrotic core. IK17 and OxPL epitopes were strongest in late lesions in macrophagerich areas, lipid pools, and the necrotic core, and they were most specifi cally associated with unstable and ruptured plaques. Specifi c OxPL were present in distal protection devices. Human atherosclerotic lesions manifest a differential expression of OSEs and apo(a) as they progress, rupture, and become clinically symptomatic.
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