Systolic Variability Research Articles

Dobutamine Stress Echocardiography for Assessment of Systolic Function in Dogs with Experimentally Induced Mitral Regurgitation

BackgroundSystolic dysfunction is associated with poor outcomes in dogs with myxomatous mitral valve disease. However, assessment of systolic variables by conventional echocardiographic methods is difficult in these dogs because of mitral regurgitation (MR).HypothesisWe hypothesized that assessment of systolic function by dobutamine stress may identify systolic dysfunction in dogs with MR, and that 2‐dimensional speckle‐tracking echocardiography (2D‐STE) could quantitatively evaluate myocardial function.AnimalsAnesthetized dogs with experimentally induced MR.MethodsDogs were examined for systolic myocardial deformations using 2D‐STE during dobutamine infusion before and 3 and 6 months after MR induction. We evaluated peak systolic rotation and rotation rate in each basal and apical view; peak systolic torsion and torsion rate were also calculated.ResultsInvasive peak positive first derivatives of left ventricular pressure (dp/dt) were significantly decreased in dogs 6 months after induction of MR compared with pre‐MR results. After 3 and 6 months of MR, dogs had diminished peak systolic torsion values and torsion rates in response to dobutamine infusion compared with pre‐MR results (3 months, P < .001 and P = .006; 6 months, P = .003 and P = .021). These results were significantly correlated with overall invasive dp/dt (r = 0.644, P < .001; r = 0.696, P < .001).Conclusions and Clinical ImportanceDecreased torsion during dobutamine infusion in dogs with MR may reflect latent systolic dysfunction. Dobutamine infusion, therefore, may be useful for the assessment of systolic function in dogs with MR.

Beat-to-Beat, Reading-to-Reading, and Day-to-Day Blood Pressure Variability in Relation to Organ Damage in Untreated Chinese

Whether target organ damage is associated with blood pressure (BP) variability independent of level remains debated. We assessed these associations from 10-minute beat-to-beat, 24-hour ambulatory, and 7-day home BP recordings in 256 untreated subjects referred to a hypertension clinic. BP variability indices were variability independent of the mean, maximum-minimum difference, and average real variability. Effect sizes (standardized β) were computed using multivariable regression models. In beat-to-beat recordings, left ventricular mass index (n=128) was not (P≥0.18) associated with systolic BP but increased with all 3 systolic variability indices (+2.97-3.53 g/m(2); P<0.04); the urinary albumin-to-creatinine ratio increased (P≤0.03) with systolic BP (+1.14-1.17 mg/mmol) and maximum-minimum difference (+1.18 mg/mmol); and pulse wave velocity increased with systolic BP (+0.69 m/s; P<0.001). In 24-hour recordings, all 3 indices of organ damage increased (P<0.03) with systolic BP, whereas the associations with BP variability were nonsignificant (P≥0.15) except for increases in pulse wave velocity (P<0.05) with variability independent of the mean (+0.16 m/s) and maximum-minimum difference (+0.17 m/s). In home recordings, the urinary albumin-to-creatinine ratio (+1.27-1.30 mg/mmol) and pulse wave velocity (+0.36-0.40 m/s) increased (P<0.05) with systolic BP, whereas all associations of target organ damage with the variability indices were nonsignificant (P≥0.07). In conclusion, while accounting for BP level, associations of target organ damage with BP variability were readily detectable in beat-to-beat recordings, least noticeable in home recordings, with 24-hour ambulatory monitoring being informative only for pulse wave velocity.

Aortic tissue Doppler imaging after tetralogy of Fallot repair: beyond aortic diameters

Purpose: Structural abnormalities of the aortic wall have been described in tetralogy of Fallot (ToF) and could be responsible for aortic stiffening leading to aortic dilatation. We aimed to study if aortic root stiffness indices assessed by tissue Doppler imaging (TDI) could be related to the aortic diameter late after ToF repair. Methods: We included adult (≥ 18 years) patients (pts) with surgically repaired ToF followed at a terciary care center from January till December 2012. We defined two groups based on the Cornell data-based z-score formulae for two-dimensional transthoracic echocardiographic diameter of the aortic root at the level of the sinuses of Valsalva (AoZ), in parasternal long-axis view: group 1 - with Ao dil (AoZ > 2) and group 2 - without Ao dil (AoZ ≤ 2). Aortic root M-mode systolic and diastolic diameters and TDI variables were measured, including systolic maximum anterior wall expansion velocity (SAo), early (EAo) and late (AAo) diastolic retraction velocity and time to peak systolic (TAo). Strain, distensibility and stiffness index of the aortic root were determined noninvasively. Results: We included 43 pts (mean age 32±11 years; 58% female); mean follow-up time since ToF repair was 22±8 years. In 21 pts (49%) an aortopulmonary (AP) shunt was done prior to complete repair, with a median interval of 3 years. In 15 pts complete repair used a transannular patch. In 10 pts (23%) we identified Ao dil (mean age 32±11 years; 5 males). Only 1 pt had moderate aortic regurgitation. Both group 1 and 2 were similar concerning age, gender, body surface area, age at ToF repair and follow up time after repair. Also, no differences could be found in systemic blood pressure, pulse pressure, and TDI variables. There was a trend to a positive correlation between the aortic root z-score and the aortic stiffness index, whereas a trend to a negative correlation was found for the aortic strain and distensibility. The aortic stiffness index was significantly increased in group 1 (14.8±6.3 vs 8.5±6.8, p=0.019) and in univariate and multivariate analysis, the aortic stiffness index was an independent predictor of aortic dilatation (odds ratio 1.30, 95% confidence interval 1.02-1.65, p=0.033). Conclusions: TDI can assess the aortic elastic properties noninvasively in this subset of pts and the aortic stiffness index may be a predictor of aortic dilatation late after ToF repair.

Consistent regional heterogeneity of passive diastolic stretch: a mechanism for normal systolic function

Purpose: Frank-Starling (FS) law states that increased LV preload induces an increase in LV performance. It also holds true on the regional level, where differences of preload measured as diastolic stretch (preS) across the LV result in regional differences in systolic strain (SS). We aimed to investigate the consistency of the normal spatial intraventricular preS distribution pattern and to compare it to that of SS. Methods: TDI (FR ∼200 Hz) of 6 LV walls were acquired in 54 subjects (42±15y) without cardiac pathology. In each wall 3 samples distributed from base to apex were tracked through cardiac cycle with custom software. The reference point for strain estimation was set at the onset of atrial activation (P wave on ECG). PreS was measured as peak positive strain after the P wave and SS as total shortening during systole. Obtained segmental values were compared between LV walls and levels. For each subject linear regression line was estimated through 18 segmental preS and SS values. Results: Segmental preS and SS correlated significantly in all study subjects (mean r2=0.68). As for regional distribution, both PreS and SS were significantly higher in the septal and inferior walls than in the lateral and anterior walls (Fig. 1a). Apical segments had lower regional preS and SS values than mid or basal ones (Fig. 1b). ![Figure][1] Figure 1. preS and SS differences between LV walls Conclusion: In a normal LV, a consistent regional distribution of preS is observed. Wall segments known to be flatter and/or later activated (related to a higher wall stress at the onset of contraction) are stretched more than spherical and/or early activated segments. A similar distribution pattern of LV SS show, that a major part of intraventricular systolic strain variability can be explained by regional differences in diastolic stretch as a direct consequence of FS mechanism. [1]: pending:yes

A comparison of the effect of convection against diffusion in hemodynamics and cytokines clearance in an experimental model of septic shock

Replacement therapies based on the use of convection have value for the removal of inflammatory mediators. Such therapies have been proposed for the management of septic shock, but diffusion has not proved useful in this scenario, unless high-flow membranes are used. The exact role of diffusion in these cases remains to be clarified because continuous replacement therapies are usually delivered with low-flow membranes and mixed convection-diffusion modalities. However, studies specifically addressing this problem have not been performed. Our aim was to define the efficacy of hemofiltration (convection) and hemodialysis (diffusion) in cytokine clearance and hemodynamic improvement in an experimental model of septic shock. Shock was induced in 15 beagle dogs (weight 10-15 kg) by infusion of 1 mg/kg of ultrapure Escherichia coli lipopolysaccharide diluted in 20 mL saline for 10 minutes. Five animals were followed without interventions (controls), five animals were treated with convection (100 mL kg h) for 6 hours, and five animals were treated with diffusion (100 mL kg h) for 6 hours. All subjects in the control group died during the study, whereas all treated subjects survived. Mean arterial pressure, cardiac output, systolic variability volume, systemic vascular resistances, dPMax, and pulmonary compliance improved in treated subjects. However, the differences in mean arterial pressure and cardiac output were significant only in the convection group and not in the diffusion-treated group.Tumor necrosis factor α rose equally in all groups and decreased only in treated subjects. Interleukin 6 rose in the three groups but decreased only in the convection group and remained unchanged in the control and diffusion groups. Convection and diffusion improved survival and hemodynamic parameters in a septic shock model. Improvement was more pronounced with convection, a difference that may be explained by convective clearance of cytokines.

The carotid body in cardiovascular disease: more chicken and egg than horse and cart?

The carotid body in cardiovascular disease: more chicken and egg than horse and cart?

Radial artery pulse wave analysis for non-invasive assessment of coronary artery disease

BackgroundAngiographically-normal coronary arteries are reported in 10–20% of patients undergoing diagnostic coronary angiography despite screening with risk factors and functional tests. We sought to validate and determine the clinical value of radial artery pulse wave analysis (PWA), a simple, quick and non-invasive marker of central artery stiffness and define its ability to predict coronary artery disease in high-risk patients. Materials and methods531 consecutive patients referred for elective coronary angiography, irrespective of previous co-morbidity, were assessed in a prospective, multicenter observational study [the Alternative Risk Markers in Coronary Artery Disease (ARM-CAD) study]. ResultsMean age was 65±11years, 33% were women, 18% had impaired left-ventricular function and 22% a prior myocardial infarction. Angiography demonstrated normal coronary arteries in 20% of participants. The only independent associations with this outcome were younger age, female gender, absence of diabetes and PWA-derived central augmentation pressure <24mm Hg. The odds ratio for the latter after adjustment for medications and baseline risk factors (including blood pressure, high-sensitivity C-reactive protein and B-type natriuretic peptide) was 3.4 (95% CI 1.2 to 9.5; p=0.021). The specificity for the multivariate model that included PWA was 95.7% with a receiver operator curve area of 0.876. Validation studies suggested that systolic variables from PWA were robust regardless of waveform quality and similar to measured aortic pressures (mean difference 2.7mm Hg). ConclusionsAssessment of radial artery waveforms is a useful non-invasive clinical test that can stratify the likelihood of coronary disease and assist in identifying patients who require diagnostic angiography.

Multilevel model estimation of age-dependent individual-specific trajectories for left ventricular echocardiographic indexes in an asymptomatic elderly cohort

Few studies have been performed on the individual-specific trajectory of left ventricular aging as assessed by echocardiography in an asymptomatic elderly cohort. In the present study, a representative cohort of elderly men, who were long-term asymptomatic for cardiovascular issues, were selected from an ongoing observational aging study. Annual echocardiographic data were used to establish an age-dependent hierarchical model. Based on two-level linear regression results, four echocardiographic indexes [left ventricular mass (LVmass; -1.872 g/yr), posterior ventricular wall thickness (-0.048 mm/yr), fraction shortening (0.097/yr), and transmitral peak A velocity (-0.006 m·s(-1)·yr(-1))] changed significantly with increasing age and were age- and subject-dependent. The most characterized results of the study were the significant, age-related, within-individual variances in echocardiographic results, which were observed using the likelihood ratio test at an occasion-dependent level. Of these, fluctuated amplitudes of two systolic variables [i.e., LVmass (con/age = -0.012 ± 0.004; P = 0.0007) and fraction shortening (con/age = -0.001 ± 0.004; P = 0.05)] were significantly attenuated with increasing age within individuals. On the other hand, the age-related variability of four diastolic Doppler variables [i.e., peak A velocity (con/age = 0.003 ± 0.002; P = 0.0009), peak E velocity (con/age = 0.004 ± 0.003; P = 0.01), E/A ratio (con/age = 0.007 ± 0.003; P = 0.0002), and deceleration time of E wave (con/age = 0.025 ± 0.007; P < 0.0001)] significantly increased with increasing age within individuals. The age-related individual variability of left ventricular indexes observed in this continuous asymptomatic cohort may reflect the mechanism of preclinical, individualized heart aging. In conclusion, successfully fitted multilevel models were applied as a valuable tool to determine the mechanism of individual cardiac aging in the elderly.

How many systolic and diastolic variables must be measured in elderly patients with symptoms of heart failure?

Objectives: To explore the concordance and the feasibility of obtaining systolic or diastolic variables of left ventricular function in elderly patients with heart failure symptoms. Methods: One hundred twenty four patients with symptoms of heart failure (mean age 77 years, 70% females) were included in a cross-sectional, explorative study. Nineteen echocardiographic variables (7 systolic and 12 diastolic) were measured. Results: Overall, feasibility ranged from 93% to 100% for 15 variables and was 48% for mitral regurgitation dp/dt(MRdp/dt), 66% for the difference between pulmonary AR-dur and mitral A-dur, 81% for the ratio between early and late mitral inflow velocity (E/A), and 76% for tissue Doppler imaging late dia-stolic velocity (TDI A’). Concordance was very good/ good in 83% and poor/missing in 17% of systolic variables, whereas it was very good/good for 67% of diastolic variables and poor/missing for 33%. Factor analysis reduced systolic variables to two factors that explained 69% of the total variance in systolic function. Conclusions: Low feasibility for some and questionable concordance of especially diastolic variables questions the rationale for routinely measuring a high number of echocardigraphic variables. The results of the factor analysis further strengthen the possibility of reducing the number of measured variables. The clinical value of such a reduction needs to be validated.

Low-dose Enalapril Reduces Angiotensin II and Attenuates Diabetic-induced Cardiac and Autonomic Dysfunctions

Activation of renin-angiotensin system has been linked to cardiovascular and autonomic dysfunctions in diabetes. Experiments were performed to investigate the effects of angiotensin-converting enzyme inhibitor (ACEI), enalapril, on cardiac and autonomic functions in diabetic rats. Diabetes was induced by streptozotocin (50 mg/kg), and rats were treated with enalapril (1 mg · kg(-1) · d(-1)). After 30 days, evaluations were performed in control, diabetic, and enalapril-treated groups. Cardiac function was evaluated by echocardiography and through cannulation of the left ventricle (at baseline and in response to volume overload). Heart rate and systolic blood pressure variabilities were evaluated in the time and frequency domains. Streptozotocin rats had left ventricular systolic and diastolic dysfunctions, expressed by reduced ejection fraction and increased isovolumic relaxation time. The ACEI prevented these changes, improved diastolic cardiac responses to volume overload and total power of heart rate variability, reduced the ACE1 activity and protein expression and cardiac angiotensin (Ang) II levels, and increased angiotensin-converting enzyme 2 activity, despite unchanged blood pressure. Correlations were obtained between Ang II content with systolic and diastolic functions and heart rate variability. These findings provide evidence that the low-dose ACEI prevents autonomic and cardiac dysfunctions induced by diabetes without changing blood pressure and associated with reduced cardiac Ang II and increased angiotensin-converting enzyme 2 activity.

Effectiveness of Amlodipine-Valsartan Single-Pill Combinations: Hierarchical Modeling of Blood Pressure and Total Cardiovascular Disease Risk Outcomes (the EXCELLENT Study)

Both patient- and physician-related factors have been shown to explain variability in the outcomes of antihypertensive treatment. Total cardiovascular risk (TCVR) is increasingly used as a determinant of treatment effectiveness but has also been proposed as a treatment outcome. To our knowledge, no studies have reported how antihypertensive treatment impacts blood pressure and TCVR outcomes. To examine in patients treated with a regimen including single-pill combinations (SPCs) of amlodipine/valsartan (1) blood pressure (BP) reduction and control, total cardiovascular risk (TCVR) change, and TCVR reduction of 1 class or more; (2) hierarchical patient- and physician-level determinants of these outcomes; and (3) predictors of uncontrolled BP and improved TCVR classification. A prospective (90 days), multicenter, multilevel pharmacoepidemiologic study was conducted in 3546 patients with hypertension treated with SPC amlodipine/valsartan by 698 general practitioners. Statistical analysis included hierarchical linear and logistic modeling of BP and TCVR outcomes. Mean (SD) systolic BP (SBP) reductions were 20.1 (15.5) mm Hg and diastolic BP (DBP) reductions were 9.8 (10.3) mm Hg, with higher reductions among high-risk patients. SBP, DBP, and SBP/DBP control rates were 33.3%, 45.3%, and 25.5%, respectively, with lower rates among high-risk patients. Mean TCVR improvement was a reduction of 0.73 (0.96) classes (-4 [best] to +4 [worst]), with higher reductions for high-risk patients; 58.2% of patients achieved a TCVR reduction of 1 or more classes, with lower percentages for high-risk patients. Twenty-two percent of systolic variability and 26% of diastolic variability in 90-day BP values were attributable to a physician class effect, as was 16% of TCVR change. Regimens that include SPC amlodipine/valsartan formulations are effective in reducing BP and TCVR in a real-world observational setting. Hierarchical modeling identified patient- and physician-related determinants of BP values and TCVR change, as well as independent predictors of uncontrolled BP and reduced TCVR. TCVR is a scientifically feasible and clinically relevant effectiveness outcome of antihypertensive treatment.

Hemodynamic Assessment of Severe Aortic Stenosis

Direct magnetic resonance imaging (MRI) planimetry of the maximal systolic aortic valve area does not consider temporal variations of the opening area during the ejection period. We evaluated an MRI-based methodology for the assessment of valvular dynamics in patients with severe aortic stenosis by measuring the systolic variability of the valvular blood stream, that is, the "vena contracta." With institutional review board approval, we examined 22 patients (13 male, 9 female; mean age, 68 ±10 years) with severe aortic stenosis using 1.5 T MRI and a standardized scanning protocol consisting of gradient-echo phase-contrast velocity imaging and steady-state free precession-cine MRI before and after valve replacement therapy. Temporal changes of the aortic valve area, represented by systolic variations of the area of poststenotic turbulent flow at its smallest convergence, that is, the proximal vena contracta, were determined by MRI and quantified by a calculated parameter of temporal valve dynamics (T). T was defined as the period which the aortic valve spent over its maximal opening area (>85%) during systole. MRI was also used to determine left ventricular hypertrophy before (LVMI) and its regression (LVMR) after valve replacement. Findings were compared with transthoracic echocardiography and cardiac catheterization. All patients had an echocardiographic effective orifice area, EOATTE, of <1.0 cm2. The comparison of T to LVMI and LVMR revealed significant correlations (LVMI: r = -0.62; P = 0.002; LVMR: r = 0.62; P = 0.002). Further significant correlations with aortic stenosis severity were observed in the comparison with manual planimetry, invasive measurements, and echocardiographic valve areas, as well as with pressure gradients. MRI can measure systolic variations of the aortic valve area. Quantitative parameters of the hemodynamic relevance of valve dynamics obtained by this method correlate with established parameters of aortic stenosis severity and LVMR.

Effects of hemodialysis on the cardiovascular system: quantitative analysis using wave intensity wall analysis and tissue velocity imaging

Cardiovascular disease is the leading cause of death in patients with end-stage renal disease (ESRD). The aim of this study was to investigate the changes in cardiovascular function induced by a single session of hemodialysis (HD) by the analysis of cardiovascular dynamics using wave intensity wall analysis (WIWA) and of systolic and diastolic myocardial function using tissue velocity imaging (TVI). Gray-scale cine loops of the left common carotid artery, conventional echocardiography, and TVI images of the left ventricle were acquired before and after HD in 45 patients (17 women, mean age 54 years) with ESRD. The WIWA indexes, W(1) and preload-adjusted W(1), W(2) and preload-adjusted W(2), and the TVI variables, isovolumic contraction velocity (IVCV), isovolumic contraction time (IVCT), peak systolic velocity (PSV), displacement, isovolumic relaxation velocity (IVRV), isovolumic relaxation time (IVRT), peak early diastolic velocity (E'), and peak late diastolic velocity (A'), were compared before and after HD. The WIWA measurements showed significant increases in W(1) (P < 0.05) and preload-adjusted W(1) (P < 0.01) after HD. W(2) was significantly decreased (P < 0.05) after HD, whereas the change in preload-adjusted W(2) was not significant. Systolic velocities, IVCV (P < 0.001) and PSV (P < 0.01), were increased after HD, whereas the AV-plane displacement was decreased (P < 0.01). For the measured diastolic variables, E' was significantly decreased (P < 0.01) and IVRT was significantly prolonged (P < 0.05), after HD. A few correlations were found between WIWA and TVI variables. The WIWA and TVI measurements indicate that a single session of HD improves systolic function. The load dependency of the diastolic variables seems to be more pronounced than for the systolic variables. Preload-adjusted wave intensity indexes may contribute in the assessment of true LV contractility and relaxation.

Enhanced blood pressure variability in a high cardiovascular risk group of African Americans: FIT4Life Study

High blood pressure (BP) levels in African Americans elicit vascular inflammation resulting in vascular remodeling. BP variability (BPV) correlates with target organ damage. We aimed to investigate the relationship between inflammatory markers and BPV in African Americans. Thirty-six African Americans underwent 24-hour ambulatory BP monitoring (ABPM). BPV was calculated using the average real variability index. Fasting blood samples were assayed for high-sensitivity C-reactive protein (hs-CRP), tumor necrosis factor-alpha (TNF-α), and white blood cell (WBC) count. Significant associations between hs-CRP and 24-hour systolic variability ( r = 0.50; P = .012) and awake systolic variability ( r = 0.45; P = .02) were identified after adjusting for age, body mass index, and 24-hour mean BP. ABPM variables were compared between the hs-CRP tertile groups. In post-hoc analysis, there was a significant difference in 24-hour and awake periods for both systolic and diastolic variability among the groups. TNF-α and WBC count showed no associations with ABPM variables. hs-CRP was associated with systolic variability, and higher levels of hs-CRP were related with greater BPV. Higher inflammatory status influences wider fluctuations in systolic BP, which in turn could facilitate early progression to target organ damage independent of absolute BP levels in African Americans.

Comparison of left ventricular contraction profiles among small, medium, and large dogs by use of two-dimensional speckle-tracking echocardiography

To assess differences in left ventricular contractile indices among dogs of 3 body sizes via 2-D speckle-tracking echocardiography (STE) and to determine body weight-independent systolic variables. 37 clinically normal adult dogs. Dogs were allocated into 3 groups on the basis of body weight: small (<7kg), medium (7 to 20kg), and large (>20kg). Right parasternal short-axis echocardiographic views were acquired to measure conventional M-mode variables (left ventricular internal diameter at end diastole, left ventricular internal diameter at end systole, and fractional shortening [FS]) and STE indices (peak systolic strain, peak systolic strain rate, synchrony time index [STI], peak systolic apical rotation, peak systolic basal rotation, peak apical twisting rate, and peak systolic torsion). Values were compared among the 3 groups. STE indices, except for peak systolic radial strain (SRad), peak systolic basal rotation, and STI, were significantly decreased in large dogs, compared with values for small and medium dogs. No significant difference was detected in stroke index, peak systolic SRad, and peak systolic basal rotation among the 3 groups. The STI in large dogs was significantly increased, compared with that of medium dogs. Results revealed that decreased systolic indices in large dogs should not be interpreted as signs of decreased systolic function. Increased STI in large dogs may contribute to decreased FS. Because peak systolic SRad was not affected by body weight, peak systolic SRad might be a better variable than FS for assessing systolic function.

Tissue Doppler and Strain Imaging in Dogs with Myxomatous Mitral Valve Disease in Different Stages of Congestive Heart Failure

Tissue Doppler imaging (TDI) including strain and strain rate (SR) assess systolic and diastolic myocardial function. TDI, strain, and SR variables of the left ventricle (LV) and the interventricular septum (IVS) differ significantly between dogs with myxomatous mitral valve disease (MMVD) with and without congestive heart failure (CHF). Sixty-one dogs with MMVD with and without CHF. Ten healthy control dogs. Prospective observational study. Radial motion: None of the systolic variables were altered and 3 of the diastolic velocities were significantly increased in dogs with CHF compared with dogs without CHF and control dogs. Longitudinal motion: 2 systolic velocities and 3 diastolic velocities were significantly increased in dogs with CHF compared with dogs without CHF and control dogs. Difference in systolic velocity time-to-peak between LV and IVS was significantly increased in dogs with MMVD with and without CHF compared with control dogs. In total, 11 (23%) of 48 TDI and strain variables differed significantly between groups. Left atrial to aortic ratio was positively correlated to early diastolic velocities, percentage increase in left ventricular internal diameter in systole was positively correlated to systolic and diastolic velocities, and mitral E wave to peak early diastolic velocity in the LV basal segment (E/Em) was positively correlated to radial strain and SR. Few TDI and strain variables were changed in dogs with MMVD with and without CHF. Intraventricular dyssynchrony may be an early sign of MMVD or may be an age-related finding.

BLOOD PRESSURE AND COGNITIVE FUNCTION IN OLDER ADULTS WITH CARDIOVASCULAR DISEASE

Background: Past studies link elevated blood pressure (BP) and BP variability to adverse neurocognitive changes in community samples. However, little is known about the relationship between BP indices and cognitive function in older CVD patients. Methods: A total of 99 older adults with CVD completed a comprehensive neuropsychological test battery. Resting BP measurements were collected every 10 min for 2 hr during a separate cardiac assessment. Five BP indices were generated: average and standard deviation of systolic blood pressure (SBP), average and standard deviation of diastolic blood pressure (DBP), and a function of systolic variability and average diastolic pressure. We examined the relationship between these BP indices and cognitive function. Results: Partial correlation adjusting for age and education revealed that the function of systolic variability and average diastolic pressure (SBP standard deviation divided by the average DBP) was most closely related to test performance, showing significant associations to both Learning/Memory (r = 0.25) and Language functioning (r = 0.22). SBP indices were also related to Language functioning (SBP avg., r = 0.22; SBP SD, r = 0.25), though DBP indices were unrelated to performance in any cognitive domain. Conclusions: The current findings indicate that BP is modestly related to cognitive function in older CVD patients. Contrary to expectations, greater BP variability was associated with better, not poorer, cognitive test performance. Such findings suggest that the relationship between BP and cognitive function is more complicated than typically believed and requires further examination.

Exercise and cardiovascular outcomes in hypertensive patients in relation to structure and function of left ventricular hypertrophy: the LIFE study

Exercise lowers blood pressure and improves cardiovascular function, but little is known about whether exercise impacts cardiovascular morbidity and mortality independent of left ventricular hypertrophy (LVH) and LV geometry. Observational analysis of prospectively obtained echocardiographic data within the context of a randomized trial of antihypertensive treatment. A total of 937 hypertensive patients with ECG LVH were studied by echocardiography in the Losartan Intervention For Endpoint reduction in hypertension study. Baseline exercise status was categorized as sedentary (never exercise), intermediate (<or=30 min twice/week), or physically active (>30 min twice/week). During 4.8-year follow-up, 105 patients suffered the primary composite endpoint of myocardial infarction (MI), stroke, or cardiovascular death. MI occurred in 39, stroke in 60, and cardiovascular death in 33 patients. Sedentary individuals (n = 212) had, compared with those physically active (n = 511), higher heart rate (P<0.001), weight (P<0.001), body surface area (P = 0.02), body mass index (P<0.001), LV mass (LVM, P = 0.04), LVM indexed for height or body surface area (P = 0.004); thicker ventricular septum (P = 0.012) and posterior wall (P = 0.016); and larger left atrium (P = 0.006). Systolic variables did not differ. In Cox regression analysis, physically active compared with sedentary patients had lower risk of primary composite endpoint [odds ratio (OR): 0.42, 95% confidence interval (CI): 0.26-0.68, P < 0.001], cardiovascular death (OR: 0.50, 95% CI: 0.22-0.1.10, NS), and stroke (OR: 0.26, 95% CI: 0.13-0.49, P < 0.001) without significant difference for MI (OR: 0.79, 95% CI: 0.35-1.75, NS) independent of systolic blood pressure, LVM index, or treatment. In hypertensive patients with LVH, physically active patients had improved prognosis for cardiovascular endpoints, mortality, and stroke that was independent of LVM.

Vascular and cognitive functions associated with cardiovascular disease in the elderly

This study examines the relationship between systemic vascular function, neurocognitive performance, and structural brain abnormalities on magnetic resonance imaging (MRI) among geriatric outpatients with treated, stable cardiovascular disease and no history of neurological illness (n = 88, ages 56–85 years). Vascular function was assessed by cardiac ejection fraction and output, sequential systolic and diastolic blood pressures, flow mediated brachial artery reactivity (BAR), and carotid intima media thickness (IMT). White matter hyperintensities (WMH) on MRI were quantified and examined relative to cognitive and vascular function. Principal component analysis revealed two primary vascular components: one associated with cardiac function, the other with atherosclerotic burden/endothelial dysfunction. Both factors were significantly associated with cognitive function and WMH volume. Reduced systolic variability and increased IMT were most strongly related to reduced attention, executive function, and information-processing speed. These findings suggest the possibility that systemic vascular indices may provide proxy measures of cerebrovascular dysfunction and reinforce the importance of achieving greater understanding of interaction between systemic vascular disease and brain dysfunction among elderly people with cardiovascular disease.

Evaluation of left ventricular systolic and diastolic function in patients with atrioventricular re-entrant tachycardia treated by radiofrequency current ablation

Little is known about the long-term influence of radiofrequency current ablation (RFCA) on left ventricular (LV) systolic and diastolic function in patients with atrioventricular re-entrant tachycardia (AVRT).Method — The study group consisted of 65 patients (33 M, mean age 39 ± 11 y) with WPW syndrome and recurrent episodes of AVRT without any concomitant diseases.The control group consisted of 50 age-matched healthy volunteers. In both study and control groups transthorasic echocardiography (TTE) and Doppler were performed in order to assess LV systolic and diastolic function. In WPW patients TTE was followed by electrophysiology study and RFCA. TTE was repeated in 6-months time in the study group.Results — At 6-month follow-up a decrease in LV end-systolic diameters (1.77 ± 0.22 vs. 1.67 ± 0.22 cm/m2, P < 0.001) and volumes (20 ± 6 vs. 17 ± 5 ml, P < 0.001) and an increase in LV FS (33 ± 6 vs. 37 ± 5%, P < 0.001), EF (54 ± 6 vs. 60 ± 5%, P < 0.001), IVS (44 ± 13 vs. 49 ± 14%, P < 0.05) and LV PW thickening (58 ± 19 vs. 62 ± 16%, P < 0.05) was found. Doppler analysis revealed an increase in E wave (78 ± 17 vs. 82 ± 14 cm/s, P < 0.001), E/A ratio (1.14 ± 0.37 vs. 1.33 ± 0.24, P < 0.001) and a decrease in A wave (68 ± 19 vs. 63 ± 12 cm/s, P < 0.05), DT (219 ± 33 vs. 180 ± 20 ms, P < 0.001), IVRT (105 ± 13 vs. 88 ± 13 ms, P < 0.001), AR (26 ± 8 vs. 18 ± 12 cm/s, P < 0.001) and difference between duration of AR and A waves (5 ± 24 vs. –12 ± 21 ms, P < 0.001). No significant differences in regard to LV systolic and diastolic variables were found between patients and controls post RFCA.Conclusion — RFCA of accessory pathway in patients with WPW syndrome and AVRT is associated with improvement of LV systolic and diastolic function.